New event "init_form_values_after" after data set on a form (#1485)

* New event "init_form_values_after" after data set on a form

Magento does not have a common event after data is set on a form.
This new event allows us to change the form, the elements and the values once data is entered, giving full flexibility.
I needed this event in a special case where I needed to change the options of a select, to include the current value that was not in the existing options list.
There was no other way to do this without overriding many forms 1 by 1.

* Update app/code/core/Mage/Adminhtml/Block/Widget/Form.php

Co-authored-by: Ng Kiat Siong <kiatsiong.ng@gmail.com>

Co-authored-by: Ng Kiat Siong <kiatsiong.ng@gmail.com>

app/code/core/Mage/Adminhtml/Block/Widget/Form.php

@@ -143,6 +143,13 @@ protected function _beforeToHtml()
     {
         $this->_prepareForm();
         $this->_initFormValues();
+        Mage::dispatchEvent(
+            'adminhtml_block_widget_form_init_form_values_after',
+            [
+                'block' => $this,
+                'form' => $this->getForm()
+            ]
+        );
         return parent::_beforeToHtml();
     }