Angular form submit event firing twice between parent and child components

Question

I have a strange problem where by the form submit event of my child form is firing twice on my parent form.

child.component.html

<form [formGroup]="childForm" (ngSubmit)="childFormSubmit()">
  ...
</form>

child.component.ts

@Component({
  selector: 'child-form',
  templateUrl: 'login.component.html',
})

export class ChildComponent {
  @Output() submit = new EventEmitter<any>();

  public childForm: FormGroup;

  childFormSubmit() {
    if (this.childForm.valid) {
      console.log('Child Form Submit')
      this.submit.emit(this.childForm.value);
    }
  }
}

parent.component.html

<child-form (submit)="parentSubmit($event)"></child-form>

parent.component.ts

@Component({
  selector: 'parent',
  templateUrl: 'parent.component.html',
})

export class ParentComponent {

  constructor() {
  }

  parentSubmit(event: any) {
    console.log('Parent Submit');
  }
}

Submitting the child form results in the following in the console output:

Child Form Submit
Parent Submit
Parent Submit

Solution

You have used a reserved word 'submit' on child component as decorator function and attribute. So if you have a form in a parent component, (submit) (which is equivalent of (ngSubmit)) is fired at the same time as the event from the child. Change it for something else, like this:

<child-form (childSubmit)="parentSubmit($event)"></child-form>

and in child component:

 @Output() childSubmit = new EventEmitter<any>();
 ...
 childFormSubmit() {
   if (this.childForm.valid) {
         console.log('Child Form Submit')
         this.childSubmit.emit();
   }
 }

Here is a working DEMO