PHP Form URL and E-mail Validation

What is URL and E-mail Validation?

URL and E-mail validation ensures that the data provided by users in the respective fields conforms to the proper format. This is crucial for processing URLs and sending emails accurately.

Why Validate URL and E-mail?

• Data Integrity: Ensures the data is in a usable format.
• User Experience: Provides instant feedback to users for correcting input.
• Security: Helps prevent issues related to invalid or malicious input.

Basic Form Example with URL and E-mail Validation

Here’s a simple HTML form that requires a user's e-mail and website URL:

<form action="form-url-email.php" method="post">
    <label for="email">E-mail:</label>
    <input type="email" id="email" name="email" required>

    <label for="url">Website URL:</label>
    <input type="url" id="url" name="url" required>

    <input type="submit" value="Submit">
</form>

Implementing URL and E-mail Validation in PHP

You can validate URL and E-mail when the form is submitted:

<?php
$emailErr = $urlErr = "";
$email = $url = "";

// Validate when the form is submitted
if ($_SERVER["REQUEST_METHOD"] == "POST") {
    // Check if E-mail is valid
    if (empty($_POST["email"])) {
        $emailErr = "E-mail is required.";
    } else {
        $email = htmlspecialchars(trim($_POST["email"]));
        if (!filter_var($email, FILTER_VALIDATE_EMAIL)) {
            $emailErr = "Invalid e-mail format.";
        }
    }

    // Check if URL is valid
    if (empty($_POST["url"])) {
        $urlErr = "Website URL is required.";
    } else {
        $url = htmlspecialchars(trim($_POST["url"]));
        if (!filter_var($url, FILTER_VALIDATE_URL)) {
            $urlErr = "Invalid URL format.";
        }
    }
}
?>

Displaying Error Messages

You can display error messages to let users know which fields are invalid:

<?php
if ($_SERVER["REQUEST_METHOD"] == "POST") {
    if (!empty($emailErr)) {
        echo "<p class='text-red-500'>" . $emailErr . "</p>";
    }
    if (!empty($urlErr)) {
        echo "<p class='text-red-500'>" . $urlErr . "</p>";
    }
}
?>

Full Example

Here’s a complete example of a form with URL and E-mail validation:

<?php
$emailErr = $urlErr = "";
$email = $url = "";

if ($_SERVER["REQUEST_METHOD"] == "POST") {
    if (empty($_POST["email"])) {
        $emailErr = "E-mail is required.";
    } else {
        $email = htmlspecialchars(trim($_POST["email"]));
        if (!filter_var($email, FILTER_VALIDATE_EMAIL)) {
            $emailErr = "Invalid e-mail format.";
        }
    }

    if (empty($_POST["url"])) {
        $urlErr = "Website URL is required.";
    } else {
        $url = htmlspecialchars(trim($_POST["url"]));
        if (!filter_var($url, FILTER_VALIDATE_URL)) {
            $urlErr = "Invalid URL format.";
        }
    }
}
?>

<form action="" method="post">
    <label for="email">E-mail:</label>
    <input type="email" id="email" name="email" value="<?php echo $email; ?>" required>
    <p class='text-red-500'><?php echo $emailErr; ?></p>

    <label for="url">Website URL:</label>
    <input type="url" id="url" name="url" value="<?php echo $url; ?>" required>
    <p class='text-red-500'><?php echo $urlErr; ?></p>

    <input type="submit" value="Submit">
</form>

Conclusion

Validating URL and E-mail fields in your PHP forms is essential for ensuring that users provide the correct format. This helps enhance user experience and prevents errors in processing the data.