The Bakery Everything CakePHP

1 - Download and install

Download the PEAR pager package from http://pear.php.net/package/Pager. Unpack it and put the libraries in (e.g.) /vendors/Pear/Pager.

2 - Make a component

Make a component "pager.php". This will act as a wrapper between CakePHP and Pager. This way, we can do all the Pager setup outside of the controller. Most parameters will probably remain unchanged between the different invocations. We have the possibility to overwrite specific parameters later from the controller.

Component Class:

Download code <?php 
class PagerComponent extends Object
{    
    /**
     * The (calling) controller object.
     *
     * @access public
     * @var object
     */
     var $Controller;

     /**
      * The pager object.
      *
      * @access public
      * @var object
      */
     var $Pager;
     
     /**
      * Configuration parameters
      *
      * @access public
      * @var array
      */
     var $params;

    /**
     * Component pseudo controller
     *
     * @access public
     * @param object $controller Calling controller object
     * @return void
     */
    function startup(&$controller) {
        $this->Controller =& $controller;
    }
    
    /**
     * Initializes the pager. Must be called before using the component.
     *
     * Takes user configuration and creates pager object ($this->Pager)
     *
     * @access public
     * @param array $config Configuration options for Pager::factory() method
     * @see http://pear.php.net/manual/en/package.html.pager.factory.php
     * @return void
     */
    function init($config)
    {        
        // Get the correct URL, even with admin routes
        $here = array();        
        if (defined('CAKE_ADMIN') && !empty($this->Controller->params[CAKE_ADMIN])) {
            $here[0] = $this->Controller->params[CAKE_ADMIN];
            $here[2] = substr($this->Controller->params['action'], strlen($this->Controller->params[CAKE_ADMIN]) + 1);
        } else {
            $here[2] = $this->Controller->params['action'];
        }
        $here[1] = Inflector::underscore($this->Controller->params['controller']);
        ksort($here);
        $url = implode('/', $here);
                
        // Set up the default configuration vars
        $this->params = array(
            'mode' => 'Sliding',
            'perPage' => 10,
            'delta' => 5,
            'totalItems' => '',
            'httpMethod' => 'GET',
            'currentPage' => 1,
            'linkClass' => 'pager',
            'altFirst' => 'First page',
            'altPrev '=> 'Previous page',
            'altNext' => 'Next page',
            'altLast' => 'Last page',
            'separator' => '',
            'spacesBeforeSeparator' => 1,
            'spacesAfterSeparator' => 1,
            'useSessions' => false,
            'firstPagePre'     => '',
            'firstPagePost' => '',
            'firstPageText' => '<img src="'.$this->Controller->base.'/img/first.gif" alt="">',
            'lastPagePre' => '',
            'lastPagePost' => '',
            'lastPageText' => '<img src="'.$this->Controller->base.'/img/last.gif" alt="">',
            'prevImg' => '<img src="'.$this->Controller->base.'/img/prev.gif" alt="">',
            'nextImg' => '<img src="'.$this->Controller->base.'/img/next.gif" alt="">',
            'altPage' => 'Page',
            'clearIfVoid' => true,
            'append' => false,
            'path' => '',
            'fileName' => $this->Controller->base . DS . $url . DS . '%d',
            'urlVar' => '',
        );
        
        vendor('Pear/Pager/Pager');
        
        // Merge with user config
        $this->params = array_merge($this->params, $config);        
 
        // sanitize requested page number
        if (!in_array($this->params['currentPage'], range(1, ceil($this->params['totalItems'] / $this->params['perPage'])))) {
            $this->params['currentPage'] = 1;
        }
        $this->Pager =& Pager::factory($this->params);
        
        // Set the template vars
        $this->Controller->set('pageLinks',   $this->Pager->getLinks());
        $this->Controller->set('currentPage', $this->params['currentPage']);
        $this->Controller->set('isFirstPage', $this->Pager->isFirstPage());
        $this->Controller->set('isLastPage',  $this->Pager->isLastPage());
    }    
?>

3 - More Features

You should add other template vars as needed. Those you see are just the most often needed (by me).

4 - Load the component

Don't forget to load the component in your application! Set

PHP Snippet:

Download code <?php 
<?php var $components = array('Pager'); ?>
?> in your controller.

5 - Controller setup

In your posts_controller.php, do the following:

Controller Class:

Download code <?php 
function index($page = 1) { 
                 
        // setup the pager 
        $params = array( 
            'perPage'     => 10, 
            'totalItems'  => $this->Post->findCount(), 
            'currentPage' => $page, 
        ); 
        $this->Pager->init($params); 
                 
        // get the data 
        $this->set('data', $this->Post->findAll(null, null, 'Post.created DESC', $this->Pager->params['perPage'], $this->Pager->params['currentPage'])); 
    } 
?>
I have chosen the more efficient of the two methods available to feed data to pager. Instead of selecting all records of a table and let Pager decide which records to show (which can be very memory intensive with large result sets), we give Pager the total number of items

PHP Snippet:

Download code <?php 
$this->Post->findCount();
?>
and fetch only the rows we need for our page to display:

PHP Snippet:

Download code <?php 
$this->Post->findAll(null, null, 'Post.created DESC', $this->Pager->params['perPage'], $this->Pager->params['currentPage'];
?>

6 - In the view

You will output the pager (if appropriate) in your index.thtml as follows:

View Template:

Download code
<?php
// Display pager if there are pages to display
if ($pageLinks['all']) {
    echo '<div id="pager" class="pager">Pages:&nbsp;&nbsp;' . $pageLinks['all'] . '</div>';
}
?>


7 - The End

That's all, folks :)