How-To Tutorials

Installation and a review of some new features Installation The program [EA2 download -Early Adapter] can be downloaded from the following URL. In the present case the Windows option that comes with JDK1.5.0_06 bundled was used. The downloaded ZIP file, sqldeveloper-5073 (100MB) can be unzipped to any suitable location and from within the sqldeveloper folder you can immediately start using the program. The program can be started by double clicking the executable which has an unambiguous fat green arrow. Review of features Adjustable Look and Feel The look and feel is adjustable. You can choose between 'Windows' and 'Oracle'. After choosing 'oracle' you can choose a variety of themes. The one shown is for 'Desert Yellow'. The View Menu The View menu is better organized as shown compared to the previous version. Tools Menu Tools menu is beefed up as well as shown. External Tools The External Tools sub menu item can find existing tools (browsers, notepad, mdb files) and also using a 4 step wizard allows you to create tools, provided you know the details for accessing them. Wizards Diff Wizard allows comparing objects of same type between schema of source and destination as well update the destination based on source. Similarly the Copy Wizard allows you to copy objects from one database schema to another. Versioning Support Versioning support is another new feature in this version.SQL Developer provides integrated support for CVS [concurrent versions system] and Subversion in its source control. CVS allows repository creation on the local PC or, on a remote machine. Source files are held in folder modules. In the case of Subversion the access to the repository is by means of a connection and this is where the master copies are held, files are checked out to a local working folder. Run menu item The Run menu item also contains the debugging options as shown. In the previous version Run and Debug were two menus. Migration Menu The Microsoft Access Exporter can export from 97,2000,2002, and 2003 like in the previous version (1.2) and seems to be essentially the same as the previous version. This version can now create off line migration scripts to ASE 15 and Sybase 12 in addition to several versions of SQL Server 7,2000,2005 and MySQL (3.23,4,5) Connecting to SQL 2005 databases As described in the previous referenced articles at the beginning  you can establish a connection to the server by clicking on the Connection node (positive green sign) in the first figure. This opens New / Select Database Connection window where you will see only Oracle and Access. This is because, at this point no JDBC drivers have been specified for connecting to the other three servers, SQL Server, MySQL, and Sybase. There are two ways you can register JDBC drivers for these databases. For SQL Servers you require the jtds.jar file from the SourceForge.com web site. In the first method you need to go through Tools|Preferences|Database|Third party JDBC Drivers| to find the path to the file as shown in the next figure and use the browse key to locate the driver and add it. The driver file should be in the correct path for the application to find. In the other method that is used here, which in the opinion of the author is simpler, is to go through Help|Check Updates... This brings up the Step 1 of wizard as shown. Read the instructions in this window. Now click Next. This takes you to the next window as shown.   The needed item is already checked. Click Next. The window that comes up next shows compatible drivers for the databases. Choose items needed by placing check marks. In this tutorial both the SQL Server and MySQL drivers were chosen. Click Next. In the window that shows up agree to the licensing[GNU Public] terms after reading the terms. Click on Next in the final window of Step 4. When Step 5 "Download" windows opens the login window also opens. As these drivers are downloaded from the Oracle site, you will have to insert your Oracle login information. Step 5 screen shot is not shown. You will be adding both the JDBC drivers on the final step. Click Finish. In order to install the updates you chose, the SQL Developer 1.5 needs to restart, and it restarts when you click on Yes in the Confirm Exit window. Do you want to Migrate User Settings?  window shows up again. For this article it is a No again. The Oracle SQL Developer window gets displayed. Now you open the screen.  You will see all the five database tabs in the New / Select Database Connection with default connection to the Oracle 10G XE on the local machine[Screen shot not shown].

Database relationship is hard to maintain even for a mid-sized PHP/MySQL application, particularly, when multiple levels of relationships are involved because complicated SQL queries are needed. CakePHP offers a simple yet powerful feature called 'object relational mapping' or ORM to handle database relationships with ease.In CakePHP, relations between the database tables are defined through association—a way to represent the database table relationship inside CakePHP. Once the associations are defined in models according to the table relationships, we are ready to use its wonderful functionalities. Using CakePHP's ORM, we can save, retrieve, and delete related data into and from different database tables with simplicity, in a better way—no need to write complex SQL queries with multiple JOINs anymore! In this article by Ahsanul Bari and Anupom Syam, we will have a deep look at various types of associations and their uses. In particular, the purpose of this article is to learn: How to figure out association types from database table relations How to define different types of associations in CakePHP models How to utilize the association for fetching related model data How to relate associated data while saving There are basically 3 types of relationship that can take place between database tables: one-to-one one-to-many many-to-many The first two of them are simple as they don't require any additional table to relate the tables in relationship. In this article, we will first see how to define associations in models for one-to-one and one-to-many relations. Then we will look at how to retrieve and delete related data from, and save data into, database tables using model associations for these simple associations. Defining One-To-Many Relationship in Models To see how to define a one-to-many relationship in models, we will think of a situation where we need to store information about some authors and their books and the relation between authors and books is one-to-many. This means an author can have multiple books but a book belongs to only one author (which is rather absurd, as in real life scenario a book can also have multiple authors). We are now going to define associations in models for this one-to-many relation, so that our models recognize their relations and can deal with them accordingly. Time for Action: Defining One-To-Many Relation Create a new database and put a fresh copy of CakePHP inside the web root. Name the database whatever you like but rename the cake folder to relationship. Configure the database in the new Cake installation. Execute the following SQL statements in the database to create a table named authors, CREATE TABLE `authors` ( `id` int( 11 ) NOT NULL AUTO_INCREMENT PRIMARY KEY , `name` varchar( 127 ) NOT NULL , `email` varchar( 127 ) NOT NULL , `website` varchar( 127 ) NOT NULL ); Create a books table in our database by executing the following SQL commands: CREATE TABLE `books` ( `id` int( 11 ) NOT NULL AUTO_INCREMENT PRIMARY KEY , `isbn` varchar( 13 ) NOT NULL , `title` varchar( 64 ) NOT NULL , `description` text NOT NULL , `author_id` int( 11 ) NOT NULL ) Create the Author model using the following code (/app/models/authors.php): <?php class Author extends AppModel{ var $name = 'Author'; var $hasMany = 'Book';} ?> Use the following code to create the Book model (/app/models/books.php): <?phpclass Book extends AppModel{ var $name = 'Book'; var $belongsTo = 'Author';}?> Create a controller for the Author model with the following code: (/app/controllers/authors_controller.php): <?phpclass AuthorsController extends AppController { var $name = 'Authors'; var $scaffold;}?>   Use the following code to create a controller for the Book model (/app/controllers/books_controller.php): <?php class BooksController extends AppController { var $name = 'Books'; var $scaffold; } ?> Now, go to the following URLs and add some test data: http://localhost/relationship/authors/ and http://localhost/relationship/books/ What Just Happened? We have created two tables: authors and books for storing author and book information. A foreign-key named author_id is added to the books table to establish the one-to-many relation between authors and books. Through this foreign-key, an author is related to multiple books, as well as, a book is related to one single author. By Cake convention, the name of a foreign-key should be underscored, singular name of target model, suffixed with _id. Once the database tables are created and relations are established between them, we can define associations in models. In both of the model classes, Author and Book, we defined associations to represent the one-to-many relationship between the corresponding two tables. CakePHP provides two types of association: hasMany and belongsTo to define one-to-many relations in models. These associations are very appropriately named: As an author 'has many' books, Author model should have hasMany association to represent its relation with the Book model. As a book 'belongs to' one author, Book model should have belongsTo association to denote its relation with the Author model. In the Author model, an association attribute $hasMany is defined with the value Book to inform the model that every author can be related to many books. We also added a $belongsTo attribute in the Book model and set its value to Author to let the Book model know that every book is related to only one author. After defining the associations, two controllers were created for both of these models with scaffolding to see how the associations are working.

SQL Anywhere 10 SQL Anywhere 10 is the latest version of Sybase's feature rich SQL Anywhere database technology. It is highly scalable from the small foot-print UltraLite database all the way to its enterprise server with gigabytes of data. It is a comprehensive database package with built-in support for a wide range of applications, including session based synchronization; data exchange with both relational and non-relational data bases; secure store and forward messaging; messaging with FTP and email; and asynchronous access to mobile web services. You may download an evaluation version of the software and take it for a test drive. Sybase Central is a graphical database management interface to the database and its various supporting applications. The integration features are used in this article to create a Windows application retrieving data from the SQL Anywhere 10’s demonstration database, a database which is a part of the default installation of the developer edition. Overview of SQL Anywhere 10 From Sybase Central you can connect to the demo database quite easily by clicking on the Connections menu item and choosing Connect with SQL Anywhere 10. Figure 1 shows the SQL Anywhere management interface, Sybase Central. Using this interface you may also create an ODBC DSN by following the trail; Tools --> SQL Anywhere 10 --> open ODBC Administrator. Figure 1   It is very easy to connect to the database using the ODBC driver which is provided with the default installation of this product. The Figure 2 shows the User DSN installed with the default installation in the ODBC Data Source Administrator window. Figure 2 The Username is DBA and the Password is sql (case sensitive) for the demo database, demo.db. Please refer to the article, "Migrating from Oracle 10G XE to SQL Anywhere 10" which describes connecting to the demo database in detail. Figure 3 shows the demo database and its objects. Figure 3 VB.NET Windows Application We will create an ASP.NET 2.0 Windows application called SqlAny. We will create forms which display retrieved data from a table on the database as well as from a stored procedure after accepting a parameter passed to the stored procedure interactively. The Figure 4 shows the details of the project in the Solution Explorer as well as the Object Browser. Figure 4 Accessing SQL Anywhere Explorer SQL Anywhere Explorer is a component of SQL Anywhere that lets you connect to SQL Anywhere and UltraLite  databases from Visual Studio .NET. From the View menu of Visual Studio, you can access the SQL Anywhere Explorer as shown in Figure 5 - SQL Anywhere 10 is integrated with Visual Studio (both 1.1 and 2.0 versions). Figure 5   Alternatively, you can access SQL Anywhere Explorer from the Tools menu item as shown in Figure 6. In this case the Sybase Central management interface opens in a separate window. Interactive SQL is another of SQL Anywhere 10's tools for working with SQL queries on this database. Figure 6   When you click on SQL Anywhere Explorer from the View menu, you will be lead to the following window shown in Figure 7 which allows you to establish a data connection. Figure 7 Click on the drop-down, Add Connection, which opens the window shown in Figure 8 where you will be given a choice of two connections that you may connect to, SQL Anywhere or UltraLite. These are both databases. Both can run on mobile devices, but UltraLite has a smaller footprint. Figure 8 By choosing to connect to SQL Anywhere you invoke the authentication window for making the connection, as shown in Figure 9. The Username is DBA and the Password is sql. After entering these values you can get to the ODBC DSN mentioned earlier, from the drop-down. You may also test the connectivity which you see as being a success, for the entered values of Username, Password, and ODBC DSN. Figure 9   Visual Studio makes a data connection as shown in Figure 10. The nodes for Tables, Views, and Procedures are all expanded in this figure showing all the objects that can be accessed on this database. Since we logged in as DBA, all permissions are in place. Figure 10 Before the connection is made, SQL Anywhere starts up as shown in Figure 11. This message console gets minimized and stays up in the system tray of the desktop. This can be restored and closed by activating the icon in the tray.   Figure 11

