Question

I have a Slider model having some associated Images (models). When editing a Slider, there’s a tab for its images. Now this can be modified, to select and deselect containing images. This, it seems, is done through an admin grid, having a checkbox column (the “values” key is for testing):

    $this->addColumn('in_slider', array(
        'header_css_class' => 'a-center',
        'type'      => 'checkbox',
        'name'      => 'in_slider',
        'values'    => array(1,2),
        'align'     => 'center',
        'index'     => 'slider_image_id'
    ));

Let’s say the Slider in the above image has one image attached, and that works fine. But, when user selects “Any” and clicks “Search”, all images must show, but those that are not associated should be deselected. I think this is standard behavior for such a feature.

What I don’t get is the mechanism behind those two buttons: Reset Filter and Search. From what I’ve managed to dig up, a grid class has a getGridUrl() method which is used to refresh the grid data (via AJAX). That URL mapping to a controller.

// in grid class
public function getGridUrl()
{
    return $this->getUrl('*/*/editGrid', array('_current' => true));
}

// Image controller
public function editGridAction()
{
    $blockMarkup = $this->getLayout()->createBlock('module/someblock')->toHtml();
    $this->getResponse()->setBody($blockMarkup);
}

But what about the “Search” button? How does that work?

How do other modules know when to show ALL entities, or searching for “Yes” or “No”?

When saving the slider, how can one grab the selected values? Working in Slider controller’s saveAction I presume, but how do you get the checkbox values?

Answer 1

What you’re looking for is a mass action. Add this function to your grid file (whatever extends Mage_Adminhtml_Block_Weidget_Grid):

protected function _prepareMassaction()
{
  $this->setMassactionIdField('some_ID');
  $this->getMassactionBlock()->setFormFieldName('element_name');  //html name of checkbox
  $this->getMassactionBlock()->addItem('some_ID', array(
    'label'=> __('Some Label'),
    'url'  => $this->getUrl('*/*/doSomething'),   //an action defined in the controller
    'selected' => 'selected',
    'confirm' => __('Are you sure?')
  ));

  return $this;
}

Here’s a good blog post that helps to explain the concept:
http://inchoo.net/ecommerce/magento/how-to-add-massactions-to-magentos-grid/