Full Page Cache: Enterprise PageCache Model Container Placeholder

How to work/flow Enterprise_PageCache_Model_Container_Placeholder class in Magento?
(Magento EE 1.13.0.2)Object: $this => Enterprise_PageCache_Model_Container_PlaceholderFollowing constant is used in above class:

• const HTML_NAME_PATTERN = ‘//i’

Following variables is used in above class:

• $_definitionMap
• $_definition
• $_name
• $_attributes

Some important functions and its purpose used in this class:

• getName(): This function is used for to get placeholder name.
• getDefinition(): Get defination of placeholder.
• getAttribute(): This function is used for get attribute by specific code.
• getReplacer(): This function is used for get placeholder content replacer.
• getStartTag(): This function return placeholder start tag for block html generation.
• getEndTag(): This function return placeholder end tag for block html generation.

Functions in class Enterprise_PageCache_Model_Container_Placeholder
There are 10 functions used in class Enterprise_PageCache_Model_Container_Placeholder

• /**Class constructor.
  * Initialize placeholder name and attributes based on definition
  * @param string $definition **/
  public function __construct($definition){}
• /**Get placeholder name
  * @return string **/
  public function getName()
  {
  return $this->_name;
  }
• /**Get placeholder definition
  * @return string **/
  public function getDefinition()
  {
  return $this->_definition;
  }
• /**Get attribute by specific code
  * @param $code string
  * @return string **/
  public function getAttribute($code)
  {
  return isset($this->_attributes[$code]) ? $this->_attributes[$code] : null;
  }
• /**Get regular expression pattern to replace placeholder content
  * @return string **/
  public function getPattern()
  {
  return ‘/’ . preg_quote($this->getStartTag(), ‘/’) . ‘(.*?)’ . preg_quote($this->getEndTag(), ‘/’) . ‘/ims’;
  }
• /**Get placeholder content replacer
  * @return string **/
  public function getReplacer(){}
• /**Get class name of container related with placeholder
  * @return string **/
  public function getContainerClass()
  {
  $class = $this->getAttribute(‘container’);
  if (strpos($class, ‘/’) !== false) {
  return Mage::getConfig()->getModelClassName($class);
  }
  return $class;
  }
• ** Retrieve placeholder definition hash
  * @return string **/
  protected function _getDefinitionHash()
  {
  $definition = $this->getDefinition();
  $result = array_search($definition, self::$_definitionMap);
  if ($result === false) {
  $result = $this->getName() . ‘_’ . md5($definition);
  self::$_definitionMap[$result] = $definition;
  }
  return $result;
  }
• **Get placeholder start tag for block html generation
  *
  * @return string
  */
  public function getStartTag()
  {
  return ‘‘;
  }
• /**Get placeholder end tag for block html generation
  * @return string **/
  public function getEndTag()
  {
  return ‘‘;
  }

Variation of sample data for different pages (Homepage, Product Listing Page, Product Info Page)
Variables: These values for Homepage
URL: https://localhost/oscp-store/mage-ent-test
$_definitionMap = array

• /** Associative array of definition hash to informative definition **/
  WELCOME_8e20186cee9cf7a5a5d1e0bc75ddfec3 = WELCOME
  container = “Enterprise_PageCache_Model_Container_Welcome”
  block = “Mage_Page_Block_Html_Welcome”
  cache_id = “bf3668918d4f26657cdbfe6550c62f39a86211ba”
  cache_lifetime = “86400”
  template =””
• $_definition=/***Original placeholder definition based on HTML_NAME_PATTERN **/
  WELCOME
  container = “Enterprise_PageCache_Model_Container_Welcome”
  block = “Mage_Page_Block_Html_Welcome”
  cache_id = “bf3668918d4f26657cdbfe6550c62f39a86211ba”
  cache_lifetime = “86400”
  template=””
• $_name = WELCOME (Placeholder name)
• $_attributes = /** * Placeholder attributes **/
  Array [5] container = Enterprise_PageCache_Model_Container_Welcome
  block = Mage_Page_Block_Html_Welcome
  cache_id = bf3668918d4f26657cdbfe6550c62f39a86211ba
  cache_lifetime = 86400
  template =

Variables: These values for product listing page
URL: https://localhost/oscp-store/mage-ent-test/furniture/living-room

