@angular/forms

AbstractControl

Class

This is the base class for FormControl, FormGroup, and FormArray.

abstract class AbstractControl {
}

This is the base class for FormControl, FormGroup, and FormArray.

It provides some of the shared behavior that all controls and groups of controls have, like running validators, calculating status, and resetting state. It also defines the properties that are shared between all sub-classes, like value, valid, and dirty. It shouldn't be instantiated directly.

The first type parameter TValue represents the value type of the control (control.value). The optional type parameter TRawValue represents the raw value type (control.getRawValue()).

value

TValue

The current value of the control.

For a FormControl, the current value.
For an enabled FormGroup, the values of enabled controls as an object with a key-value pair for each member of the group.
For a disabled FormGroup, the values of all controls as an object with a key-value pair for each member of the group.
For a FormArray, the values of enabled controls as an array.

validator

2 overloads

Returns the function that is used to determine the validity of this control synchronously. If multiple validators have been added, this will be a single composed function. See Validators.compose() for additional information.

asyncValidator

2 overloads

Returns the function that is used to determine the validity of this control asynchronously. If multiple validators have been added, this will be a single composed function. See Validators.compose() for additional information.

parent

FormGroup<any> | FormArray<any>

The parent control.

status

FormControlStatus

The validation status of the control.

valid

boolean

A control is valid when its status is VALID.

invalid

boolean

A control is invalid when its status is INVALID.

pending

boolean

A control is pending when its status is PENDING.

disabled

boolean

A control is disabled when its status is DISABLED.

Disabled controls are exempt from validation checks and are not included in the aggregate value of their ancestor controls.

enabled

boolean

A control is enabled as long as its status is not DISABLED.

errors

ValidationErrors

An object containing any errors generated by failing validation, or null if there are no errors.

pristine

boolean

A control is pristine if the user has not yet changed the value in the UI.

dirty

boolean

A control is dirty if the user has changed the value in the UI.

touched

boolean

True if the control is marked as touched.

A control is marked touched once the user has triggered a blur event on it.

untouched

boolean

True if the control has not been marked as touched

A control is untouched if the user has not yet triggered a blur event on it.

events

Observable<ControlEvent<TValue>>

A multicasting observable that emits an event every time the state of the control changes. It emits for value, status, pristine or touched changes.

Note: On value change, the emit happens right after a value of this control is updated. The value of a parent control (for example if this FormControl is a part of a FormGroup) is updated later, so accessing a value of a parent control (using the value property) from the callback of this event might result in getting a value that has not been updated yet. Subscribe to the events of the parent control instead. For other event types, the events are emitted after the parent control has been updated.

valueChanges

Observable<TValue>

A multicasting observable that emits an event every time the value of the control changes, in the UI or programmatically. It also emits an event each time you call enable() or disable() without passing along {emitEvent: false} as a function argument.

Note: the emit happens right after a value of this control is updated. The value of a parent control (for example if this FormControl is a part of a FormGroup) is updated later, so accessing a value of a parent control (using the value property) from the callback of this event might result in getting a value that has not been updated yet. Subscribe to the valueChanges event of the parent control instead.

TODO: this should be piped from events() but is breaking in G3

statusChanges

Observable<FormControlStatus>

A multicasting observable that emits an event every time the validation status of the control recalculates.

updateOn

FormHooks

Reports the update strategy of the AbstractControl (meaning the event on which the control updates itself). Possible values: 'change' | 'blur' | 'submit' Default value: 'change'

setValidators

void

Sets the synchronous validators that are active on this control. Calling this overwrites any existing synchronous validators.

When you add or remove a validator at run time, you must call updateValueAndValidity() for the new validation to take effect.

If you want to add a new validator without affecting existing ones, consider using addValidators() method instead.

@paramvalidatorsValidatorFn | ValidatorFn[]

@returnsvoid

setAsyncValidators

void

Sets the asynchronous validators that are active on this control. Calling this overwrites any existing asynchronous validators.

