Form Email Validation in backend PHP - php

Question

I am using a form to get newsletter sign ups on my website. I am using a contact.php file which works well but there is no validation so I occasionaly and sometimes frequently get blank responses.
I'm not sure why this is, but I believe I need validation.
This is my original code
<?php
/*
Author: Andrew Walsh
Date: 30/05/2006
Codewalkers_Username: Andrew
This script is a basic contact form which uses AJAX to pass the information to php, thus making the page appear to work without any refreshing or page loading time.
*/
$to = "hello#interzonestudio.com"; //This is the email address you want to send the email to
$subject_prefix = ""; //Use this if you want to have a prefix before the subject
if(!isset($_GET['action']))
{
die("You must not access this page directly!"); //Just to stop people from visiting contact.php normally
}
/* Now lets trim up the input before sending it */
$subject = "Newsletter Sign Up"; //The senders subject
$message = trim($_GET['email']); //The senders subject
$email = trim($_GET['email']); //The senders email address
mail($to,$subject,$message,"From: ".$email.""); //a very simple send
echo 'contactarea|Thank you. We promise you won’t regret it.'; //now lets update the "contactarea" div on the contact.html page. The contactarea| tell's the javascript which div to update.
?>
and this is the code I tried to add to validate but it doesnt work.
<?php
/*
Author: Andrew Walsh
Date: 30/05/2006
Codewalkers_Username: Andrew
This script is a basic contact form which uses AJAX to pass the information to php, thus making the page appear to work without any refreshing or page loading time.
*/
$to = "jcash1#gmail.com"; //This is the email address you want to send the email to
$subject_prefix = ""; //Use this if you want to have a prefix before the subject
if(!isset($_GET['action']))
{
die("You must not access this page directly!"); //Just to stop people from visiting contact.php normally
}
/* Now lets trim up the input before sending it */
$subject = "Newsletter Sign Up"; //The senders subject
$message = trim($_GET['email']); //The senders subject
$email = trim($_GET['email']); //The senders email address
/* Validation */
$error=0; // check up variable
$errormsg = '<ul class="errorlist">';
/* get it checking */
if(!check_email($email))
{
$errormsg.= "<li class='errormessage'>ERROR: not a valid email.</li>";
$error++;
}
$errormsg .= '</ul>';
if($error == 0) {
mail($to,$subject,$message,"From: ".$email.""); //a very simple send
echo 'contactarea|Thank you. We promise you won’t regret it.'; //now lets update the "contactarea" div on the contact.html page. The contactarea| tell's the javascript which div to update.
} else {
echo 'error|'. $errormsg;
}
?>
Can anyone offer some insight?
I cannot for the life of me get this to work...
I am getting an Error with the plugin and I have loaded it correctly
so I tried adding this :
if (filter_var($email, FILTER_VALIDATE_EMAIL) === true) {
//your email sending code here
} else {
echo("$email is not a valid email address");
}
like so:
<?php
/*
Author: Andrew Walsh
Date: 30/05/2006
Codewalkers_Username: Andrew
This script is a basic contact form which uses AJAX to pass the information to php, thus making the page appear to work without any refreshing or page loading time.
*/
$to = "hello#interzonestudio.com"; //This is the email address you want to send the email to
$subject_prefix = ""; //Use this if you want to have a prefix before the subject
if(!isset($_GET['action']))
{
die("You must not access this page directly!"); //Just to stop people from visiting contact.php normally
}
/* Now lets trim up the input before sending it */
if (filter_var($email, FILTER_VALIDATE_EMAIL) === true) {
$subject = "Newsletter Sign Up"; //The senders subject
$message = trim($_GET['email']); //The senders subject
$email = trim($_GET['email']); //The senders email address
mail($to,$subject,$message,"From: ".$email.""); //a very simple send
echo 'contactarea|<div id="thanks">Thank you. We promise you won’t regret it.</div>'; //now lets update the "contactarea" div on the contact.html page. The contactarea| tell's the javascript which div to update.
} else {
echo("$email is not a valid email address");
}
?>
Which is not working. I think it is beauce I have implemented the code in the wrong place but I am not sure. Any help would be greatly appreciated.

Answer 1

You can use filter_var() function in PHP for validating email addresses.
For simply validating email addresses in PHP you can use it like this,
if(filter_var($email, FILTER_VALIDATE_EMAIL)){
echo "Valid email";
}
And your code can be improved like this.
if(filter_var($email, FILTER_VALIDATE_EMAIL)){
mail($to,$subject,$message,"From: ".$email.""); //a very simple send
echo 'contactarea|Thank you. We promise you won’t regret it.'; //now lets update the "contactarea" div on the contact.html page. The contactarea| tell's the javascript which div to update.
}
else {
$errormsg.= "<li class='errormessage'>ERROR: not a valid email.</li>";
$error++;
echo '</ul> error|'. $errormsg;
}
If you want to know more about it, visit official PHP documentation page here : http://php.net/manual/en/filter.filters.validate.php

Answer 2

Or use jquery validation plugin. I highly recommend it.
Code will look similar to below
$( "#myform" ).validate({
rules: {
field: {
required: true,
email: true
}
}
});

Answer 3

You can use server side validation by using this code
if (filter_var($email, FILTER_VALIDATE_EMAIL) === true) {
//your email sending code here
} else {
echo("$email is not a valid email address");
}