You use Designer, one of the DataStage clients, for ETL jobs development. When you start Designer, in addition to entering your host system and credential, you must also specify the project you’d like to work on. A DataStage project stores jobs and define their environment, such as their security and execution resources. Your project, as well as your user account, is typically created by your DataStage administrator. To develop a new job, on the icon toolbar, click the drop-down arrow to the right of the New icon (I circle in red). We’ll develop a parallel job, so click the Parallel Job from the drop-down list. In DataStage, a parallel job can execute in parallel mode (in simple terms, this means the job does not process its data records sequentially, one record after another). We can now start to design our job in the job canvas. For now, our parallel job name is Untitled 1, as shown on the canvas title. Our job extracts its input data from a customer sequential file, transforms the data, and then loads it into an Oracle table. The customer file contains new customers and name changes of the existing customers. The customer file has more data (more columns) than we need; we’ll extract only those we need. In DataStage, you build a job by selecting and linking stages on the job canvas. So, on the Palette, click File, look for Sequential File stage by clicking the up or down arrow. Drag and drop our first stage, the Sequential File stage, from the Palette to the left side of the canvas. We’d like to layout our stages left to right to visualize them processing data in that direction, so we start placing the input stage on the left of the canvas (we can move stages around the canvas, though, by dragging them). Rename the Sequential File stage to Customer by selecting (clicking) and clicking it again, and typing over the default name (Sequential_File_1). Next, add Transformer stage (under Processing palette) and Oracle Enterprise stage (under Database palette) that we need for our job. Rename them as shown. We use the Transformer stage to change (transform) customer names to uppercase. Now that we have the stages we need for our job, we’ll link them together. Right click the Customer stage, hold and drag & drop on the Uppercase stage, and then, from Uppercase stage to the Customer_Dim stage. You can rename the links just like the way you rename stages. Just in case something happens to our system, we’d like to save our works so far. Name the job Load_Customer_Dim and you can choose the folder (called Category in DataStage) of your choice where you want to put the job. Notice the canvas title now reflects the name of our parallel job (changes from its default name given when we’re creating it). The Customer stage has a warning sign (the yellow! sign), which indicates that it has an error. This is because we haven’t specified its parameters. For example, the file it refers to. So, let’s fix it. Double-click the Customer stage. On the Properties tab select the File property, and type in the file name including its full path. The sequential file must be accessible by the DataStage server. Next, we need to specify the format of our file. For example, set the Record level’s Final delimiter and Field default’s Delimiter as shown. We must also specify the record layout, i.e. its fields (columns). To test that the stage will be able to read the data as specified, click the View Data button (upper right hand corner). You can specify the number of rows (records) you’d like to view. When you click OK and you have set the correct specification for the file, you’d see the data. When you finish viewing the data, close the view window as well as the property window. We’re done with the Customer stage.

When writing Chapter 12, "It's All about the Data," of Learning Ext JS, I switched things up a bit and switched the server-side processes to utilizing Adobe's ColdFusion application server, instead of the PHP we had been using in the rest of the book. There were a few reasons we decided to do this. To show that Ext JS can work with any server-side technology. ColdFusion 8 includes Ext JS 1.1 for it's new Ajax form components. Adobe uses a custom format for the serialized JSON return of query data, making it perfect for our example needs. I'm a ColdFusion programmer. Some time ago, before writing Chapter 12, I had begun to use a Custom Data Reader that I had found on the Ext JS forums. Another Ext user and ColdFusion programmer, John Wilson, had written the custom reader to consume Adobe's custom JSON return for queries. First, let me show you why Adobe's format differs from the generally expected serialized JSON return of a query. Here's an example of a typical query response. { 'results': 2, 'rows': [ { 'id': 1, 'firstname': 'Bill', occupation: 'Gardener' }, // a row object { 'id': 2, 'firstname': 'Ben' , occupation: 'Horticulturalist' } // another row object ] } And here's an example of how ColdFusion returns a query response.     {        "COLUMNS":["INTPROPERTIESID","STRDEVELOPMENT","INTADDRESSID", "STRSTREET","STRSTREET2", "STRCITY","CHSTATEID","INTZIP"],        "DATA":[            [2,"Abbey Road",6,"456 Abbey Road","Villa 5","New York","NY",12345],            [6,"Splash",39,"566 aroundthe bend dr",null,"Nashville","TN",37221]        ]    } You can see, when examining the two formats that they are very divergent. The typical format returns an array of row objects of the query's results, whereas ColdFusion's format is an array (DATA) of arrays (each row of the query result), with each row array only containing the data. The ColdFusion format has extracted the column names into it's own array (COLUMNS), as opposed to the name/value pairing found in the object notation of the typical return. It's actually very smart, on Adobe's part, to return the data in this fashion, as it would ultimately mean smaller data sets returned from a remote call, especially with large recordsets. John's CFJsonReader, a custom data reader and an extended component of Ext's base DataReader, was able to translate ColdFusion's data returns by properly parsing the JSON return into Records of an Ext Store. It worked fairly well, with a few minor exceptions. it didn't handle the column aliasing you could do with any other Ext JS data reader (name:'development',mapping:'STRDEVELOPMENT') it didn't allow data type association with a value, as other Ext JS data readers (INTZIP is of type 'int', STRDEVELOPMENT is of type 'string', etc) So, it worked, but ultimately was limited. When I was writing Chapter 13, "Code for Reuse: Extending Ext JS", I really dove into extending existing Ext JS components. This helped me gain a better understanding of what John had done, when writing CFJsonReader. But, after really reviewing the code, I saw there was a better way of handling ColdFusion's JSON return. What it basically came down to was that John was extending Ext's base DataReader object, and then hand parsing almost the entire return. Looking at the above examples, you'll notice that Adobe's implementation is an array of arrays, rather than an array of objects. Ext JS already comes with an ArrayReader object, so I knew that by writing a custom data reader that extended it I would be able to get the desired results. Half an hour later, I had "built a better mousetrap" and we now have a Custom Data Reader for properly parsing ColdFusion's JSON return, without the previous limitations. /* * Ext JS Library 2.0 * Copyright(c) 2006-2007, Ext JS, LLC. * licensing@extjs.com * * http://extjs.com/license * ******************************************* * Steve 'Cutter' Blades (CutterBl) no.junkATcutterscrossingDOTcom * http://blog.cutterscrossing.com * * Inspired by the CFJsonReader, originally writtin by John Wilson (Daemach) * http://extjs.com/forum/showthread.php?t=21408&highlight=cfjsonreader * * This Custom Data Reader will take the JSON return of a ColdFusion * Query object, rather returned straight up, or via the ColdFusion * QueryForGrid() method. * * The CFQueryReader constructor takes two arguments * @meta : object containing single key/value pair for the 'id' of each record * @recordType : field mapping object * * The recordType object allows you to alias the returned ColdFusion column * name (which is always passed in upper case) to any 'name' you wish, as * well as assign a data type, which your ExtJS app will attempt to cast * whenever the value is referenced. * * ColdFusion's JSON return, for a ColdFusion Query object, will appear in the * following format: * * {"COLUMNS":["INTVENDORTYPEID","STRVENDORTYPE","INTEXPENSECATEGORIESID", * "STREXPENSECATEGORIES"],"DATA" :[[2,"Carpet Cleaning",1,"Cleaining"], * [1,"Cleaning Service",1,"Cleaining"]]} * * The ColdFusion JSON return on any query that is first passed through * ColdFusion's QueryForGrid() method will return the object in the * following format: * * {"TOTALROWCOUNT":3, "QUERY":{"COLUMNS":["MYIDFIELD","DATA1","DATA2"], * "DATA":[[1,"Bob","Smith"],[6,"Jim","Brown"]]}} * * The Ext.data.CFQueryReader is designed to accomodate either format * automatically. You would create your reader instance in much the same * way as the CFJsonReader was created: * * var myDataModel = [ * {name: 'myIdField', mapping: 'MYIDFIELD'}, * {name: 'data1', mapping: 'DATA1'}, * {name: 'data2', mapping: 'DATA2'} * ]; * * var myCFReader = new Ext.data.CFJsonReader({id:'myIdField'},myDataModel); * * Notice that the 'id' value mirrors the alias 'name' of the record's field. */ Ext.data.CFQueryReader = function(meta, recordType){ this.meta = meta || {}; Ext.data.CFQueryReader.superclass.constructor.call(this, meta, recordType || meta.fields); }; Ext.extend(Ext.data.CFQueryReader, Ext.data.ArrayReader, { read : function(response){ var json = response.responseText; var o = eval("("+json+")"); if(!o) { throw {message: "JsonReader.read: Json object not found"}; } if(o.TOTALROWCOUNT){ this.totalRowCount = o.TOTALROWCOUNT; } return this.readRecords(((o.QUERY)? o.QUERY : o)); }, readRecords : function(o){ var sid = this.meta ? this.meta.id : null; var recordType = this.recordType, fields = recordType.prototype.fields; var records = []; var root = o.DATA; // give sid an integer value that equates to it's mapping sid = fields.indexOfKey(sid); // re-assign the mappings to line up with the column position // in the returned json response for(var a = 0; a < o.COLUMNS.length; a++){ for(var b = 0; b < fields.length; b++){ if(fields.items[b].mapping == o.COLUMNS[a]){ fields.items[b].mapping = a; } } } for(var i = 0; i < root.length; i++){ var n = root[i]; var values = {}; var id = ((sid || sid === 0) && n[sid] !== undefined && n[sid] !== "" ? n[sid] : null); for(var j = 0, jlen = fields.length; j < jlen; j++){ var f = fields.items[j]; var k = f.mapping !== undefined && f.mapping !== null ? f.mapping : j; var v = n[k] !== undefined ? n[k] : f.defaultValue; v = f.convert(v, n); values[f.name] = v; } var record = new recordType(values, id); record.json = n; records[records.length] = record; } if(!this.totalRowCount){ this.totalRowCount = records.length; } return { records : records, totalRecords : this.totalRowCount }; } }); So, this changes our examples for Chapter 12 just a little bit. First of all, we'll need to have the CFQueryReader included, in place of the CFJsonReader. You can change the script tags in the samples for Examples 3 and 4. ... <script language="javascript" type="text/javascript" src="/scripts/custom-ext/CFQueryReader.js"></script> ... Next, we'll change the scripts for these two examples. We'll remove our configuration references for CFJsonReader, and replace them with the updated configuration for the CFQueryReader. /* * Chapter 12 Example 3 * Data Store from custom reader * * Revised: SGB (Cutter): 12.17.08 * Replaced CFJsonReader with CFQueryReader */ // Save all processing until the // DOM is completely loaded Ext.onReady(function(){ var ourStore = new Ext.data.Store({ url:'Chapter12Example.cfc', baseParams:{ method: 'getFileInfoByPath', returnFormat: 'JSON', queryFormat: 'column', startPath: '/images/' }, reader: new Ext.data.CFQueryReader({ id: 'NAME', // This is supposed to match the 'mapping' fields:[ {name:'file_name',mapping:'NAME'}, {name:'file_size',mapping:'SIZE'}, {name:'type',mapping:'TYPE'}, {name:'lastmod',mapping:'DATELASTMODIFIED'}, {name:'file_attributes',mapping:'ATTRIBUTES'}, {name:'mode',mapping:'MODE'}, {name:'directory',mapping:'DIRECTORY'} ] }), fields: recordModel, listeners:{ beforeload:{ fn: function(store, options){ if (options.startPath && (options.startPath.length > 0)){ store.baseParams.startPath = options.startPath; } }, scope:this }, load: { fn: function(store,records,options){ console.log(records); } }, scope:this } }); ourStore.load(); }); /* * Chapter 12 Example 4 * Data Store from custom reader - Filtering * * Revised: SGB (Cutter): 12.17.08 * Replaced CFJsonReader with CFQueryReader */ // Simple function/object to 'clone' objects cloneConfig = function (config) { for (i in config) { if (typeof config[i] == 'object') { this[i] = new cloneConfig(config[i]); } else this[i] = config[i]; } } // Save all processing until the // DOM is completely loaded Ext.onReady(function(){ var initialBaseParams = { method: 'getDirectoryContents', returnFormat: 'JSON', queryFormat: 'column', startPath: '/testdocs/' }; var ourStore = new Ext.data.Store({ url:'Chapter12Example.cfc', baseParams: new cloneConfig(initialBaseParams), reader: new Ext.data.CFQueryReader({ id: 'NAME', // This is supposed to match the 'mapping' fields:[ {name:'file_name',mapping:'NAME'}, {name:'file_size',mapping:'SIZE'}, {name:'type',mapping:'TYPE'}, {name:'lastmod',mapping:'DATELASTMODIFIED'}, {name:'file_attributes',mapping:'ATTRIBUTES'}, {name:'mode',mapping:'MODE'}, {name:'directory',mapping:'DIRECTORY'} ] }), listeners:{ beforeload:{ fn: function(store, options){ for(var i in options){ if(options[i].length > 0){ store.baseParams[i] = options[i]; } } }, scope:this }, load: { fn: function(store, records, options){ console.log(records); }, scope: this }, update: { fn: function(store, record, operation){ switch (operation){ case Ext.record.EDIT: // Do something with the edited record break; case Ext.record.REJECT: // Do something with the rejected record break; case Ext.record.COMMIT: // Do something with the committed record break; } }, scope:this } } }); ourStore.load({recurse:true}); filterStoreByType = function (type){ ourStore.load({dirFilter:type}); } filterStoreByFileType = function (fileType){ ourStore.load({fileFilter:fileType}); } clearFilters = function (){ ourStore.baseParams = new cloneConfig(initialBaseParams); ourStore.load(); } }); Summary These very basic changes have no overall effect on our examples. They function exactly as they did before. The new Custom Data Reader loads the data, returned from ColdFusion, exactly as it should. Now, we can also work with these data stores in the same manor as we would with any other data store set up through Ext JS, having the ability to alias columns, define field data types, and more.

