Angular and Web Components: Bridging Frameworks in Large Teams

August 11, 2023

Modern web development often involves multiple frameworks and libraries coexisting in a single project, especially in large teams or legacy migration scenarios. One way to bridge this diversity is through Web Components, a set of standards that enable encapsulated, reusable UI elements native to the browser.

Angular supports Web Components through Angular Elements, allowing you to create Angular components and package them as standard custom elements. This lets you integrate Angular functionality into non-Angular apps—or vice versa—smoothly.

---

Why Use Web Components with Angular?

• Framework interoperability: Share UI components between Angular, React, Vue, or even plain HTML/JS projects.
• Incremental migration: Gradually migrate legacy apps to Angular by embedding Angular Elements.
• Team scalability: Different teams can build isolated components using different tech, then integrate via Web Components.

---

Creating an Angular Element

Let’s walk through creating a simple Angular component and turning it into a Web Component.

Step 1: Create an Angular Component

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

@Component({
  selector: 'app-greeting',
  template: `<h2>Hello, {{name}}!</h2>`,
})
export class GreetingComponent {
  @Input() name = 'Guest';
}

Step 2: Convert it to a custom element

In your app.module.ts or a dedicated module:

import { Injector, NgModule } from '@angular/core';
import { BrowserModule } from '@angular/platform-browser';
import { createCustomElement } from '@angular/elements';

import { GreetingComponent } from './greeting.component';

@NgModule({
  declarations: [GreetingComponent],
  imports: [BrowserModule],
  entryComponents: [GreetingComponent],
})
export class AppModule {
  constructor(private injector: Injector) {}

  ngDoBootstrap() {
    const el = createCustomElement(GreetingComponent, { injector: this.injector });
    customElements.define('app-greeting', el);
  }
}

Step 3: Use the Angular Element anywhere

After building and bundling, you can use <app-greeting> as a standard HTML element in any web page or framework:

<app-greeting name="Angular"></app-greeting>

---

Packaging Angular Elements

Angular Elements rely on polyfills and Angular runtime code. To optimize delivery:

• Use Angular CLI with custom builders or tools like ngx-build-plus to bundle elements into a single JS file.
• Lazy load Angular Elements only when needed.

---

Using Angular Elements in Other Frameworks

For example, in React:

import React from 'react';

function App() {
  return <app-greeting name="React" />;
}

export default App;

Ensure you load the Angular Elements bundle before using the tag.

---

Tips for Large Teams

• Define clear API contracts: Use component inputs and outputs consistently.
• Isolate styles with Shadow DOM: Angular Elements support encapsulated styling to avoid conflicts.
• Version and deploy elements independently: Enables teams to ship updates without affecting the whole app.

---

Summary

• Angular Elements let you create framework-agnostic components.
• Useful for cross-framework collaboration and incremental migrations.
• Packaging and loading strategies are important for performance.
• Large teams can scale by isolating development and integration via Web Components.