• $_definitionMap = Array [2] [0]WELCOME_8e20186cee9cf7a5a5d1e0bc75ddfec3 = WELCOME
  container = “Enterprise_PageCache_Model_Container_Welcome”
  block = “Mage_Page_Block_Html_Welcome”
  cache_id = “bf3668918d4f26657cdbfe6550c62f39a86211ba”
  cache_lifetime = “86400”
  template=””[1]ACCLINKS_ef551a42665572f16be6f8a990c96b37 = ACCLINKS
  container =”Enterprise_PageCache_Model_Container_Accountlinks”
  block = “Mage_Page_Block_Template_Links”
  cache_id = “b8f9b3383abc7a26a71bfdc86c4a9d5bff6e3693”
  cache_lifetime = “86400”
  template = “page/template/links.phtml”
  links = garbage value
  name=”account.links”
• $_definition = CART_SIDEBAR
  container = “Enterprise_PageCache_Model_Container_Sidebar_Cart”
  block = “Mage_Checkout_Block_Cart_Sidebar”
  cache_id = “3ee95d5974c12590e902688083b2097637487b5d” cache_lifetime=”86400″
  template = “checkout/cart/cartheader.phtml” item_renders=”default|checkout/cart_item_renderer|
  checkout/cart/sidebar/default.phtml|simple|checkout/cart_item_renderer|
  checkout/cart/sidebar/default.phtml|grouped|checkout/cart_item_renderer_grouped|
  checkout/cart/sidebar/default.phtml|configurable|
  checkout/cart_item_renderer_configurable|checkout/cart/sidebar/default.phtml|bundle|
  bundle/checkout_cart_item_renderer|checkout/cart/sidebar/default.phtml”
• $_name = CART_SIDEBAR
• $_attributes = Array [6] container = Enterprise_PageCache_Model_Container_Sidebar_Cart
  block = Mage_Checkout_Block_Cart_Sidebar
  cache_id = 3ee95d5974c12590e902688083b2097637487b5d
  cache_lifetime = 86400
  template = checkout/cart/cartheader.phtml
  item_renders = default|checkout/cart_item_renderer|checkout/cart/sidebar/default.phtml|simple|
  checkout/cart_item_renderer|checkout/cart/sidebar/default.phtml|grouped|
  checkout/cart_item_renderer_grouped|checkout/cart/sidebar/default.phtml|configurable|
  checkout/cart_item_renderer_configurable|checkout/cart/sidebar/default.phtml|bundle|
  bundle/checkout_cart_item_renderer|checkout/cart/sidebar/default.phtml

Variables: These values for product Info page
URL: https://localhost/oscp-store/mage-ent-test/furniture/living-room/couch.html

• $_definitionMap = Array [3] [0]WELCOME_8e20186cee9cf7a5a5d1e0bc75ddfec3 = WELCOME
  container = “Enterprise_PageCache_Model_Container_Welcome”
  block = “Mage_Page_Block_Html_Welcome”
  cache_id = “bf3668918d4f26657cdbfe6550c62f39a86211ba”
  cache_lifetime = “86400”
  template=””[1]ACCLINKS_ef551a42665572f16be6f8a990c96b37 = ACCLINKS
  container =”Enterprise_PageCache_Model_Container_Accountlinks”
  block =”Mage_Page_Block_Template_Links”
  cache_id = “b8f9b3383abc7a26a71bfdc86c4a9d5bff6e3693”
  cache_lifetime = “86400”
  template = “page/template/links.phtml”
  links = garbage value
  name=”account.links”[2]CART_SIDEBAR_ccd944c424b10c67d0f564f5cd4534e0 = CART_SIDEBAR
  container = “Enterprise_PageCache_Model_Container_Sidebar_Cart”
  block = “Mage_Checkout_Block_Cart_Sidebar”
  cache_id = “3ee95d5974c12590e902688083b2097637487b5d”
  cache_lifetime = “86400”
  template = “checkout/cart/cartheader.phtml”
  item_renders = “default|checkout/cart_item_renderer|checkout/cart/sidebar/default.phtml|simple|
  checkout/cart_item_renderer|checkout/cart/sidebar/default.phtml|grouped|
  checkout/cart_item_renderer_grouped|checkout/cart/sidebar/default.phtml|configurable|
  checkout/cart_item_renderer_configurable|checkout/cart/sidebar/default.phtml|bundle|
  bundle/checkout_cart_item_renderer|checkout/cart/sidebar/default.phtml”
• $_definition = CART_SIDEBAR
  container =”Enterprise_PageCache_Model_Container_Sidebar_Cart”
  block = “Mage_Checkout_Block_Cart_Sidebar”
  cache_id = “3ee95d5974c12590e902688083b2097637487b5d”
  cache_lifetime = “86400”
  template = “checkout/cart/cartheader.phtml”
  item_renders = “default|checkout/cart_item_renderer|checkout/cart/sidebar/default.phtml|simple|
  checkout/cart_item_renderer|checkout/cart/sidebar/default.phtml|grouped|
  checkout/cart_item_renderer_grouped|checkout/cart/sidebar/default.phtml|configurable|
  checkout/cart_item_renderer_configurable|checkout/cart/sidebar/default.phtml|bundle|
  bundle/checkout_cart_item_renderer|checkout/cart/sidebar/default.phtml”
• $_name = CART_SIDEBAR
• $_attributes = Array [6] container = Enterprise_PageCache_Model_Container_Sidebar_Cart
  block = Mage_Checkout_Block_Cart_Sidebar
  cache_id = 3ee95d5974c12590e902688083b2097637487b5d
  cache_lifetime = 86400
  template = checkout/cart/cartheader.phtml
  item_renders = default|checkout/cart_item_renderer|checkout/cart/sidebar/default.phtml|simple|
  checkout/cart_item_renderer|checkout/cart/sidebar/default.phtml|grouped|
  checkout/cart_item_renderer_grouped|checkout/cart/sidebar/default.phtml|configurable|
  checkout/cart_item_renderer_configurable|checkout/cart/sidebar/default.phtml|bundle|
  bundle/checkout_cart_item_renderer|checkout/cart/sidebar/default.phtml