How to make form fields required? [duplicate] - php

Question

This question already has answers here:
Making email field required in php [closed]
(4 answers)
Closed 8 years ago.
I have this existing code and I am wondering how to make the name and email field required?
<?php
if(isset($_POST['submit'])){
$to = "xxx#email.com"; // this is your Email address
$from = $_POST['gift_email']; // this is the sender's Email address
$first_name = $_POST['gift_name'];
$subject = "Free Gift Request";
$msg = "A free gift has been requested from the following:"."\n";
$msg .= "Name: ".$_POST["gift_name"]."\n";
$msg .= "E-Mail: ".$_POST["gift_email"];
$headers = "From:" . $from;
mail($to,$subject,$msg,$headers);
//echo "Mail Sent. Thank you " . $first_name . ", we will contact you shortly.";
header('Location:free_program_thankyou.php');
}
?>

Answer 1

For form
<input type="text" name="gift_email" required>
<input type="text" name="gift_name" required>
For Php
if(empty($_POST['gift_email']))
{
echo 'This field is required';
}else {
//Do what you want to do here
}

Answer 2

A two basic ways to do this:-
Within the php program check each required form field has been filled in send a new page with an error message back if it is not. Be sure to return the contents of any fields already filled in or your users will wish a plague of boils on your person.
Validate in javascript. Have a function triggered by the "onsubmit" condition which checks for all required forms fields are filled and highlights any that are not. see here
In practice a robust web site will do both. This seems like duplication however the javascript function is much more responsive and user friendly, BUT, the php server side validation cannot be gamed by turning JS off or spoofing responses.