How to restrict magento footer content to get cached

Question

I don't want footer content and static blocks to get cached due to presence of some dynamic content in it. How Can I do it from code.

Answer 1

You can add an observer on this event: core_block_abstract_to_html_before

    <global>
        ...
        <events>
            <core_block_abstract_to_html_before>
                <observers>
                    <your_observer_key>
                        <class>yourmodule/observer</class>
                        <method>cleanFooterCache</method>
                    </your_observer_key>
                </observers>
            </core_block_abstract_to_html_before>
        </events>
        ...
    </global>

Then in your observer method:

public function cleanFooterCache(Varien_Event_Observer $observer)
{
    if (!Mage::app()->getStore()->isAdmin()) {
        $block = $observer->getEvent()->getBlock();
        if ($block instanceof Mage_Page_Block_Html_Footer || $block instanceof Mage_Cms_Block_Block) {

            //Get the cache instance, because Mage::app()->cleanCache($tags=array()); cleans by any matching tag.
            $cacheModel = Mage::app()->getCacheInstance();
            $mode = Zend_Cache::CLEANING_MODE_MATCHING_TAG;
            $cacheTags = $block->getCacheTags(); //This method is available in Mage_Core_Block_Abstract

            //Copy the methods _tags() and _id() functionality from Mage_Core_Model_Cache
            foreach ($cacheTags as $key => $value) {
                $cacheTags[$key] = $value? strtoupper($value) : $value; 
            }
            //Clean the cache for the given tags.
            $cacheModel->getFrontend()->clean($mode, $cacheTags);
        }
    }
}

Answer 2

Write Below code in your local.xml or any other your custom layout file and your footer will not be cache

<reference name="footer">
    <action method="setCacheLifetime"><lifetime>null</lifetime></action>
</reference>