Angular 5 ngModel doesn't update value

Question

I have the following component:

export class ModuleComponentComponent implements OnInit {
    dropzoneConf;
    fileService = environment.getFileUrl;

    constructor(
        private moduleComponentService: ModuleComponentService) {
    }

    @Input()
    selectedComponent: ModuleComponent;

    ngOnInit() {
        this.setDropZoneConfig();
    }    
}

And in that I have the following HTML:

<h3 class="m-portlet__head-text m--font-success">
   <input class="form-control" type="text" [ngModel]="selectedComponent.title" />
</h3>

and the way I add the component in my HTML:

<div class="col-lg-8 col-x1-12" *ngIf="selectedComponent != null">
   <app-module-component [selectedComponent]="selectedComponent"></app-module-component>
</div>

When I type something into the input field it doesn't update the selectedComponent.title variable

What might be going on?

score 6 · Accepted Answer · answered Jun 13 '18 at 12:28

6

Use the two way binding

 [(ngModel)]="selectedComponent.title"

answered Jun 13 '18 at 12:28

Sachila Ranawaka

39,756
7
56
80

score 2 · Answer 2 · edited Apr 05 '19 at 15:32

2

you should use two-way data binding

[(ngModel)]

<input class="form-control" type="text" [(ngModel)]="selectedComponent.title" />

and make sure to import forms module in app.module.ts

import { FormsModule } from '@angular/forms';

edited Apr 05 '19 at 15:32

Herman Andres Figueroa

513
3
9
26

answered Jun 13 '18 at 12:33

VAMSI AILA

61
1
13

score 2 · Answer 3 · answered Jun 13 '18 at 12:44

We need to use two way data binding with [(ngModel)]

<h3 class="m-portlet__head-text m--font-success">
   <input class="form-control" type="text" [(ngModel)]="selectedComponent.title" />
</h3>

You should read the part about two way data binding on Angular documentation

If you want to use [ngModel] only, you could but you have to catch changes with (ngModelChange)

<h3 class="m-portlet__head-text m--font-success">
   <input class="form-control" type="text" [ngModel]="selectedComponent.title" (ngModelChanges)="setTitle($event)" />
</h3>

You could improve it with forms, just ask me for any questions about that

Angular 5 ngModel doesn't update value

3 Answers3