ControlValueAccessor

Defined in: projects/view-angular-core/util/create-view-control-link.ts:4

Methods

registerOnChange()

registerOnChange(fn): void

Defined in: projects/view-angular-core/util/create-view-control-link.ts:59

Parameters

fn

any

The callback function to register

Returns

void

Description

Registers a callback function that is called when the control’s value changes in the UI.

This method is called by the forms API on initialization to update the form model when values propagate from the view to the model.

When implementing the registerOnChange method in your own value accessor, save the given function so your class calls it at the appropriate time.

Usage Notes

Store the change function

The following example stores the provided function as an internal method.

registerOnChange(fn: (_: any) => void): void {
  this._onChange = fn;
}

When the value changes in the UI, call the registered function to allow the forms API to update itself:

host: {
   '(change)': '_onChange($event.target.value)'
}

---

registerOnTouched()

registerOnTouched(fn): void

Defined in: projects/view-angular-core/util/create-view-control-link.ts:91

Parameters

fn

any

The callback function to register

Returns

void

Description

Registers a callback function that is called by the forms API on initialization to update the form model on blur.

When implementing registerOnTouched in your own value accessor, save the given function so your class calls it when the control should be considered blurred or “touched”.

Usage Notes

Store the callback function

The following example stores the provided function as an internal method.

registerOnTouched(fn: any): void {
  this._onTouched = fn;
}

On blur (or equivalent), your class should call the registered function to allow the forms API to update itself:

host: {
   '(blur)': '_onTouched()'
}

---

setDisabledState()?

optional setDisabledState(isDisabled): void

Defined in: projects/view-angular-core/util/create-view-control-link.ts:109

Parameters

isDisabled

boolean

The disabled status to set on the element

Returns

void

Description

Function that is called by the forms API when the control status changes to or from ‘DISABLED’. Depending on the status, it enables or disables the appropriate DOM element.

Usage Notes

The following is an example of writing the disabled property to a native DOM element:

setDisabledState(isDisabled: boolean): void {
  this._renderer.setProperty(this._elementRef.nativeElement, 'disabled', isDisabled);
}

---

writeValue()

writeValue(obj): void

Defined in: projects/view-angular-core/util/create-view-control-link.ts:25

Parameters

obj

any

The new value for the element

Returns

void

Description

Writes a new value to the element.

This method is called by the forms API to write to the view when programmatic changes from model to view are requested.

Usage Notes

Write a value to the element

The following example writes a value to the native DOM element.

writeValue(value: any): void {
  this._renderer.setProperty(this._elementRef.nativeElement, 'value', value);
}