在Zend Framework PHP中的页面之间持久存储数据时，使用会话变量与请求参数

Question

I'm trying to better understand what the best method would be to persist data between requests in this scenario (using Zend Framework):

Say I have an Events controller and the default (index) view displays any existing Announcements (if there are any), and a link to Add a new Announcement (Both Event and Announcement are arbitrary objects). I'm trying to retrieve the eventId so I can associate the new Announcement with it when saving it to the database. Compositionally, an Event consists of 0 to many Announcements. From my limited understanding of the Zend Framework, I see two main options.

Option one: Make the URL something like '/event/addAnnouncement/eventId/5', which makes retrieving the eventId easy via route/path parameters.

Option two: In the indexAction of the controller, save the eventId to a session variable, which can then be retrieved in the addAnnouncementAction of the Event controller. This way the Add Announcement link would simply be '/event/addAnnouncement/'.

Can anyone shed some light on which of these two ways is better, or if there is another way I'm not aware of?

As always, any help is much appreciated. Thanks.

Answer 1

The question to ask yourself is, how long do you need to persist the data?
If you only need to save the data to pass it to the next action you can use POST or GET , the GET would pass through the url and the POST would not( typically ).

The example you presented would suggest that you need to persist the data just long enough to validate, filter and process the data. So you would likely be very satisfied passing the few pieces of data around as parameters( POST or GET ). This would provide the temporary persistence you need and also provide the added benefit of the data expiring as soon as a request was made that did not pass the variables.

A quick example (assume your form passes data with the POST method):

   if ($this->getRequest()->isPost()) {
        if ($form->isValid($this->getRequest()->getPost()){
            $data = $form->getValues();//filtered values from form
            $model = new Appliction_Model_DbTable_MyTable();
            $model->save($data);
            //but you need to pass the users name from the form to another action
            //there are many tools in ZF to do this with, this is just one example
            return $this->getHelper('Redirector')->gotoSimple(
                                                   'action' => 'newaction', 
                                                    array('name' => $data['name'])//passed data
                                                   ); 
        }

}

if you need to persist data for a longer period of time then the $_SESSION may come in handy. In ZF you will typically use Zend_Session_Namespace() to manipulate session data.
It's easy to use Zend_Session_Namespace , here is an example of how I often use it.

class IndexController extends Zend_Controller_Action {
protected $_session;

public function init() {
    //assign the session to the property and give the namespace a name.
    $this->_session = new Zend_Session_Namespace('User');
}
public function indexAction() {
    //using the previous example
    $form = new Application_Form_MyForm();

     if ($this->getRequest()->isPost()) {
        if ($form->isValid($this->getRequest()->getPost()){
            $data = $form->getValues();//filtered values from form
            //this time we'll add the data to the session
            $this->_session->userName = $data['user'];//assign a string to the session
            //we can also assign all of the form data to one session variable as an array or object
            $this->_session->formData = $data;
            return $this->getHelper('Redirector')->gotoSimple('action'=>'next');
        }
    }
    $this->view->form = $form;
}
public function nextAction() {
   //retrieve session variables and assign them to the view for demonstration
   $this->view->userData = $this->_session->formData;//an array of values from previous actions form
   $this->view->userName = $this->_session->userName;//a string value
    }
  }
}

any data you need to persist in your application can sent to any action, controller or module. Just remember that if you resubmit that form the information saved to those particular session variables will be over written.

There is one more option in ZF that kind of falls between passing parameters around and storing data in sessions, Zend_Registry . It's use is very similar to Zend_Session_Namespace and is often used to save configuration data in the bootstrap (but can store almost anything you need to store) and is also used by a number of internal Zend classes most notably the flashmessenger action helper .

 //Bootstrap.php
 protected function _initRegistry() {

        //make application.ini configuration available in registry
        $config = new Zend_Config($this->getOptions());
        //set data in registry
        Zend_Registry::set('config', $config);
    }
 protected function _initView() {
        //Initialize view
        $view = new Zend_View();
        //get data from registry
        $view->doctype(Zend_Registry::get('config')->resources->view->doctype);
        //...truncated...
        //Return it, so that it can be stored by the bootstrap
        return $view;
    }

I hope this helps. Pleas check out these links if you have more questions:

The ZF Request Object
Zend_Session_Namespace
Zend_Registry

Answer 2

Option 1 is better, although in your example this is not a POST (but it could be done with a POST).

The problems with option 2 are:

• If a user had multiple windows or tabs open at the same time, relating to different events, how would you track which event ID should be used?
• If a user bookmarked the add event page and came back later, the session var may not be set

Option 2 is also a little more complicated to implement, and adds a reliance on sessions.