Advanced Component styling with Angular (v4+)

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Text

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Angular In Flip Flops

Music Player Component

Layout

hover

Title/Artist

Selected

Song Track Component

@Component({
  selector: 'song-track',   // <song-track></song-track>
  template: ` 
    <div class="container">
      <track-image image="http://..."></track-image>
      <div class="track-information">
        <track-title>{{track}}</track-title>
        <track-artist>{{artist}}</track-artist>
      </div>
    </div>`
})
export class SongTrack { }

Component Styles

Inline Styles

@Component({
  selector: 'song-track',
  styles: [`.container { color: white; }`]
})
export class SongTrack { }

Template Inline Styles

@Component({
 template: `
   <style>
   .container { color: deepskyblue; }
   </style>   
   <div class="container">...</div>
 `
})
export class SongTrack { }

External Styles

//song-track.component.ts
@Component({
  styleUrls: ['src/shared.css'],
})
export class SongTrack { }

//shared.css
.container { ... }

Styling

Directives

Selecting a Track

ngClass (single)

<song-track ngClass="selected" class="large"></song-track>
<song-track [ngClass]="'selected'"></song-track>   
<song-track [ngClass]="['selected']"></song-track> 
<song-track [ngClass]="{'selected': true}"></song-track>

<song-track class="selected large"></song-track>
<song-track class="selected"></song-track>

ngClass (multiple)

<song-track ngClass="selected large">             
<song-track [ngClass]="'selected large'">      
<song-track [ngClass]="['selected', 'large']">   
<song-track [ngClass]="{'selected': true, 'large': true}">
<song-track [ngClass]="{'selected large': true}">

<song-track class="selected large"></song-track>

Styling

Song Title

ngStyle (single)

<song-track [ngStyle]="{'color': 'white'}" style="font-size: 12px;">
<song-track [ngStyle]="{'font-size.px': '12'}">
<song-track [ngStyle]="{'font-size': '12px'}">

<song-track style="color: white; font-size: 12px;">
<song-track style="font-size: 12px;">

ngStyle (multiple)

<song-track [ngStyle]="{'color': 'white', 'font-size': '12px'}">

<song-track style="color: white; font-size: 12px;">

Using host metadata

@Component.host (styling)

@Component({
  host: {
    //setting multiple values
    'class': 'selected disabled',
    'style': 'color: purple; margin: 5px;',
    
    //setting single values (using binding)
    '[class.selected]': 'true',    
    '[class.selected]': '!!selected', //add class if selected = true
    '[style.color]': '"purple"'   //expression must be a string
  } 
})
export class SongTrack { }

@HostBinding (styling)

@Component({
})
export class SongTrack {   
  //<host class="selected"></host>   
  @HostBinding('class.selected') selected = true;

  //<host style="color: red;"></host>     
  @HostBinding('style.color') color = 'red';
}

Shadow DOM

Shadow DOM

  • Isolated DOM
  • Scoped CSS
  • Composition
  • Productivity

Browser Support

safari

safari

Styles Encapsulation

Emulated

Shadow DOM

Emulated Shadow DOM

@Component({
  selector: 'song-track',
  encapsulation: ViewEncapsulation.Emulated
})

<head>
  <style>
    .container[_ngcontent-ikt-1] { ... } 
  </style>
</head>
<body>
  <my-app>
    <song-track _nghost-ikt-1>
      <div _ngcontent-ikt-1 class="container"></div>
    </song-track>
  </my-app>
</body>

Native Shadow DOM

Native Shadow DOM

@Component({
  selector: 'song-track',
  encapsulation: ViewEncapsulation.Native
})

<body>
  <my-app>
    <song-track>    
      ▾ #shadow-root (open)    
        <style>.container { ... }</style>   
        <div class="container"></div>
    </song-track>
  </my-app>
</body>

Disabled  Shadow DOM

Disabled Shadow DOM

@Component({
  selector: 'song-track',
  encapsulation: ViewEncapsulation.None
})

<head>
  <style>.container { ... }</style>
</head>
<body>
  <my-app>
    <song-track>    
      <div class="container"></div>
    </song-track>
  </my-app>
</body>

Styling

Shadow DOM

Container Styling (:host)

@Component({
 styles: [`
  :host { color: black; }          
  :host(.selected) { color: red; } 
 `]
})
export class SongTrack { }


<song-track></song-track>
<song-track class="selected"></song-track>

Context Styling (:host-context)

:host-context(.theme) { color: red; }   
:host-context(#player1) { color: red; }


<div class="theme">
 <song-track></song-track>
</div>

<div id="player1">
 <song-track></song-track>
</div>

Overriding Styles (/deep/)

@Component({
 styles: [`
  :host  /deep/ .h3 { color: red; }
  :host   >>>   .h4 { color: purple; }
 `],
 template: `
    <div class="container">
      <track-image image="http://..."></track-image>
      <div class="track-information">
        <track-title>{{track}}</track-title>     //<h3><ng-content></h3>
        <track-artist>{{artist}}</track-artist>  //<h4><ng-content></h4>
      </div>
    </div>`
})
export class SongTrack { }

Angular

Platforms

ElementRef (only browser)

import { ElementRef } from '@angular/core';

@Component(...)
export class SongTrack {
  constructor(private element: ElementRef){
    let elem = this.element.nativeElement;

    elem.style.color = "blue";
    elem.style.cssText = "color: blue; ..."; // multiple styles
    elem.setAttribute("style", "color: blue;"); 
  }
}

Renderer2 (all platforms)

import { ElementRef, Renderer2 } from '@angular/core';

@Component(...)
export class SongTrack {
  constructor(
     private element: ElementRef,
     private renderer: Renderer2
  ){
    let elem = this.element.nativeElement;

    renderer.setStyle(elem, "color", "blue");
    renderer.addClass(elem, "selected", true);
  }
}

Playground

Song Track Example

  • Encapsulation Modes

  • Inline, Template inline, External Styles

  • ngClass, ngStyle

  • Shadow DOM Selectors

  • Host bindings/listeners

Blog Post

Thanks!

Advanced Component styling with Angular (v4+)

By Gerard Sans

Advanced Component styling with Angular (v4+)

In this talk we are going to cover all the different ways we can style our Angular Components. From introductory to advanced. We will learn how to style using Shadow DOM selectors, Light Dom, @HostBinding, ElementRef and more.

  • 2,533
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