Why REST API
A RESTful API is an application program interface (API) that uses HTTP requests to GET, PUT, POST and DELETE data.
A RESTful API (also referred to as a RESTful web service) is based on representational state transfer (REST) technology, an architectural style and approach to communications often used in web services development.
Why Angular
Angular is an open-source software engineering framework used for building single-page web apps (SPA). Developers also use it to create animated menus for HTML web pages.
Angular uses the Model-View-Controller (MVC) architecture, which is used in web app development. This type of architecture consists of:
- Model – the data structure that manages information and receives input from the controller
- View – the representation of information
- Controller – responds to input and interacts with the model
In the context of Angular, the model is the framework, while the view is HTML, and the control is JavaScript.
What is Http Client
Most front-end applications communicate with back-end services over the HTTP protocol. Modern browsers support two different APIs for making HTTP requests: XMLHttpRequest interface and Fetch API.
The HttpClient in @angular/common/http offers a simplified client HTTP API for Angular applications that rests on the XMLHttpRequest interface exposed by browsers. Additional benefits of HttpClient include testability features, typed request and response objects, request and response interception, Observable APIs, and streamlined error handling.
Let’s Get to Code
Download and install the following tools:
Environment Setup
//on the desktop you might want to run this on gitbash or integrated terminal ng new restapi-app //once installation is complete then run below command from terminal cd restapi-app // to start the angular app ng serve
Create a Model: We do this by going into the src/app folder, then we can create a model folder which will contain the objects instance of the data to be fetched from the external API.
expor class User {
id : number;
name : string;
username : string;
email : string;
}
Create a Service: We do this by going into the src/app folder, then we can create a service folder. In the service folder we will be making use of the HttpClient imported from @angular/common/http, user instance created in our model from earlier code and finally we made a GET request to our external API … Interesting?!
import { Injectable } from '@angular/core';
import { HttpClient } from '@angular/common/http';
import { User } from '../models/user';
@Injectable({
providedIn: 'root'
})
export class UserService {
apiUrl = 'https://jsonplaceholder.typicode.com/users';
constructor(private http:HttpClient) { }
getUsers() {
return this.http.get<User[]>(this.apiUrl, { headers: { accept: "Accept: application/json"} });
}
}
Next on the app.component.ts found in the app folder would need to be modified to contain imports of the UserService, User class and data returned from the API request.
import { Component, OnInit } from '@angular/core';
import { UserService } from './services/user.service';
import { User } from './models/user';
@Component({
selector: 'app-root',
templateUrl: './app.component.html',
styleUrls: ['./app.component.css']
})
export class AppComponent implements OnInit {
title = 'Restful API Using Angular';
name = 'by @devLarry';
users: User[];
constructor(private service: UserService) { }
ngOnInit() {
return this.service.getUsers().subscribe(data => { this.users = data; });
}
}
Next is modify the changes to the app.module.ts file also in the app folder. This would include our imports and providers.
import { BrowserModule } from '@angular/platform-browser';
import { NgModule } from '@angular/core';
import { AppRoutingModule } from './app-routing.module';
import { AppComponent } from './app.component';
import { HttpClientModule } from '@angular/common/http';
import { UserService } from './services/user.service';
@NgModule({
declarations: [
AppComponent
],
imports: [
BrowserModule,
AppRoutingModule,
HttpClientModule
],
providers: [UserService],
bootstrap: [AppComponent]
})
export class AppModule { }
Finally we need to effect our changes on the app.component.html. This is what is been rendered to the users of the application . I have made modification to this as well and here I have the updated source codes.
