Ionic 4 - Ionic Input Two-Way Binding

Question

In Ionic 4 how do you do two-way binding. In Ionic 3 I would do the following:

<ion-item color="light"> <ion-input type="string" placeholder="Username" [(ngModel)]="username"></ion-input> </ion-item>

However in Ionic 4 I get the following error:

Can't bind to 'ngModel' since it isn't a known property of 'ion-input'.
1. If 'ion-input' is an Angular component and it has 'ngModel' input, then verify that it is part of this module.
2. If 'ion-input' is a Web Component then add 'CUSTOM_ELEMENTS_SCHEMA' to the '@NgModule.schemas' of this component to suppress this message.
3. To allow any property add 'NO_ERRORS_SCHEMA' to the '@NgModule.schemas' of this component. ("d>
          <ion-item color="light">
              <ion-input type="string" placeholder="Username" [ERROR ->][(ngModel)]="username"></ion-input>
          </ion-item>
          <ion-item color="light">
"): ng:///AppModule/LoginPage.html@12:62

How do I get this working in Ionic 4?

Answer 1

Please keep in mind to add the FormsModule to your module or create a SharedModule to import and export FormsModule

@NgModule({
  imports: [
    CommonModule,
    FormsModule,
    IonicModule,
    RouterModule.forChild([
      {
        path: '',
        component: HomePage
      }
    ])
  ],
  declarations: [HomePage]
})
export class HomePageModule { }

Answer 2

Ionic 3/4 with angular 6

In order to be able to use two-way data binding for form inputs you need to import the FormsModule package in your Angular module. For more info see the Angular official tutorial here

For Example

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

[...]

@NgModule({
  imports: [
    [...]
    FormsModule
  ],
  [...]
})

Answer 3

You just need to import FormsModule in app.module.ts. As i have already gave the answer in detail. Visit to the link for detail https://stackoverflow.com/a/55684045/7983887

Answer 4

Add FormsModule in the your Angular module