Introduction Business needs often necessitate data migration from a smaller, less secure database to a higher end, faster database server with a more reliable availability. A typical scenario is the migration of data from a desktop sized database such as MS Access or Fox Pro to any other higher end database servers such as MS SQL Server, Oracle, DB2 or SQL Anywhere Server. Most of the database vendors provide tools to migrate from third party to their own database servers. In his three previous articles, the author has described the built-in tools to migrate from MS Access to SQL 2000 Server, SQL Anywhere Server, and from Oracle 10G XE to SQL Anywhere server.   In an earlier article on this site, the author showed how you may connect to an MS Access 2003 database and execute SQL statements using the Oracle SQL Developer 1.2 tool. In this tutorial the author shows you how to migrate an MS Access database to an Oracle 10G XE Server delineating all the steps involved in the migration process. Oracle SQL Developer 1.2 with this latest version is sometimes called the Migration version as it supports migrating data from three vendors (MySQL, SQL Server and MS Access) to an Oracle database. In fact, it has been designed to migrate from more than one version of MS Access. This feature was not available in the version 1.1 of this tool. Overview of this Tutorial Like in the earlier article, a simple MS Access 2003 database file will be created with just one table, a query and a linked table. This database file, about 292 KB, will be migrated to Oracle 10G XE database. Oracle 10G XE, by design, can have just one database on a computer. However, you can have separate applications by having different user schemas. Oracle 10G XE comes bundled with a sample database schema and data which can be accessed by using the credentials, username hr with a password hr. For the purposes of this example a new user will be created and his authentication will be used for creating necessary migration related schemas to be stored in a repository. This will become clear as you follow the various details and the steps. Once the ‘Repository’ is created then you can begin by capturing the metadata of the source followed by converting the captured source information into Oracle specific model where a mapping between the source data and the Oracle will be accomplished. After this process, you generate the data definition language script which will create the Oracle objects such as tables, views, etc. In the final step these tables will be populated by transferring the data from the source to Oracle 10G XE. MS Access 2003 Source An empty MS Access database file TestMigration.mdb is created in the default directory, My Documents. An Employees table will be imported, an Orders table will be linked and a TestQuery based on selecting a few columns of Employees table will be created. The Employees table and the Orders table may be found in the Northwind Database that ships with most of the MS Access versions. Creating a New User in Oracle 10G XE As described in the overview, the MS Access Database will be migrated to a User schema in Oracle 10G XE, but this requires reating this schema. Only a user with DBA privileges can create a new user. Open the Homepage of the Oracle 10G XE Server. Login with the credentials you supplied while installing the software where the user is system and the password is what you chose at that time, as shown in the next figure.   This gives you access to several of the tools that you can use to administer as well as work with database objects. Click on the icon for Administration and follow the drop-downs till you get to the menu item, Create User, as shown in the next figure. Create a new user MigrateAccess with some password that you choose and confirm. Keep the account status unlocked. This uses the default tablespace called USERS. The default user privilege does not include the DBA role but for this example, the DBA is also included by placing a check mark in this selection. Also several other system wide privileges are also granted. Please follow steps described in the earlier article for the details. The next figure shows all the details filled in. After this when you click the Create button you will have created the user, MigrateAccess. When you click the button Create, you will notice that the ‘bread crumb’ will change to Manage Database Users. You will notice that the new user MigrateAccess has been added to the list of users, as shown in the next figure. As no expiry was set for this user in the previous screen, you can notice that there is no expiry shown in the following screen. Now if you logout (remember you logged in as SYSTEM) and login with the new credentials, MigrateAccess/[chosen password] you can access all the tools on the database. Of course, all the objects (tables, views, etc) will be empty. Creating the Repository to Store Schemas Migration using this tool requires an Oracle database schema to store the Meta data it collects about the source. You will create a connection from the Oracle SQL Developer to the Oracle 10 XE, in which, you just finished creating a new user schema. This user’s schema is where the repository contents will be stored. Making a connection to the Oracle Right click on the Connections node, and from the drop-down menu select New Connection. This brings up the New / Select Database Connection (this has been described in the earlier referenced article) window. It comes up with the default connection to an Oracle database. It even recognizes the local Oracle 10G XE, capturing all its details as shown. You need to provide a Connection Name, a Username and a Password. The connection name is your choice (herein called conMigrate) and the user name and password is the same that was used while creating the new user MigrateAccess. When you click on the button ‘Test’, a (success) status message will be posted to this form above the Help button, as shown in the next figure after a little while, preceded by a little progress window. Now click on the OK button on the New / Select Database Connection window. This adds the conMigrate connection to the list of Connections as shown in the next figure. Notice that objects are all empty as we discussed earlier. Create Repository Click on the main menu item Migrate. From the drop-down, click on Repository Management –> Create Repository as shown in the next figure. This brings up the Create Repository window showing the connection conMigrate as shown in the next figure. You may connect or disconnect this from the tool as long as the authentication information is available. Now click on the Create button. This brings up the Installing Repository window which reports the various objects installed and finally shows a message “Repository Built Successfully” as shown in the next figure. Click on the Close button on this window. Now login to the Oracle 10G XE with the credentials for the user MigrateAccess, and click on the object browser. Now you see all the Tables, Views, etc in the repository as shown. You will notice that either two more windows, named captured and converted models appear below the Connections node in Oracle SQL Developer, or if they are not found in the Connections node, you may find in the submenu of the main menu, View. The next figure shows the submenus of the View menu. Connect to the Source Database Right click on the connection node and establish a new connection so that you can connect to the source database, conTestMigration as shown in the next figure. When you click the Test button you will see a message that gets posted to the screen indicating the connection was a success. Click on the Connect button. This adds the conTestMigrate connection to the list of Connections in the navigator window.

