Angular 2 component input without value
Material2 wrote the following method:
/** Coerces a data-bound value (typically a string) to a boolean. */
export function coerceBooleanProperty(value: any): boolean {
return value != null && `${value}` !== 'false';
}
Write something like that in your app-document
component:
private _editMode: boolean;
@Input()
get editMode() { return this._editMode; }
set editMode(value: any) { this._editMode = coerceBooleanProperty(value); }
Then:
editMode == true
<app-document editMode></app-document>
editMode == false
<app-document></app-document>
If you use Material2 you can simply import the method as follows:
import {coerceBooleanProperty} from '@angular/cdk/coercion';
You can use boolean @Input
s to achieve this.
HTML:
<app-document [editMode] ...></app-document>
TS:
export class AppDocumentComponent {
@Input() editMode: boolean = true;
// ...
}
Now you have a boolean which you can use to change your behavior.
note for better understanding:
The default value true
kicks in, if there is a (valueless) attribute.
If there is none, editMode
does not get the default value but a falsy undefined. (So, that is why this works).