When you add or remove a validator at run time, you must call updateValueAndValidity() for the new validation to take effect.

If you want to add a new validator without affecting existing ones, consider using addAsyncValidators() method instead.

@paramvalidatorsAsyncValidatorFn | AsyncValidatorFn[]

@returnsvoid

addValidators

void

Add a synchronous validator or validators to this control, without affecting other validators.

When you add or remove a validator at run time, you must call updateValueAndValidity() for the new validation to take effect.

Adding a validator that already exists will have no effect. If duplicate validator functions are present in the validators array, only the first instance would be added to a form control.

@paramvalidatorsValidatorFn | ValidatorFn[]

The new validator function or functions to add to this control.

@returnsvoid

addAsyncValidators

void

Add an asynchronous validator or validators to this control, without affecting other validators.

When you add or remove a validator at run time, you must call updateValueAndValidity() for the new validation to take effect.

Adding a validator that already exists will have no effect.

@paramvalidatorsAsyncValidatorFn | AsyncValidatorFn[]

The new asynchronous validator function or functions to add to this control.

@returnsvoid

removeValidators

void

Remove a synchronous validator from this control, without affecting other validators. Validators are compared by function reference; you must pass a reference to the exact same validator function as the one that was originally set. If a provided validator is not found, it is ignored.

@paramvalidatorsValidatorFn | ValidatorFn[]

The validator or validators to remove.

@returnsvoid

Usage notes

Reference to a ValidatorFn

          
            // Reference to the RequiredValidatorconst ctrl = new FormControl<string | null>('', Validators.required);ctrl.removeValidators(Validators.required);// Reference to anonymous function inside MinValidatorconst minValidator = Validators.min(3);const ctrl = new FormControl<string | null>('', minValidator);expect(ctrl.hasValidator(minValidator)).toEqual(true)expect(ctrl.hasValidator(Validators.min(3))).toEqual(false)ctrl.removeValidators(minValidator);

When you add or remove a validator at run time, you must call updateValueAndValidity() for the new validation to take effect.

removeAsyncValidators

void

Remove an asynchronous validator from this control, without affecting other validators. Validators are compared by function reference; you must pass a reference to the exact same validator function as the one that was originally set. If a provided validator is not found, it is ignored.

When you add or remove a validator at run time, you must call updateValueAndValidity() for the new validation to take effect.

@paramvalidatorsAsyncValidatorFn | AsyncValidatorFn[]

The asynchronous validator or validators to remove.

@returnsvoid

hasValidator

boolean

Check whether a synchronous validator function is present on this control. The provided validator must be a reference to the exact same function that was provided.

@paramvalidatorValidatorFn

The validator to check for presence. Compared by function reference.

@returnsboolean

Usage notes

Reference to a ValidatorFn

          
            // Reference to the RequiredValidatorconst ctrl = new FormControl<number | null>(0, Validators.required);expect(ctrl.hasValidator(Validators.required)).toEqual(true)// Reference to anonymous function inside MinValidatorconst minValidator = Validators.min(3);const ctrl = new FormControl<number | null>(0, minValidator);expect(ctrl.hasValidator(minValidator)).toEqual(true)expect(ctrl.hasValidator(Validators.min(3))).toEqual(false)

hasAsyncValidator

boolean

Check whether an asynchronous validator function is present on this control. The provided validator must be a reference to the exact same function that was provided.

@paramvalidatorAsyncValidatorFn

The asynchronous validator to check for presence. Compared by function reference.

@returnsboolean

clearValidators

void

Empties out the synchronous validator list.

When you add or remove a validator at run time, you must call updateValueAndValidity() for the new validation to take effect.

@returnsvoid

clearAsyncValidators

void

Empties out the async validator list.

When you add or remove a validator at run time, you must call updateValueAndValidity() for the new validation to take effect.

@returnsvoid

markAsTouched

void

Marks the control as touched. A control is touched by focus and blur events that do not change the value.