<!-- * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * -->
<!-- * * * * * * * * * * * The content below * * * * * * * * * * * -->
<!-- * * * * * * * * * * is only a placeholder * * * * * * * * * * -->
<!-- * * * * * * * * * * and can be replaced. * * * * * * * * * * * -->
<!-- * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * -->
<!-- * * * * * * * * * Delete the template below * * * * * * * * * * -->
<!-- * * * * * * * to get started with your project! * * * * * * * * -->
<!-- * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * -->
<style>
:host {
font-family: -apple-system, BlinkMacSystemFont, "Segoe UI", Roboto, Helvetica, Arial, sans-serif, "Apple Color Emoji", "Segoe UI Emoji", "Segoe UI Symbol";
font-size: 14px;
color: #333;
box-sizing: border-box;
-webkit-font-smoothing: antialiased;
-moz-osx-font-smoothing: grayscale;
}
h1,
h2,
h3,
h4,
h5,
h6 {
margin: 8px 0;
}
p {
margin: 0;
}
.spacer {
flex: 1;
}
.toolbar {
height: 60px;
margin: -8px;
display: flex;
align-items: center;
background-color: #1976d2;
color: white;
font-weight: 600;
}
.toolbar img {
margin: 0 16px;
}
.toolbar #twitter-logo {
height: 40px;
margin: 0 16px;
}
.toolbar #twitter-logo:hover {
opacity: 0.8;
}
.content {
display: flex;
margin: 32px auto;
padding: 0 16px;
max-width: 960px;
flex-direction: column;
align-items: center;
}
svg.material-icons {
height: 24px;
width: auto;
}
svg.material-icons:not(:last-child) {
margin-right: 8px;
}
.card svg.material-icons path {
fill: #888;
}
.card-container {
display: flex;
flex-wrap: wrap;
justify-content: center;
margin-top: 16px;
}
.card {
border-radius: 4px;
border: 1px solid #eee;
background-color: #fafafa;
height: 40px;
width: 200px;
margin: 0 8px 16px;
padding: 16px;
display: flex;
flex-direction: row;
justify-content: center;
align-items: center;
transition: all 0.2s ease-in-out;
line-height: 24px;
}
.card-container .card:not(:last-child) {
margin-right: 0;
}
.card.card-small {
height: 16px;
width: 168px;
}
.card-container .card:not(.highlight-card) {
cursor: pointer;
}
.card-container .card:not(.highlight-card):hover {
transform: translateY(-3px);
box-shadow: 0 4px 17px rgba(black, 0.35);
}
.card-container .card:not(.highlight-card):hover .material-icons path {
fill: rgb(105, 103, 103);
}
.card.highlight-card {
background-color: #1976d2;
color: white;
font-weight: 600;
border: none;
width: auto;
min-width: 30%;
position: relative;
}
.card.card.highlight-card span {
margin-left: 60px;
}
svg#rocket {
width: 80px;
position: absolute;
left: -10px;
top: -24px;
}
svg#rocket-smoke {
height: 100vh;
position: absolute;
top: 10px;
right: 180px;
z-index: -10;
}
a,
a:visited,
a:hover {
color: #1976d2;
text-decoration: none;
}
a:hover {
color: #125699;
}
.terminal {
position: relative;
width: 80%;
max-width: 600px;
border-radius: 6px;
padding-top: 45px;
margin-top: 8px;
overflow: hidden;
