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Building News App using Angular 5

geeksamu profile image Ahmed Abdelsalam Originally published at Medium on ・7 min read

Angular5 , news app ( image source topal)

This is the seventh part in a seven-part series about the JavaScript framework, Angular 5.

In this part, we'll go over turning our application into a News Application.

This is not intended to be a complete guide, but rather an overview of the basics to get you up and running so you can get to know using Angular Services and how to turn your Angular 5 application into a News app.

Before we begin, English is not my first language, so if you see something weird, please, calmly point it out in the comment section or email me, there’s no need for violence :)

Article Series:

  1. Creating Angular 5 application with Angular-cli
  2. UsingAngular Material withAngular 5
  3. Deploy Angular 5 Application to Netlify
  4. BuildPWA with Angular 5 App
  5. Build Dynamic themes forAngular Material
  6. UsingFlexLayout with Angular 5
  7. Building News App using Angular 5(You are here)

Final Demo here

I’m going to turn the application We created in the 6 previous articles, so you have to check them first!

No, you must check all of them!

Our News app will be:

  • a Progressive web application (PWA)
  • With Angular Material Design
  • with a grid-system using Flex-Layout
  • Deployed to Netlify
  • With 2 dynamic themes
  • Later we can improve it with more option you can suggest or ask me what you want in the next article

Build News Service

In the previous articles We created a component named posts. I'll use it to show our news posts.

First Let’s discuss the layout of our posts component.

I want to build two things: part for filtering the news and part for displaying the news itself

I’ll use newsapi.org's api to get the news, so you have to signup and get a key.

Next, we have to create new angular service to get the news from the API. I'll name it news service.

Now, in your application's root directory open your terminal and run:

ng g service services/news --module app.module.ts

This command will create our news service and will update our app.module.ts.

We need to add something first in our app.module.ts to use it in new.service.ts

import { HttpModule } from '@angular/http';

and add it to the imports

Now your app.module.ts should look like

import { BrowserModule } from '@angular/platform-browser';
import { NgModule } from '@angular/core';
import { BrowserAnimationsModule } from '@angular/platform-browser/animations';
import { MaterialModule } from './material.module';
import { FlexLayoutModule } from '@angular/flex-layout';
import { HttpModule } from '@angular/http'; 
import { AppRoutingModule } from './app-routing.module';
import { FormsModule,ReactiveFormsModule } from '@angular/forms';

import { ServiceWorkerModule } from '@angular/service-worker';
import { AppComponent } from './app.component';

import { environment } from '../environments/environment';
import { PostsComponent } from './posts/posts.component';
import { HomeComponent } from './home/home.component';
import { NavbarComponent } from './navbar/navbar.component';
import { ThemeService } from './services/theme.service';
import { NewsService } from './services/news.service';

@NgModule({
 declarations: [
 AppComponent,
 PostsComponent,
 HomeComponent,
 NavbarComponent
 ],
 imports: [
 BrowserModule,
 BrowserAnimationsModule,
 MaterialModule,
 FlexLayoutModule,
 AppRoutingModule,
 FormsModule,
 ReactiveFormsModule,
 HttpModule,
 ServiceWorkerModule.register('/ngsw-worker.js', { enabled: environment.production })
 ],
 providers: [ThemeService, NewsService],
 bootstrap: [AppComponent]
})
export class AppModule { }

First Let’s explain what we’re going to do, I know that this part is so boring but you have to know it, so you can handle things later yourself.

Next you have to replace your-key-here with your API key you got from your account here > https://newsapi.org/account

Details of News Service

Next we need to build the functions to call the api from our news.service

We’ll build 3 functions getTopHeadLines(), getNewBySource() and getSources().

getTopHeadLines: will get the Top Headlines news. and this will be displayed as the default news.

getSources: it will give us all the news sources, we'll use them to filter our news.

getNewBySource: We'll use the previous function to get the sources to use it in this function.

Here’s the code of our service

import { Injectable } from '@angular/core';
import { Http, Headers, RequestOptions } from '@angular/http';
import { environment } from '../../environments/environment';

@Injectable()
export class NewsService {
 key = 'your-key-here';
 constructor(private http: Http) { }
 getTopHeadLines(){
 return this.http.get('[https://newsapi.org/v2/top-headlines?country=us&category=business&apiKey=](https://newsapi.org/v2/top-headlines?country=us&category=business&apiKey=)'+this.key);
 }
 getNewBySource(source){
 return this.http.get('[https://newsapi.org/v2/top-headlines?sources=](https://newsapi.org/v2/top-headlines?sources=)'+source+'&apiKey='+this.key);
 }
 getSources(){
 return this.http.get('[https://newsapi.org/v2/sources?apiKey=](https://newsapi.org/v2/sources?apiKey=)'+this.key);
 }
}

Adding `News Service to posts.component.ts

Now we need to edit our posts.component.ts. As we created 3 functions in our servicewe'll use them here in posts.component.ts

First

you have to import new.service.ts.

Second

create 2 variable:

1st: will be news= {articles:[]}

2nd: will be newsSources= {sources:[]}

Third

I’ll display articles from getTopHeadLines in ngOnInit and the new resources also.

