W3cubDocs

/Angular

FormGroup

class final

Tracks the value and validity state of a group of FormControl instances.

See more...

class FormGroup<TControl extends {
    [K in keyof TControl]: AbstractControl<any>;
} = any> extends AbstractControl<ɵTypedOrUntyped<TControl, ɵFormGroupValue<TControl>, any>, ɵTypedOrUntyped<TControl, ɵFormGroupRawValue<TControl>, any>> {
  constructor(controls: TControl, validatorOrOpts?: ValidatorFn | AbstractControlOptions | ValidatorFn[], asyncValidator?: AsyncValidatorFn | AsyncValidatorFn[])
  controls: ɵTypedOrUntyped<TControl, TControl, {...}
  registerControl<K extends string & keyof TControl>(name: K, control: TControl[K]): TControl[K]
  addControl<K extends string & keyof TControl>(name: K, control: Required<TControl>[K], options: { emitEvent?: boolean; } = {}): void
  removeControl(name: string, options: { emitEvent?: boolean; } = {}): void
  setControl<K extends string & keyof TControl>(name: K, control: TControl[K], options: { emitEvent?: boolean; } = {}): void
  contains<K extends string & keyof TControl>(controlName: K): boolean
  setValue(value: ɵIsAny<TControl, { [key: string]: any; }, { [K in keyof TControl]: ɵRawValue<TControl[K]>; }>, options: { onlySelf?: boolean; emitEvent?: boolean; } = {}): void
  patchValue(value: ɵIsAny<TControl, { [key: string]: any; }, Partial<{ [K in keyof TControl]: ɵValue<TControl[K]>; }>>, options: { onlySelf?: boolean; emitEvent?: boolean; } = {}): void
  reset(value: ɵIsAny<TControl, any, ɵIsAny<TControl, { [key: string]: any; }, Partial<{ [K in keyof TControl]: ɵValue<TControl[K]>; }>>> = {} as unknown as ɵFormGroupValue<TControl>, options: { onlySelf?: boolean; emitEvent?: boolean; } = {}): void
  getRawValue(): ɵTypedOrUntyped<TControl, ɵFormGroupRawValue<TControl>, any>

  // inherited from forms/AbstractControl
  constructor(validators: ValidatorFn | ValidatorFn[], asyncValidators: AsyncValidatorFn | AsyncValidatorFn[])
  value: TValue
  validator: ValidatorFn | null
  asyncValidator: AsyncValidatorFn | null
  parent: FormGroup | FormArray | null
  status: FormControlStatus
  valid: boolean
  invalid: boolean
  pending: boolean
  disabled: boolean
  enabled: boolean
  errors: ValidationErrors | null
  pristine: boolean
  dirty: boolean
  touched: boolean
  untouched: boolean
  valueChanges: Observable<TValue>
  statusChanges: Observable<FormControlStatus>
  updateOn: FormHooks
  root: AbstractControl
  setValidators(validators: ValidatorFn | ValidatorFn[]): void
  setAsyncValidators(validators: AsyncValidatorFn | AsyncValidatorFn[]): void
  addValidators(validators: ValidatorFn | ValidatorFn[]): void
  addAsyncValidators(validators: AsyncValidatorFn | AsyncValidatorFn[]): void
  removeValidators(validators: ValidatorFn | ValidatorFn[]): void
  removeAsyncValidators(validators: AsyncValidatorFn | AsyncValidatorFn[]): void
  hasValidator(validator: ValidatorFn): boolean
  hasAsyncValidator(validator: AsyncValidatorFn): boolean
  clearValidators(): void
  clearAsyncValidators(): void
  markAsTouched(opts: { onlySelf?: boolean; } = {}): void
  markAllAsTouched(): void
  markAsUntouched(opts: { onlySelf?: boolean; } = {}): void
  markAsDirty(opts: { onlySelf?: boolean; } = {}): void
  markAsPristine(opts: { onlySelf?: boolean; } = {}): void
  markAsPending(opts: { onlySelf?: boolean; emitEvent?: boolean; } = {}): void
  disable(opts: { onlySelf?: boolean; emitEvent?: boolean; } = {}): void
  enable(opts: { onlySelf?: boolean; emitEvent?: boolean; } = {}): void
  setParent(parent: FormGroup<any> | FormArray<any>): void
  abstract setValue(value: TRawValue, options?: Object): void
  abstract patchValue(value: TValue, options?: Object): void
  abstract reset(value?: TValue, options?: Object): void
  getRawValue(): any
  updateValueAndValidity(opts: { onlySelf?: boolean; emitEvent?: boolean; } = {}): void
  setErrors(errors: ValidationErrors, opts: { emitEvent?: boolean; } = {}): void
  get<P extends string | ((string | number)[])>(path: P): AbstractControl<ɵGetProperty<TRawValue, P>> | null
  getError(errorCode: string, path?: string | (string | number)[]): any
  hasError(errorCode: string, path?: string | (string | number)[]): boolean
}

