Angular, Disable submit button using [disabled] to check form validity

Question

I'm trying to disable a submit button using [disable]=form.controls[...].invalid condition checking. The submit button should be disabled if there is an input fields is empty or invalid. But looks like i'm doing it wrong. The button is disabled when i fill some fields and left some fields empty, except for the first input field . When i filled the first input field, the button become enabled (while the other input fields are still empty or invalid).

//component.ts
form01: FormGroup;
public myDatePickerOptions: IMyDpOptions = {
  dateFormat: 'dd-mmm-yyyy',
};

setDate(): void {
  let date = new Date();
  this.form01.patchValue({
    DoB: {
      date: {
        year: date.getFullYear(),
        month: date.getMonth() + 1,
        day: date.getDate()
      }
    }
  });
}

clearDate(): void {
  this.form01.patchValue({
    DoB: null
  });
}

constructor(public builder: FormBuilder) {
  this.form01 = this.builder.group({
    email: [null, Validators.required], //text
    DoB: [null, Validators.required], //radio button
    gender: [null, Validators.required], //date picker
  });
}

results: object = new Object();
functionForm01() {
  this.results = [{
    {
      "email": this.form01.controls.email.value
    },
    {
      "DoB": this.form01.controls.DoB.value
    },
    {
      "gender": this.form01.controls.gender.value
    }
  }]
  console.log(this.result);

  this.form01.reset();
}

<!--component.html-->
<div>
  <form [formGroup]="form01">
    email:<input type="text" name="email" formControlName="email" required/> gender:
    <input type="radio" name="gender" formControlName="gender" value="male"> male<br>
    <input type="radio" name="gender" formControlName="gender" value="female"> female<br> DoB:
    <my-date-picker name="DoB" [options]="myDatePickerOptions" formControlName="DoB" required></my-date-picker>

    <button type="submit" [disabled]="form01.controls['email' || 'DoB' || 'gender'].invalid" (click)="functionForm01()">Click</button>
  </form>
</div>

I'm using Angular typescript and myDatePicker package from this link. Can anyone help me please?

Lydon

Answer 1

You can enable/disable the button by checking the validity of your form:

<button type="submit" [disabled]="!disableBtn">Click</button>

Inside your component:

let disableBtn = false;
this. form01.valueChanges 
            .subscribe((changedObj: any) => {
                 this.disableBtn = this. form01.valid;
            });

Or via HTML:

<button type="submit" [disabled]="!form01.valid" (click)="functionForm01()">Click</button>

Frantz

property valid doesn't exist on type ()=> void – Lydon

FormGroup has that property ?? I using the valid & dirty check to show a save bar and enable/disable the save/cancel button. can you provide a plunkr or stackblitz.com ? – Frantz

Answer 2

Since you have your formGroup object, you can disable the button if form01 is not valid

<!--component.html-->
    <div>
      <form [formGroup]="form01">
        email:<input type="text" name="email" formControlName="email" required/> gender:
        <input type="radio" name="gender" formControlName="gender" value="male"> male<br>
        <input type="radio" name="gender" formControlName="gender" value="female"> female<br> DoB:
        <my-date-picker name="DoB" [options]="myDatePickerOptions" formControlName="DoB" required></my-date-picker>

    <button type="submit" [disabled]="!form01.valid" (click)="functionForm01()">Click</button>

      </form>
    </div>

Rectocele

so we dont need to check one by one? – Lydon

no, why you would like to check one by one? FormGroup will check for you one by one :) – Frantz

moohkooh is right, form01 contains all the controls and form01 is invalid if any of its controls are invalid. – Rectocele

Answer 3

<button type="submit" [disabled]=" form01.controls['email' ].invalid || form01.controls['DoB' ].invalid || form01.controls['gender' ].invalid " (click)="functionForm01()">Click</button>

Sydelle

Answer 4

You need to import FormsModule inside the app.module.ts under imports import { FormsModule, ReactiveFormsModule } from '@angular/forms';

@NgModule({
imports: [
     FormsModule      
])}

Absinthism