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Angular 2 Cookbook
Angular 2 Cookbook

Angular 2 Cookbook: Discover over 70 recipes that provide the solutions you need to know to face every challenge in Angular 2 head on

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Profile Icon Patrick Gillespie Profile Icon Matthew Frisbie
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€22.99 €32.99
Full star icon Full star icon Full star icon Full star icon Half star icon 4.2 (24 Ratings)
eBook Jan 2017 464 pages 1st Edition
eBook
€22.99 €32.99
Paperback
€41.99
Subscription
Free Trial
Renews at €18.99p/m
Arrow left icon
Profile Icon Patrick Gillespie Profile Icon Matthew Frisbie
Arrow right icon
€22.99 €32.99
Full star icon Full star icon Full star icon Full star icon Half star icon 4.2 (24 Ratings)
eBook Jan 2017 464 pages 1st Edition
eBook
€22.99 €32.99
Paperback
€41.99
Subscription
Free Trial
Renews at €18.99p/m
eBook
€22.99 €32.99
Paperback
€41.99
Subscription
Free Trial
Renews at €18.99p/m

What do you get with eBook?

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Angular 2 Cookbook

Chapter 2. Conquering Components and Directives

Your objective is to iterate through this and display the article title only if it is set as active. This chapter will cover the following recipes:

  • Using decorators to build and style a simple component
  • Passing members from a parent component to a child component
  • Binding to native element attributes
  • Registering handlers on native browser events
  • Generating and capturing custom events using EventEmitter
  • Attaching behavior to DOM elements with Directives
  • Projecting nested content using ngContent
  • Using ngFor and ngIf structural directives for model-based DOM control
  • Referencing elements using template variables
  • Attribute property binding
  • Utilizing component life cycle hooks
  • Referencing a parent component from a child component
  • Configuring mutual parent-child awareness with ViewChild and forwardRef
  • Configuring mutual parent-child awareness with ContentChild and forwardRef

Introduction

Directives as you came to know them in Angular 1 have been done away with. In their place, we have two new entities: components and the new version of directives. Angular 2 applications are now component-driven; with further exposure, you will discover why this style is superior.

Much of the syntax is entirely new and may seem strange at first. Fear not! The underpinnings of the Angular 2 style are elegant and marvelous once completely understood.

Using decorators to build and style a simple component

When writing an application component in TypeScript, there are several new paradigms that you must become familiar and comfortable with. Though possibly intimidating initially, you will find that you'll be able to carry over much of your comprehension of Angular 1 directives.

Note

The code and a live example of this are available at http://ngcookbook.herokuapp.com/6577/.

Getting ready

One of the simplest imaginable components we can build is a template element that interpolates some values into its template. In Angular 1, one way this could be achieved was by creating an element directive, attaching some data to the scope inside the link function, and a template that would reference the data. I selected this description specifically because nearly all those concepts have been binned.

Suppose you want to create a simple article component with a pseudo template as follows:

<p>{{date}}</p> 
<h1>{{title}}</h1&gt...

Passing members from a parent component into a child component

With the departure of the Angular 1.x concept of $scope inheritance, mentally (partially or entirely) remodeling how information would be passed around your application is a must. In its place, you have an entirely new system of propagating information throughout the application's hierarchy.

Gone also is the concept of defaulting to bidirectional data binding. Although it made for an application that was simpler to reason about, bidirectional data binding incurs an unforgivably expensive drag on performance. This new system operates in an asymmetric fashion: members are propagated downwards through the component tree, but not upwards unless explicitly performed.

Note

The code, links, and a live example of this are available at http://ngcookbook.herokuapp.com/6543/.

Getting ready

Suppose you had a simple application that intended to (but currently cannot) pass data from a parent ArticleComponent to a child AttributionComponent...