Subclasses

Description

A FormGroup aggregates the values of each child FormControl into one object, with each control name as the key. It calculates its status by reducing the status values of its children. For example, if one of the controls in a group is invalid, the entire group becomes invalid.

FormGroup is one of the four fundamental building blocks used to define forms in Angular, along with FormControl, FormArray, and FormRecord.

When instantiating a FormGroup, pass in a collection of child controls as the first argument. The key for each child registers the name for the control.

FormGroup is intended for use cases where the keys are known ahead of time. If you need to dynamically add and remove controls, use FormRecord instead.

FormGroup accepts an optional type parameter TControl, which is an object type with inner control types as values.

Further information is available in the Usage Notes...

Constructor

Creates a new FormGroup instance.

This class is "final" and should not be extended. See the public API notes.

constructor(controls: TControl, validatorOrOpts?: ValidatorFn | AbstractControlOptions | ValidatorFn[], asyncValidator?: AsyncValidatorFn | AsyncValidatorFn[])

Parameters
controls TControl

A collection of child controls. The key for each child is the name under which it is registered.

validatorOrOpts ValidatorFn | AbstractControlOptions | ValidatorFn[]

A synchronous validator function, or an array of such functions, or an AbstractControlOptions object that contains validation functions and a validation trigger.

Optional. Default is undefined.

asyncValidator AsyncValidatorFn | AsyncValidatorFn[]

A single async validator or array of async validator functions

Optional. Default is undefined.

Properties

Property Description
controls: ɵTypedOrUntyped<TControl, TControl, { [key: string]: AbstractControl<any>; }>

Methods

Registers a control with the group's list of controls. In a strongly-typed group, the control must be in the group's type (possibly as an optional key).

registerControl<K extends string & keyof TControl>(name: K, control: TControl[K]): TControl[K]

Parameters
name K

The control name to register in the collection

control TControl[K]

Provides the control for the given name

Returns

TControl[K]

registerControl(name: string, control: AbstractControl<any, any>): AbstractControl<any>

Parameters
name string
control AbstractControl<any, any>
Returns

AbstractControl<any>

This method does not update the value or validity of the control. Use FormGroup#addControl instead.

Add a control to this group. In a strongly-typed group, the control must be in the group's type (possibly as an optional key).

addControl(name: string, control: AbstractControl<any, any>, options?: { emitEvent?: boolean; }): void

Parameters
name string

The control name to add to the collection

control AbstractControl<any, any>

Provides the control for the given name

options object

Specifies whether this FormGroup instance should emit events after a new control is added.

  • emitEvent: When true or not supplied (the default), both the statusChanges and valueChanges observables emit events with the latest status and value when the control is added. When false, no events are emitted.

Optional. Default is undefined.

Returns

void

addControl<K extends string & keyof TControl>(name: K, control: Required<TControl>[K], options?: { emitEvent?: boolean; }): void

Parameters
name K
control Required<TControl>[K]
options object

Optional. Default is undefined.

Returns

void

If a control with a given name already exists, it would not be replaced with a new one. If you want to replace an existing control, use the FormGroup#setControl method instead. This method also updates the value and validity of the control.

Remove a control from this group. In a strongly-typed group, required controls cannot be removed.

removeControl(name: string, options?: { emitEvent?: boolean; }): void

Parameters
name string
options object

Optional. Default is undefined.

Returns

void

removeControl<S extends string>(name: ɵOptionalKeys<TControl> & S, options?: { emitEvent?: boolean; }): void

Parameters
name ɵOptionalKeys<TControl> & S
options object

Optional. Default is undefined.

Returns

void

This method also updates the value and validity of the control.

