DefaultValueAccessor — Angular

The default ControlValueAccessor for writing a value and listening to changes on input elements. The accessor is used by the FormControlDirective, FormControlName, and NgModel directives.

API

class DefaultValueAccessor extends BaseControlValueAccessor implements ControlValueAccessor {
  constructor(renderer: Renderer2, elementRef: ElementRef<any>, _compositionMode: boolean): DefaultValueAccessor;
}

constructor

DefaultValueAccessor

@paramrendererRenderer2

@paramelementRefElementRef<any>

@param_compositionModeboolean

@returnsDefaultValueAccessor

Description

The default ControlValueAccessor for writing a value and listening to changes on input elements. The accessor is used by the FormControlDirective, FormControlName, and NgModel directives.

Exported by

ReactiveFormsModule
FormsModule

Usage Notes

Using the default value accessor

The following example shows how to use an input element that activates the default value accessor (in this case, a text field).

const firstNameControl = new FormControl();

<input type="text" [formControl]="firstNameControl">

This value accessor is used by default for <input type="text"> and <textarea> elements, but you could also use it for custom components that have similar behavior and do not require special processing. In order to attach the default value accessor to a custom element, add the ngDefaultControl attribute as shown below.

<custom-input-component ngDefaultControl [(ngModel)]="value"></custom-input-component>