---
title: "Explain the Custom validation in AngularJS"
description: "Let's understand custom validation in Angularjs, how it works, and how you can create your own validation."
author: "Ashutosh Patel"
published: 2025-04-23
updated: 2025-11-05
canonical: https://www.mindstick.com/articles/339110/explain-the-custom-validation-in-angularjs
category: "angular js"
tags: ["angular js", "angularJS form"]
reading_time: 2 minutes
---
# Explain the Custom validation in AngularJS
AngularJS has built-in validation (such as `required`, `email`, `minlength`, etc.), but **[custom validation](https://www.mindstick.com/forum/1973/custom-validation-attribute)** allows you to,
- Define your own logic for [input validation](https://www.mindstick.com/forum/1335/input-validation-and-ui-exceptions-with-mvvm-light).
- Display custom [error messages](https://answers.mindstick.com/qa/99815/how-can-you-diagnose-and-resolve-issues-with-application-crashes-or-error-messages).
- Integrate with AngularJS's form validation conditions.
#### How Validation Works in AngularJS
Angular uses [directives](https://www.mindstick.com/articles/336201/directives-in-angularjs) and validation conditions such as given below,
`$valid`, `$invalid`, `$touched`, `$dirty`, etc. You can create a **[custom directive](https://www.mindstick.com/articles/335813/create-custom-directive-in-angularjs)** to plug your own validation logic into this system.
**Example:** Validate that a username does not contain spaces
```html
Angular Custom Validation
```
## Summary
`no-space`: [Custom attribute](https://www.mindstick.com/interview/492/how-do-you-specify-a-custom-attribute-for-the-entire-assembly-rather-than-for-a-class) directive
`ctrl.$validators.noSpace`: [Register](https://answers.mindstick.com/qa/49005/what-year-was-cash-register-invented-and-how) a new [validator](https://www.mindstick.com/interview/598/give-the-details-of-xml-files-used-in-validator-framework)
`value.indexOf(' ') === -1;`: Return `false` if space found.
`userForm.username.$error.noSpace`: Error shown if [validation fails](https://www.mindstick.com/forum/34291/how-to-raise-a-callback-when-asp-dot-net-mvc-client-validation-fails)
**Also, read:** [Form Validation in Angularjs](https://www.mindstick.com/articles/336202/form-validation-in-angularjs)
---
Original Source: https://www.mindstick.com/articles/339110/explain-the-custom-validation-in-angularjs
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