Difference between FormControl and FormGroup

Angular provides powerful tools for handling forms, with FormControl and FormGroup being fundamental building blocks. While both serve similar purposes, they have distinct roles and functionalities within Angular applications. In this article, we'll learn more about FormControl and FormGroup and will also see the differences between them.

Steps to Create Angular Application

Step 1: Create a basic angular application

ng new my-app

Step 2: Move to the project directory.

cd my-app

Step 3: Start the application using the following command.

ng serve --open

Folder Structure:

The updated Dependencies in package.json file.

  "dependencies": {
    "@angular/animations": "^17.2.0",
    "@angular/common": "^17.2.0",
    "@angular/compiler": "^17.2.0",
    "@angular/core": "^17.2.0",
    "@angular/forms": "^17.2.0",
    "@angular/platform-browser": "^17.2.0",
    "@angular/platform-browser-dynamic": "^17.2.0",
    "@angular/platform-server": "^17.2.0",
    "@angular/router": "^17.2.0",
    "@angular/ssr": "^17.2.3",
    "express": "^4.18.2",
    "ngx-webstorage": "^13.0.1",
    "rxjs": "~7.8.0",
    "tslib": "^2.3.0",
    "zone.js": "~0.14.3"
  }

FormControl

A FormControl represents a single form control element, such as an input field, a dropdown, or a checkbox. It tracks the value and validation status of that input field.

Syntax:

import { FormControl } from '@angular/forms';
const myFormControl = new FormControl('Initial Value', [Validators]);

Features:

• Tracks the value changes of a single form control.
• Provides built-in and custom validation for individual form controls.
• Emits value changes and validation status changes as observables.
• Can be used with directives like ngModel or formControlName in template-driven or reactive forms.
• Supports synchronous and asynchronous validators for real-time validation.

Example:

JavaScript

//app.component.ts

import { Component } from '@angular/core';
import { FormControl } from '@angular/forms';

@Component({
    selector: 'app-root',
    template: `
    <input type="text" [formControl]="myControl">
    <p>Value: {{ myControl.value }}</p>
  `
})
export class AppComponent {
    myControl = new FormControl('Initial Value');
}

Output:

FormControl Output

FormGroup

A FormGroup represents a collection of form controls as a single unit, allowing you to manage and validate multiple form controls together. It's used to group related form controls together.

Syntax:

import { FormGroup, FormControl } from '@angular/forms';

const myFormGroup = new FormGroup({
  control1: new FormControl('Value 1'),
  control2: new FormControl('Value 2')
});

Features:

• Groups related form controls together for easier management.
• Tracks the value and validity of the entire group of form controls.
• Can be nested to create hierarchical forms.
• Provides methods to retrieve form control values and set their values programmatically.
• Supports validation at the group level, in addition to individual control validation.

Example:

JavaScript

//app.component.ts

import { Component } from '@angular/core';
import { FormGroup, FormControl } from '@angular/forms';

@Component({
    selector: 'app-root',
    template: `
    <form [formGroup]="myForm">
      <input type="text" formControlName="name">
      <input type="text" formControlName="email">
      <p>Form Value: {{ myForm.value | json }}</p>
    </form>
  `
})
export class AppComponent {
    myForm = new FormGroup({
        name: new FormControl('Batman'),
        email: new FormControl('bruce.wayne@dc.inc')
    });
}

Output:

FormGroup Output

Differences Between FormControl and FormGroup

Feature	FormControl	FormGroup
Representation	Single form control element	Group of form controls
Value Access	Provides access to the control's value	Provides access to values of all controls in the group
Validation	Can have synchronous and asynchronous validators	Can have synchronous and asynchronous validators for the entire group
Nested Structure	Cannot contain nested form controls	Can contain nested FormGroups and FormArrays
Event Observables	Provides value changes and status changes for the control	Provides value changes and status changes for the entire group

Conclusion

In Angular forms, FormControl and FormGroup play distinct roles in managing form controls and their validation. While FormControl is used for individual form controls, FormGroup is used to group related controls together. Understanding the differences between FormControl and FormGroup is important for effectively designing and implementing forms in Angular applications, ensuring better organization, validation, and user interaction.