Making a Change For the next few months, the Center of Excellence paid off. Projects were identifying services early in the lifecycle. Those same projects were successfully identifying other potential consumers of these new services. Implementation technologies were being chosen correctly and interface design was being properly done. Most importantly, everyone felt the SOA effort was on track. By this time, it had been almost two years since Spencer's team developed the Customer Information Service for the auto insurance and home insurance divisions. While these two groups were very happy with the results, no additional teams had leveraged it. Outside of the annuity project, this wasn't a case of projects going in another direction; it was more due to lack of opportunities. That was about to change. Spencer was eating lunch in the cafeteria when Ramesh walked up. "Mind if I join you, Spencer?" "Hey Ramesh, it's been quite some time. Go ahead and pull up a chair." "Do you remember two years ago you tried to convince Ryan to use your Customer Information Service?" "I sure do. I didn't want to show my face in the annuity area for about a month after that. He really wasn't very receptive to the idea." "Well, I have some good news and some better news for you. The good news is that about six months later, Ryan decided to leave Advasco. The better news is that we've now got a major initiative to revamp a number of our systems in the annuity department. I'd like to take advantage of the Customer Information Service as part of that effort." "That's good news Ramesh. I didn't harbor any resentment towards Ryan, but I'm certainly happy about having another potential consumer for the Customer Information Service. I'll put you in touch with the service manager for it." "Thanks Spencer. That would be great. We're just getting started on our architecture, so the timing is perfect." "Let me know if you run into any problems. I'm still part of the SOA Center of Excellence, so it's still my job to make sure it goes well!" Spencer put Ramesh in contact with the service manager for the Customer Information Service, Maria. Maria had recently transferred over after her work on the account maintenance effort, and now had responsibilities for the Customer Information Service. In the meeting with Ramesh, she brought her technical lead, Craig, with her "Spencer told me that you're interested in utilizing the Customer Information Service in some of the new systems you're building in the annuity department, Ramesh." "That's right. We're rewriting a number of our systems, and based on what I remembered from Spencer two years ago, I thought we might be able to leverage the service." "Great, I'd be happy to help you out. This is Craig, the technical lead who covers the Customer Information Service. He's here if you've got any technical questions. Have you had a chance to review the information available in the service repository?" "I have. I reviewed the service interface, and while it certainly looks like there's enough there to warrant using the service rather than building our own, there's also a number of additional things that we'll need." Craig responded, "What kind of changes are you looking for? Are there new operations that you need that are specific to the annuity area?" Ramesh said, "There are two or three operations that we'd like to see, but most of the changes are actually in the message schemas for the existing operations. There are some additional attributes that we need, and some of the relationships between the attributes are different in our representation." For the rest of the meeting, Ramesh and Craig went through the changes that Ramesh wanted to be made to accommodate his needs. In the end, it was clear that some changes to the existing schemas would have to be made. Maria asked, "We're going to need to go back and look over these changes, along with the integration approach for your existing database. What does the schedule for your efforts currently look like?" Ramesh replied, "We're still in the initial stages of planning, which is why I wanted to make sure I talked to you now. Right now, the project sponsors would like to have something within six months, but they also know that nine months is far more likely. Since I have some flexibility in my schedule, why don't you take a week to look into the effort required for the changes, and let's work out the schedule then. Does that work for you?" "That works for me. We'll get back to you next week with what we think it will take to implement the changes." On the way back to their desks, Craig commented to Maria, "You know, while I don't have any concerns about getting the work done for Ramesh, I do have some concerns on how these changes are going to impact our existing consumers. Some of these changes are going to break the existing interfaces." Maria said, "That is a concern. I know that there aren't any resources available to do any work on the home insurance side of things. Any suggestions on how we should handle this?" Craig said, "Well, we definitely should make the existing consumers aware that a change is going to be made and at least get a clear idea of what the impact will be. If you can take care of that, I can take this to Spencer and the SOA Center of Excellence, and see what suggestions they have." "That sounds like a good plan to me," replied Maria Over the next week, the Customer Information Service team did the analysis required to estimate how long the changes would take to implement. Maria used the communication features of the service registry/repository to push out a message to the existing consumers about the pending change, and as she suspected, the biggest problem was going to be the home insurance system. Due to other priorities, the earliest they could even begin to make changes to their consumer would be nine months from now, potentially three months after the service needed to go live. Craig met with Spencer and explained the problem to him. Spencer agreed to facilitate a decision-making session to explore the different options. Representatives from all of the existing consumers were there, along with Ramesh, Craig, and Maria Spencer started the meeting, "I'm sure all of you saw the notification from Maria last week that some changes are necessary to the Customer Information Service in order to support its usage by the annuity department. The problem that we face is that these changes will break the existing consumers of the service, and not all of you can make the changes to your systems in the currently proposed timeframe. Let's start out by listing all possible options, regardless of whether we all presently agree or disagree on their viability." Craig started out, "Well, if we're listing all possible options, the first one is toupdate the service, and then get whatever push we need from management to get resources allocated to the consuming systems so they can make the changes in the time required." Maria replied, "Come on Craig, you know that we can't just pull resources off projects that easily." Jason, from the auto insurance department, added, "Aren't all of these changes a result of the annuity department? Why can't they just include modifying our applications within their project scope? They already have resources allocated to their project." Paul, from the home insurance department, replied, "Do you really want some developers that have never seen your application before mucking around in your code? I know I don't." Spencer said, "Let's remember, we're listing all options, regardless of whether we all know that the option won't fly. We want to make sure we've explored all of the options. I'm going to just leave this as one option, since we still wind up with the same result, regardless of where the resources come from. I'll capture the concerns about the option." Paul, from the home insurance group, added, "Okay, here's another option. Why don't we leave the existing service in place, and simply have the annuity project write a new service that just they use. Then, none of us using the existing service would be impacted." Craig replied, "That's true, but isn't that going against everything we're trying to do with SOA? I thought we were trying to avoid redundant implementations of the same capability." Spencer replied, "Duly noted, Craig. Just as with the last option, let's keep it on the board, and I'll make sure that your concerns are captured. Paul, that option actually triggered another one in my mind. In addition to having Maria's team write the new service for the annuity system, why couldn't they also keep the existing version of the service available in production for the rest of you? You can then migrate as your schedules allow." Paul and Jason both replied in tandem, "That would work for us!" Maria jumped into the conversation, "While I'm sure it would, that sets a very dangerous precedent for my team. How many versions of the service are we going to have to maintain? While it's a little bit better when all the implementations are owned by one team, we still have multiple implementations." Jason then asked, "Isn't there a way to make the new service backwards compatible with the messages associated with the old service? That way, Maria's teamwould only have one implementation, but we could each continue to use our existing interface." Spencer replied, "That's a very good question Jason. While we all agree that the service interface needs to change to support the annuity department's requirements, I don't know that any of us have thought about whether we can easily transform messages associated with the previous version to messages that will work with the new version, and vice versa. Craig, you're the one most familiar with the new proposed schemas. Do you think we could leverage XSLT to apply transformations for backward compatibility?" "Yes, I think it's possible. The only concern I have is what impact this will have on the service implementation. Working with XSLT within Java code isn't the easiest thing to do, and as we make future modifications, that's just going to get uglier and uglier." Spencer said, "There's another option for that. A year ago, we put some XML appliances in place for security purposes. I know they have XSLT capabilities and they're already in the request path." Craig replied, "Of all the options, I think that one would work out the best. I really don't like the idea of maintaining multiple versions of the service, and having to maintain all of that XSLT code within the service is only slightly better. Allowing the annuity group to write their own goes against everything we're trying to do with SOA." Spencer said, "Well, we know where Craig stands. Are there any other options that we should look into? No? Well, what does everyone think?" Paul was first, "We know that we're not going to find resources to make the changes in all of the consumers at the same time, so that option is out. Likewise, it doesn't make sense for Ramesh's team to write their own service given our SOA goals, so that one is out, too. As for whether Maria's team maintains two versions of the service or utilizes some transformations somewhere, it really doesn't matter to me. From my perspective, both options give me the freedom to migrate at the time that works best for me." Jason immediately added, "I agree with everything Paul just said." Ramesh then offered his opinion, "Well, I certainly know that I don't want to give up any of my developers to work on Jason's and Paul's systems. We need every developer we can get right now. As for writing our own service, we've already been down that path two years ago, and now we're obviously changing the system again. If we had migrated to the service earlier, it would be one less thing that we had to touch as part of these changes. As long as Maria's team delivers my service on time for my projects, it doesn't matter to me what Maria's team chooses to do on their side." Spencer replied, "Well Maria, it looks like everyone else thinks that we need a solution that will allow all of the consumers to continue to use their existing interfaces or the new one, but the details of how that happens is completely up to you and Craig." Maria said, "Let's not jump to conclusions yet. If I'm going to maintain multiple versions, I need some kind of guarantee that the existing consumers will eventually migrate to the new version. If my team allows continuous use of the old interface for 12 months from the time the new interface goes live, would that be an adequate time to complete whatever modifications are necessary?" Jason and Paul thought about it and decided that this was reasonable. For the past three years, they'd averaged an update every nine months. Maria said, "I'll make sure to remind you, early and often, that the old version and its associated interfaces are going to be decommissioned. In the meantime, I'd like to first get the new version built. I'm going to need to keep both versions around initially just to compare messages. Ramesh's team can begin using the new service, and…" As she was talking, she stopped mid-sentence. Spencer said, "Is there a problem, Maria?" She replied, "Well, I was just thinking, how are we going to avoid having two URL's out there? The existing consumers are using a URL that points to the XML appliances, right? We want to apply transformations to that path. What URL will Ramesh's team use? We don't want to try to apply transformations to their requests." Spencer said, "Fortunately, I don't think we'll need to do that. We'll need to talk to the team that operates the appliances to be sure, but I'm pretty sure that the appliances can apply processing based upon incoming attributes on the message. As long as we can determine which requests came from which consumer based on the message content, we should be able to control when transformations happen, while having all the existing consumers using a single URL. We'll obviously need multiple URLs behind the intermediary, but that will be hidden from the consumers." Maria replied, "Okay, that eases some of my fears. Just make sure you find out quickly whether the appliances can handle it or not. Until we find out, can we set up a simple routing rule so that requests from the annuity group go to the new service, while the old ones stay where they are? That way, Ramesh can use the new service as soon as it is available, and Craig and his team can start working on the transformations for backward compatibility. I'd like to wait and see how that work goes before deciding whether to leave both versions out there for 12 months or to leverage the intermediary. We've never used that functionality before, and I don't want to take a chance on impacting Ramesh's schedule in case we run into difficulty. By keeping both services available in production at first, we can eliminate any dependency between the decommissioning of the old service and Ramesh's schedule." Craig added, "From my point of view, that shouldn't be a problem. I can treat the new version as if it were a completely new service, as long as the intermediary shields the consumers from that change. I will need to check how we can manage both versions at the source code level, though." Maria responded, "Good points, Craig. Taking all of this into account, I think this approach poses the least risk overall." Spencer said, "Then we're all in agreement, right? Maria's team will build a new version of the service according to the new interface, and the old interface will be available for 12 months from the time the new service is deployed. Initially, both versions will be available in production, but Maria can decommission the old service before 12 months are up, so long as the new version can be made backwards compatible via XSLT transformations. Maria will notify all consumers prior to decommissioning the old service, since regression testing will be required to ensure that backward compatibility has been maintained. She will also notify all consumers as we get closer to the 12 month cutoff when the older interface will no longer be supported." Everyone in the meeting agreed with this approach, and the teams went off and made it happen. Craig's team investigated the best way to apply the transformations, testing them using the latest Java libraries, as well as the XML appliances that Advasco had recently installed. They found that the XML appliances performed very well, and kept the programming model of the service very clean. While the Java libraries performed satisfactorily, the resulting programming model was not as clean as the team desired. With the use of the routing rules in the appliance, they were able to remove the older version of the service from production, while still supporting the older messages for the full 12 months as promised.