background-color: rgb(15, 15, 16);
}
.terminal::before {
content: "\2022 \2022 \2022";
position: absolute;
top: 0;
left: 0;
height: 4px;
background: rgb(58, 58, 58);
color: #c2c3c4;
width: 100%;
font-size: 2rem;
line-height: 0;
padding: 14px 0;
text-indent: 4px;
}
.terminal pre {
font-family: SFMono-Regular,Consolas,Liberation Mono,Menlo,monospace;
color: white;
padding: 0 1rem 1rem;
margin: 0;
}
.circle-link {
height: 40px;
width: 40px;
border-radius: 40px;
margin: 8px;
background-color: white;
border: 1px solid #eeeeee;
display: flex;
justify-content: center;
align-items: center;
cursor: pointer;
box-shadow: 0 1px 3px rgba(0, 0, 0, 0.12), 0 1px 2px rgba(0, 0, 0, 0.24);
transition: 1s ease-out;
}
.circle-link:hover {
transform: translateY(-0.25rem);
box-shadow: 0px 3px 15px rgba(0, 0, 0, 0.2);
}
footer {
margin-top: 8px;
display: flex;
align-items: center;
line-height: 20px;
}
footer a {
display: flex;
align-items: center;
}
.github-star-badge {
color: #24292e;
display: flex;
align-items: center;
font-size: 12px;
padding: 3px 10px;
border: 1px solid rgba(27,31,35,.2);
border-radius: 3px;
background-image: linear-gradient(-180deg,#fafbfc,#eff3f6 90%);
margin-left: 4px;
font-weight: 600;
font-family: -apple-system,BlinkMacSystemFont,Segoe UI,Helvetica,Arial,sans-serif,Apple Color Emoji,Segoe UI Emoji,Segoe UI Symbol;
}
.github-star-badge:hover {
background-image: linear-gradient(-180deg,#f0f3f6,#e6ebf1 90%);
border-color: rgba(27,31,35,.35);
background-position: -.5em;
}
.github-star-badge .material-icons {
height: 16px;
width: 16px;
margin-right: 4px;
}
svg#clouds {
position: fixed;
bottom: -160px;
left: -230px;
z-index: -10;
width: 1920px;
}
/* Responsive Styles */
@media screen and (max-width: 767px) {
.card-container > *:not(.circle-link) ,
.terminal {
width: 100%;
}
.card:not(.highlight-card) {
height: 16px;
margin: 8px 0;
}
.card.highlight-card span {
margin-left: 72px;
}
svg#rocket-smoke {
right: 120px;
transform: rotate(-5deg);
}
}
@media screen and (max-width: 575px) {
svg#rocket-smoke {
display: none;
visibility: hidden;
}
}
</style>
<!-- Toolbar -->
<div class="toolbar" role="banner">
<img
width="40"
alt="Angular Logo"
src="data:image/svg+xml;base64,PHN2ZyB4bWxucz0iaHR0cDovL3d3dy53My5vcmcvMjAwMC9zdmciIHZpZXdCb3g9IjAgMCAyNTAgMjUwIj4KICAgIDxwYXRoIGZpbGw9IiNERDAwMzEiIGQ9Ik0xMjUgMzBMMzEuOSA2My4ybDE0LjIgMTIzLjFMMTI1IDIzMGw3OC45LTQzLjcgMTQuMi0xMjMuMXoiIC8+CiAgICA8cGF0aCBmaWxsPSIjQzMwMDJGIiBkPSJNMTI1IDMwdjIyLjItLjFWMjMwbDc4LjktNDMuNyAxNC4yLTEyMy4xTDEyNSAzMHoiIC8+CiAgICA8cGF0aCAgZmlsbD0iI0ZGRkZGRiIgZD0iTTEyNSA1Mi4xTDY2LjggMTgyLjZoMjEuN2wxMS43LTI5LjJoNDkuNGwxMS43IDI5LjJIMTgzTDEyNSA1Mi4xem0xNyA4My4zaC0zNGwxNy00MC45IDE3IDQwLjl6IiAvPgogIDwvc3ZnPg=="
/>
<span>Welcome</span>
<div class="spacer"></div>
<a aria-label="Angular on twitter" href="https://twitter.com/lanromanero" title="Twitter">
