How to validate form [duplicate] - php

Question

This question already has an answer here:
How to validate form in php
(1 answer)
Closed 8 years ago.
Anyone please help me on how to validate a form? I have the code, it is working ok..but I found that after I hit the submit button & php shows the errors, there is an input field, asking the user to answer the math Ques..when I enter the answer, then hit submit button again, it just says mail successfully sent, but other fields are still empty. Any ideas how to fix it. Also, the php value in the answerbox input tags, is not saving the text in box, it disappears. by the way, I got some help from other users, i'm a noob in php, so if you don't mind please explain.
Thanks for your time!
<form name="contact" action="formtest.php" method="post">
<label for="YourName">Your Name:</label>
<input type="text" name="name" class="required" value="<?= isset($_POST['name']) ? $_POST['name'] : '' ?>" />
<label for="YourEmail">Your Email:</label>
<input type="text" name="email" class="required" value="<?= isset($_POST['email']) ? $_POST['email'] : '' ?>"/>
<label for="Subject">Subject:</label>
<input type="text" name="subject" class="required" value="<?= isset($_POST['subject']) ? $_POST['subject'] : '' ?>" />
<label for="YourMessage">Your Message:</label>
<textarea name="message" class="required"><?= isset($_POST['message']) ? $_POST['message'] : '' ?></textarea>
<p class="c3">10 + 5 =<input type="text" name="answerbox" id="answerbox" "<?= isset($_POST['answerbox']) ? $_POST['answerbox'] : '' ?>"/></p>
<fieldset>
<input type="submit" name="submit" id="submit" value="Send" class="required"/>
<input type="reset" id="reset" value="Reset"/>
</fieldset>
<?php
if(isset($_POST['submit'])){
$name = trim($_POST["name"]);
$email = trim($_POST["email"]);
$subject = trim($_POST["subject"]);
$message = trim($_POST["message"]);
$answerbox = trim($_POST["answerbox"]);
if(empty($_POST['name'])){
print "<div class='formerrors'><li>Please type your name.</li></div>";
}
else {
if (ctype_alpha($name) === false) {
print "<div class='formerrors'><li>Your name only should be in letters!</li></div>";
}
}
if(empty($_POST['email'])){
print "<div class='formerrors'><li>You've forgot to type your email address.</li></div>";
} else{
if(filter_var($email, FILTER_VALIDATE_EMAIL) === false){
print "<div class='formerrors'><li>Your email is not valid, please check.</li></div>";
}
}
if(empty($_POST['subject'])){
print "<div class='formerrors'><li>Please type a subject.</li></div>";
}
if(empty($_POST['message'])){
print "<div class='formerrors'><li>You've forgot to type your message.</li></div>";
}
if(empty($_POST['answerbox'])){
print "<div class='formerrors'><li>Please answer the math question.</li></div>";
}
else {
if($answerbox != 15){
print"<div class='formerrors'><li>Answer is not correct.</li></div>";
}
else{
$headers = 'From: '.$email. "\r\n" .
'Reply-To: '.$email . "\r\n" .
'X-Mailer: PHP/' . phpversion();
mail('me#mymail.me',$subject,$message,$headers);
print "<div class='formerrors'><li>mail succesuffully sent</li></div>";
}
}
}
?>
</form>

Answer 1

Try placing your php code above the html as it is php setting the values of the variables, and you are calling them before they are set.
It is best practice to have php code at the top of the file, and then html below it, or even have the php on a separate file, but include it at the top.
Also I find it better to create an array of errors, and then if the array count is 0, then perform the action (send email) else call the error of arrays within the html, not the php. Then you can choose where to display it on the page, and style it accordingly.

Answer 2

Change your form action to
<?php $PHP_SELF; ?>
So it has to be
<form name="contact" action="<?php $PHP_SELF; ?>" method="post">
For the other issue you must place your code above the form.