In this article by Karl Swedberg and Jonathan Chaffer, we will use an online bookstore as our model website, but the techniques we cook up can be applied to a wide variety of other sites as well, from weblogs to portfolios, from market-facing business sites to corporate intranets. In this article, we will use jQuery to apply techniques for increasing the readability, usability, and visual appeal of tables, though we are not dealing with tables used for layout and design. In fact, as the web standards movement has become more pervasive in the last few years, table-based layout has increasingly been abandoned in favor of CSS‑based designs. Although tables were often employed as a somewhat necessary stopgap measure in the 1990s to create multi-column and other complex layouts, they were never intended to be used in that way, whereas CSS is a technology expressly created for presentation. But this is not the place for an extended discussion on the proper role of tables. Suffice it to say that in this article we will explore ways to display and interact with tables used as semantically marked up containers of tabular data. For a closer look at applying semantic, accessible HTML to tables, a good place to start is Roger Johansson's blog entry, Bring on the Tables at www.456bereastreet.com/archive/200410/bring_on_the_tables/. Some of the techniques we apply to tables in this article can be found in plug‑ins such as Christian Bach's Table Sorter. For more information, visit the jQuery Plug‑in Repository at http://jQuery.com/plugins. Sorting One of the most common tasks performed with tabular data is sorting. In a large table, being able to rearrange the information that we're looking for is invaluable. Unfortunately, this helpful operation is one of the trickiest to put into action. We can achieve the goal of sorting in two ways, namely Server-Side Sorting and JavaScript Sorting. Server-Side Sorting A common solution for data sorting is to perform it on the server side. Data in tables often comes from a database, which means that the code that pulls it out of the database can request it in a given sort order (using, for example, the SQL language's ORDER BY clause). If we have server-side code at our disposal, it is straightforward to begin with a reasonable default sort order. Sorting is most useful when the user can determine the sort order. A common idiom is to make the headers of sortable columns into links. These links can go to the current page, but with a query string appended indicating the column to sort by: <table id="my-data">   <tr>     <th class="name"><a href="index.php?sort=name">Name</a></th>     <th class="date"><a href="index.php?sort=date">Date</a></th>   </tr>   ... </table> The server can react to the query string parameter by returning the database contents in a different order. Preventing Page Refreshes This setup is simple, but requires a page refresh for each sort operation. As we have seen, jQuery allows us to eliminate such page refreshes by using AJAX methods. If we have the column headers set up as links as before, we can add jQuery code to change those links into AJAX requests: $(document).ready(function() {   $('#my-data .name a').click(function() {     $('#my-data').load('index.php?sort=name&type=ajax');     return false;   });   $('#my-data .date a').click(function() {     $('#my-data').load('index.php?sort=date&type=ajax');     return false;   }); }); Now when the anchors are clicked, jQuery sends an AJAX request to the server for the same page. We add an additional parameter to the query string so that the server can determine that an AJAX request is being made. The server code can be written to send back only the table itself, and not the surrounding page, when this parameter is present. This way we can take the response and insert it in place of the table. This is an example of progressiveenhancement. The page works perfectly well without any JavaScript at all, as the links for server-side sorting are still present. When JavaScript is present, however, the AJAX hijacks the page request and allows the sort to occur without a full page load. JavaScript Sorting There are times, though, when we either don't want to wait for server responses when sorting, or don't have a server-side scripting language available to us. A viable alternative in this case is to perform the sorting entirely on the browser using JavaScript client-side scripting. For example, suppose we have a table listing books, along with their authors, release dates, and prices: <table class="sortable">   <thead>     <tr>       <th></th>       <th>Title</th>       <th>Author(s)</th>       <th>Publish&nbsp;Date</th>       <th>Price</th>     </tr>   </thead>   <tbody>     <tr>       <td>         <img src="../covers/small/1847192386.png" width="49"              height="61" alt="Building Websites with                                                 Joomla! 1.5 Beta 1" />       </td>       <td>Building Websites with Joomla! 1.5 Beta 1</td>       <td>Hagen Graf</td>       <td>Feb 2007</td>       <td>$40.49</td>     </tr>     <tr>       <td><img src="../covers/small/1904811620.png" width="49"                height="61" alt="Learning Mambo: A Step-by-Step                Tutorial to Building Your Website" /></td>       <td>Learning Mambo: A Step-by-Step Tutorial to Building Your           Website</td>       <td>Douglas Paterson</td>       <td>Dec 2006</td>       <td>$40.49</td>     </tr>     ...   </tbody> </table> We'd like to turn the table headers into buttons that sort by their respective columns. Let us look into ways of doing this.   Row Grouping Tags Note our use of the <thead> and <tbody> tags to segment the data into row groupings. Many HTML authors omit these implied tags, but they can prove useful in supplying us with more convenient CSS selectors to use. For example, suppose we wish to apply typical even/odd row striping to this table, but only to the body of the table: $(document).ready(function() {   $('table.sortable tbody tr:odd').addClass('odd');   $('table.sortable tbody tr:even').addClass('even'); }); This will add alternating colors to the table, but leave the header untouched: Basic Alphabetical Sorting Now let's perform a sort on the Titlecolumn of the table. We'll need a class on the table header cell so that we can select it properly: <thead>   <tr>     <th></th>    <th class="sort-alpha">Title</th>     <th>Author(s)</th>     <th>Publish&nbsp;Date</th>     <th>Price</th>   </tr> </thead> To perform the actual sort, we can use JavaScript's built in .sort()method. It does an in‑place sort on an array, and can take a function as an argument. This function compares two items in the array and should return a positive or negative number depending on the result. Our initial sort routine looks like this: $(document).ready(function() {   $('table.sortable').each(function() {     var $table = $(this);     $('th', $table).each(function(column) {       if ($(this).is('.sort-alpha')) {         $(this).addClass('clickable').hover(function() {           $(this).addClass('hover');         }, function() {           $(this).removeClass('hover');         }).click(function() {           var rows = $table.find('tbody > tr').get();           rows.sort(function(a, b) {             var keyA = $(a).children('td').eq(column).text()                                                       .toUpperCase();             var keyB = $(b).children('td').eq(column).text()                                                       .toUpperCase();             if (keyA < keyB) return -1;             if (keyA > keyB) return 1;             return 0;           });           $.each(rows, function(index, row) {             $table.children('tbody').append(row);           });         });       }     });   }); }); The first thing to note is our use of the .each() method to make iteration explicit. Even though we could bind a click handler to all headers with the sort-alpha class just by calling $('table.sortable th.sort-alpha').click(), this wouldn't allow us to easily capture a crucial bit of information—the column index of the clicked header. Because .each() passes the iteration index into its callback function, we can use it to find the relevant cell in each row of the data later. Once we have found the header cell, we retrieve an array of all of the data rows. This is a great example of how .get()is useful in transforming a jQuery object into an array of DOM nodes; even though jQuery objects act like arrays in many respects, they don't have any of the native array methods available, such as .sort(). With .sort() at our disposal, the rest is fairly straightforward. The rows are sorted by comparing the textual contexts of the relevant table cell. We know which cell to look at because we captured the column index in the enclosing .each() call. We convert the text to uppercase because string comparisons in JavaScript are case-sensitive and we wish our sort to be case-insensitive. Finally, with the array sorted, we loop through the rows and reinsert them into the table. Since .append() does not clone nodes, this moves them rather than copying them. Our table is now sorted. This is an example of progressive enhancement's counterpart, gracefuldegradation. Unlike with the AJAX solution discussed earlier, we cannot make the sort work without JavaScript, as we are assuming the server has no scripting language available to it in this case. The JavaScript is required for the sort to work, so by adding the "clickable" class only through code, we make sure not to indicate with the interface that sorting is even possible unless the script can run. The page degrades into one that is still functional, albeit without sorting available. We have moved the actual rows around, hence our alternating row colors are now out of whack: We need to reapply the row colors after the sort is performed. We can do this by pulling the coloring code out into a function that we call when needed: $(document).ready(function() {   var alternateRowColors = function($table) {     $('tbody tr:odd', $table).removeClass('even').addClass('odd');     $('tbody tr:even', $table).removeClass('odd').addClass('even');   };     $('table.sortable').each(function() {     var $table = $(this);     alternateRowColors($table);     $('th', $table).each(function(column) {       if ($(this).is('.sort-alpha')) {         $(this).addClass('clickable').hover(function() {           $(this).addClass('hover');         }, function() {           $(this).removeClass('hover');         }).click(function() {           var rows = $table.find('tbody > tr').get();           rows.sort(function(a, b) {             var keyA = $(a).children('td').eq(column).text()                                                       .toUpperCase();             var keyB = $(b).children('td').eq(column).text()                                                       .toUpperCase();             if (keyA < keyB) return -1;             if (keyA > keyB) return 1;             return 0;           });           $.each(rows, function(index, row) {             $table.children('tbody').append(row);           });           alternateRowColors($table);         });       }     });   }); }); This corrects the row coloring after the fact, fixing our issue:   The Power of Plug-ins The alternateRowColors()function that we wrote is a perfect candidate to become a jQuery plug-in. In fact, any operation that we wish to apply to a set of DOM elements can easily be expressed as a plug-in. In this case, we only need to modify our existing function a little bit: jQuery.fn.alternateRowColors = function() {   $('tbody tr:odd', this).removeClass('even').addClass('odd');   $('tbody tr:even', this).removeClass('odd').addClass('even');   return this; }; We have made three important changes to the function. It is defined as a new property of jQuery.fn rather than as a standalone function. This registers the function as a plug-in method. We use the keyword this as a replacement for our $table parameter. Within a plug-in method, thisrefers to the jQuery object that is being acted upon. Finally, we return this at the end of the function. The return value makes our new method chainable. More information on writing jQuery plug-ins can be found in Chapter 10 of our book Learning jQuery. There we will discuss making a plug-in ready for public consumption, as opposed to the small example here that is only to be used by our own code. With our new plug-in defined, we can call $table.alternateRowColors(), which is a more natural jQuery syntax, intead of alternateRowColors($table). Performance Concerns Our code works, but is quite slow. The culprit is the comparator function, which is performing a fair amount of work. This comparator will be called many times during the course of a sort, which means that every extra moment it spends on processing will be magnified. The actual sort algorithm used by JavaScript is not defined by the standard. It may be a simple sort like a bubble sort (worst case of Θ(n2) in computational complexity terms) or a more sophisticated approach like quick sort (which is Θ(n log n) on average). In either case doubling the number of items increases the number of times the comparator function is called by more than double. The remedy for our slow comparator is to pre-compute the keys for the comparison. We begin with the slow sort function: rows.sort(function(a, b) {   keyA = $(a).children('td').eq(column).text().toUpperCase();   keyB = $(b).children('td').eq(column).text().toUpperCase();   if (keyA < keyB) return -1;   if (keyA > keyB) return 1;   return 0; }); $.each(rows, function(index, row) {   $table.children('tbody').append(row); }); We can pull out the key computation and do that in a separate loop: $.each(rows, function(index, row) {   row.sortKey = $(row).children('td').eq(column).text().toUpperCase(); }); rows.sort(function(a, b) {   if (a.sortKey < b.sortKey) return -1;   if (a.sortKey > b.sortKey) return 1;   return 0; }); $.each(rows, function(index, row) {   $table.children('tbody').append(row);   row.sortKey = null; }); In the new loop, we are doing all of the expensive work and storing the result in a new property. This kind of property, attached to a DOM element but not a normal DOM attribute, is called an expando.This is a convenient place to store the key since we need one per table row element. Now we can examine this attribute within the comparator function, and our sort is markedly faster.  We set the expando property to null after we're done with it to clean up after ourselves. This is not necessary in this case, but is a good habit to establish because expando properties left lying around can be the cause of memory leaks. For more information, see Appendix C.   Finessing the Sort Keys Now we want to apply the same kind of sorting behavior to the Author(s) column of our table. By adding the sort-alpha class to its table header cell, the Author(s)column can be sorted with our existing code. But ideally authors should be sorted by last name, not first. Since some books have multiple authors, and some authors have middle names or initials listed, we need outside guidance to determine what part of the text to use as our sort key. We can supply this guidance by wrapping the relevant part of the cell in a tag: <tr>   <td>     <img src="../covers/small/1847192386.png" width="49" height="61"             alt="Building Websites with Joomla! 1.5 Beta 1" /></td>   <td>Building Websites with Joomla! 1.5 Beta 1</td>   <td>Hagen <span class="sort-key">Graf</span></td>   <td>Feb 2007</td>   <td>$40.49</td> </tr> <tr>   <td>     <img src="../covers/small/1904811620.png" width="49" height="61"          alt="Learning Mambo: A Step-by-Step Tutorial to Building                                                 Your Website" /></td>   <td>     Learning Mambo: A Step-by-Step Tutorial to Building Your Website   </td>   <td>Douglas <span class="sort-key">Paterson</span></td>   <td>Dec 2006</td>   <td>$40.49</td> </tr> <tr>   <td>     <img src="../covers/small/1904811299.png" width="49" height="61"                   alt="Moodle E-Learning Course Development" /></td>   <td>Moodle E-Learning Course Development</td>   <td>William <span class="sort-key">Rice</span></td>   <td>May 2006</td>   <td>$35.99</td> </tr> Now we have to modify our sorting code to take this tag into account, without disturbing the existing behavior for the Titlecolumn, which is working well. By prepending the marked sort key to the key we have previously calculated, we can sort first on the last name if it is called out, but on the whole string as a fallback: $.each(rows, function(index, row) {   var $cell = $(row).children('td').eq(column);   row.sortKey = $cell.find('.sort-key').text().toUpperCase()                                   + ' ' + $cell.text().toUpperCase(); }); Sorting by the Author(s)column now uses the last name:     If two last names are identical, the sort uses the entire string as a tiebreaker for positioning.