Binding to native element attributes

In Angular 1, it was expected that the developer would utilize the built-in replacement directives for element attributes that had meaningful DOM behavior attached to them. This was due to the fact that many of these attributes had behavior that was incompatible with how Angular 1 data binding operated. In Angular 2, these special attribute directives are done away with, and the binding behavior and syntax is subsumed into the normal binding behavior.

Note

The code, links, and a live example of this are available at http://ngcookbook.herokuapp.com/8313/.

How to do it...

Binding to the native attribute is as simple as placing square brackets around the attribute and treating it as normal bound data:

[app/logo.component.ts] 
 
import {Component} from '@angular/core'; 
 
@Component({ 
  selector: 'logo', 
  template: '<img [src]="logoUrl">' 
}) 
export class LogoComponent { 
  logoUrl:string = 
    '//angular...

Introduction


Directives as you came to know them in Angular 1 have been done away with. In their place, we have two new entities: components and the new version of directives. Angular 2 applications are now component-driven; with further exposure, you will discover why this style is superior.

Much of the syntax is entirely new and may seem strange at first. Fear not! The underpinnings of the Angular 2 style are elegant and marvelous once completely understood.

Using decorators to build and style a simple component


When writing an application component in TypeScript, there are several new paradigms that you must become familiar and comfortable with. Though possibly intimidating initially, you will find that you'll be able to carry over much of your comprehension of Angular 1 directives.

Note

The code and a live example of this are available at http://ngcookbook.herokuapp.com/6577/.

Getting ready

One of the simplest imaginable components we can build is a template element that interpolates some values into its template. In Angular 1, one way this could be achieved was by creating an element directive, attaching some data to the scope inside the link function, and a template that would reference the data. I selected this description specifically because nearly all those concepts have been binned.

Suppose you want to create a simple article component with a pseudo template as follows:

<p>{{date}}</p> 
<h1>{{title}}</h1> 
...

Passing members from a parent component into a child component


With the departure of the Angular 1.x concept of $scope inheritance, mentally (partially or entirely) remodeling how information would be passed around your application is a must. In its place, you have an entirely new system of propagating information throughout the application's hierarchy.

Gone also is the concept of defaulting to bidirectional data binding. Although it made for an application that was simpler to reason about, bidirectional data binding incurs an unforgivably expensive drag on performance. This new system operates in an asymmetric fashion: members are propagated downwards through the component tree, but not upwards unless explicitly performed.

Note

The code, links, and a live example of this are available at http://ngcookbook.herokuapp.com/6543/.

Getting ready

Suppose you had a simple application that intended to (but currently cannot) pass data from a parent ArticleComponent to a child AttributionComponent:

 [app...

Binding to native element attributes


In Angular 1, it was expected that the developer would utilize the built-in replacement directives for element attributes that had meaningful DOM behavior attached to them. This was due to the fact that many of these attributes had behavior that was incompatible with how Angular 1 data binding operated. In Angular 2, these special attribute directives are done away with, and the binding behavior and syntax is subsumed into the normal binding behavior.

Note

The code, links, and a live example of this are available at http://ngcookbook.herokuapp.com/8313/.

How to do it...

Binding to the native attribute is as simple as placing square brackets around the attribute and treating it as normal bound data:

[app/logo.component.ts] 
 
import {Component} from '@angular/core'; 
 
@Component({ 
  selector: 'logo', 
  template: '<img [src]="logoUrl">' 
}) 
export class LogoComponent { 
  logoUrl:string = 
    '//angular...

Registering handlers on native browser events


In Angular 2, the other hemisphere of binding that is needed for a fully functioning application is event binding. The Angular 2 event binding syntax is similar to that of data binding.

Note

The code, links, and a live example of this are available at http://ngcookbook.herokuapp.com/4437/.

Getting ready

Suppose you wanted to create an article application that counted shares, and you began with the following skeleton:

[app/article.component.ts]
import {Component} from '@angular/core'; 
 
@Component({ 
  selector: 'article', 
  template: ` 
    <h1>{{title}}</h1> 
    <p>Shares: {{shareCt}}</p> 
    <button>Share</button> 
  ` 
}) 
export class ArticleComponent { 
  title:string = 'Police Apprehend Tiramisu Thieves'; 
  shareCt:number = 0; 
} 

How to do it...

