Syncs a nested FormArray to a DOM element.

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See also

• Reactive Forms Guide

• AbstractControl

Exported from

• ReactiveFormsModule

Selectors

• [formArrayName]

Properties

Property	Description
@Input('formArrayName')name: string | number | null	Tracks the name of the FormArray bound to the directive. The name corresponds to a key in the parent FormGroup or FormArray. Accepts a name as a string or a number. The name in the form of a string is useful for individual forms, while the numerical form allows for form arrays to be bound to indices when iterating over arrays in a FormArray.
control: FormArray	Read-Only The FormArray bound to this directive.
formDirective: FormGroupDirective | null	Read-Only The top-level directive for this group if present, otherwise null.
path: string[]	Read-Only Returns an array that represents the path from the top-level form to this control. Each index is the string name of the control on that level.

Inherited from ControlContainer

• name: string | number | null
• formDirective: Form | null
• path: string[] | null

Inherited from AbstractControlDirective

• abstract control: AbstractControl | null
• value: any
• valid: boolean | null
• invalid: boolean | null
• pending: boolean | null
• disabled: boolean | null
• enabled: boolean | null
• errors: ValidationErrors | null
• pristine: boolean | null
• dirty: boolean | null
• touched: boolean | null
• status: string | null
• untouched: boolean | null
• statusChanges: Observable<any> | null
• valueChanges: Observable<any> | null
• path: string[] | null
• validator: ValidatorFn | null
• asyncValidator: AsyncValidatorFn | null

Description

This directive is designed to be used with a parent FormGroupDirective (selector: [formGroup]).

It accepts the string name of the nested FormArray you want to link, and will look for a FormArray registered with that name in the parent FormGroup instance you passed into FormGroupDirective.

Example

import {Component} from '@angular/core';
import {FormArray, FormControl, FormGroup} from '@angular/forms';

@Component({
  selector: 'example-app',
  template: `
    <form [formGroup]="form" (ngSubmit)="onSubmit()">
      <div formArrayName="cities">
        <div *ngFor="let city of cities.controls; index as i">
          <input [formControlName]="i" placeholder="City">
        </div>
      </div>
      <button>Submit</button>
    </form>

    <button (click)="addCity()">Add City</button>
    <button (click)="setPreset()">Set preset</button>
  `,
})
export class NestedFormArray {
  form = new FormGroup({
    cities: new FormArray([
      new FormControl('SF'),
      new FormControl('NY'),
    ]),
  });

  get cities(): FormArray {
    return this.form.get('cities') as FormArray;
  }

  addCity() {
    this.cities.push(new FormControl());
  }

  onSubmit() {
    console.log(this.cities.value);  // ['SF', 'NY']
    console.log(this.form.value);    // { cities: ['SF', 'NY'] }
  }

  setPreset() {
    this.cities.patchValue(['LA', 'MTV']);
  }
}

Inherited from AbstractControlDirective

• reset(value: any = undefined): void
• hasError(errorCode: string, path?: string | (string | number)[]): boolean
• getError(errorCode: string, path?: string | (string | number)[]): any