What is the best approach to handling an undefined quantity of input FormControls within Angular?

Question

What is the best approach to handling an undefined quantity of input FormControls within Angular?

I have a unique task in my Angular application where I need to collect an unspecified number of entries, such as names, into a list.

My goal is to convert this list of names into an array. To facilitate this process, I would like to offer users the ability to input their names using an input field.

Each time a user inputs a name, I want it to be validated and added to the names array, while simultaneously displaying a new blank input field for the next entry.

Based on my understanding, I believe I will require an array of FormControls within my FormGroup. How can I correctly reference each element by form control name in my HTML form?

angular typescript angular-reactive-forms

Answer 1

Answer №1

To begin, ensure that your form model contains a formArray to store names:

this.form = this.formBuilder.group({ names: this.formBuilder.array([]) })

If form is your main form group, you can create a button to add a new name control:

<button type="button" (click)="addNameControl()">Add Name</button>

The function triggered by the button click should look like this:

addNameControl(): void { (this.form.get('names') as FormArray).push(this.formBuilder.control('')) }

If validation is needed, it can be performed during submission by iterating over controls and checking values or using Validators when setting up the control.

Your final HTML structure would be:

<div [formGroup]="form">
  <div formArrayName="names">
    <div *ngFor="let name of names.controls">
      <input type="text" [formControl]="i">
    </div>
  </div>
</div>

Answer 2

To begin, ensure that your form model contains a formArray to store names:

this.form = this.formBuilder.group({ names: this.formBuilder.array([]) })

If form is your main form group, you can create a button to add a new name control:

<button type="button" (click)="addNameControl()">Add Name</button>

The function triggered by the button click should look like this:

addNameControl(): void { (this.form.get('names') as FormArray).push(this.formBuilder.control('')) }

If validation is needed, it can be performed during submission by iterating over controls and checking values or using Validators when setting up the control.

Your final HTML structure would be:

<div [formGroup]="form">
  <div formArrayName="names">
    <div *ngFor="let name of names.controls">
      <input type="text" [formControl]="i">
    </div>
  </div>
</div>

Answer 3

Answer №2

Suppose you have a FormGroup named myForm. If you want to make it accessible publicly, you can include the following code snippet in your HTML file:

    <span *ngFor="let item of formControls">
              <input id="{{item}}"
                     type="text"
                     formControlName="myForm.get(item)"
                     class="form-control" />
    </span>

Answer 4

Suppose you have a FormGroup named myForm. If you want to make it accessible publicly, you can include the following code snippet in your HTML file:

    <span *ngFor="let item of formControls">
              <input id="{{item}}"
                     type="text"
                     formControlName="myForm.get(item)"
                     class="form-control" />
    </span>

What is the best approach to handling an undefined quantity of input FormControls within Angular?

Answer №1

Answer №2

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