Zend Framework Use Filter with Paginator

Feb 21, 2012 zend-framework

This post is more than 18 months old. Since technology changes too rapidly, this content may be out of date (but that's not always the case). Please remember to verify any technical or programming information with the current release.

By default, when using the Zend Paginator, the result set will come back as an array. If you are using a paginator associated with a database result set, and that db has a class defined for its row, it will come back as that class. However, if this is not the case, or you are not using information from a database, you may still want a different result than just a plain array.

Enter the Filter.

The Zend_Paginator class has a function called setFilter() that will accept a Zend_Filter_Interface’d object and apply it to each result set.

So, for example, check out this code:

class MyObject
{
  public function __construct(array $items = array())
  {
    foreach ($items as $key=>$value) {
      $this->$key = $value;
    }
  }
}

class MyObjectPopulator implements Zend_Filter_Interface
{
  public function filter($item)
  {
    return new MyObject($item);
  }
}

// ...
$paginator = new Zend_Paginator($adapter);
$paginator->setFilter(new MyObjectPopulator());

First, the MyObject class is constructed in such a way to add an array of elements to itself as properties if passed to the constructor. Next, a filter called MyObjectPopulator is created. The filter() method of this class will take the item passed in (which originates from the Zend_Paginator query of the Zend_Paginator_Adapter), and return a new instance of the object (created from that array item). Finally, when the paginator is created (from an adapter of your choice), adda new instance of the filter using the setFilter() call. Now, all results of that paginator will be instances of MyObject instead of arrays.