Solved

Question on $_POST , does it persist?

Posted on 2015-01-27
5
160 Views
Last Modified: 2015-01-27
hi,

I am a little confused on $_POST.

I basically have a form that submits a $_POST value , and calling another php page.
Later, in a completely different php page, i'd like to reuse the $_POST that was submitted earlier, and I find that it isnt available to me.

The php.net states that its a superglobal. But it looks to me like it disappears as soon as I navigate away from the page, unlike $_SESSION. Is this true?
0
Comment
5 Comments
 
LVL 13

Assisted Solution

by:Phil Phillips
Phil Phillips earned 125 total points
ID: 40574040
The $_POST variable gets whatever data is in the POST request submitted by using the form.  That data is only available to the page that receives the POST request.

You can copy the $_POST data to the session to save that information for future requests.
0
 
LVL 75

Accepted Solution

by:
käµfm³d   👽 earned 250 total points
ID: 40574042
You need to get a basic understanding of how HTTP works, then you'll understand why you are seeing this behavior. Ray Paseur has an introductory article on the topic:

http://www.experts-exchange.com/Web_Development/Web_Languages-Standards/A_11271-Understanding-Client-Server-Protocols-and-Web-Applications.html

The short of it is that you post to the server only exists on the server for that one request. Once the request is processed, there is no reason to keep that information. If you need to persist that information, then you move to session state--or for the hardcore, a database.

Session is used to persist information across requests.

His session article may be useful also:

http://www.experts-exchange.com/Programming/Languages/Scripting/PHP/A_11909-PHP-Sessions-Simpler-Than-You-May-Think.html
0
 
LVL 34

Assisted Solution

by:gr8gonzo
gr8gonzo earned 125 total points
ID: 40574044
A superglobal is just a variable that can be accessed from within the scope of a function without having to explicitly bring it in. For example:

$not_a_superglobal = "foo";
$_POST["something"] = "bar";

function show_scope()
{
  echo $_POST["something"]; // shows "bar"
  echo $not_a_superglobal; // Undefined variable

  global $not_a_superglobal; // Brings it into the scope
  echo $not_a_superglobal; // "foo"  
}

In short, $_POST does not persist across pages. Only $_SESSION persists.
0
 
LVL 75

Assisted Solution

by:käµfm³d 👽
käµfm³d   👽 earned 250 total points
ID: 40574048
The term superglobals just means that those particular variables can be accessed from within anywhere inside of your application. It does not imply that they persist data  in any such way.
0
 

Author Closing Comment

by:NeverEndingFlashStories
ID: 40574054
Whoa, I blinked, and 4 comments popped up :). Thanks everyone, it confirmed what i expected - i was wondering if i had an error in my syntax.
0

Featured Post

Efficient way to get backups off site to Azure

This user guide provides instructions on how to deploy and configure both a StoneFly Scale Out NAS Enterprise Cloud Drive virtual machine and Veeam Cloud Connect in the Microsoft Azure Cloud.

Question has a verified solution.

If you are experiencing a similar issue, please ask a related question

Suggested Solutions

Title # Comments Views Activity
Configuring a checkbox in CSS and php 18 88
Making API calls from hashed passwords 26 53
does post require a form or curl to be post 4 30
PHP not parsing ' character 12 39
Introduction HTML checkboxes provide the perfect way for a web developer to receive client input when the client's options might be none, one or many.  But the PHP code for processing the checkboxes can be confusing at first.  What if a checkbox is…
Password hashing is better than message digests or encryption, and you should be using it instead of message digests or encryption.  Find out why and how in this article, which supplements the original article on PHP Client Registration, Login, Logo…
Explain concepts important to validation of email addresses with regular expressions. Applies to most languages/tools that uses regular expressions. Consider email address RFCs: Look at HTML5 form input element (with type=email) regex pattern: T…
The viewer will learn how to dynamically set the form action using jQuery.

770 members asked questions and received personalized solutions in the past 7 days.

Join the community of 500,000 technology professionals and ask your questions.

Join & Ask a Question