How to stop form from sending empty or wrong data? - php

Question

I have just now completed building this form and it is running quite well, thanks to the user community of stackoverflow; but I have now noticed an issue with my form while testing it in different scenarios.
The major problem is that it is sending information regardless of any information being present and regardless of whether the user has entered correct data. The error is showing up on the page, but the data is being sent, even when error is being displayed on the page.
I want to find out how to stop the form from sending an E-mail, when the fields are empty or have wrong content entered into them?
Here is the PHP code, I am using:
<?php
function test_input($data){
$data = trim($data);
$data = stripslashes($data);
$data = htmlspecialchars($data);
return $data;
}
function clean_string($string) {
$bad = array("content-type","bcc:","to:","cc:","href");
return str_replace($bad,"",$string);
}
// define variables and set to empty values
$first_nameErr = $last_nameErr = $emailErr = $overviewErr = "";
$first_name = $last_name = $email = $overview = "";
if(isset($_POST['email'])) {
$email_to = "myself#mydomain.com";
$email_subject = "Contact us - My company's name";
{
if (empty($_POST["first_name"]))
{$first_nameErr = "(First Name is required)";}
else
{$first_name = test_input($_POST["first_name"]);
// check if name only contains letters and whitespace
if (!preg_match("/^[a-zA-Z ]*$/",$first_name))
{
$first_name = "(Only letters and white space allowed)";
}
}
if (empty($_POST["last_name"]))
{$last_nameErr = "(Last Name is required)";}
else
{$last_name = test_input($_POST["last_name"]);
// check if name only contains letters and whitespace
if (!preg_match("/^[a-zA-Z ]*$/",$last_name))
{
$last_name = "(Only letters and white space allowed)";
}
}
if (empty($_POST["email"]))
{$emailErr = "(Email ID is required)";}
else
{$email = test_input($_POST["email"]);
// check if e-mail address syntax is valid
if (!preg_match("/([\w\-]+\#[\w\-]+\.[\w\-]+)/",$email))
{
$emailErr = "(Invalid email format)";
}
}
if (empty($_POST["overview"]))
{$overviewErr = "(Overview is required)";}
else
{$overview = test_input($_POST["overview"]);
// check if name only contains letters and whitespace
if (!preg_match("/^[a-zA-Z ]*$/",$overview))
{
$overview = "(Only letters and white space allowed)";
}
}
}
//Email & SEND INFO
$email_message = "Form details below.\n\n";
$email_message .= "First Name: ".clean_string($first_name)."\n";
$email_message .= "Last Name: ".clean_string($last_name)."\n";
$email_message .= "Email: ".clean_string($email)."\n";
$email_message .= "Services: ".clean_string(implode(', ', $service))."\n";
$email_message .= "Overview: ".clean_string($overview)."\n";
// create email headers
$headers = 'From: '.$email_from."\r\n".
'Reply-To: '.$email_from."\r\n" .
'X-Mailer: PHP/' . phpversion();
mail($email_to, $email_subject, $email_message, $headers);
?>
<!-- Success HTML -->
Thank you for contacting us. We will be in touch with you very soon.
<?php
}
?>

Answer 1

I believe you are wanting to stop the form from sending any data if there is nothing to send in the forms, right? If so then you need to do that via javascript. The easiest way would be with jquery. I suggest This tutorial. That will help you get off the ground

Answer 2

I think your code blocks might be incorrect try this:
<?php
function test_input($data) {
$data = trim($data);
$data = stripslashes($data);
$data = htmlspecialchars($data);
return $data;
}
function clean_string($string) {
$bad = array("content-type","bcc:","to:","cc:","href");
return str_replace($bad,"",$string);
}
// define variables and set to empty values
$first_nameErr = $last_nameErr = $emailErr = $overviewErr = "";
$first_name = $last_name = $email = $overview = "";
if(isset($_POST['email'])) {
$email_to = "myself#mydomain.com";
$email_subject = "Contact us - My company's name";
}
if (empty($_POST["first_name"])) {
$first_nameErr = "(First Name is required)";
} else {
$first_name = test_input($_POST["first_name"]);
}
// check if name only contains letters and whitespace
if (!preg_match("/^[a-zA-Z ]*$/",$first_name)) {
$first_name = "(Only letters and white space allowed)";
}
if (empty($_POST["last_name"])) {
$last_nameErr = "(Last Name is required)";
} else {
$last_name = test_input($_POST["last_name"]);
}
// check if name only contains letters and whitespace
if (!preg_match("/^[a-zA-Z ]*$/",$last_name)) {
$last_name = "(Only letters and white space allowed)";
}
if (empty($_POST["email"])) {
$emailErr = "(Email ID is required)";
} else {
$email = test_input($_POST["email"]);
}
// check if e-mail address syntax is valid
if (!preg_match("/([\w\-]+\#[\w\-]+\.[\w\-]+)/",$email)) {
$emailErr = "(Invalid email format)";
}
if (empty($_POST["overview"])) {
$overviewErr = "(Overview is required)";
} else {
$overview = test_input($_POST["overview"]);
}
// check if name only contains letters and whitespace
if (!preg_match("/^[a-zA-Z ]*$/",$overview)) {
$overview = "(Only letters and white space allowed)";
}
//Email & SEND INFO
$email_message = "Form details below.\n\n";
$email_message .= "First Name: ".clean_string($first_name)."\n";
$email_message .= "Last Name: ".clean_string($last_name)."\n";
$email_message .= "Email: ".clean_string($email)."\n";
$email_message .= "Services: ".clean_string(implode(', ', $service))."\n";
$email_message .= "Overview: ".clean_string($overview)."\n";
// create email headers
$headers = 'From: '.$email_from."\r\n".
'Reply-To: '.$email_from."\r\n" .
'X-Mailer: PHP/' . phpversion();
mail($email_to, $email_subject, $email_message, $headers);
if ($first_nameErr || $last_nameErr || $emailErr || $overviewErr) {
echo "Thank you for contacting us. We will be in touch with you very soon.";
} else {
echo "There are some errors in your form: " . $first_nameErr . ', ' . $last_nameErr . ', ' . $emailErr . ', ' . $overviewErr;
}
Not sure if that'll fix everything but it should be easier to see what's going on.