Tag Archives: angular2

Angular 2 Tutorial – movies App

Last time I wrote a blog created the MovieAPI and now I am using that API as back end services to create an angular 2 app.

the final source code could find at my github repository.  here is the link download

For the MovieAPI open it, build it will install the packages automatically, then run the service first.

After the service is done, go to the angular2 folder, open command window

–run npm install,

— npm start

It will look like this:

home

create.PNG

added

Step 1 : Setting up your angular 2 application, I already have a blog  click here to found it. Or also could download from the source file from https://github.com/angular/quickstart/blob/master/README.md but it add a lot of unnecessary setting, probably confuse for beginning learner.

It was better do few times manually setting it up to get understand all of the necessary for start anguar 2 application.

Step 2:  In angualr 2 everything is component, for me normally like to create the service first. I just create a file named movies.service.ts under folder movies


import {Injectable} from 'angular2/core';
import {IMovie} from './movie';
import {Http, RequestOptions , Response, Headers} from 'angular2/http';
import {Observable} from 'rxjs/Observable';

@Injectable() 
export class MovieService {   
    private _movieUrl = 'http://localhost:53871/api/movies';

    constructor(private _http: Http) { }

    getMovies(): Observable<IMovie[]> {
        return this._http.get(this._movieUrl)
            .map((response: Response) => <IMovie[]>response.json()) //arrow function, tranceform response to json object and is array of IMovie[]
            .do(data => console.log("All: " + JSON.stringify(data))) //for debug
            .catch(this.handleError);
    }


    createMovie(movie: IMovie): Observable {
        let body = JSON.stringify(movie); 
        let headers = new Headers({ 'Content-Type': 'application/json' });
        let options = new RequestOptions({ headers: headers });

        return this._http.post(this._movieUrl, body, options)               
                .map(this.extractData)
                .catch(this.handleError);
    }

    private extractData(res: Response) {
        let body = res.json();
        return body.data || {};
    }

    private handleError(error: Response) {
        console.error(error);
        return Observable.throw(error.json().error || 'Server error');
    }
}

In there MovieService I have a IMovie here is my movie.ts I put it in the same folder with MovieService .


//interface won't compile to js file, it just for typescript do type checking
 export interface IMovie { 
    movieId: number;
    title: string;
    genre: string;
    classification: string;
    releaseDate: number;
    rating: number;
    cast: string[];

}


export class Movie implements IMovie {
    movieId: number;
    title: string;
    genre: string;
    classification: string;
    releaseDate: number;
    rating: number;
    cast: string[];
}

Step 3: Inject the services.
Go to the app.component.ts this is our container component, for anguar 2 only need inject once, then all of the nest container could using it ( by import it ).

Inject a service has two steps:

1) import the file into the app.component,

2) Inject it as providers

here is my app.component.ts

angular2_injection

Step 4: Create the movies-list.component.ts


//for using component, simply import it into this file
import {Component, OnInit} from 'angular2/core';
import { ROUTER_DIRECTIVES } from 'angular2/router';

import {IMovie} from './movie';
import {MovieService} from './movies.service';
import {MovieFilterPipe} from './movie-filter.pipe';
import { StarComponent } from '../shared/star.component';

@Component({
    selector: 'sz-movies',
    templateUrl: 'app/movies/movies-list.component.html',
    styleUrls: ['app/movies/movies-list.component.css'],  
    pipes: [MovieFilterPipe],
    directives: [StarComponent, ROUTER_DIRECTIVES]
   
})
export class MovieListComponent implements OnInit {
    pageTitle: string = 'Movie List';   
   
    listFilter: string;
    errorMessage: string;
    movies: IMovie[];


    constructor(private _movieService: MovieService) {

    }
    
    ngOnInit(): void {
        this._movieService.getMovies()
            .subscribe(
            movies => this.movies = movies,
            error => this.errorMessage = error);
    }

}

here is the movies-list.component.htmlmovies_html

 

for this component I have a nested StarComponent.

