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Learn how to properly bind checkbox values to a FormControlName in Angular reactive forms for better user experience and data handling.
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How to Successfully Assign Checkbox Values to FormControlName in Angular

In the world of web development, forms are essential for collecting user data, and Angular makes this task easier with its powerful reactive forms. However, you might run into issues when trying to assign custom values from checkboxes to a FormControlName. In this guide, we will explore how to achieve this effectively.

The Problem

You've created a reactive form in Angular that includes a checkbox, but you're facing a challenge: the checkbox is only accepting true or false values, while you need it to return a custom string (e.g., the selected size value that should be displayed). This limitation can hinder your ability to gather the exact data you need from users.

Understanding Reactive Forms and Checkboxes

To better understand the solution, let's clarify a couple of key points regarding Angular reactive forms and how checkboxes work:

Reactive Forms: Angular provides a way to manage and validate forms using FormGroup, FormControl, and other directives.

Checkbox Behavior: By default, checkboxes return boolean values; however, they can be customized to return different values using binding.

The Solution

1. Avoid Using formControlName with value

One important realization is that you should not use formControlName along with a static value attribute on the checkbox. Instead, we will utilize Angular's property binding to properly bind the value we want.

2. Use Property Binding for Value

Instead of using the value attribute directly in the <mat-checkbox>, you need to utilize property binding:

[[See Video to Reveal this Text or Code Snippet]]

This will bind the value of the checkbox directly to the Angular variable selectedSizeValue.

3. Create a Function to Handle Checkbox Changes

Inside your component TypeScript file, implement a method to handle the change event of the checkbox. This is where you will assign the checkbox value to your FormControl.

Updated HTML Form:

[[See Video to Reveal this Text or Code Snippet]]

Updated Component TypeScript:

[[See Video to Reveal this Text or Code Snippet]]

4. Summary of Changes

Checkbox Value: Set using [value]="selectedSizeValue" which allows you to bind custom values instead of default boolean.

Checkbox Change Handling: GetStats($event) will extract the checkbox value whenever there's a change, and it will be stored in a variable (test).

Form Submission: On form submission, the selected value will be assigned to the FormControl, allowing you to collect and use the required data.

Conclusion

In this post, we've tackled the problem of assigning custom values from checkboxes to Angular FormControlNames. Using property binding and event handling effectively resolves the limitation of default checkbox behavior. By implementing these strategies, you'll enhance your forms and improve data collection in your Angular applications.

Implement these strategies and watch how your forms become more flexible and capable of handling user inputs more effectively!