<svg id="twitter-logo" height="24" data-name="Logo — FIXED" xmlns="http://www.w3.org/2000/svg" viewBox="0 0 400 400">
<defs>
<style>
.cls-1 {
fill: none;
}
.cls-2 {
fill: #ffffff;
}
</style>
</defs>
<rect class="cls-1" width="400" height="400" />
<path class="cls-2" d="M153.62,301.59c94.34,0,145.94-78.16,145.94-145.94,0-2.22,0-4.43-.15-6.63A104.36,104.36,0,0,0,325,122.47a102.38,102.38,0,0,1-29.46,8.07,51.47,51.47,0,0,0,22.55-28.37,102.79,102.79,0,0,1-32.57,12.45,51.34,51.34,0,0,0-87.41,46.78A145.62,145.62,0,0,1,92.4,107.81a51.33,51.33,0,0,0,15.88,68.47A50.91,50.91,0,0,1,85,169.86c0,.21,0,.43,0,.65a51.31,51.31,0,0,0,41.15,50.28,51.21,51.21,0,0,1-23.16.88,51.35,51.35,0,0,0,47.92,35.62,102.92,102.92,0,0,1-63.7,22A104.41,104.41,0,0,1,75,278.55a145.21,145.21,0,0,0,78.62,23"
/>
</svg>
</a>
</div>
<div class="content" role="main">
<!-- Highlight Card -->
<div class="card highlight-card card-small">
<svg id="rocket" alt="Rocket Ship" xmlns="http://www.w3.org/2000/svg" width="101.678" height="101.678" viewBox="0 0 101.678 101.678">
<g id="Group_83" data-name="Group 83" transform="translate(-141 -696)">
<circle id="Ellipse_8" data-name="Ellipse 8" cx="50.839" cy="50.839" r="50.839" transform="translate(141 696)" fill="#dd0031"/>
<g id="Group_47" data-name="Group 47" transform="translate(165.185 720.185)">
<path id="Path_33" data-name="Path 33" d="M3.4,42.615a3.084,3.084,0,0,0,3.553,3.553,21.419,21.419,0,0,0,12.215-6.107L9.511,30.4A21.419,21.419,0,0,0,3.4,42.615Z" transform="translate(0.371 3.363)" fill="#fff"/>
<path id="Path_34" data-name="Path 34" d="M53.3,3.221A3.09,3.09,0,0,0,50.081,0,48.227,48.227,0,0,0,18.322,13.437c-6-1.666-14.991-1.221-18.322,7.218A33.892,33.892,0,0,1,9.439,25.1l-.333.666a3.013,3.013,0,0,0,.555,3.553L23.985,43.641a2.9,2.9,0,0,0,3.553.555l.666-.333A33.892,33.892,0,0,1,32.647,53.3c8.55-3.664,8.884-12.326,7.218-18.322A48.227,48.227,0,0,0,53.3,3.221ZM34.424,9.772a6.439,6.439,0,1,1,9.106,9.106,6.368,6.368,0,0,1-9.106,0A6.467,6.467,0,0,1,34.424,9.772Z" transform="translate(0 0.005)" fill="#fff"/>
</g>
</g>
</svg>
<span>{{ title }} <a href="https://twitter.com/lanromanero" style="color:#fff">{{ name }}</a></span>
<svg id="rocket-smoke" alt="Rocket Ship Smoke" xmlns="http://www.w3.org/2000/svg" width="516.119" height="1083.632" viewBox="0 0 516.119 1083.632">
<path id="Path_40" data-name="Path 40" d="M644.6,141S143.02,215.537,147.049,870.207s342.774,201.755,342.774,201.755S404.659,847.213,388.815,762.2c-27.116-145.51-11.551-384.124,271.9-609.1C671.15,139.365,644.6,141,644.6,141Z" transform="translate(-147.025 -140.939)" fill="#f5f5f5"/>
</svg>
</div>
<!-- Main page API CONTENTS -->
<div class="terminal">
<pre *ngFor="let user of users">{{user.id}}. {{user.name}} {{user.email}}</pre>
</div>
<!-- Footer -->
<footer>
Link to repo ?
<a href="https://github.com/LarrySul/ng-alc-api" target="_blank" rel="noopener"> Give repo a star.