The Angular 2 event binding syntax is accomplished with a pair of parentheses surrounding...

Generating and capturing custom events using EventEmitter


In the wake of the disappearance of $scope, Angular was left with a void for propagating information up the component tree. This void is filled in part by custom events, and they represent the Yin to the downward data binding Yang.

Note

The code, links, and a live example of this are available at http://ngcookbook.herokuapp.com/8611/.

Getting ready

Suppose you had an Article application as follows:

[app/text-editor.component.ts] 
 
import {Component} from '@angular/core'; 
 
@Component({ 
  selector: 'text-editor', 
  template: ` 
    <textarea></textarea> 
  ` 
}) 
export class TextEditorComponent {} 
 
[app/article.component.ts] 
 
import {Component} from '@angular/core'; 
 
@Component({ 
  selector: 'article', 
  template: ` 
    <h1>{{title}}</h1> 
    <p>Word count: {{wordCount}}</p> 
    &lt...

Attaching behavior to DOM elements with directives


In the course of creating applications, you will often find it useful to be able to attach component-style behavior to DOM elements, but without the need to have templating. If you were to attempt to construct an Angular 2 component without providing a template in some way, you will meet with a stern error telling you that some form of template is required.

Here lies the difference between Angular 2 components and directives: components have views (which can take the form of a template, templateUrl, or @View decorator), whereas directives do not. They otherwise behave identically and provide you with the same behavior.

Note

The code, links, and a live example of this are available at http://ngcookbook.herokuapp.com/3292/.

Getting ready

Suppose you have the following application:

[app/article.component.ts] 
 
import {Component} from '@angular/core'; 
 
@Component({ 
  selector: 'article', 
  template: `<h1>{...

Projecting nested content using ngContent


Utilizing components as standalone tags that are self-contained and wholly manage their contents is a clean pattern, but you will frequently find that your component tags demand that they enclose content.

Note

The code, links, and a live example of this are available at http://ngcookbook.herokuapp.com/6172/.

Getting ready

Suppose you had the following application:

[app/ad-section.component.ts] 
 
import {Component} from '@angular/core'; 
 
@Component({ 
  selector: 'ad-section', 
  template: ` 
    <a href="#">{{adText}}</a> 
  ` 
}) 
export class AdSectionComponent { 
  adText:string = 'Selfie sticks 40% off!'; 
} 
 
[app/article.component.ts] 
 
import {Component} from '@angular/core'; 
 
@Component({ 
  selector: 'article', 
  template: ` 
    <h1>{{title}}</h1> 
    <p>U.S. senators are up in arms following the...

Using ngFor and ngIf structural directives for model-based DOM control


Any developer that has used a client framework is intimately familiar with two basic operations in an application: iterative rendering from a collection and conditional rendering. The new Angular 2 implementations look a bit different but operate in much the same way.

Note

The code, links, and a live example are available at http://ngcookbook.herokuapp.com/3211/.

Getting ready

Suppose you had the following application:

[app/article-list.component.ts] 
 
import {Component} from '@angular/core'; 
 
@Component({ 
  selector: 'article-list', 
  template: '' 
}) 
export class ArticleListComponent { 
  articles:Array<Object> = [ 
    {title: 'Foo', active: true},  
    {title: 'Bar', active: false}, 
    {title: 'Baz', active: true} 
  ]; 
} 

Your objective is to iterate through this and display the article title only if it is set as active.

How to do...

Referencing elements using template variables


Many developers will begin with Angular 2 and reach for something that resembles the trustworthy ng-model in Angular 1. NgModel exists in Angular 2, but there is a new way of referencing elements in the template: local template variables.

Note

The code, links, and a live example of this are available at http://ngcookbook.herokuapp.com/5094/.