Replace an existing control. In a strongly-typed group, the control must be in the group's type (possibly as an optional key).

setControl<K extends string & keyof TControl>(name: K, control: TControl[K], options?: { emitEvent?: boolean; }): void

Parameters
name K

The control name to replace in the collection

control TControl[K]

Provides the control for the given name

options object

Specifies whether this FormGroup instance should emit events after an existing control is replaced.

  • emitEvent: When true or not supplied (the default), both the statusChanges and valueChanges observables emit events with the latest status and value when the control is replaced with a new one. When false, no events are emitted.

Optional. Default is undefined.

Returns

void

setControl(name: string, control: AbstractControl<any, any>, options?: { emitEvent?: boolean; }): void

Parameters
name string
control AbstractControl<any, any>
options object

Optional. Default is undefined.

Returns

void

If a control with a given name does not exist in this FormGroup, it will be added.

Check whether there is an enabled control with the given name in the group.

contains<K extends string>(controlName: K): boolean

Parameters
controlName K

The control name to check for existence in the collection

Returns

boolean: false for disabled controls, true otherwise.

contains(controlName: string): boolean

Parameters
controlName string
Returns

boolean

Reports false for disabled controls. If you'd like to check for existence in the group only, use AbstractControl#get instead.

Sets the value of the FormGroup. It accepts an object that matches the structure of the group, with control names as keys.

setValue(value: ɵIsAny<TControl, { [key: string]: any; }, { [K in keyof TControl]: ɵRawValue<TControl[K]>; }>, options: { onlySelf?: boolean; emitEvent?: boolean; } = {}): void

Parameters
value ɵIsAny<TControl, { [key: string]: any; }, { [K in keyof TControl]: ɵRawValue<TControl[K]>; }>

The new value for the control that matches the structure of the group.

options object

Configuration options that determine how the control propagates changes and emits events after the value changes. The configuration options are passed to the AbstractControl#updateValueAndValidity method.

  • onlySelf: When true, each change only affects this control, and not its parent. Default is false.
  • emitEvent: When true or not supplied (the default), both the statusChanges and valueChanges observables emit events with the latest status and value when the control value is updated. When false, no events are emitted.

Optional. Default is {}.

Returns

void

Throws

Error When strict checks fail, such as setting the value of a control that doesn't exist or if you exclude a value of a control that does exist.

Usage Notes

Set the complete value for the form group
const form = new FormGroup({
  first: new FormControl(),
  last: new FormControl()
});

console.log(form.value);   // {first: null, last: null}

form.setValue({first: 'Nancy', last: 'Drew'});
console.log(form.value);   // {first: 'Nancy', last: 'Drew'}

Patches the value of the FormGroup. It accepts an object with control names as keys, and does its best to match the values to the correct controls in the group.

patchValue(value: ɵIsAny<TControl, { [key: string]: any; }, Partial<{ [K in keyof TControl]: ɵValue<TControl[K]>; }>>, options: { onlySelf?: boolean; emitEvent?: boolean; } = {}): void

Parameters
value ɵIsAny<TControl, { [key: string]: any; }, Partial<{ [K in keyof TControl]: ɵValue<TControl[K]>; }>>

The object that matches the structure of the group.

options object

Configuration options that determine how the control propagates changes and emits events after the value is patched.

  • onlySelf: When true, each change only affects this control and not its parent. Default is true.
  • emitEvent: When true or not supplied (the default), both the statusChanges and valueChanges observables emit events with the latest status and value when the control value is updated. When false, no events are emitted. The configuration options are passed to the AbstractControl#updateValueAndValidity method.

Optional. Default is {}.

Returns

void

It accepts both super-sets and sub-sets of the group without throwing an error.

Usage Notes

Patch the value for a form group
const form = new FormGroup({
   first: new FormControl(),
   last: new FormControl()
});
console.log(form.value);   // {first: null, last: null}

form.patchValue({first: 'Nancy'});
console.log(form.value);   // {first: 'Nancy', last: null}

Resets the FormGroup, marks all descendants pristine and untouched and sets the value of all descendants to their default values, or null if no defaults were provided.

reset(value: ɵIsAny<TControl, any, ɵIsAny<TControl, { [key: string]: any; }, Partial<{ [K in keyof TControl]: ɵValue<TControl[K]>; }>>> = {} as unknown as ɵFormGroupValue<TControl>, options: { onlySelf?: boolean; emitEvent?: boolean; } = {}): void

Parameters
value ɵIsAny<TControl, any, ɵIsAny<TControl, { [key: string]: any; }, Partial<{ [K in keyof TControl]: ɵValue<TControl[K]>; }>>>

Resets the control with an initial value, or an object that defines the initial value and disabled state.

