Angular5 and 6:
angular 5 and 6 recommended way is to use @HostBindings and @HostListeners instead of the host property
remove host and add @HostListener
@HostListener('ngModelChange', ['$event'])
onModelChange(event) {
this.onInputChange(event, false);
}
@HostListener('keydown.backspace', ['$event'])
keydownBackspace(event) {
this.onInputChange(event.target.value, true);
}
Working Online stackblitz Link: https://angular6-phone-mask.stackblitz.io
Stackblitz Code example: https://stackblitz.com/edit/angular6-phone-mask
Official documentation link https://angular.io/guide/attribute-directives#respond-to-user-initiated-events
Angular2 and 4:
original
One way you could do it is using a directive that injects NgControl and manipulates the value
(for details see inline comments)
@Directive({
selector: '[ngModel][phone]',
host: {
'(ngModelChange)': 'onInputChange($event)',
'(keydown.backspace)': 'onInputChange($event.target.value, true)'
}
})
export class PhoneMask {
constructor(public model: NgControl) {}
onInputChange(event, backspace) {
// remove all mask characters (keep only numeric)
var newVal = event.replace(/\D/g, '');
// special handling of backspace necessary otherwise
// deleting of non-numeric characters is not recognized
// this laves room for improvement for example if you delete in the
// middle of the string
if (backspace) {
newVal = newVal.substring(0, newVal.length - 1);
}
// don't show braces for empty value
if (newVal.length == 0) {
newVal = '';
}
// don't show braces for empty groups at the end
else if (newVal.length <= 3) {
newVal = newVal.replace(/^(\d{0,3})/, '($1)');
} else if (newVal.length <= 6) {
newVal = newVal.replace(/^(\d{0,3})(\d{0,3})/, '($1) ($2)');
} else {
newVal = newVal.replace(/^(\d{0,3})(\d{0,3})(.*)/, '($1) ($2)-$3');
}
// set the new value
this.model.valueAccessor.writeValue(newVal);
}
}
@Component({
selector: 'my-app',
providers: [],
template: `
<form [ngFormModel]="form">
<input type="text" phone [(ngModel)]="data" ngControl="phone">
</form>
`,
directives: [PhoneMask]
})
export class App {
constructor(fb: FormBuilder) {
this.form = fb.group({
phone: ['']
})
}
}