Directive:
// highlight.directive.ts
import { Directive, ElementRef, Input } from '@angular/core';
@Directive({
selector: '[appHighlight]',
})
export class HighlightDirective {
@Input() yourColor: any = 'red';
constructor(private el: ElementRef) {
el.nativeElement.style.backgroundColor = this.yourColor;
}
}
Consumer:
// app.component.html
<div appHighlight [yourColor]="'blue'">Testing</div>
Result:
Question
Why can't I pass blue
to yourColor
?
CodePudding user response:
You should move your code from constructor
to ngOnInit
. Use constructor
in Angular only for injecting dependencies, but ngOnInit
for executing a code when component is mounted.
Here is more info about that: Difference between Constructor and ngOnInit
CodePudding user response:
Here is a solution using two-way binding:
// highlight.directive.ts
export class HighlightDirective {
yourColor: any = 'red';
ngOnInit() {
// change color in method
this.yourColor = ‘blue’;
}
}
// app.component.html
<div appHighlight style=“background-color= {{yourColor}}”>Testing</div>