@paramopts{ onlySelf?: boolean; emitEvent?: boolean; }

Configuration options that determine how the control propagates changes and emits events after marking is applied.

onlySelf: When true, mark only this control. When false or not supplied, marks all direct ancestors. Default is false.
emitEvent: When true or not supplied (the default), the events observable emits a TouchedChangeEvent with the touched property being true. When false, no events are emitted.

@returnsvoid

markAllAsTouched

void

Marks the control and all its descendant controls as touched.

@paramopts{ emitEvent?: boolean; }

Configuration options that determine how the control propagates changes and emits events after marking is applied.

emitEvent: When true or not supplied (the default), the events observable emits a TouchedChangeEvent with the touched property being true. When false, no events are emitted.

@returnsvoid

markAsUntouched

void

Marks the control as untouched.

If the control has any children, also marks all children as untouched and recalculates the touched status of all parent controls.

@paramopts{ onlySelf?: boolean; emitEvent?: boolean; }

Configuration options that determine how the control propagates changes and emits events after the marking is applied.

onlySelf: When true, mark only this control. When false or not supplied, marks all direct ancestors. Default is false.
emitEvent: When true or not supplied (the default), the events observable emits a TouchedChangeEvent with the touched property being false. When false, no events are emitted.

@returnsvoid

markAsDirty

void

Marks the control as dirty. A control becomes dirty when the control's value is changed through the UI; compare markAsTouched.

@paramopts{ onlySelf?: boolean; emitEvent?: boolean; }

Configuration options that determine how the control propagates changes and emits events after marking is applied.

onlySelf: When true, mark only this control. When false or not supplied, marks all direct ancestors. Default is false.
emitEvent: When true or not supplied (the default), the events observable emits a PristineChangeEvent with the pristine property being false. When false, no events are emitted.

@returnsvoid

markAsPristine

void

Marks the control as pristine.

If the control has any children, marks all children as pristine, and recalculates the pristine status of all parent controls.

@paramopts{ onlySelf?: boolean; emitEvent?: boolean; }

Configuration options that determine how the control emits events after marking is applied.

onlySelf: When true, mark only this control. When false or not supplied, marks all direct ancestors. Default is false.
emitEvent: When true or not supplied (the default), the events observable emits a PristineChangeEvent with the pristine property being true. When false, no events are emitted.

@returnsvoid

markAsPending

void

Marks the control as pending.

A control is pending while the control performs async validation.

@paramopts{ onlySelf?: boolean; emitEvent?: boolean; }

Configuration options that determine how the control propagates changes and emits events after marking is applied.

onlySelf: When true, mark only this control. When false or not supplied, marks all direct ancestors. Default is false.
emitEvent: When true or not supplied (the default), the statusChanges observable emits an event with the latest status the control is marked pending and the events observable emits a StatusChangeEvent with the status property being PENDING When false, no events are emitted.

@returnsvoid

disable

void

Disables the control. This means the control is exempt from validation checks and excluded from the aggregate value of any parent. Its status is DISABLED.

If the control has children, all children are also disabled.

@paramopts{ onlySelf?: boolean; emitEvent?: boolean; }

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

onlySelf: When true, mark only this control. When false or not supplied, marks all direct ancestors. Default is false.
emitEvent: When true or not supplied (the default), the statusChanges, valueChanges and events observables emit events with the latest status and value when the control is disabled. When false, no events are emitted.

@returnsvoid

enable

void

Enables the control. This means the control is included in validation checks and the aggregate value of its parent. Its status recalculates based on its value and its validators.

By default, if the control has children, all children are enabled.

@paramopts{ onlySelf?: boolean; emitEvent?: boolean; }

Configure options that control how the control propagates changes and emits events when marked as untouched

onlySelf: When true, mark only this control. When false or not supplied, marks all direct ancestors. Default is false.
emitEvent: When true or not supplied (the default), the statusChanges, valueChanges and events observables emit events with the latest status and value when the control is enabled. When false, no events are emitted.

