将PHP电子邮件验证添加到变量样式的代码中

Question

Simply, I found this code to validate email:

filter_var($user_email, FILTER_VALIDATE_EMAIL)

But unfortunately I don't know how to add this to my PHP code that get info from the form:

<?php $name = $_POST['name'];
    $email = $_POST['email'];
    $message = $_POST['message'];
    $formcontent="From: $name \n Message: $message";
    $recipient = "example@example.com";
    $subject = "Contact Form";
    $mailheader = "From: $email \r\n";
    mail($recipient, $subject, $formcontent, $mailheader) or die("Error!");
?>

I used Ajax to get form's submitted information.

Answer 1

You can use filter_input function. This function will check if email argument has been sent in the POST request and if it has been, then it will validate it and return validated email or FALSE. Do it like this:

<?php 
    $email = filter_input( INPUT_POST, 'email', FILTER_VALIDATE_EMAIL );
    if ( $email ) {
        $name = $_POST['name'];
        $message = $_POST['message'];
        $formcontent="From: $name \n Message: $message";
        $recipient = "example@example.com";
        $subject = "Contact Form";
        $mailheader = "From: $email \r\n";
        mail($recipient, $subject, $formcontent, $mailheader) or die("Error!");
    } else {
        die("Email is ivalid!")
    }
?>

Answer 2

You can use it like this:

<?php
    if(filter_var($_POST['email'], FILTER_VALIDATE_EMAIL)){
        $email = $_POST['email'];
        $message = $_POST['message'];
        $formcontent="From: $name \n Message: $message";
        $recipient = "example@example.com";
        $subject = "Contact Form";
        $mailheader = "From: $email \r\n";
        mail($recipient, $subject, $formcontent, $mailheader) or die("Error!");

    } else {
        header("Location: your_form.html");

    }

If you're gonna insert this to a database it'll be good to sanitize your data with mysql_real_escape_string

Also display a good message when the email is wrong.

Answer 3

<?php 

    //if the form has been submitted
    if ( isset($_POST['submit']) ) {
        $name = $_POST['name'];
        $user_email = $_POST['email'];
        $message = $_POST['message'];

        //if user's email is not empty and is valid, send mail
        if ( !empty($user_email) && filter_var($user_email, FILTER_VALIDATE_EMAIL) ) {
            $formcontent="From: $name \n Message: $message";
            $recipient = $user_email;
            $subject = "Contact Form";
            $mailheader = "From: youremail@example.com \r\n";
            mail($recipient, $subject, $formcontent, $mailheader) or die("Error!");
        } else {
            //show error
            exit("Your email seems to be invalid.");
        }
    }

?>

Answer 4

If what you need is a good PHP function that checks that the input is a valid email address, you can use this:

function validateEmail($email) {
$e = false;
if ((trim ( $email )) == "") {
    $e = true;
} elseif (strlen ( $email ) > 40) {
    $e = true;
} elseif (! ((strpos ( $email, "." ) > 0) && (strpos ( $email, "@" ) > 0)) || preg_match ( "/[^a-zA-Z0-9.@_-]/", $email )) {
    $e = true;
}
return !$e;
}

As you see it limits email length to 40 characters.