Setp 5: create nested StarComponent, here is the star.component.ts under the share folder


import { Component, OnInit, Input} from 'angular2/core';
@Component({
    selector: 'sz-star',
    templateUrl: 'app/shared/star.component.html',
    styleUrls: ['app/shared/star.component.css']
})
export class StarComponent implements OnInit {
    @Input() rating: number;
    starWidth: number;
    ngOnInit(): void {
        this.starWidth = this.rating * 86 / 5;
    }
}

star.component.htmlstar.PNG

css:

star_css

In angular 2: data flow is unidirectional, for passing data from view to the class

first: you passing data into the directive could bind it to the property

passing_data_down.PNG

Second: need import the Input from angular2/core, and bind it to the property

inData

Now, one nested movies-list.component and nested star.componet down.

Now using the same steps create the MovieCreateComponent


import {Component, OnInit} from 'angular2/core';

import {IMovie, Movie} from '../movie';
import {Router} from 'angular2/router';
import {MovieService} from '../movies.service';

@Component({
    templateUrl: 'app/movies/create/movie-create.component.html'
})

export class MovieCreateComponent implements OnInit {
    title: string = 'Create New Movie';
    newMovie: IMovie;

    constructor(
        private _moviesService: MovieService,
        private _router: Router
    ) { }

    ngOnInit() {
        this.newMovie = new Movie;
    }

    createMovie(event) {
        let _this = this;

        this._moviesService.createMovie(this.newMovie)
            .subscribe(function () {
                _this._router.navigate(['Movies']);
            });
    }

    cancelCreate(event) {
        this._router.navigate(['Movies']);
    }

}angular2_form.PNG
Router:
route.PNG

In the index.html page, put the baseurl:
baseUrl.png

Done, have fun!

Key different compare angular 2 to 1

  1. angualr 2 using bootstraping the app,
    import { bootstrap } from 'angular2/platform/browser';
    
    // Our main component
    import { AppComponent } from './app.component';
    
    bootstrap(AppComponent);

    and in angular 2 we bind it to html tag <body ng-app=”insuranceApp”>

  2. In angular 2 we create a application by create multiply components, and a component must contain: template(html layout also could included directives) + class(properties and methods) + Metadata(Extra data for angular, defined with a decorator). example:
    import { Component} from 'angular2/core';//must include the import
    @Component({ //metadata and template
        selector: 'rate-star',
        template: '

    {{greatingText}}

    ' })export class HelloComponent {//class with property and methods greatingText:string = "hello"; }

    In angular 1 we create controller + view

    First Name:
    Last Name:

    Full Name: {{firstName + ” ” + lastName}}

    var app = angular.module(‘myApp’, []);
    app.controller(‘myCtrl’, function($scope) {
    $scope.firstName = “John”;
    $scope.lastName = “Doe”;
    });

  3. In Angular 2 the data flow is unidirectional and angular 1 is two way bind
  4. In angular 2 bind property using [], bind event using () and removed
    <button (click)="onClickMe()">Click me!</button>//bind event
    //bind property
    angular2_bind_dom_property
    
    

     

  5. In Angular 2 there are not $scope anymore, for communicate with different components using service. And in angular 2 create service using class
import { Injectable } from 'angular2/core';

@Injectable() // working with constructor to do injection
export class BooksService {
     GetAllBooks = () =>
	[
		{ title: 'Ulysses', author: 'James Joyce', available: true, category: Category.Fiction },
		{ title: 'A Farewell to Arms', author: 'Ernest Hemingway', available: false, category: Category.Fiction },
		{ title: 'I Know Why the Caged Bird Sings', author: 'Maya Angelou', available: true, category: Category.Poetry },
		{ title: 'Moby Dick', author: 'Herman Melville', available: true, category: Category.Fiction }
	];	
}
but in angularjs 1 we could using priovide, service, value, factories to create a service.