Email Validation in Angular 4

Steve clarckson -

Angular 4 is a popular JavaScript framework that is used for building web
applications. One of the features of Angular 4 is email validation, which is
important for ensuring that users enter valid email addresses. In this
article, we will explore email validation in Angular 4 and answer some of the
most commonly asked questions about this topic.

What is Email Validation?

Email validation is the process of checking if an email address is valid or
not. An email address is considered valid if it conforms to the syntax rules
of the email protocol. These rules specify the format of email addresses and
the characters that are allowed in them. Email validation is important for
ensuring that users enter valid email addresses when filling out forms or
registering for services.

Why is Email Validation Important?

Email validation is important for several reasons:

  • Preventing typos: Email validation can help prevent users from entering incorrect email addresses due to typos or other errors.
  • Preventing fraud: Email validation can help prevent fraud by ensuring that users enter valid email addresses that can be verified.
  • Improving user experience: Email validation can improve the user experience by providing immediate feedback if an email address is invalid.

Email Validation in Angular 4


Angular 4 provides several built-in validators for validating form input. One
of these validators is the EmailValidator, which can be used to validate email
addresses. To use the EmailValidator, you need to import it from the
@angular/forms module:

import { Validators } from '@angular/forms';export class MyComponent {emailFormControl = new FormControl('', [Validators.required,Validators.email,]);}

In the example above, we create a FormControl for the email input field and
add two validators to it: Validators.required and Validators.email. The
Validators.email validator uses the EmailValidator to validate the input as an
email address.

Custom Email Validation

You can also create custom validators to validate email addresses according to
your own requirements. To create a custom validator, you need to define a
function that takes a FormControl as input and returns an object that
indicates whether the input is valid or not:

export function emailValidator(control: FormControl): {[key: string]: any} | null {const emailRegex = /^[a-z0-9._%+-]+@[a-z0-9.-]+\.[a-z]{2,}$/i;const valid = emailRegex.test(control.value);return valid ? null : { 'invalidEmail': true };}export class MyComponent {emailFormControl = new FormControl('', [Validators.required,emailValidator,]);}

In the example above, we define a custom emailValidator function that uses a
regular expression to validate the input as an email address. We then add the
custom validator to the email input field along with the required validator.

Conclusion

Email validation is an important feature for web applications, and Angular 4
provides built-in support for email validation through the EmailValidator. You
can also create custom validators to validate email addresses according to
your own requirements. By using email validation, you can improve the user
experience and prevent errors and fraud.