Optional. Default is {} as unknown as ɵFormGroupValue<TControl>.

options object

Configuration options that determine how the control propagates changes and emits events when the group is reset.

  • onlySelf: When true, each change only affects this control, and not its parent. Default is false.
  • emitEvent: When true or not supplied (the default), both the statusChanges and valueChanges observables emit events with the latest status and value when the control is reset. When false, no events are emitted. The configuration options are passed to the AbstractControl#updateValueAndValidity method.

Optional. Default is {}.

Returns

void

You reset to a specific form state by passing in a map of states that matches the structure of your form, with control names as keys. The state is a standalone value or a form state object with both a value and a disabled status.

Usage Notes

Reset the form group values
const form = new FormGroup({
  first: new FormControl('first name'),
  last: new FormControl('last name')
});

console.log(form.value);  // {first: 'first name', last: 'last name'}

form.reset({ first: 'name', last: 'last name' });

console.log(form.value);  // {first: 'name', last: 'last name'}
Reset the form group values and disabled status
const form = new FormGroup({
  first: new FormControl('first name'),
  last: new FormControl('last name')
});

form.reset({
  first: {value: 'name', disabled: true},
  last: 'last'
});

console.log(form.value);  // {last: 'last'}
console.log(form.get('first').status);  // 'DISABLED'

The aggregate value of the FormGroup, including any disabled controls.

getRawValue(): ɵTypedOrUntyped<TControl, ɵFormGroupRawValue<TControl>, any>

Parameters

There are no parameters.

Returns

ɵTypedOrUntyped<TControl, ɵFormGroupRawValue<TControl>, any>

Retrieves all values regardless of disabled status.

Usage notes

Create a form group with 2 controls

const form = new FormGroup({
  first: new FormControl('Nancy', Validators.minLength(2)),
  last: new FormControl('Drew'),
});

console.log(form.value);   // {first: 'Nancy', last; 'Drew'}
console.log(form.status);  // 'VALID'

The type argument, and optional controls

FormGroup accepts one generic argument, which is an object containing its inner controls. This type will usually be inferred automatically, but you can always specify it explicitly if you wish.

If you have controls that are optional (i.e. they can be removed, you can use the ? in the type):

const form = new FormGroup<{
  first: FormControl<string|null>,
  middle?: FormControl<string|null>, // Middle name is optional.
  last: FormControl<string|null>,
}>({
  first: new FormControl('Nancy'),
  last: new FormControl('Drew'),
});

Create a form group with a group-level validator

You include group-level validators as the second arg, or group-level async validators as the third arg. These come in handy when you want to perform validation that considers the value of more than one child control.

const form = new FormGroup({
  password: new FormControl('', Validators.minLength(2)),
  passwordConfirm: new FormControl('', Validators.minLength(2)),
}, passwordMatchValidator);


function passwordMatchValidator(g: FormGroup) {
   return g.get('password').value === g.get('passwordConfirm').value
      ? null : {'mismatch': true};
}

Like FormControl instances, you choose to pass in validators and async validators as part of an options object.

const form = new FormGroup({
  password: new FormControl('')
  passwordConfirm: new FormControl('')
}, { validators: passwordMatchValidator, asyncValidators: otherValidator });

Set the updateOn property for all controls in a form group

The options object is used to set a default value for each child control's updateOn property. If you set updateOn to 'blur' at the group level, all child controls default to 'blur', unless the child has explicitly specified a different updateOn value.

const c = new FormGroup({
  one: new FormControl()
}, { updateOn: 'blur' });

Using a FormGroup with optional controls

It is possible to have optional controls in a FormGroup. An optional control can be removed later using removeControl, and can be omitted when calling reset. Optional controls must be declared optional in the group's type.

const c = new FormGroup<{one?: FormControl<string>}>({
  one: new FormControl('')
});

Notice that c.value.one has type string|null|undefined. This is because calling c.reset({}) without providing the optional key one will cause it to become null.

© 2010–2023 Google, Inc.
Licensed under the Creative Commons Attribution License 4.0.
https://angular.io/api/forms/FormGroup