Here’s the code of our src/posts/posts.component.ts

`
import { Component, OnInit } from "@angular/core";
import { NewsService } from '../services/news.service';

@Component({
selector: "app-posts",
templateUrl: "./posts.component.html",
styleUrls: ["./posts.component.scss"],
providers:[NewsService]
})
export class PostsComponent implements OnInit {
news= {articles:[]};
newsSources= {sources:[]};
filterSource='google-news';

constructor(private newsService: NewsService){}

ngOnInit() {
this.newsService.getTopHeadLines()
.subscribe(
response => this.news = response.json()
);
this.getnewsSources();
}

filterNews(source) {
this.news={articles:[]};
this.newsService.getNewBySource(source)
.subscribe(
response => this.news = response.json()
);
}

getnewsSources() {
this.newsService.getSources()
.subscribe(
response => this.newsSources = response.json()
);
}
}
`

For the view of this component in posts.component.html

I made 2 parts as I said at the beginning of this article:

one for filtering the news and one to show them. I used Flex-Layout also.

I added two things for the posts:

Fix damaged images

You might noticed that there are some images that does not load correctly, to solve this problem I added this attribute onError="this.src='/assets/blank.png';"

It will display default image for damaged images.

Spinner loader

Also I added a spinner to been displayed while our application fetching the data from the api, I used the Angular Material module MatSpinnerModule.

Here’s the code of posts.component.html

`
<div class="container margin-top" fxLayout="wrap row" fxLayout.xs="column" fxLayoutGap="1%" fxLayoutAlign="center">
<mat-card class="filter">
<form #filternewsForm="ngForm">
<mat-form-field>
<mat-select placeholder="News Source" [(ngModel)]='filterSource' name="source" required>
<mat-option *ngFor="let source of newsSources.sources" [value]="source.id">
{{source.name}} - {{ source.language }}
</mat-option>
</mat-select>
</mat-form-field>
<button mat-raised-button color="primary" (click)='filterNews(filterSource)' [disabled]="!filternewsForm.form.valid">Filter News to
<span style="text-transform: capitalize; ">{{filterSource}}</span>
</button>

</form>
</mat-card>
</div>

<div class="loader" *ngIf="!((news.articles)?.length > 0)">
<mat-spinner></mat-spinner>
</div>
<div class="container" fxLayout="wrap row" fxLayout.xs="column" fxLayoutGap="1%" fxLayoutAlign="center">
<div *ngFor="let post of news.articles" fxFlex="20%">

<mat-card class=singleNews>
<img mat-card-image src="{{post.urlToImage}}" onError="this.src='/assets/blank.png';">
<div class="cardbody">
<mat-card-title>{{post.title}}</mat-card-title>
<mat-card-content>
<p>{{post.description}}</p>
</mat-card-content>
</div>

<mat-card-actions align="end">
<a href="{{post.url}}" target="_balnk" mat-raised-button color="accent">Read More</a>
</mat-card-actions>
</mat-card>

</div>

</div>
`

I did some small styling in src/app/posts/posts.component.scss


.singleNews {
margin-bottom: 15px;
img {
height: 200px;
}
mat-card-title {
font-size: 16px;
font-weight: bold;
}
.cardbody {
height: 100px;
overflow-y: auto;
margin: 0 -15px;
padding: 10px;
}
}
.filter {
margin-top: 100px;
margin-bottom: 50px;
}

and I added some styling for the loader in src/styles.scss


@import "./assets/styles/material-theme";
body {
margin: 0;
}
.loader mat-spinner {
margin: 10px auto;
}

Change homepage content to Top News

For our home screen I want to make it dynamic, so let’s display our Top Hot-lines there.

We’ll use the same code and service:

Open src/app/home/home.component.html

and add the following code:

`
<div class="homebtn" fxLayout="wrap row" fxLayout.xs="column" fxLayoutGap="1%" fxLayoutAlign="center">
<a routerLink="/posts" mat-raised-button color="primary">Choose News Source</a>
</div>
<div class="loader" *ngIf="!((news.articles)?.length > 0)">
<mat-spinner></mat-spinner>
</div>
<div class="container" fxLayout="wrap row" fxLayout.xs="column" fxLayoutGap="1%" fxLayoutAlign="center">

<div *ngFor="let post of news.articles" fxFlex="20%">

<mat-card class=singleNews>
<img mat-card-image src="{{post.urlToImage}}" onError="this.src='/assets/blank.png';">
<div class="cardbody">
<mat-card-title>{{post.title}}</mat-card-title>
<mat-card-content>
<p>{{post.description}}</p>
</mat-card-content>
</div>

<mat-card-actions align="end">
<a href="{{post.url}}" target="_balnk" mat-raised-button color="accent">Read More</a>
</mat-card-actions>
</mat-card>

</div>

</div>
`

And replace the code into src/app/home/home.component.ts with

`
import { Component, OnInit } from '@angular/core';
import { NewsService } from '../services/news.service';

@Component({
selector: 'app-home',
templateUrl: './home.component.html',
styleUrls: ['./home.component.scss'],
providers:[NewsService]

})
export class HomeComponent implements OnInit {
news= {articles:[]};

constructor(private newsService: NewsService){}

ngOnInit() {
this.newsService.getTopHeadLines()
.subscribe(
response => this.news = response.json()
);
}
}
`

Finally let’s add some styling open src/app/home/home.component.scss


.singleNews {
margin-bottom: 15px;
img {
height: 200px;
}
mat-card-title {
font-size: 16px;
font-weight: bold;
}
.cardbody {
height: 100px;
overflow-y: auto;
margin: 0 -15px;
padding: 10px;
}
}
.homebtn{
margin:40px 0;
}

Now our application is done! Here’s the final result

And you can find the demo here

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