Workshop - week 06

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Consuming an existing web feed

First you need to create a new controller, with just one "index" action.

In this action you simply create an instance of the Zend_Feed class, and call its "import" function to import a feed from a remote location (the BBC news website in this example). You then copy the content of the feed to an array, and pass the array to the view.

<?php

// application/controllers/FeedController.php

class FeedController extends Zend_Controller_Action 
{
    protected $_model;

    public function indexAction()
    {
        // Read remote feed
        try
        {
            $rss = Zend_Feed::import('http://newsrss.bbc.co.uk/rss/newsonline_uk_edition/front_page/rss.xml');
        } 
        catch (Zend_Feed_Exception $e)
        {
            // feed import failed
            echo "Exception caught importing feed: {$e->getMessage()}\n";
            exit;
        }

        // Initialize the channel data array
        $channel = array(
            'title'       => $rss->title(),
            'link'        => $rss->link(),
            'description' => $rss->description(),
            'items'       => array()
            );
        
        // Loop over each item and store relevant data
        foreach ($rss as $item) {
            $channel['items'][] = array(
                'title'       => $item->title(),
                'link'        => $item->link(),
                'description' => $item->description()
                );
        }

        // Pass to view
        $this->view->entries = $channel['items'];
    }

}

You also need to create a view for your new controller/action.

<!-- application/views/scripts/feed/index.hhtml -->

Feed Entries: <br />
<dl>
    <!-- Loop through the entries provided by the controller -->
    <? foreach ($this->entries as $entry): ?>
    <dt><?= $this->escape($entry['title']) ?></dt>
    <dd><?= $this->escape($entry['description']) ?></dd>
    <? endforeach ?>
</dl>

You can then simply access your consumed feed at the following URL: http://mi-linux.wlv.ac.uk/~0123456/zend/public/feed/ (please replace 0123456 by your own student numbeer!)

What you should see on your screen:

Note: For simplicity and clarity we are importing the feed in the controller, but a feed is an XML file, and as such could (should?) be considered as a data source. In line with MVC principles it would therefore be better practice to move the feed import code to a "model" file.

Producing your own web feed

Let's create a new "feed" action in out existing "Guestbook" controller.

We don't want any layouts for this action, as we are displaying pure XML, not an HTML page. One way of achieving this is to change the current layout to an empty file located in our layout folder (and called "blank.phtml" in this example).

You then transfer your data from the model to an array, and convert the array to a feed using the Zend_Feed::importArray function.

Easy!

    // application/controllers/GuestbookController.php

    public function feedAction()
    {
      // Change layout to blank.phtml (empty file)
      $this->_helper->layout->setLayout('blank');

      // Set feed values
      $array['title'] = 'Guestbook feed';
      $array['link'] = 'http://www.somewhere.com/';
      $array['description'] = 'This is guestbook feed';
      $array['charset'] = 'utf8';
      
      // Loop through db records and add feed items to array
      $model = $this->_getModel();
      foreach($model->fetchEntries() as $one_item)
      {
        $array['entries'][] = array(
          'title' => $one_item['email'],
          'link' => 'http://www.somewhere.com/123',
          'description' => $one_item['comment']
        );
      }
            
      // Import rss feed from array
      $feed = Zend_Feed::importArray($array, 'rss');

      // Send http headers and dump the feed
      $feed->send();
    }

To test your new "feed" action simply visit the following URL: http://mi-linux.wlv.ac.uk/~0123456/zend/public/guestbook/feed (please replace 0123456 by your own student numbeer!)

What you should see on your screen (if you are using Firefox anyway... not sure what feeds look like in other browsers):

More on web feeds with Zend

• http://framework.zend.com/manual/en/zend.feed.html