how to trigger a validation of child component from parent component OnSubmit Angular 4?

Question

I Have forms like this, in parent i am including multiple child components each child component is formgroup. now i need to check all this child forms validation on parent form when user click OnSubmit.

How should i trigger child form validations from parent on submit. I have used FormBuilder in each childcomponent.

I am able to do validation when user click on child fields but if user doesn't enter anything or touched anything and try to submit validations not showing errors.

parent.component.html

<form>
    <child1></child1>
    <child2></child2>
    <child3></child4>
    <child4></child4>
''''
''''
''''
</form>

child1.component.html

<div formgroup="child1group">
      <div formarray= "child1array">
      ....
      ...
      ...
      </div>
</div

child2.component.html

<div formgroup="child2group">
      <div formarray= "child2array">
      ....
      ...
      ...
      </div>
</div

please someone tell me how to do this validation on angular 4 ?

Munna Babu Munna Babu · Accepted Answer · 2017-11-14T09:39:19

Pass the Formcontrol to Parent as OUTPUT and then do validation by calling function SaveConsole() in button click

child1.component.ts

@Output() public childControls = new EventEmitter();

 public ngOnInit() {
        this.childControls.emit(this.child1group);   
        this.child1group.valueChanges.subscribe(() => {
            this.childControls.emit(this.child1group);
        });
  }

parent.component.html

   <form>
        <child1 (childControls)="child1Control = $event"></child1>
         <button (Click)=SaveConsole()> Submit </butto>
   </form>

parent.ts

   public child1Control: FormGroup;
   public SaveConsole() {
          if (this.child1Control.valid) {
            // SAVE FORM
          } else {
            this.validateAllFormFields(this.child1Control);  
          }
      }
     public validateAllFormFields(formGroup: FormGroup) {
      Object.keys(formGroup.controls).forEach(field => {
      const control = formGroup.get(field);
      if (control instanceof FormControl) {
        control.markAsTouched({ onlySelf: true });
      } else if (control instanceof FormGroup) {
        this.validateAllFormFields(control);
      }
    });
}

how to trigger a validation of child component from parent component OnSubmit Angular 4?

1 Answers