codeigniter session issue - some session info not sticking - session

Question

I'm using codeigniter session library to hold data that is used in a series of 3 pages and I'm experiencing strange behavior. My session variables remain in tact but the values disapear. Even stranger: I'm trying to store a serialized array in my session data and the first item of the array ends up being stored in a different variable?
I've attached a link that starts at the first page in the series where it is possible to click to the next page. I've printed the user_session data at the top of both pages (the third page isn't set up yet).
http://playmatics.com/nypl/site/index.php/member_area/quest/accept_quest/12
Sessions work everywhere else, for example I'm using a session to store login data and that works fine.
I've attached my controller and view below
//CONTROLLER:
function accept_quest() {
$assoc_quest_id = end($this->uri->segments);
if(!isset($quest_id)) {
redirect('member_area/quest');
//SEND A MESSAGE: NO QUEST STARTED
}
$quest_rows = $this->quest_model->get_quest_with_images($assoc_quest_id);
$quest = current($quest_rows);
$images = $this->pull_out_images($quest_rows);
//the data array is used both in the session,
//to pass values over to the next function in the quest chain
//and in the template
$data = array();
$data['quest_id'] = $assoc_quest_id;
$data['instruction_text'] = $quest->instructions;
$data['quest_title'] = $quest->name;
$data['quest_time_limit'] = $quest->time_limit;
$data['points_awarded'] = $quest->points_availible;
$data['quest_images'] = serialize($images);
//save data in a flash session to be used in the next function call in the quest chain: quest_action
$this->session->set_userdata($data);
print_r($this->session->all_userdata());
//the following data aren't needed in the session so they are added to the data array after the session has been set
$data['annotation_text'] = $quest->note;
$data['main_content'] = 'quests/quest_desc';
$this->load->view('includes/template', $data);
}
function quest_action() {
print_r($this->session->all_userdata());
$quest_id = $this->session->userdata('quest_id');
echo "the quest id is: $quest_id";
if(!isset($quest_id)) {
redirect('member_area/quest');
//SEND A MESSAGE: NO QUEST STARTED
}
$data['quest_id'] = $quest_id;
$data['quest_title'] = $this->session->userdata('quest_title');
$data['quest_images'] = $this->session->userdata('images');
$data['instruction_text'] = $this->session->userdata('instructions');
$data['quest_time_limit'] = $this->session->userdata('quest_time_limit');
$data['main_content'] = 'quests/quest_action';
$this->load->view('includes/template', $data);
}
//VIEW
//quest_desc:
<h1><?= $quest_title ?></h1>
<div id="quest_elements">
<figure>
<? foreach(unserialize($quest_images) as $image): ?>
<img class="media" src="<?= $image ?>" alt="<?= $quest_title ?> image"/>
<? endforeach; ?>
<figcaption>annotation: <?= $annotation_text ?></figcaption>
</figure>
<?= anchor("member_area/quest/quest_action", "Start Quest", array('title' => 'start quest')); ?>
</div><!-- end quest_elements -->
//quest_action:
<h1><?= $quest_title ?></h1>
<div id="quest_elements">
<figure>
<? foreach(unserialize($quest_images) as $image): ?>
<img class="media" src="<?= $image ?>" alt="<?= $quest_title ?> image"/>
<? endforeach; ?>
<figcaption>instructions: <?= $instruction_text ?></figcaption>
</figure>
<div id="timer">
<?= $quest_time_limit; ?>
</div>
<?= anchor("#start_timer", "Start Timer", array('title' => 'start quest timer')); ?>
</div>

Answer 1

If you are hitting the cookie size limit, I would suggest switching to CodeIgniter's native Database Sessions class. This enables you to store session information in a database, effectively removing the cookie size limitation, you are simply restricted to the size of the user_data field in the ci_sessions database.
Following the link above, the section on utilizing database sessions is near the bottom, providing you the proper DB schema and the config switch to database sessions.

Answer 2

As others have said, it is likely that you are hitting the 4k cookie limit of CI's session library. There are other alternative libraries available that use standard PHP sessions - http://codeigniter.com/wiki/PHPSession/ and http://codeigniter.com/wiki/Native_session/ for instance.