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NgClass

npm Package @angular/common
Module import { NgClass } from '@angular/common';
Source common/src/directives/ng_class.ts
NgModule CommonModule

Adds and removes CSS classes on an HTML element.

Overview

      
      @Directive({ selector: '[ngClass]' })
class NgClass implements DoCheck {
  set klass: string
  set ngClass: string | string[] | Set<string> | {...}
  ngDoCheck(): void
}

How To Use

      
      <some-element [ngClass]="'first second'">...</some-element>

<some-element [ngClass]="['first', 'second']">...</some-element>

<some-element [ngClass]="{'first': true, 'second': true, 'third': false}">...</some-element>

<some-element [ngClass]="stringExp|arrayExp|objExp">...</some-element>

<some-element [ngClass]="{'class1 class2 class3' : true}">...</some-element>

Selectors

      
      [ngClass]

Inputs

class bound to NgClass.klass
ngClass bound to NgClass.ngClass

Description

The CSS classes are updated as follows, depending on the type of the expression evaluation:

  • string - the CSS classes listed in the string (space delimited) are added,
  • Array - the CSS classes declared as Array elements are added,
  • Object - keys are CSS classes that get added when the expression given in the value evaluates to a truthy value, otherwise they are removed.

Constructor

      
      constructor(_iterableDiffers: IterableDiffers, _keyValueDiffers: KeyValueDiffers, _ngEl: ElementRef, _renderer: Renderer2)

Members

      
      set klass: string
    
      
      set ngClass: string | string[] | Set<string> | {
    [klass: string]: any;
}
    
      
      ngDoCheck(): void