How to make $_POST variables global after form redirect?

Question

I'm trying to use the $_POST information submitted through a standard form (name, email address, details) to build the content on the page after a redirect. Here is my code:

<?php

//creating variables from form data submission
if ($_SERVER["REQUEST_METHOD"] == "POST") {

$name = trim(filter_input(INPUT_POST,"name",FILTER_SANITIZE_STRING));
$email = trim(filter_input(INPUT_POST,"email",FILTER_SANITIZE_STRING));
$details = trim(filter_input(INPUT_POST,"details",FILTER_SANITIZE_SPECIAL_CHARS));

//Redirecting after succesful completion of form
header("location:index.php?status=complete");

//Error message if form is failed to complete
if ($name == "" || $email == "" || $details == "") {
  echo "Please fill in required fields";
  exit;

}
}



?>

<!DOCTYPE html>
<html>
  <head>
    <meta charset="utf-8">
    <title></title>
    <link rel="stylesheet" href="CSS/stylesheet.css">
  </head>
  <body>
  <div class="header" style="background-color: white" href="index.php">
  <header>
      <a href="index.html"><h1>Test site</h1></a>

  </header>
</div>
  </body>

<div class="wrapper">

  <?php

//Using echo and var_dump to test content from form submission as
//defined in the variables in the topmost $_POST conditional******

  if (isset($_GET['status']) && $_GET['status'] == "complete") {

      echo "you successfully completed the form!";
      echo $name;
      var_dump($name);


  } else { ?>


  <form method="post" action="index.php">
    <label for="name">Name</input><br>
    <input type="text" id="name" name="name"></input><br>

    <label for="email">Email</input><br>
    <input type="text" id="email" name="email"></input><br>

    <label for="details">Details</input><br>
    <input type="text" id="details" name="details"></input><br>

    <input type="submit"></input>

  </form>

<?php } ?>

</div>

  </body>
</html>

When I run this, I get the warning:

Notice: Undefined variable: name

on the page that I redirect to following form submission (relevant code section marked with ***** above)

I understand that this is probably because when I first set $name, $email, and $details in the topmost php section of the code, those variables are defined locally.

How can I create variables out of the $_POST data from the index.php form to be used after the page redirect, and on any other pages on the site?

Answer 1 · 2017-11-10T19:09:39Z

November 10, 2017 7:09pm

As Ben Payne said, your best approach here is to use the superglobal $_SESSION. I recommend you read this brief tutorial and google 'PHP Sessions', or watch some videos on youtube. Also don't forget you're on Treehouse. Pretty sure there is some courses on Sessions throughout the beginner/intermediate PHP Courses (I can't remember, but there probably is as sessions are very useful).

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Sam Butler

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How to make $_POST variables global after form redirect?

Ben Payne

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1 Answer

Matthew Lang

Matthew Lang

Ben Payne

Ben Payne