DefaultValueAccessor

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.

NgModules

• ReactiveFormsModule

• FormsModule

Selectors

• input:not([type=checkbox])[formControlName]
• textarea[formControlName]
• input:not([type=checkbox])[formControl]
• textarea[formControl]
• input:not([type=checkbox])[ngModel]
• textarea[ngModel]
• [ngDefaultControl]

Properties

Property	Description
onChange: (_: any) => { }	The registered callback function called when an input event occurs on the input element.
onTouched: () => { }	The registered callback function called when a blur event occurs on the input element.

Description

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">

Methods

writeValue()
Sets the "value" property on the input element.
writeValue(value: any): void Parameters value any The checked value Returns void

registerOnChange()
Registers a function called when the control value changes.
registerOnChange(fn: (_: any) => void): void Parameters fn (_: any) => void The callback function Returns void

registerOnTouched()
Registers a function called when the control is touched.
registerOnTouched(fn: () => void): void Parameters fn () => void The callback function Returns void

setDisabledState()
Sets the "disabled" property on the input element.
setDisabledState(isDisabled: boolean): void Parameters isDisabled boolean The disabled value Returns void