Session lost after form submit in wordpress - php

Question

The session I set is lost after the form is submitted.
I had built the session class to set new session, unset and so on. In function.php of wordpress template.
function.php
if (!session_id()) {
session_start();
}
include get_template_directory() . "/custom/session.php";
Session.php
class session {
function __construct() {
}
function set_flashdata($name, $value) {
$_SESSION[$name] = $value;
}
function flashdata($name) {
if (isset($_SESSION[$name])) {
$str = $_SESSION[$name];
return $str;
} else {
return FALSE;
}
}
function userdata($name) {
if (isset($_SESSION[$name])) {
return $_SESSION[$name];
} else {
return FALSE;
}
}
function set_userdata($name, $value) {
$_SESSION[$name] = $value;
}
function unset_userdata($name) {
if (isset($_SESSION[$name])) {
unset($_SESSION[$name]);
}
}
}
I try to set session as :
<?php
$sess = new session();
$sess->set_userdata('sess_name',"some value");
?>
<form action="get_permalink(212);">
//input buttons
</form>
After submit the form it goes to the permalink(212). Then I tried.
<?php
$sess = new session();
$value = $sess->userdata('sess_name');
var_dump($value); //returns false. That means session is lost after form submit. Why?
?>

Answer 1

You need to move session start/resume into your Session's constructor.
Like so:
class session
{
function __construct()
{
if (! session_id()) {
session_start();
}
}
Another thing to mention, every time you'll do new Session you'll be getting an object of the same functionality working with same global variable $_SESSION.
You don't need more than one $session object, it would be a good time to look into Singleton pattern.

Answer 2

You have to call always session_start() for each request.
The mission of session_start() is:
Creates a new session
Restart an existing session
That means, if you have created a session, and you don't call to the method session_start(), the variable $_SESSION is not going to be fulfilled.
Except: If in your php.ini you have set the option session.auto_start to 1, then, in that case it is not needed to call the session_start() because the variable $_SESSION is fulfilled implicitly.

Answer 3

You need to use wordpress global variable for condition that session is set or not something like :
global $session;
if (!session_id()) {
session_start();
}
include get_template_directory() . "/custom/session.php";

Answer 4

It might be due to www. at the start of your website domain. Make sure that both of pages use the same structure.
Also I faced with the same issue long time ago when the form sends the data to a secured address (https://)
I hope these two items may help you.

Answer 5

Sounds to me like session_start() is not set at the start of the page that get_permalink(212;) refers to.
I have almost no experience with WP itself though, so I might misunderstand the functionality of get_permalink()

Answer 6

I agree with the answer from #rock3t to initialize session in constructor of class, but every time a class object is initiated, it will go to check for session!
Instead, if you are fine, the simplest way to get access to session is by adding following lines to your wp-config.php file before the call to wp-settings
if (!session_id())
session_start();
This will set/initialize session globally and you won't need to set/check for session_start in constructor of a class.
Thank you.