Getting ready

Suppose you had the following application and wanted to directly access the input element:

[app/article.component.ts] 
 
import {Component} from '@angular/core'; 
 
@Component({ 
  selector: 'article', 
  template: ` 
    <input> 
    <h1>{{title}}</h1> 
  ` 
}) 
export class ArticleComponent {} 

How to do it...

Angular 2 allows you to have a # assignment within the template itself, which can consequently be referenced from inside the template. For example, refer to the following code:

[app/article.component.ts] 
 &...

Attribute property binding


One of the great new benefits of the new Angular binding style is that you are able to more accurately target what you are binding to. Formerly, the HTML attribute that was used as a directive or data token was simply used as a matching identifier. Now, you are able to use property bindings within the binding markup for both the input and output.

Note

The code, links, and a live example of this is available at http://ngcookbook.herokuapp.com/8565/.

Getting ready

Suppose you had the following application:

[app/article.component.ts] 
 
import {Component} from '@angular/core'; 
 
@Component({ 
  selector: 'article', 
  template: ` 
    <input #title (keydown)="setTitle(title.value)"> 
    <h1>{{myTitle}}</h1> 
  ` 
}) 
export class ArticleComponent { 
  myTitle:string; 
 
  setTitle(val:string):void { 
    this.myTitle = val; 
  } 
} 

Your objective is to modify...

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Key benefits

  • A first-rate reference guide with a clear structure and intuitive index that gives you as a developer exactly the information you want in exactly the way you want it
  • Covers no legacy material from the outdated Angular release candidates; it is up-to-date with the latest release of Angular 2.4
  • All the code in the book is explicitly written out, and every piece of code shown is a step towards building a simple working example

Description

Angular 2 introduces an entirely new way to build applications. It wholly embraces all the newest concepts that are built into the next generation of browsers, and it cuts away all the fat and bloat from Angular 1. This book plunges directly into the heart of all the most important Angular 2 concepts for you to conquer. In addition to covering all the Angular 2 fundamentals, such as components, forms, and services, it demonstrates how the framework embraces a range of new web technologies such as ES6 and TypeScript syntax, Promises, Observables, and Web Workers, among many others. This book covers all the most complicated Angular concepts and at the same time introduces the best practices with which to wield these powerful tools. It also covers in detail all the concepts you'll need to get you building applications faster. Oft-neglected topics such as testing and performance optimization are widely covered as well. A developer that reads through all the content in this book will have a broad and deep understanding of all the major topics in the Angular 2 universe.

Who is this book for?

This book is for developers who are competent with JavaScript and are looking to dive headfirst into the TypeScript edition of Angular 2. This book is also geared towards developers with experience in Angular 1 who are looking to make the transition.

What you will learn

  • Understand how to best move an Angular 1 application to Angular 2
  • Build a solid foundational understanding of the core elements of Angular 2 such as components, forms, and services
  • Gain an ability to wield complex topics such as Observables and Promises
  • Properly implement applications utilizing advanced topics such as dependency injection
  • Know how to maximize the performance of Angular 2 applications
  • Understand the best ways to take an Angular 2 application from TypeScript in a code editor to a fully function application served on your site
  • Get to know the best practices when organizing and testing a large Angular 2 application

Product Details

Country selected
Publication date, Length, Edition, Language, ISBN-13
Publication date : Jan 20, 2017
Length: 464 pages
Edition : 1st
Language : English
ISBN-13 : 9781785887505
Vendor :
Google
Languages :
Tools :

What do you get with eBook?