We have come a long way from the day the WEB was created in 1992 by T.B.LEE in Switzerland. From hyper linking which was the only thing at that time, to streaming videos, instant gratification with AJAX, and a host of other do-dads that has breathed new life to JavaScript and internet usability. Silverlight among several others, is a push in this direction to satisfy the ever increasing needs of the internet users. Even so, the web application displays fall short of the rich experience one can achieve with desktop applications, and this is where the tools are being created and honed for creating RIA, short for Rich Internet Applications. In order to create such applications, a great deal of development has taken place in the Microsoft ecosystem . These are all described in the .NET and Windows Presentation Foundation which supports developers to create easily deployable Rich Internet Applications. We have to wait and see how it percolates to the Semantic Web in the future. Silverlight is a cross-platform, cross-browser plug-in that renders XAML, the declarative tag-based files while exposing the JavaScript programming interface. It makes both developers and designers to collaborate and contribute to rich and interactive designs that are well integrated with Microsoft's Expression series of programs. Initial Steps to Take In this article we will be using Silverlight 1.0 with JavaScript. Initially you need to make your browser understand the XAML, and for this you need to install Silverlight available here. There is no need for a server to work with these Silverlight application files as they will be either HTML pages, XAML pages, or JavaScript pages. Of course these files may be hosted on the server as well. The next figure shows some details you need to know before installing the plug-in. Silverlight Project Details After having enabled the browser to recognize XAML - the Extensible Application Mark up Language, you need to consider the different components that will make Silverlight happen. In the present tutorial we will look at using Silverlight 1.0. Silverlight 2.0 is still in Beta stage. If you have Silverlight already installed you may be able to verify the version in the Control Panel / Add Remove Programs and display information as shown in the next figure. To make Silverlight happen you need the following files: An HTML page that you can browse to where the Silverlight plug-in is spawned A XAML page which is all the talk is about which provides the 'Richness' Supporting script files that will create the plug-in and embeds it in the HTML page The next figure shows how these interact with one another somewhat schematically. Basically you can start with your HTML page. You need to reference two .JS files as shown in the above figure. The script file Silverlight.js exposes the properties, methods, etc. of Silverlight. This file will be available in the SDK download. You can copy this file and move it around to any location. The second script createSilvelight.js creates a plug-in which you will embed in the HTML page using yet another short script. You will see how this is created later in the tutorial. The created plug-in then brings-in the XAML page which you will create as well. The first step is to create a blank HTML page, herein called, TestSilverLight.htm as shown in the following listing: Listing 1:TestSilverLight.htm Scaffold file <html><head><script type="text/javascript" src="Silverlight.js"></script><script type="text/javascript" src="createSilverlight.js"></script><title> </title> </head> <body> Next, you go ahead and create the createSilvelight.js file. The following listing shows how this is coded. This is slightly modified although taken from a web resource. Listing 2: createSilverlight.js function createSilverlight() { Silverlight.createObject( "TestSilver.xaml", // Source property value. parentElement, // DOM reference to hosting DIV tag. "SilverlightPlugInHost1", // Unique plug-in ID value. { // Plug-in properties. width:'1024', // Width of rectangular in pixels. height:'530', // Height of rectangular in pixels. inplaceInstallPrompt:false, // install prompt if invalid version is detected. background:'white', // Background color of plug-in. isWindowless:'false', // Determines whether to display in windowless mode. framerate:'24', // MaxFrameRate property value. version:'1.0' // Silverlight version. }, { onError:null, // OnError property value onLoad:null // OnLoad property value }, null, // initParams null); // Context value } This function, createSilverlight(), when called from within a place holder location will create a Silverlight object at that location with some defined properties. You may go and look up the various customizable items in this code on the web. The object that is going to be created will be the TestSilver.xaml at the "id" of the location which will be found using the ECMA script we will see later. The "id" is also named here, found by the "parentElement". To proceed further we need to create (a) the TestSilver.xaml file and (b) create a place holder in the HTML page. At first the changes made to Listing 1 are shown in bold. This is the place holder <div> </div> tags inside the 'body' tags as shown in the next listing with the "id" used in the createSilverlight.js file. You may also use <span> </span> tags, provided you associate a "id" with it. Listing 3: Place holder created in the HTML Page <head><script type="text/javascript" src="Silverlight.js"></script><script type="text/javascript" src="createSilverlight.js"></script><title> </title> </head> <body><div id="SilverlightPlugInHost1"> </div></body> </html> Creating the XAML File If you have neither used XAML, nor created a XAML page you should access the internet where you will find tons of this stuff. A good location is MSDN's Silvelight home page. You may also want to read up this article which will give some idea about XAML. Although this article is focusing on 'Windows' and not 'Web', the idea of what XAML is the same. The next listing describes the declarative syntax that will show a 'canvas', a defined space on your web page in which an image has been brought in. The 'Canvas' is the container and the image is the contained object. A XAML file should be well formed similar to an XML file. Listing 4: A Simple XAML file <Canvas Width="200" Height="200" Background="powderblue"><Image Canvas.Left="50" Canvas.Top="50" Width="200"Source="Fish.JPG"/></Canvas> Save the above file (text) with the extension XAML. If your Silverlight 1.0 is working correctly you should see this displayed on the browser when you browse to it. You also note the [.] notation to access the properties of the Canvas. For example, Canvas.Left is 50 pixels relative to the Canvas. The namespace is very important, more about it later. Without going into too much details, the pale blue area is the canvas whose width and height are 200 pixels each. The fish image is off set by the amounts shown relative to the canvas. Canvas is the portion of the browser window which functions as a place holder. While you use "Canvas" in web, you will have "Window" for desktop applications. The namespace of the canvas should be as shown otherwise you may get errors of various types depending on the typos. Inside the canvas you may place any type of object, buttons, textboxes, shapes, and even other canvases. If and when you design using the Visual Studio designer with intellisense guiding you along you will see a bewildering array of controls, styles, etc. The details of the various XAML tags are outside the scope of this tutorial. Although Notepad is used in this tutorial, you really should use a designer as you cannot possibly remember correctly the various Properties, Methods and Events supported. In some web references you may notice one more additional namespace . Remove this namespace reference as "Canvas" does not exist in this namespace. If you use it, you will get an XamlParseException. Also if you are of the cut and paste type make sure you save the XAML file as of type "All files" with XAML extension. With the above brief background review the TestSilver.xaml file whose listing is shown in the next paragraph. Listing 5: TestSilver.xaml file referenced in Plug-in script <Canvas Width="200" Height="150" Background="powderblue"> <Canvas Width="150" Height="250" Background="PaleGoldenRod"> <Ellipse Width="100" Height="100" Stroke="Black" StrokeThickness="2" Fill="Green" /> </Canvas><Image Canvas.Left="50" Canvas.Top="50" Width="200" Source="http://localhost/IMG_0086.JPG"/></Canvas> In the above code you see a second canvas embedded inside the first with its own independent window. The order they would appear will depend on where they are in the code unless the default order is changed. You also see that the image is now referenced to a graphic file on the local server. Later on you will see the Silverlight.htm hosted on the server. If you are using more recent versions of ASP.NET used on your site, or version of IE you may get to see the complete file and some times you may get to see only part of the XMAL content and additional error message such as this one. For example, while the image in the project folder is displayed, the image on the local server may be skipped. If the setting and versions are optimum, you will get to see this displayed on your browser when you browse to the above file. Script in HTML to Embed Silverlight Plug-in This really is the last piece left to be taken care of to complete this project. The code shown in the next listing shows how this is done. The code segment shown in bold is the script that is added to the place holder we created earlier. Listing 6: Script added to bring Plug-in <html><head><script type="text/javascript" src="Silverlight.js"></script><script type="text/javascript" src="createSilverlight.js"></script><title> </title> </head> <body><div id="SilverlightPlugInHost1"> <script type="text/javascript"> var parentElement = document.getElementById("SilverlightPluginHost1"); createSilverlight();</script></div></body> </html> Hosted Files on the IIS The various files used are then saved to a folder and can be set up as the target of a virtual directory on your IIS as shown. Now you can browse the Silverlight123.htm file on your browser to see the following displayed on your IE. Summary The present tutorial shows how to create a Silverlight project describing the various files used and how they interact with each other. The importance of using the correct namespace and some tips on creating the XAML files as well as hosting them on IIS are also described. A Windows XP with SP2 was used and the Silverlight.htm file tested on IIS 5.1; IE Ver 7.0.5370IC and web site enabled for ASP.NET Version 2.0.50727 with the registered MimeType application/xaml+xml.

To do this, we are essentially completing the tasks in the home screen of the Windows SBS Console, which should look like the following screenshot. Assumptions I'm assuming that you understand the concepts of firewalls and ports; otherwise, you will struggle to safely configure your network. I'm also aware that OneCare, for servers, only provides an introductory offer for anti-malware and another product will be required; however, it is easier to describe the installation of one product rather than trying to answer for all products, so I'm using OneCare as a template. You will, however, need an anti-malware product that is server aware, or need to exclude server product locations such as the exchange data stores and other locations. Network security configuration There are a few areas where we can improve the security of the network. They are around the firewall, reducing the traffic that arrives at the SBS 2008 server, and the security certificate that is used to secure and identify the server communications. Configuring the firewall ports You will need the following ports configured on your firewall to direct traffic to SBS 2008: If you were using SBS 2003, then you can close down ports 444 and 4125, which might have previously been open. Loading a third-party security certificate SBS 2008 creates a security certificate to secure its communications. Certificates are only valuable if everybody seeing them trusts the system that issues the certificate. All computers that are part of the SBS 2008 network trust the SBS 2008 server, so trust is achieved in this way. For those that are not part of the SBS 2008 network, a special certificate must be loaded onto those machines so they will trust SBS 2008, else they will provide warnings to users about the integrity of the communication. There are organizations called Certificate Authorities who have established trust in the marketplace and most IT systems trust the certificates they issue. If you wish to have a more publically trusted certificate, then you will need to purchase one of these. One area where third-party certificates are often needed is when using mobile devices, to enable the loading of the SBS 2008 certificate onto the phones. Without the certificate on the phone, synchronization of Outlook information to the phone cannot take place. Importing a certificate If you already have a certificate or have purchased one and have been sent a file containing the certificate including the private keys, then you should follow this process. There are two steps to follow: Importing the certificate into the Local Computer Certificate store Assigning the certificate using the SBS Console Importing the certificate Start Windows SBS Console (Advanced Mode) from the Start menu and click on the Network tab and then the connectivity button. As this is the advanced console, you will see extra tasks available on the righthand side. Click on the Manage certificates task—if this is not present, check you are running the Advanced Mode console: it will say so in the title bar. This will run a management console with the certificates for your computer made visible. Expand the Personal tree and right-click on Certificates and select Import from the All Tasks menu item. Click Next to pass through the welcome screen for the Certificate Import Wizard and then click on the Browse button to locate the certificate. Then, click on Next to continue. You will now be required to enter your Password to enable access to the key. I would put a check mark in the two remaining check boxes to Mark the key as exportable to enable you to export the certificate should you need to in the future and include the extended properties. Then, click on Next. You will be required to confirm the location, which should be Personal and again click on Next. If it is not set to Personal, click on the Browse button and change the Certification store to Personal. Now click on Finish to complete the process and you will see a message stating that The import was successful. Close the Certificates Management console. Assigning the certificate In the Windows SBS Console, click the task Add a trusted certificate to start the process. Click on Next to skip past the introduction. If you have assigned a certificate before, you will be told that A valid trusted certificate already exists and you have the choice of renewing your existing certificate or replacing it. Select I want to replace the existing certificate with a new one and click on Next. If you have not added a trusted certificate before, then you will not see this screen. On the Get the certificate page, select the option to use a certificate already installed on the server and click on Next. The certificate that you installed will show in the list with a Type of Trusted, while the certificates issued by SBS 2008 will show as Self-issued. Select your Trusted certificate and click on Next. Click on Next to start the process and then Finish to exit the wizard.

Kushal Sharma: What is the vision behind Miro? Nicholas Reville: There's an opportunity to build a new, open mass medium of online television. We're developing the Miro Internet TV platform so that watching Internet video channels will be as easy as watching TV and broadcasting a channel will be open to everyone. Unlike traditional TV, everyone will have a voice. KS: Does PCF finance the entire project or do you have any other contributors? NR: We have tons of help from volunteers – translating the software, coding, testing, and providing user support. We would not be able to do nearly enough without our community. KS: Are the developers full-time PCF employees or is it similar to other Open Source projects where people voluntarily contribute to the community in their spare-time? NR: We have 6 full-time developers and also volunteers. We're a hybrid model, like Mozilla. KS: Please highlight the most crucial features of Miro, and the idea behind having those features as part of this application. NR: The most crucial feature of Miro is the ability to download and play video RSS feeds. It's a truly open way to distribute video online. Using RSS means that creators can publish with any company they want and users can bring together video from multiple sources into one application. KS: How many languages is Miro translated into? NR: Miro is at least partially translated into more than 40 languages, but we always need helping revising and improving the translations. KS: How is Miro different from other players from the technological perspective? NR: Above all, Miro is open-source. That means that anyone can work on the code, improve, and customize it. Beyond this, Miro is unique in a number of ways. It runs on Mac, Windows, and Linux. It can play almost any video format. And it has more HD content available than any other Internet TV application. KS: Are the Torrent download capabilities as well developed as any other standalone Bit Torrent Client? Please tell us something more about it's download capabilities, the share ratio, configurable upload limits while downloading the torrents etc. compared to other software? NR: Our current version of Miro keeps the BitTorrent capabilities very simple and doesn't provide many options. We think that most users don't even notice when they are downloading a torrent feed, however, we want to expand our options and features for power users in future versions – expect much more bit torrent control in 3 months or so. KS: What type of support do you have for Miro? NR: Most of our support is provided user-to-user in the discussion forums – they are very useful, actually. In addition, because we are an open project, anyone can file a bug or even fix a bug. In the long-term this means we will have a more stable user experience than closed competitors. KS: With a host of TV channels and video content going online, viewers could really use a common solution for all their media needs rather than keeping tabs on multiple sources. How do you see Miro being instrumental in providing this? NR: We think that an open platform for video is the only way to create a unified experience for video. Miro is the only really open Internet video solution right now and we think we have a crucial role to play in unifying Internet TV in an open way. KS: Does Miro download Internet TV programs and store it on the hard disk or does it stream live media like any other online service? NR: For now, Miro downloads everything that's watched. This is useful in two key ways: first, you can watch HD video with no skipping or buffering delays. Second, you can move those files onto any external device, with no DRM or other restrictions. In the future we may add a streaming option for some special cases, or the ability to start watching while the download is in progress. KS: Subscription-free content is a great gift that viewers get with Internet TV, however, bandwidth issues could be a concern for some users. What minimum bandwidth requirements would you suggest for satisfactory Internet TV performance on Miro? Furthermore, does Miro have an alternate solution for users having low Internet bandwidth? NR: Miro actually works better than most Internet video solutions for low bandwidth users. On a dial-up connection, streaming video solutions are unusable. Miro will download videos in those circumstances – it may happen slowly, but once you have the video you can watch it full speed with no skipping. KS: I remember a statement on the PCF site saying “Miro is designed to eliminate gatekeepers”. Could you please elaborate on this? NR: Miro works with open standards and is designed to be decentralized, like the web. That means that users can use Miro to connect directly to any video publisher – they don't need our permission and the files don't travel through our servers. Companies like Joost design their software to be highly centralized so that they can control both users and creators. It's time to leave that model behind. KS: So far, what has the response been like? NR: Response has been great. Last month alone, we had more than 200,000 downloads and we've been growing with each release. I expect that when we release version 1.0 in November we'll see even faster growth. KS: What are your future plans for Miro in terms of releases, updates, functionality, etc.? NR: After version 1.0 is released, we'll be making major changes to Miro to improve performance and add an extension system that will give people new ways of customizing the software to fit their needs. KS: To me, Miro’s agenda is a lot more than simply creating a good player. You’re attempting to change the face of Internet Video and the way it’s being hosted right now. How would you describe the future of Miro and Internet Video to our readers? NR: We want Miro to push online video in an open direction. We're hoping to build the best video experience possible, something that can be a true substitute for traditional television. But that doesn't mean we want to control the future of online video – we want other people to build open video distribution platforms as well. Openness is vital to the future of our mass media. KS: What other projects is the PCF involved in? NR: Right now, PCF is exclusively focused on making video more open and Miro is at the center of that. KS: Thank you for your time Nicholas, and good luck developing Miro!

