Angular: conditional class with *ngClass
That's the normal structure for ngClass
is:
[ngClass]="{'classname' : condition}"
So in your case, just use it like this...
<ol class="breadcrumb">
<li [ngClass]="{'active': step==='step1'}" (click)="step='step1'">Step1</li>
<li [ngClass]="{'active': step==='step2'}" (click)="step='step2'">Step2</li>
<li [ngClass]="{'active': step==='step3'}" (click)="step='step3'">Step3</li>
</ol>
Another solution would be using [class.active]
.
Example :
<ol class="breadcrumb">
<li [class.active]="step=='step1'" (click)="step='step1'">Step1</li>
</ol>
[ngClass]=...
instead of *ngClass
.
*
is only for the shorthand syntax for structural directives where you can for example use
<div *ngFor="let item of items">{{item}}</div>
instead of the longer equivalent version
<template ngFor let-item [ngForOf]="items">
<div>{{item}}</div>
</template>
See also https://angular.io/docs/ts/latest/api/common/index/NgClass-directive.html
<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>
See also https://angular.io/docs/ts/latest/guide/template-syntax.html
<!-- toggle the "special" class on/off with a property --> <div [class.special]="isSpecial">The class binding is special</div> <!-- binding to `class.special` trumps the class attribute --> <div class="special" [class.special]="!isSpecial">This one is not so special</div>
<!-- reset/override all class names with a binding --> <div class="bad curly special" [class]="badCurly">Bad curly</div>
Angular version 2+ provides several ways to add classes conditionally:
type one
[class.my_class] = "step === 'step1'"
type two
[ngClass]="{'my_class': step === 'step1'}"
and multiple option:
[ngClass]="{'my_class': step === 'step1', 'my_class2' : step === 'step2' }"
type three
[ngClass]="{1 : 'my_class1', 2 : 'my_class2', 3 : 'my_class4'}[step]"
type four
[ngClass]="step == 'step1' ? 'my_class1' : 'my_class2'"
You can find these examples on the documentation page