Email Validation in flutter

Introduction

In real-world applications, email addresses are very important for identity verification, communication, and information sharing. Email validation is very important to make sure that the application is a safe place for its users. In Flutter, we can achieve this by either writing regex or using packages such as email_validator.

Using RegExp

We can use regex to validate emails. In Flutter, we've got this class called 'RegExp' for this purpose.

    bool isEmailValid(String email) {
      String emailPattern = r"^[a-zA-Z0-9.a-zA-Z0-9.!#$%&'*+-/=?^_`{|}~]+@[a-zA-Z0-9]+\.[a-zA-Z]+";
      RegExp regExp = new RegExp(emailPattern);
      return regExp.hasMatch(email);
    }
                    

Using email_validator

We can use the email_validator package, which provides us with utility functions to validate emails.

Add the email_validator package to your pubspec.yaml file.

    dependencies:
      flutter:
        sdk: flutter
      email_validator: '^2.1.16'
                    

And then you can use it like this

    import 'package:email_validator/email_validator.dart';

    bool isEmailValid(String email) {
      return EmailValidator.validate(email);
    }
                    

Using Flutter Form Validation

We can use built-in form validation mechanisms to validate email addresses. Flutter's TextFormField widget provides a validator parameter, which we can use to define a validation function.

    TextFormField(
      keyboardType: TextInputType.emailAddress,
      decoration: InputDecoration(labelText: 'Email'),
      validator: (value) {
        if (value.isEmpty) {
          return 'Please enter an email address';
        }
        if (!isEmailValid(value)) {
          return 'Please enter a valid email address';
        }
        return null;
      },
    )
                    

Output:

What is Email Validation?

Email validation is the process of identifying the legitimacy of the email address provided by the user. As developers, we should always make sure that the input we get from users is sanitized properly to make sure there are fewer inconsistencies in the data.

Process for email validation:

• Syntax Check: The most basic form of validation that can happen on both the client and server sides is a syntax check. In syntax check, we check whether the email is in the proper format or not. For example, check if it contains '@'.
• Domain Verification: After confirming the syntax, we check if the email has a valid domain by verifying it through DNS (Domain Name Service) records for a valid MX (Mail Exchange) record.
• Disposable Email Address Check: There are many services that provide users with a disposable email address that can be used to send and receive emails. If a system doesn't have a proper disposable mail check in place, then there are high chances that there might be some fraudulent and spam users. In order to tackle this issue, we might need to check the email address through some known disposable email providers and block them from registering.
• Role-based Email Check: There might be instances where a user might want to register an account using emails such as info@flutteradda.com or support@flutteradda.com. Although these emails are valid, this might not be suitable for some services that rely on one-to-one communication. Our validation process must flag these types of emails and reject them if they do not meet the criteria.
• Real-time Verification: Real-time verification of an email address is a very reliable form of validation. In this process, an OTP, a secret code, or a link is sent to the email address provided by the user. This process is reliable and has lower spam rates.

The Importance of Email Validation

• Data Integrity: Validation email addresses while onboarding a user or authenticating a user help us to ensure that the data being collected is accurate and reliable, hence can be used for communication and marketing purposes.
• User Experience: Validating email addresses on the client side improves the user experience of our applications as it helps users get real-time feedback on their input.
• Security: Various security risks can be reduced once we implement a proper validation mechanism. Security risks such as spam, phishing attacks, and account takeover attempts can be easily mitigated.
• Communication: Validation helps the company or individual behind an application communicate with their users effectively and grow their community.
• Compliance: GDPR (General Data Protection Regulation) advises us to implement proper validation for personal information.

Overall, email validation is an essential step in data processing workflows, ensuring data accuracy, enhancing the user experience, bolstering security measures, and facilitating compliance with regulations.