[Workaround found] CodeIgniter 3.0 cannot access native $_SESSION

Just a guess:

session_start() starts a new session or resumes an existing session". By doing another page request without calling session_start you will loose you session. You MUST call session_start() to resume your session. Why do you call session_start()?

In CodeIgniter it is sufficient to use $this->load->library('session'); You session will be available with every page request and you can access it using $this->session.

I think var_dump($_SESSION); and var_dump($this->session); will give you the same result. However I never checked it and cannot check it now.

I have call session_start() in my external script:

PHP Code:

<?php
    if(!isset($_SESSION)){
        session_start();
    }
    var_dump($_SESSION); 


Yes var_dump($_SESSION) and var_dump($this->session->all_userdata()) will give the same result, but it has nothing to do with my problem.

My problem is:

$_SESSION in my non-codeigniter php application is different from $_SESSION in codeigniter application.
Thus Codeigniter and non-codeigniter php application cannot share session.

You could do a check when the user enters your CI application.
If you have created your sessions in the other app with the normal $_SESSION functionality you could just do something like this when the user enters the CI app:

PHP Code:

if(isset($_SESSION['whatever'])) {
    # add it to the CI session
    $this->session->userdata....
} 


You could also do it the other way around. Just make sure to validate them when passing them between the scopes.

Have you try it?
I don't think it will work.

First, you have $_SESSION['whatever'] from other application.

Now, when you do $this->load->driver('session'), there will be no $_SESSION['whatever']
When you load session library, and use "files" as driver, $_SESSION in the next code will be totally different.
$_SESSION will be an alias to codeigniter session, and it will be totally off.

The documentation (http://www.codeigniter.com/userguide3/li...ssion-data) said that 
these script are the same:

PHP Code:

$name = $_SESSION['name'];

// or:

$name = $this->session->name

// or:

$name = $this->session->userdata('name'); 


But it miss something important. Once you load session library, you will never able to access the original native php session anymore.

I think I have mention it, but I'll say it again:

I have a controller: application/controllers/welcome.php

PHP Code:

<?php
defined('BASEPATH') OR exit('No direct script access allowed');

class Welcome extends CI_Controller {
    public function index()
    {
        $this->load->library('session');
        var_dump($_SESSION);
    }
} 


I have another PHP file: x.php

PHP Code:

<?php
    if(!isset($_SESSION)){
        session_start();
    }
    var_dump($_SESSION); 


I access this url : http://localhost/index.php/welcome.
It yield this:

array (size=1)



  '__ci_last_regenerate' => int 1429025329


I access this url : http://localhost/x.php.
It yield this:

array (size=0)

  empty

This mean that $_SESSION in welcome.php is different from $_SESSION in x.php
The $_SESSION should always be the same. Thus, CodeIgniter and any other application which is written in plain PHP cannot share session.
This behavior is unexpected, or do you think otherwise?
Or do you have a different result from mine?
Please at least try the example I provide before rush to comment.
I have no problem with codeigniter 2.1.4 and 3.0 dev. This problem only occurred with CodeIgniter 3.0.