Product feature icon Instant access to your Digital eBook purchase
Product feature icon Download this book in EPUB and PDF formats
Product feature icon Access this title in our online reader with advanced features
Product feature icon DRM FREE - Read whenever, wherever and however you want

Product Details

Publication date : Jan 20, 2017
Length: 464 pages
Edition : 1st
Language : English
ISBN-13 : 9781785887505
Vendor :
Google
Languages :
Tools :

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Table of Contents

10 Chapters
1. Strategies for Upgrading to Angular 2 Chevron down icon Chevron up icon
2. Conquering Components and Directives Chevron down icon Chevron up icon
3. Building Template-Driven and Reactive Forms Chevron down icon Chevron up icon
4. Mastering Promises Chevron down icon Chevron up icon
5. ReactiveX Observables Chevron down icon Chevron up icon
6. The Component Router Chevron down icon Chevron up icon
7. Services, Dependency Injection, and NgModule Chevron down icon Chevron up icon
8. Application Organization and Management Chevron down icon Chevron up icon
9. Angular 2 Testing Chevron down icon Chevron up icon
10. Performance and Advanced Concepts Chevron down icon Chevron up icon

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Full star icon Full star icon Full star icon Full star icon Half star icon 4.2
(24 Ratings)
5 star 45.8%
4 star 33.3%
3 star 16.7%
2 star 0%
1 star 4.2%
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Kevin White Apr 24, 2017
Full star icon Full star icon Full star icon Full star icon Full star icon 5
I'm writing as a software engineer veteran, very comprehensive, excellent pointers on various Angular2 techniques. Professionals will want to seek additional information, such as best practices concerning authentication/authorisation (check out: OpenIddict), but this book covers a lot nonetheless. Novices will probably get lost in some of the technical detail, but perfect for intermediate/advanced and professionals. You should be familiar with basic OOP concepts, such as encapsulation, to get the most from this book. Being an Angular2 novice myself, I started with another excellent book "ASP.NET Core and Angular2". Great introduction but light on detail. The latter book does cross the server/client-side boundary though.
Amazon Verified review Amazon
Dhananjaya Oct 03, 2017
Full star icon Full star icon Full star icon Full star icon Full star icon 5
Excellant book
Amazon Verified review Amazon
Michael Feb 15, 2017
Full star icon Full star icon Full star icon Full star icon Full star icon 5
To put it simply, this has become my main go-to Angular book. Due to my job, I am typically forced to be a glass-pane back learner, which means I am confronted with specific issues that require specific solutions, and a solution needs to be thoroughly understood and implemented very quickly. I usually don't have the option to start with the basics and move up. The "cookbook" format of this book is perfect for that approach. However, the way this book is structured, you can also read it front-to-back, and build concepts in the traditional fashion. It's the best of both worlds.If you've read many technical programming books, then you know that the author's style is usually prioritized at the bottom of the list. Not so with this book. Its simply a pleasure. The author is very clear, grammatically correct (rare in this genre), and simply fun to read. Add to that the interactivity the author implements via on-line code samples for hands-on learning, and you have the perfect tool that covers all the bases for all types of learners.And finally, and most important for Angular 2 books... IT'S CURRENT!!! How cool is that???I can't recommend it enough.
Amazon Verified review Amazon
Thomas Q Brady Apr 28, 2017
Full star icon Full star icon Full star icon Full star icon Full star icon 5
Had to learn Angular (2/4) as quickly as possible for work, having dabbled in AngularJS (1.x).This book dives in with examples pretty quickly, so you might want to start with some more basic "getting started" kinds of content first, but you'll quickly come back to this book as your reference for how to actually get things done in Angular. The "getting started" type content introduces you to the vocabulary, syntax, etc., which you'll need to be able to understand the recipes in this book, but this book picks up at the "great, but how do I build anything other than this example to do list?" and remains useful for quite some time as a reference.
Amazon Verified review Amazon
Zebulah Fadade Jun 03, 2017
Full star icon Full star icon Full star icon Full star icon Full star icon 5
Really nice, step-by-step explanation of how (and) why things are done in Angular 2. Answered a lot of my questions.Warning: If you purchased the book before mid-June 2017, you might have received a hoaxed version of the book (identified by lack of page numbers and chapter headers, and generally poor formatting). This problem has apparently been fixed now. You should be able to return the hoaxed book version to Amazon.
Amazon Verified review Amazon
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