Adding new button from observer issue

Question

I am using this event to add a new button:

controller_action_layout_render_before_adminhtml_sales_billing_agreement_view

This is my function:

    var_dump(Mage::getSingleton('core/layout')->getUpdate()->getHandles());
    if (!$block = Mage::app()->getLayout()->getBlock('adminhtml_sales_billing_agreement_view')) {
        return $this;
    }
    $block->addButton('test',[
        'label' => Mage::helper('mynamespace_mymodule')->__('Test'),
        'class' => 'test'
    ]);

    return $this;

The result of my var_dump is array(4) { [0]=> string(7) "default" [1]=> string(11) "STORE_admin" [2]=> string(31) "THEME_adminhtml_default_default" [3]=> string(38) "adminhtml_sales_billing_agreement_view" }. But I cannot get my block, it doesn't get to the point to add my new button. It always returns $this. Maybe my block name is incorrect. Any idea ?

Thank you

Answer 1

Please try this:

• change event to adminhtml_block_html_before

• observer code

  if ($block->getType() == 'sales/adminhtml_billing_agreement_view') {
      $block->addButton('test', array(
          'label' => 'Test',
          'class' => 'test'
      ));
  }
  

Answer 2

Using this event: adminhtml_widget_container_html_before

and in the function called :

public function adminhtmlWidgetContainerHtmlBefore(Varien_Event_Observer $observer)
{
   $block = $observer->getBlock();

   if ($block instanceof your_class_here)    {
       $block->addButton('truncate_quote', array(
                'label'     =>  Mage::helper('mynamespace_mymodule')->__('Your Label Name'),
                'class'     => 'go'
            ));
       //or remove a button
       $block->removeButton('your button');
   }

}