Why do we still use WWW? If you were tasked with finding the letter that, when spoken out loud repeatedly, was more awkward than any other, you would come up with W. Every other letter in the English alphabet is pronounced with a single syllable, yet the W is unique in requiring an impressive three syllables to utter. The irony is that ‘World Wide Web’ can be said in just three syllables, yet the abbreviation WWW encounters a tongue-twisting nine! How can any abbreviation take three times the effort to speak than the very words it is an abbreviation of!? ‘duh-bull-you duh-bull-you duh-bull-you’. WWW is such a prolific term these days and so hard to verbalize that this abbreviation has been abbreviated further with phrases such as “dub dub dub” or “all the Ws”. Almost every website we use starts with WWW and mankind is desperately seeking a way to make the oration of these website addresses an easier and less embarrassing task. The answer, you may be surprised to hear, is shockingly easy. Don’t uses Ws! Websites don’t need them, we don’t like to speak them, the internet will run equally well without them. Addressing the Internet A website address is made up of 3 key parts. Take for example www.google.co.uk The google part combined with the .co.uk part makes up the domain name. When Google purchased this address they purchased google.co.uk, NOT www.google.co.uk. The .co.uk part typically indicates the country, or type of domain (known as Top Level Domain or TLD). The www part is a sub-domain that can indicate anything at all, or can even be omitted. When a domain such as google.co.uk is purchased, it is the web developer who decides what sub-domains should be used, and by following convention and perceived wisdom they will normally opt for WWW. Why do they do this when they could use anything or even nothing at all? Why not w.google.co.uk, or web.google.co.uk or why not just google.co.uk? Many web developers have seen the light and make sure that their websites work even when a sub-domain is omitted. Try browsing to google.co.uk for example, or yahoo.com, or digg.com, they all work just as well as the same domain names with the Ws. Forward Slash is killing me So now that we have freed up the sub-domain, let’s make some good use of it. How many times have you heard an advert for a website followed by ‘forward slash deals’ or similar. Forward slash gives us another three syllable description of a single punctuation character. Easy to type, annoying to verbalize. It sounds either crude or demonic, and the alternative ‘stroke’ is equally cringe-worthy. We like dots. DotCom is easy to say – and with sub-domains we can ditch the slashes and strokes in favor of the smallest punctuation mark with the shortest name. Try these examples... www.google.co.uk/adwords contains 22 syllables yet adwords.google.co.uk just 10. That’s less than half the time to read, less than half to remember and 17% less to type. If your website sells cars and bikes, you might currently use www.123autos.com/cars and www.123autos.com/bikes. How much more succinct it would be to use 123autos.com for the main website, cars.123autos.com for the car pages, and bikes.123autos.com for the bike pages? Drop ‘em This campaign is to encourage people to forget that WWW ever existed. Don’t type it, don’t speak it, and complain to every website that still requires it. Drop the forward slashes, strokes and hyphens too. The only punctuation that should be used is the mighty yet humble dot and to achieve this, sub-domains are your loyal friends. Let’s make the World Wide Web an easier place to talk about.

What is an RSS Feed? First of all, let us understand what a web feed is. Basically, it is a data format that provides frequently updated content to users. Content distributors syndicate the web feed, allowing users to subscribe, by using feed aggregator. RSS feeds contain data in an XML format. RSS is the term used for describing Really Simple Syndication, RDF Site Summary, or Rich Site Summary, depending upon the different versions. RDF (Resource Description Framework), a family of W3C specification, is a data model format for modelling various information such as title, author, modified date, content etc through variety of syntax format. RDF is basically designed to be read by computers for exchanging information. Since, RSS is an XML format for data representation, different authorities defined different formats of RSS across different versions like 0.90, 0.91, 0.92, 0.93, 0.94, 1.0 and 2.0. The following table shows when and by whom were the different RSS versions proposed. RSS Version Year Developer's Name RSS 0.90 1999 Netscape introduced RSS 0.90. RSS 0.91 1999 Netscape proposed the simpler format of RSS 0.91. 1999 UserLand Software proposed the RSS specification. RSS 1.0 2000 O'Reilly released RSS 1.0. RSS 2.0 2000 UserLand Software proposed the further RSS specification in this version and it is the most popular RSS format being used these days. Meanwhile, Harvard Law school is responsible for the further development of the RSS specification. There had been a competition like scenario for developing the different versions of RSS between UserLand, Netscape and O'Reilly before the official RSS 2.0 specification was released. For a detailed history of these different versions of RSS you can check http://www.rss-specifications.com/history-rss.htm The current version RSS is 2.0 and it is the common format for publishing RSS feeds these days. Like RSS, there is another format that uses the XML language for publishing web feeds. It is known as ATOM feed, and is most commonly used in Wiki and blogging software. Please refer to http://en.wikipedia.org/wiki/ATOM for detail. The following is the RSS icon that denotes links with RSS feeds. If you're using Mozilla's Firefox web browser then you're likely to see the above image in the address bar of the browser for subscribing to an RSS feed link available in any given page. Web browsers like Firefox and Safari discover available RSS feeds in web pages by looking at the Internet media type application/rss+xml. The following tag specifies that this web page is linked with the RSS feed URL: http://www.example.com/rss.xml<link href="http://www.example.com/rss.xml" rel="alternate" type="application/rss+xml" title="Sitewide RSS Feed" /> Example of RSS 2.0 format First of all, let’s look at a simple example of the RSS format. <?xml version="1.0" encoding="UTF-8" ?><rss version="2.0"><channel> <title>Title of the feed</title> <link>http://www.examples.com</link> <description>Description of feed</description> <item> <title>News1 heading</title> <link>http://www.example.com/news-1</link> <description>detail of news1 </description> </item> <item> <title>News2 heading</title> <link>http://www.example.com/news-2</link> <description>detail of news2 </description> </item></channel></rss> The first line is the XML declaration that indicates its version is 1.0. The character encoding is UTF-8. UTF-8 characters support many European and Asian characters so it is widely used as character encoding in web. The next line is the rss declaration, which declares that it is a RSS document of version 2.0 The next line contains the <channel> element which is used for describing the detail of the RSS feed. The <channel> element must have three required elements <title>, <link> and <description>. The title tag contains the title of that particular feed. Similarly, the link element contains the hyperlink of the channel and the description tag describes or carries the main information of the channel. This tag usually contains the information in detail. Furthermore, each <channel> element may have one or more <item> elements which contain the story of the feed. Each <item> element must have the three elements <title>, <link> and <description> whose use is similar to those of channel elements, but they describe the details of each individual items. Finally, the last two lines are the closing tags for the <channel> and <rss> elements. Creating RSS Web Widget The RSS widget we're going to build is a simple one which displays the headlines from the RSS feed, along with the title of the RSS feed. This is another widget which uses some JavaScript, PHP CSS and HTML. The content of the widget is displayed within an Iframe so when you set up the widget, you've to adjust the height and width. To parse the RSS feed in XML format, I've used the popular PHP RSS Parser – Magpie RSS. The homepage of Magpie RSS is located at http://magpierss.sourceforge.net/. Introduction to Magpie RSS Before writing the code, let's understand what the benefits of using the Magpie framework are, and how it works. It is easy to use. While other RSS parsers are normally limited for parsing certain RSS versions, this parser parses most RSS formats i.e. RSS 0.90 to 2.0, as well as ATOM feed. Magpie RSS supports Integrated Object Cache which means that the second request to parse the same RSS feed is fast— it will be fetched from the cache. Now, let's quickly understand how Magpie RSS is used to parse the RSS feed. I'm going to pick the example from their homepage for demonstration. require_once 'rss_fetch.inc';$url = 'http://www.getacoder.com/rss.xml';$rss = fetch_rss($url);echo "Site: ", $rss->channel['title'], "<br>";foreach ($rss->items as $item ) { $title = $item[title]; $url = $item[link]; echo "<a href=$url>$title</a></li><br>";} If you're more interested in trying other PHP RSS parsers then you might like to check out SimplePie RSS Parser (http://simplepie.org/) and LastRSS (http://lastrss.oslab.net/). You can see in the first line how the rss_fetch.inc file is included in the working file. After that, the URL of the RSS feed from getacoder.com is assigned to the $url variable. The fetch_rss() function of Magpie is used for fetching data and converting this data into RSS Objects. In the next line, the title of RSS feed is displayed using the code $rss->channel['title']. The other lines are used for displaying each of the RSS feed's items. Each feed item is stored within an $rss->items array, and the foreach() loop is used to loop through each element of the array. Writing Code for our RSS Widget As I've already discussed, this widget is going to use Iframe for displaying the content of the widget, so let's look at the JavaScript code for embedding Iframe within the HTML code. var widget_string = '<iframe src="http://www.yourserver.com/rsswidget/rss_parse_handler.php?rss_url=';widget_string += encodeURIComponent(rss_widget_url);widget_string += '&maxlinks='+rss_widget_max_links;widget_string += '" height="'+rss_widget_height+'" width="'+rss_widget_width+'"';widget_string += ' style="border:1px solid #FF0000;"';widget_string +=' scrolling="no" frameborder="0"></iframe>';document.write(widget_string); In the above code, the widget string variable contains the string for displaying the widget. The source of Iframe is assigned to rss_parse_handler.php. The URL of the RSS feed, and the headlines from the feed are passed to rss_parse_handler.php via the GET method, using rss_url and maxlinks parameters respectively. The values to these parameters are assigned from the Javascript variables rss_widget_url and rss_widget_max_links. The width and height of the Iframe are also assigned from JavaScript variables, namely rss_widget_width and rss_widget_height. The red border on the widget is displayed by assigning 1px solid #FF0000 to the border attribute using the inline styling of CSS. Since, Inline CSS is used, the frameborder property is set to 0 (i.e. the border of the frame is zero). Displaying borders from the CSS has some benefit over employing the frameborder property. While using CSS code, 1px dashed #FF0000 (border-width border-style border-color) means you can display a dashed border (you can't using frameborder), and you can use the border-right, border-left, border-top, border-bottom attributes of CSS to display borders at specified positions of the object. The scrolling property is set to no here, which means that the scroll bar will not be displayed in the widget if the widget content overflows. If you want to show a scroll bar, then you can set this property to yes. The values of JavaScript variables like rss_widget_url, rss_widget_max_links etc come from the page where we'll be using this widget. You'll see how the values of these variables will be assigned from the section at the end where we'll look at how to use this RSS widget.  

