angular2-angular-cli-icoderslab

Develop your First Angular 2 App using Angular CLI

This tutorial introduces basics of Angular 2 with the goal of creating and serves a basic Angular CLI App.
Angular 2 is an open source modern JavaScript framework for front end Applications. Angular 2 is complete rewrite of Angular 1 and is 5 times faster than Angular1. Lets start developing your first App on Angular 2 using Angular CLI.

Prerequisite:

  1. Install NodeJs
  2. Install WebStorm 2016.2.
  3. Install Typescript by writing following command at terminal => npm install -g typescript
  4. Install Angular CLI by writing following command at terminal => npm install -g angular-cli

Getting Started

Start up WebStorm then click on “Create New Project”.

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Select Angular CLI from left side panel.

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Write the name “Angular2FirstApp” with complete App path in Location Field then click on Create button.

This will take few minutes to setup all prerequisites and download all dependencies.

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Once it finished Your First app is ready now take a look first at Project directory structure.

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We will write all development code in src/app that need to compiled.

Before we proceed we have to review some basic building blocks of Angular 2.

Components:

Angular 2 is a component based Framework. Angular 2 app is a tree of loosely coupled component having a root component that contains all other components.

In our App “main.ts” is root file

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look at this line

bootstrap(AppComponet);

bootstrap method is used to load top-level components.

Check out AppComponet.

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In first line of “app.component.ts” we import build-in Component Module from “@angular/core”.

A component is like a widget, a piece of content that can be reused in your application. It can a complete view or a part of view having all code required to create, display and manage it.

 

Decorators

A component have 2 main parts.

  1. Class
  2. Meta data

Class is simple typescript class having constructor and all related code.

Metadata tells Angular how to process a class. Metadata is attached by using decorator.

@Component decorators allow developers to configure classes as particular elements by setting metadata on them.

@Component({
selector: ‘app-root’,
templateUrl: ‘app.component.html’,
styleUrls: [‘app.component.css’]
})

in above decorator 3 properties are defined

  1. selector – css selector that identifies this component in a template
  2. templateUrl – url to an external file containing a template for the view
  3. styleUrls – list of urls to stylesheets to be applied to this component’s view

 

Now take a look at body part of index.html

<body><app-root>Loading…</app-root>

</body>

Here selector “app-root” is used that mean it will load all the html defined in template whose selector is “app-root”.

As “app.component.ts” class metadata has selector “app-root” and its “templateUrl ” is “’app.component.html” that means it loads all the html defined in “app.component.html”.

In “app.component.html” following code is defined.

<h1>
{{title}}
</h1>

Here Angular Data Binding is used , these double curly bracket “{{}}” shows value of title is come from typescript class.

Serve and Test Your First App

To serve our app write on terminal of webStorm.

ng serve

above command will build a server for us with Node and open up our browser.

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You can see result at http://localhost:4200

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Now in “app.component.html” add following lines

<p>This is my first Angular 2 test app </p>
<button (click)=ClickMe();”>Click me</button>

Define ClickMe() function in “app.component.ts”

Updated “app.component.ts” looks like this

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All these changes will automatically update and you can see the result.

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In this tutorial we covered some basic concepts of Angular 2 app and we simply create a simple Angular CLI app and serve it.

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