<div class="github-star-badge">
<svg class="material-icons" xmlns="http://www.w3.org/2000/svg" width="24" height="24" viewBox="0 0 24 24"><path d="M0 0h24v24H0z" fill="none"/><path d="M12 17.27L18.18 21l-1.64-7.03L22 9.24l-7.19-.61L12 2 9.19 8.63 2 9.24l5.46 4.73L5.82 21z"/></svg>
Star
</div>
</a>
<a href="https://dazzling-wiles-0a1a50.netlify.com" target="_blank" rel="noopener">
<svg class="material-icons" xmlns="http://www.w3.org/2000/svg" width="24" height="24" viewBox="0 0 24 24"><path d="M10 6L8.59 7.41 13.17 12l-4.58 4.59L10 18l6-6z" fill="#1976d2"/><path d="M0 0h24v24H0z" fill="none"/></svg>
</a>
</footer>
<svg id="clouds" alt="Gray Clouds Background" xmlns="http://www.w3.org/2000/svg" width="2611.084" height="485.677" viewBox="0 0 2611.084 485.677">
<path id="Path_39" data-name="Path 39" d="M2379.709,863.793c10-93-77-171-168-149-52-114-225-105-264,15-75,3-140,59-152,133-30,2.83-66.725,9.829-93.5,26.25-26.771-16.421-63.5-23.42-93.5-26.25-12-74-77-130-152-133-39-120-212-129-264-15-54.084-13.075-106.753,9.173-138.488,48.9-31.734-39.726-84.4-61.974-138.487-48.9-52-114-225-105-264,15a162.027,162.027,0,0,0-103.147,43.044c-30.633-45.365-87.1-72.091-145.206-58.044-52-114-225-105-264,15-75,3-140,59-152,133-53,5-127,23-130,83-2,42,35,72,70,86,49,20,106,18,157,5a165.625,165.625,0,0,0,120,0c47,94,178,113,251,33,61.112,8.015,113.854-5.72,150.492-29.764a165.62,165.62,0,0,0,110.861-3.236c47,94,178,113,251,33,31.385,4.116,60.563,2.495,86.487-3.311,25.924,5.806,55.1,7.427,86.488,3.311,73,80,204,61,251-33a165.625,165.625,0,0,0,120,0c51,13,108,15,157-5a147.188,147.188,0,0,0,33.5-18.694,147.217,147.217,0,0,0,33.5,18.694c49,20,106,18,157,5a165.625,165.625,0,0,0,120,0c47,94,178,113,251,33C2446.709,1093.793,2554.709,922.793,2379.709,863.793Z" transform="translate(142.69 -634.312)" fill="#eee"/>
</svg>
</div>
<!-- * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * -->
<!-- * * * * * * * * * * * The content above * * * * * * * * * * * -->
<!-- * * * * * * * * * * is only a placeholder * * * * * * * * * * -->
<!-- * * * * * * * * * * and can be replaced. * * * * * * * * * * * -->
<!-- * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * -->
<!-- * * * * * * * * * * End of Placeholder * * * * * * * * * * * -->
<!-- * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * -->
<router-outlet></router-outlet>
Once all this set we can proceed to run ng build to help aid a minified build of the project. To get this project working on our local machine run ng serve. This starts the application development on our terminal and effects the changes on a port that can be accessible, usually on http://localhost:4200/.
PUBLISHING OUR APP ON GITHUB
Here what we need to do is to create a repository on GitHub and push our app to it. I have created my repository and pushed my source code here. For resource on how to create and work on GitHub I strongly recommend GitHub Guides and Git & GitHub Crash Course For Beginners.
Continous Integration on Netlify
To get started on Netlify you need to first sign up on the platform https://www.netlify.com/.
Next, click on the button “New site from Git“.
Since I worked with Github, I would need to select Github and also the repository. Once repository has been selected you can proceed to configure the build command ng build –prod. Also specify the publish directory dist/restapp-api (in our own case).
Finally click on “Deploy site” and a link is generated (in my own case: https://dazzling-wiles-0a1a50.netlify.com/).
🎉Viola the site is up and running! 🎉
