Describe block instantiation Block instantation in Magento takes place when the controller calls the method loadLayout. public function loadLayout($handles = null, $generateBlocks = true, $generateXml = true) { . . . // add default layout handles for this action $this->addActionLayoutHandles(); $this->loadLayoutUpdates(); if (!$generateXml) { return $this; } $this->generateLayoutXml(); if (!$generateBlocks) { return $this; } $this->generateLayoutBlocks(); […]

Describe the stages in the lifecycle of a block Which class is responsible for creating an instance of the block? In Magento, the whole block hierarchy during a page generation is created by the class Mage_Core_Model_Layout. The method generateBlocks is responsible of that. Let’s take a look… public function generateBlocks($parent=null) { if (empty($parent)) { $parent […]

Describe the relationship between templates and blocks Can any block in Magento use a template file? The template file usage in Magento is restricted to Mage_Core_Block_Template and blocks inheriting from it. Other blocks in Magento like Mage_Core_Block_Text does not inherit from it but from Mage_Core_Block_Abstract so it cannot use a template file for rendering. How […]

Describe the programmatic structure of blocks in Magento What are blocks used for in Magento? Blocks are the main design element in Magento. A hierarchy of blocks is used to layout any page in a Magento store. Blocks in Magento divide into two big groups: Structural Blocks Content Blocks Programmatically there are no difference between […]