@returnsvoid

setParent

void

Sets the parent of the control

@paramparentFormGroup<any> | FormArray<any>

The new parent.

@returnsvoid

setValue

void

Sets the value of the control. Abstract method (implemented in sub-classes).

@paramvalueTRawValue

@paramoptionsObject

@returnsvoid

patchValue

void

Patches the value of the control. Abstract method (implemented in sub-classes).

@paramvalueTValue

@paramoptionsObject

@returnsvoid

reset

void

Resets the control. Abstract method (implemented in sub-classes).

@paramvalueTValue

@paramoptionsObject

@returnsvoid

getRawValue

any

The raw value of this control. For most control implementations, the raw value will include disabled children.

@returnsany

updateValueAndValidity

void

Recalculates the value and validation status of the control.

By default, it also updates the value and validity of its ancestors.

@paramopts{ onlySelf?: boolean; emitEvent?: boolean; }

Configuration options determine how the control propagates changes and emits events after updates and validity checks are applied.

onlySelf: When true, only update this control. When false or not supplied, update all direct ancestors. Default is false.
emitEvent: When true or not supplied (the default), the statusChanges, valueChanges and events observables emit events with the latest status and value when the control is updated. When false, no events are emitted.

@returnsvoid

setErrors

void

Sets errors on a form control when running validations manually, rather than automatically.

Calling setErrors also updates the validity of the parent control.

@paramerrorsValidationErrors

@paramopts{ emitEvent?: boolean; }

Configuration options that determine how the control propagates changes and emits events after the control errors are set.

emitEvent: When true or not supplied (the default), the statusChanges observable emits an event after the errors are set.

@returnsvoid

Usage notes

Manually set the errors for a control

          
            const login = new FormControl('someLogin');login.setErrors({  notUnique: true});expect(login.valid).toEqual(false);expect(login.errors).toEqual({ notUnique: true });login.setValue('someOtherLogin');expect(login.valid).toEqual(true);

get

2 overloads

Retrieves a child control given the control's name or path.

This signature for get supports strings and const arrays (.get(['foo', 'bar'] as const)).

@parampathP

@returnsAbstractControl<ɵGetProperty<TRawValue, P>, ɵGetProperty<TRawValue, P>>

Retrieves a child control given the control's name or path.

This signature for get supports non-const (mutable) arrays. Inferred type information will not be as robust, so prefer to pass a readonly array if possible.

@parampathP

@returnsAbstractControl<ɵGetProperty<TRawValue, P>, ɵGetProperty<TRawValue, P>>

getError

any

Reports error data for the control with the given path.

@paramerrorCodestring

The code of the error to check

@parampathstring | (string | number)[]

A list of control names that designates how to move from the current control to the control that should be queried for errors.

@returnsany

Usage notes

For example, for the following FormGroup:

          
            form = new FormGroup({  address: new FormGroup({ street: new FormControl() })});

The path to the 'street' control from the root form would be 'address' -> 'street'.

It can be provided to this method in one of two formats:

An array of string control names, e.g. ['address', 'street']
A period-delimited list of control names in one string, e.g. 'address.street'

hasError

boolean

Reports whether the control with the given path has the error specified.

@paramerrorCodestring

The code of the error to check

@parampathstring | (string | number)[]

A list of control names that designates how to move from the current control to the control that should be queried for errors.

@returnsboolean

Usage notes

For example, for the following FormGroup:

          
            form = new FormGroup({  address: new FormGroup({ street: new FormControl() })});

The path to the 'street' control from the root form would be 'address' -> 'street'.

It can be provided to this method in one of two formats:

An array of string control names, e.g. ['address', 'street']
A period-delimited list of control names in one string, e.g. 'address.street'

If no path is given, this method checks for the error on the current control.

root

AbstractControl<any, any>

Retrieves the top-level ancestor of this control.