In this article by Jayant Kumar , author of the book Apache Solr Search Patterns , we will discuss use cases for Solr in e-commerce and job sites. We will look at the problems faced while providing search in an e-commerce or job site: The e-commerce problem statement The job site problem statement Challenges of large-scale indexing
In this article by Siddharta Govindaraj , author of the book Test-Driven Python Development , we will look at the Event class. The Event class is very simple: receivers can register with the event to be notified when the event occurs. When the event fires, all the receivers are notified of the event. A more detailed description is as follows: Event classes have a connect method, which takes a method or function to be called when the event fires When the fire method is called, all the registered callbacks are called with the same parameters that are passed to the fire method Writing tests for the connect method is fairly straightforward—we just need to check that the receivers are being stored properly. But, how do we write the tests for the fire method? This method does not change any state or store any value that we can assert on. The main responsibility of this method is to call other methods. How do we test that this is being done correctly? This is where mock objects come into the picture. Unlike ordinary unit tests that assert on object state , mock objects are used to test that the interactions between multiple objects occurs as it should.
This article is written by Brenton J.W. Blawat , the author of Mastering Windows PowerShell Scripting . When you are automating tasks on servers and workstations, you will frequently run into situations where you need to manage files, folders, and registry items. PowerShell provides a wide variety of cmdlets that enable you to create, view, modify, and delete items on a system. In this article, you will learn many techniques to interact with files, folders, and registry items. These techniques and items include: Registry provider Creating files, folders, registry keys, and registry named values Adding named values to registry keys Verifying the existence of item files, folders, and registry keys Renaming files, folders, registry keys, and named values Copying and moving files and folders Deleting files, folders, registry keys, and named values To properly follow the examples in this article, you will need to sequentially execute the examples. Each example builds on the previous examples, and some of these examples may not function properly if you do not execute the previous steps.
This article by Vinith Menon , the author of Microsoft Hyper-V PowerShell Automation , delves into the basics of Hyper-V, right from installing Hyper-V to resizing virtual hard disks. The Hyper-V PowerShell module includes several significant features that extend its use, improve its usability, and allow you to control and manage your Hyper-V environment with more granular control. Various organizations have moved on from Hyper-V (V2) to Hyper-V (V3). In Hyper-V (V2), the Hyper-V management shell was not built-in and the PowerShell module had to be manually installed. In Hyper-V (V3), Microsoft has provided an exhaustive set of cmdlets that can be used to manage and automate all configuration activities of the Hyper-V environment. The cmdlets are executed across the network using Windows Remote Management. In this article, we will cover: The basics of setting up a Hyper-V environment using PowerShell The fundamental concepts of Hyper-V management with the Hyper-V management shell The updated features in Hyper-V
In this article by John Chapman and Aman Dhally , authors of the book, Automating Microsoft Azure with PowerShell , you will see that Microsoft Azure offers a variety of different services to store and retrieve data in the cloud. This includes File and Blob storage. Within Azure, each of these types of data is contained within an Azure storage account. While Azure SQL databases are also storage mechanisms, they are not part of an Azure storage account.
In this article by Alex Ogorek , author of the book Mastering Cocos2d Game Development you'll be learning how to implement the really complex, subtle game mechanics that not many developers do. This is what separates the good games from the great games. There will be many examples, tutorials, and code snippets in this article intended for adaption in your own projects, so feel free to come back at any time to look at something you may have either missed the first time, or are just curious to know about in general. In this article, we will cover the following topics: Adding a table for scores Adding subtle sliding to the units Creating movements on a Bézier curve instead of straight paths
In this article by Samarth Shah , author of the book Learning Raspberry Pi ,we will take your Raspberry Pi to the real world. Make sure you have all the components listed for you to go ahead: Raspberry Pi with Raspbian OS. A keyboard/mouse. A monitor to display the content of Raspberry Pi. If you don't have Raspberry Pi, you can install the VNC server on Raspberry Pi, and on your laptop using the VNC viewer, you will be able to display the content. Hook up wires of different colors (keep around 30 wires of around 10 cm long). To do: Read instructions on how to cut the wires. An HD44780-based LCD. Note; I have used JHD162A. A breadboard. 10K potentiometer (optional). You will be using potentiometer to control the contrast of the LCD, so if you don't have potentiometer, contrast would be fixed and that would be okay for this project. Potentiometer is just a fancy word used for variable resistor. Basically, it is just a three-terminal resistor with sliding or rotating contact, which is used for changing the value of the resistor.
In this article by Munish Sethi , author of the book Jasmine Cookbook , we will see the implementation of Jasmine tests using spies.
One of the biggest features that draws developers to Ext JS is the vast array of UI widgets available out of the box. The ease with which they can be integrated with each other and the attractive and consistent visuals each of them offers is also a big attraction. No other framework can compete on this front, and this is a huge reason Ext JS leads the field of large-scale web applications. In this article by Stuart Ashworth and Andrew Duncan by authors of the book, Ext JS Essentials , we will look at how UI widgets fit into the framework's structure, how they interact with each other, and how we can retrieve and reference them. We will then delve under the surface and investigate the lifecycle of a component and the stages it will go through during the lifetime of an application.
In this article by Loiane Groner , author of the book Mastering Ext JS, Second Edition , we will start implementing the application's core features, starting with static data management. What exactly is this? Every application has information that is not directly related to the core business, but this information is used by the core business logic somehow. There are two types of data in every application: static data and dynamic data. For example, the types of categories, languages, cities, and countries can exist independently of the core business and can be used by the core business information as well; this is what we call static data because it does not change very often. And there is the dynamic data, which is the information that changes in the application, what we call core business data. Clients, orders, and sales would be examples of dynamic or core business data. We can treat this static information as though they are independent MySQL tables (since we are using MySQL as the database server), and we can perform all the actions we can do on a MySQL table.
Most systems using the Arduino have a similar architecture. They have a way of reading data from the environment—a sensor—they make decision using the code running inside the Arduino and then output those decisions to the environment using various actuators, such as a simple motor. Using three recipes from the book, Arduino Development Cookbook , by Cornel Amariei , we will build such a system, and quite a useful one—a fan controlled by the air temperature. Let's break the process into three key steps, the first and easiest will be to connect an LED to the Arduino, a few of them will act as a thermometer, displaying the room temperature. The second step will be to connect the sensor and program it, and the third will be to connect the motor. Here, we will learn this basic skills.