CakePHP: Value from $this->request->data being lost on pagination postback - php

Question

I have an application that takes a value from a dropdown list and uses it to filter an index view. Here is the controller code for that:
public function browse() {
$this->loadModel('ReqMissionId');
$missions = $this->ReqMissionId->find('list', array('fields' => array('mission_id', 'mission_id')));
$this->set(compact('missions'));
}
This is the Controller code for the index:
public function index() {
if($this->request->is('post')) {
$options = array('Requirement.mission_id' => $this->request->data['Requirement']['mission_id']);
$this->set('mission_id', $this->request->data['Requirement']['mission_id']); //Used to display the mission_id on the index page.
$this->Paginator->settings = $this->paginate;
$this->set('requirements', $this->Paginator->paginate('Requirement', $options));
}
}
The dropdown in the View is simple:
<?php
echo $this->Form->input('mission_id', array('label' => 'Mission ID'));
echo $this->Form->submit(__('View'));
echo $this->Form->end();
?>
My problem is pagination. Since Cake does a postback when it sorts the columns, the value of 'Requirement.mission_id' gets lost and I get a "Call to member function sort() on null" error. I feel like I can take care of this with a session variable, but I'm unclear on the implementation. Is that correct, or is there something else I should be doing?

Answer 1

Check the session for the model that you're paginating. Try something like this:
Try something like this:
if(!empty($this->request->data['Requirement']))
$this->Session->write('Requirement', $this->request->data['Requirement']);
else
$this->request->data['Requirement'] = $this->Session->read('Requirement');
To get it into your $options. Try use array merge like this:
$options = array_merge($options, $this->getOptions($this->request->data));
Implement getOptions under:
function getOptions($data = null){
$options = array();
if(!empty($data['Requirement']['mission_id']))
$options = array_merge($options, array('mission_id' => $data['Requirement']['mission_id']));
return $options;
}