Save Ajax response in Magento block html cache

Question

For this particular Magento EE site, I've got a controller that creates a block and returns it via Ajax.

$this->loadLayout();
$block = $this->getLayout()->createBlock('catalog/product_list_related','catalog.product.related')->setTemplate(...
$this->getResponse()->setBody($block->toHtml());

Simple enough. I'd like to cache the response with the key being SKU - CUSTOMER GROUP - DATE. I've put the appropriate methods in the block for setting key, tags and lifetime. All good.

However, nothing is saved to the cache.

I figured, since it's an EE site, that the Enterprise_PageCache placeholders were blocking it. But even after removing those, it's not saving.

I've been digging through app/code/core/Mage/Core/Block/Abstract.php to see what's going on. But I thought I'd check if there were any known "gotchas" with caching a block set by createBlock in controller.

Thanks! Wilson

Answer 1

Easy but tricky.

First you should insert the block throug the xml (it works better with the cache).

Second you have just to insert a pice of code like this one on the block file (ex: /fishpig/wordpress/block/post/post.php)

public function __construct(){
    parent::__construct();
    $this->addData(array(
        'cache_lifetime' => 86400, // lifetime on second
        'cache_tags'     => array(Mage_Core_Model_Store::CACHE_TAG, Mage_Cms_Model_Block::CACHE_TAG), // cache tag
        'cache_key'      => 'Fishpig_Wordpress_Block_Post_List_'.$this->getRequest()->getRequestUri() // cache unique ID IT MUST BE UNIQUE, MUST BE UNIQUE, MUST BE UNIQUE, MUST BE UNIQUE, MUST BE UNIQUE, MUST BE UNIQUE, MUST BE UNIQUE
    ));
}

If you need any help with that code i might be able to help you.