Angular Reactive forms : how to reset form state and keep values after submit

Question

In an Angular reactive form. How to reset only the state of form after successful submit?

Here is the process:

• Create the form and setValue from service result
• Modify values and submit the form
• If form is properly submitted to service, then reset and keep values

How to keep values as modified and reset the form to its pristine state.

A form.reset() simply empty the form. But if I don't call it, the state is not reset and for example my validations depending on form state classes (pristine, dirty, valid etc.) are still there.

Answer 1

The solution of @smnbbrv works pretty well.

You can also provide your actual form value to reset() method.

Given the fact myReactiveForm is a Reactive form in your component. After successful submit of your form (by calling a service for example), then your can do:

this.myReactiveForm.reset(this.myReactiveForm.value);

It will reset the form and set the "new" form values to the same value you form had.

This method can be see within Tour of Hero example Official Angular.io doc

Answer 2

That's pretty much easy:

this.form.markAsPristine();
this.form.markAsUntouched();

This resets the form metadata and the form is pristine again

Answer 3

Caution for users of angular/material2

There's an added complication if you're using angular material controls, with mat-error to display your errors. Such errors are displayed based on the result of an ErrorStateMatcher (in addition to any *ngIf you may have applied).

The default ErrorStateMatcher displays errors if the following is true:

isErrorState(control: FormControl | null, form: FormGroupDirective | NgForm | null): boolean 
{
   return !!(control && control.invalid && (control.touched || (form && form.submitted)));
}

So what this says is if the form has ever been submitted and a control becomes invalid (per validation rules) then the error will be displayed. This is often not what you want (especially if you're reading this question!).

Looking at the source code - there isn't a way to set submitted = false unless you call resetForm on the ngForm directive (not the FormGroup object). Setting states as pristine or untouched don't reset submitted to false.

If you're using mat-error you may find it easier to create your own ErrorStateMatcher (simple interface) for custom logic if this is an issue.

Also note that ErrorStateMatcher is only in angular material - and not a part of standard angular forms.

Answer 4

04-06-2020: Ionic 5+ and Angular 9+

Just a single line. i.e. this.form.reset();

Resets the FormGroup, marks all descendants are marked pristine and untouched, and the value of all descendants to null.

 form: FormGroup;

 constructor(private formBuilder: FormBuilder, ) { }

  resetTheForm(): void {
    this.form.reset();
  }

Answer 5

For reactive forms what worked for me when using angular 7: was to use template-driven form and pass it via the form submit handler like so

// component.html
 <form #f="ngForm" [formGroup]="form" (ngSubmit)="onSubmit(f)" novalidate>
 ....
</form>


// component.ts

onSubmit(form: NgForm) {

// reset form here
 form.form.markAsPristine();
 form.resetForm();
}

It will reset the form and the submitted state to default.

Answer 6

Adding a another answers, if you have a disabled input in your form, use getRawValue() as a parameter of ngForm.resetForm(). See the sample:

in HTML:

<form
  (ngSubmit)="formSubmit(myForm)"
  #myForm="ngForm"
>
    ...
</form>

in .TS:

formSubmit(myForm: NgForm) {
   myForm.resetForm(myForm.form.getRawValue());
}

Answer 7

Some time this.myForm.reset(this.myForm.value); may not reset to initial values So it is better to create a separate function to initialize the form and call it in ngOnInit() and before call this.myForm.reset(this.myForm.value);

ngOnInit(){
  myFormValues();
}

myFormValues() {
  this.myForm= this.fb.group({
      id: ['', Validators.required],
      name: ['', Validators.required],
    });
}

submitForm() {
  // save data
  myFormValues();
  this.myForm.reset(this.myForm.value)
}