Donations play a crucial role in supporting Free and Open Source Software projects. At times readers will write in to share their positive experience with a utility or program or a distribution that I have written about. Now don't confuse them with your average technical-bent-of-mind Linux user. These are accountants, home-office businessman, and even carpenters and plumbers, who've saved a lot of money thanks to open source software. And they have one question in mind -- how do I help the person behind the program? I generally recommend everyone to find the project's forum boards, or IRC channel, or mailing list and try and help other new users. Some do, and eventually even graduate to write documentation, like simple installation steps or how to install dependencies, in forum board posts. But some readers are incapable of even that kind of help. After my interview with Sebastian Trüg of K3b, a reader wrote in surprised that the software he had been using for writing MP3s for his grandchildren, ever since his grandson installed Kubuntu on his box, was written by a college student. He wanted to help, but didn't know how. K3b just worked for him. His demands from the distribution were minimal and so was his technical understanding. Recommending such people (and in fact others too) to donate to their favorite projects, isn't a bad idea. In fact I point them to Ladislav Bodnar's DistroWatch donations program to get a feel for the idea. I am not sure how many people take my advice seriously and do actually donate, but a couple of them wrote back after my interview with Bodnar, where he expressed surprise about the lack of response or even a courteous "thank you" from big projects after receiving donations. "What do they use the money for", they all wanted to know. Some suggested themselves that it's because "they are such big groups, and they all have jobs." So why are donations important? Since it seems to bother so many people, I thought I'd ask someone in the know. Fabio Erculiani, lead-developer of the two-man development team that churns out the popular Gentoo-based Sabayon Linux lists some common expenses of running a FOSS project. "We have hosting bills," explains Erculiani who has passed on a job offer by Google to complete his studies, "backup systems such as NASs, RAID arrays (hard drives tend to break often here... I had two breakages in around 6 months), new hardware, especially video cards, processors, wifi cards (usb, pcmcia, pci). We also bought a Mac Mini with a fundraiser at the end of 2006. I think that the most important thing, at our stage, is to keep a good and tested support. We also need to finance the development. This means two things: first, paying the electricity to run 2-3 servers 24/7/365 and secondly, spend time on long term projects, like Entropy, our upcoming new binary package manager." That's quite a list. "I think donations are important for projects that are done by developers in their spare time like I did the first 8 years of K3b," agrees Sebastian Trüg, lead-developer at K3b, the popular CD/DVD burning app. Trüg now works full time on free software, sponsored by Mandriva and spends about 30% of his time working on K3b. If you think donations aren't important for big projects whose developers have regular jobs, think again. "Donations are critical to the CentOS Project," comments Johnny Hughes, one of CentOS's 14 volunteer developers that develop this enterprise-class distribution. "Money is required to allow developers to attend FOSS events outside their area. Money and hardware donations are also required for development machines to build CentOS and for a network to distribute CentOS. We have been much more successful at obtaining hardware donations than at obtaining monetary donations, but both are important." But for Samuel Baggen, who works full-time on his popular Elive Live CD, donations are not just important, they are essential. "The donations received are required," explains Baggen, "so I can work on Elive full time without needing a regular job. With enough donations I can spend all my time on Elive, support the community and respond and work on their feedback." With enough donations Baggen hopes to start paying for serious services for Elive like professional designers, coders, etc. Encouraging users to donate Since it's such a critical component to their existence, many projects take great measures to get users to donate. Donations to the GIMP project for example are tax exempt in the US. Many projects also throw in a little extra for their donating users. Erculiani offers Sabayon branded goodies and is thinking of offering a premium membership where users will be able to get extra stuff like dedicated mirrors and discounted prices in the e-shop. "Last year we bought two new Dual Core processors," he says, "and this year I have finally updated my server with a new CPU, mainboard, RAM and two hard drives. We have also paid the hosting service and even gave some money to other projects." Hughes though doesn't like the idea of providing faster mirrors, goodies, or anything else extra about their distribution to people who donate. "As we believe strongly in free software," underlines Hughes, "we want CentOS to be available to everyone, and hope that they will use it and then donate." But CentOS does provide hardware donors with free advertising on their website and in the future will be offering some paid support for users that want that service. Trüg has only asked for donations once. "I hope that users will get the idea themselves :)." He also believes that since he offers no extra goodies, users will only donate out of good will. When he had that fund raiser for new hardware, Trüg overshot his goal by 500%. Currently, you can buy the official K3b Handbook which is so far only in German but an English translation will be available soon. Baggen on the other hand has tried a more "adventurous" strategy to get users to donate and was even criticized by some users. He made donations mandatory to download stable releases of Elive. "There are many users," shares Baggen, "who only donate $0.01 but I don't worry about that too much because the users who are satisfied with Elive and support a better future for Elive will bring more cool people into the Elive world. The donation for download system is sufficient enough to maintain the future of the project. More donations though will mean more features and a brighter future. We will be looking into fun ways to raise money in the future." Baggen has recently started offering paid bonus-disks that allow users to install popular software with the click of a button. But what really triggers donations? Are goodies motivating enough to donate? I am skeptical. Without blowing my own trumpet, I wonder if that K3b user would have donated (if he ever did) if I hadn't interviewed Trüg. Hughes agrees there is a connection between a project's popularity, the press coverage it receives and its user base. "How a project gets that press," he explains, "is obviously to provide a quality product that people need and are willing to write and talk about." Contests and awards, according to Hughes, provide another avenue for getting press coverage and expanding the user base. "Since only a small percentage of users actually donate, the bigger your user base, the larger the donation group." That might work for a big project like a complete distribution but for an application like K3b, a broad user-base doesn't guarantee donations. Trüg nails this perfectly. "The way I experienced it," he shares, "there is a phase in which the project becomes popular, that is, when people discover it as a better alternative. That is when they donate the most. Now, K3b comes with every distribution and is the default burning application which means there is no more "discovering of a new project". The result is that the donations are less frequent." Final thoughts Donations are important to FOSS projects, big and small. Some projects go out of their way to ensure donating users get more in return than the satisfaction of helping their favorite project. While it would seem a project's popularity and a sizable user-base would ensure monetary support, as applications become more reliable and just work out of the box, they might adversely affect a project's chances of receiving donations. But one thing's certain. Irrespective of whether you decide to donate or not, the developer or developers behind the project will continue hacking. Spirit, after all, cannot be donated.   You might also be interested in reading: Open Source Receives Royalties Boost 2007 Open Source Content Management System Award

GoboLinux is popular for its filesystem hierarchy which breaks away from the traditional Unix Filesystem Hierarchy Standard (FHS). So basically you wouldn't find any /etc or /usr directries under Gobo. In turn, files of a particular program are stored in their own separate directories like /Programs/GCC/2.95.3/lib. This means Gobo's package management system has its advantages since users can now install multiple versions of the same program without conflicts. To find out more about Gobo and why it does things the way it does, I talk to one of its main developers Lucas Villa Real. Mayank Sharma: So why did you break away from the traditional FHS? Are there any particular advantages? Lucas Villa Real: The major aim was to have a simple way of creating and sharing binary packages from programs compiled and installed from their source code. Splitting the filesystem tree into per-program subtrees was the most logical thinking, as packages could be created just by compressing its directory, or removed by deleting that. Another interesting advantage is that more than one version of the same program can be installed in the system at a given time, as each version lives inside its own directory. And this gives us a very unique feature: no database is needed to tell which packages are installed and what files each of them offer; that's just a matter of checking the directory contents inside /Programs. MS: How do you maintain UNIX compatibility in the background? Doesn't this effect the speed of complex programs like OpenOffice.org? LVR: Every time a new application is installed in GoboLinux, its contents are linked inside a global /System/Links tree. This tree presents subdirs such as Executables, Libraries, Headers and Shared, among others. So, having a centralized point where programs' contents can be reached makes it possible to achieve UNIX compatibility by presenting symlinks that point the desired legacy entry to the /System/Links corresponding one. And this comes with a great advantage: by having entries such as /bin, /sbin, /usr/bin and /usr/sbin pointing to /System/Links/Executables, the applications will always find what they're looking for—given that the file exists. This extra level of indirection introduced by the symlinks require one more step when opening or getting information on files, but that's a really cheap and fast procedure, especially when compared to the entire file manipulation operations. And anyways that already happens in traditional systems when an application tries to open a shared library, which is usually presented as a symlink to the real shared object. It's interesting to note that although we have those compatibility symlinks they're all hidden from the end user by default, thanks to a kernel extension written by us. MS: I've read Gobo's filesystem makes installing applications easier. But wouldn't this require application developers to package their apps to conform with Gobo's filesystem? LVR: Many application developers are already doing that by using autoconf, automake or just by writing well behaved Makefiles. In fact GoboLinux doesn't require anything special from application developers other than the usual care that they should already take regarding portability in their projects. MS: How does Gobo's "design" let users install multiple versions of the same app? How about uninstallation? LVR: Every installed program gets its own directory, such as /Programs/GCC/4.2.1. That avoids conflicts  with files coming from different versions, as they'll be stored in a different location (eg: /Programs/GCC/4.1.1). For uninstallation, it's just as simple as removing the desired program or version from the /Programs tree. The broken symlinks that'll be left over can be either treated automatically by a daemon such as the GoboLinux Listener or manually by a script shipped with the distribution. MS: So why haven't other distros taken to Gobo's filesystem? Is it difficult to implement from the distro developer's point of view? LVR: It's difficult, because they would have to make many important changes to their package management scripts and to many existing distro-specific applications, such as boot scripts configuration, for example. MS: Apart from the filesystem what are the other features that make Gobo unique? What's a rootless Gobo install? LVR: A Rootless GoboLinux is a set of scripts that makes it possible for anyone running an UNIX-like operating system to run GoboLinux tools inside their own home directory. That makes it possible for users in eg: Mac OS X to run Compile and get the program installed in a GoboLinux-like structure. And that doesn't require special admin privileges, as everything is installed inside the directory specified by the user (usually their home dir, or another where he/she has write access to). Answering the first question, we have, as principle, to try to ship every package as close as possible to the original one, avoiding patches that modify their behavior. This contrasts with many distributions out there, which usually try to merge as many patches as possible to enhance applications (and sometimes breaking them). Also, the alternative design of Gobo tends to attract a very diverse group of people who like to "think outside the box", such as users of alternative shells and lesser-known programming languages. They usually contribute with many good ideas when we're brainstorming for new features. MS: What does the immediate future hold for Gobo? Any areas where you could use some help? LVR: We're doing a series of snapshot releases in the process of stabilizing 014. The best help we can use now is to get people to download those snapshots, give them a try and report any problems they find at http://bugs.gobolinux.org. We're also always open for new contributors to help maintain the "recipes tree" for the Compile tool. MS: Where do you see Gobo in a couple of years? LVR: In a couple of years, I expect Gobo to be fully grown from being a small niche distro into a larger community. The main technical foundations have been laid and we already have a small but vibrant community of users. We still have some more work on infrastructure ahead of us but from now on I think the prospects are the best possible. MS: Thanks for you time Lucas, and best of luck developing Gobo.   You might also be interested in reading: The Economics of Open Source Donations 2007 Open Source Content Management System Award