ERROR Error: No value accessor for form control with unspecified name attribute on switch

Question

Here is my component in Angular 4:

@Component( {
    selector: 'input-extra-field',
    template: `
            <div class="form-group" [formGroup]="formGroup" >
                <switch [attr.title]="field.etiquette" 
                    [attr.value]="field.valeur" [(ngModel)]="field.valeur"
                    [formControl]="fieldControl" [attr.id]="name" [attr.disabled]="disabled">
                </switch>
                <error-messages [control]="name"></error-messages>
            </div>
    `
} )

Here is my Class:

export class SwitchExtraField extends ExtraField {
    @Input() field: ExtraFormField;
    @Input() entity: { fields: Object };
    @Input() formGroup: FormGroup;

    constructor( formDir: NgForm ) {
        super( null, null, formDir );
    }

    get disabled(): string {
        if ( this.field && !!this.field.saisissable && !this.field.saisissable )     {
            return 'disabled';
        }
        return null;
    }
}

This is the error I get when compiling:

ERROR Error: No value accessor for form control with unspecified name attribute
    at _throwError (forms.es5.js:1918)
    at setUpControl (forms.es5.js:1828)
    at FormControlDirective.webpackJsonp.../../../forms/@angular/forms.es5.js.FormControlDirective.ngOnChanges (forms.es5.js:4617)

When I change the element switch to input it works, knowing that I'm using the same structure to other components and it works fine.

Answer 1

I fixed this error by adding the name="fieldName" ngDefaultControl attributes to the element that carries the [(ngModel)] attribute.