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Step by Step for Creating First Angular Element with Example -

What's Angular Elements?

Angular Element is a package which is part of the Angular framework- @angular/elements and it was introduced in Angular 6 and hopefully, this will improve with Angular 7 or higher versions.

Angular Elements was the brainchild of Angular’s and it one of the most anticipated features of Angular 6 release. Explore in detail about Angular Elements …

Now come to – “How to Create a Custom Angular Elements?”

There are following steps involving to Creating Custom Elements.

1. Install Angular 6 platforms and Angular CLI, if not installed.

2. Create a new project using Angular CLI.

3. Once successfully created your new project, change the directory of your created.

4. Install Angular elements.

5. Install web components custom elements.

6. Create your reusable component and it will be used as an Angular Element.

7. Register your comments which are required like reusable components, Injector, and createCustomElement.

8. Use the created custom element in your app.

9. Result

Steps 1 - Install Angular 6, if not install.

Steps 2 – Create a new project using Angular CLI

ng new ngprod

In the above command, the “ngprod” is the name of my project which I used to create this demo.

Steps 3 - Once successfully created your new project, change the directory of your created project just like - ngprod.

Steps 4 - Now install Angular elements using the below CLI command.

npm install @angular/elements

Steps 5 - Once done the web components custom elements, install

npm install @webcomponents/custom-elements

This will work for older browsers and also we will need to open and add below two lines in your project file - polyfills.ts.

* APPLICATION IMPORTS */

import '@webcomponents/custom-elements/src/native-shim';

import '@webcomponents/custom-elements/custom-elements.min';

Steps 6 - Create your reusable component and it will be used as an Angular Element.

In this example, I have created a custom element for displays the list of active users (active-user.component.ts and active-user.component.html) and my created component contains the list of activeUsers, applications access user name, and title.

active-user.component.ts -

import { Component, OnInit, Input } from '@angular/core';

@Component({

selector: 'app-activeuser',

templateUrl: './active-user.component.html',

styleUrls: ['./active-user.component.css']

})

export class ActiveUserComponent implements OnInit {

public activeUsers :any;

public title :any;

@Input() user: string;

constructor() {

this.title ='Angular - Create Custom Elements';

}

ngOnInit() {

this.activeUsers = [

{"name" :"Anil Singh"},

{"name" :"Alok Singh"},

{"name" :"Dilip Singh"},

{"name" :"Sunil Singh"},

{"name" :"Aradhya Singh"},

{"name" :"Reena Singh"}

];

}

And active-user.component.html -

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

<h2>You are welcome, {{user}}!</h2>

<h4>Active Users - </h4>

<div>

</table>

</div>

Steps 7 - Register the active-user.component in the app.module.ts.

import { ActiveUserComponent } from './active-user/active-user.component';

And comment the line - bootstrap ( //bootstrap: [AppComponent]) from the NgModule class.

And also added the line - entryComponents (entryComponents: [ActiveUserComponent]) in the NgModule.

See in the below code.

import { BrowserModule } from '@angular/platform-browser';

import { NgModule, Injector } from '@angular/core';

import { FormsModule } from '@angular/forms';

import { RouterModule, Routes } from '@angular/router';

import { AppComponent } from './app.component';

import { UserComponent } from './user/user.component';

import { UserListComponent } from './user-list/user-list.component';

import {DataTableModule} from "angular-6-datatable";

import { ActiveUserComponent } from './active-user/active-user.component';

import { createCustomElement } from '@angular/elements';

@NgModule({

declarations: [

AppComponent,

UserComponent,

UserListComponent,

ActiveUserComponent

imports: [

BrowserModule,

DataTableModule,

FormsModule,

RouterModule.forRoot([

{ path: 'user-link', component: UserComponent },

{ path: 'user-list', component: UserListComponent }

])

providers: [],

// bootstrap: [AppComponent],

bootstrap: [],

entryComponents: [ActiveUserComponent]

})

export class AppModule {

}

Steps 8 - Register the Injector and createCustomElement in the app.module.ts.

import { NgModule, Injector } from '@angular/core';

import { createCustomElement } from '@angular/elements';

After register the required modules in the app.module.ts, we will need to create custom element in the AppModule.

See in the below code.

export class AppModule {

//An instance of the element is created or upgraded.

constructor(private injector: Injector) {

//The customElements is used for defining a custom element globaly.

const customElement = createCustomElement(ActiveUserComponent, { injector });

//Defining a new element

customElements.define('app-activeuser', customElement);

}

ngDoBootstrap() {}

}

And the app.module.ts looks like –

import { BrowserModule } from '@angular/platform-browser';

import { NgModule, Injector } from '@angular/core';

import { FormsModule } from '@angular/forms';

import { RouterModule, Routes } from '@angular/router';

import { AppComponent } from './app.component';

import { UserComponent } from './user/user.component';

import { UserListComponent } from './user-list/user-list.component';

import {DataTableModule} from "angular-6-datatable";

import { ActiveUserComponent } from './active-user/active-user.component';

import { createCustomElement } from '@angular/elements';

@NgModule({

declarations: [

AppComponent,

UserComponent,

UserListComponent,

ActiveUserComponent

imports: [

BrowserModule,

DataTableModule,

FormsModule,

RouterModule.forRoot([

{ path: 'user-link', component: UserComponent },

{ path: 'user-list', component: UserListComponent }

])

providers: [],

// bootstrap: [AppComponent],

bootstrap: [],

entryComponents: [ActiveUserComponent]

})

export class AppModule {

//An instance of the element is created or upgraded.

constructor(private injector: Injector) {

//The customElements is used for defining a custom element globaly.

const customElement = createCustomElement(ActiveUserComponent, { injector });

//Defining a new element

customElements.define('app-activeuser', customElement);

}

ngDoBootstrap() {}

}

Steps 9 - Use the created custom element in your app.

<body>

<app-activeuser user="Anil Singh"></app-activeuser>

</body>

Note - I am using created custom element in the - index.html page.

Result looks like -

Conclusion –

An Angular Custom element gives you a new tool for defining new HTML tags in the browsers and creating reusable components.

Reference link - https://developers.google.com/web/fundamentals/web-components/customelements

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Anil Singh is an author, tech blogger, and software programmer. Book writing, tech blogging is something do extra and Anil love doing it. For more detail, kindly refer to this link..

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