Clearing the cache

When data is imported into your TYPO3 CMS installation, you may want to clear the cache for a number of pages in order for the new data to be displayed as soon as it is available. One way to achieve this is to rely purely on TYPO3 CMS and use the TSconfig property:

TCEMAIN.clearCacheCmd = xx,yy

on the page(s) where the data is stored to automatically trigger the clearing of the cache for the given pages (xx and yy) when any record they contain is modified or deleted, or some new record inserted.

This works fine but has one big drawback: it is triggered for each record. If you manipulate a lot of records, the cache clearing may be called hundreds or thousands of times. This can be very bad for your site, especially if you have a very large cache.

It is also possible to trigger the clearing of the cache after the whole import process has completed for a given configuration. Instead of using TSconfig, the configuration would be something like:

$GLOBALS['TCA']['tx_news_domain_model_news']['external']['general']['0']['clearCache'] = 'xx,yy';

This will clear the cache for pages "xx" and "yy", but only after all records have been inserted, updated and deleted. The process still relies on DataHandler for clearing the cache of each page, so you may rely on the usual clear cache hooks if needed.

Besides page numbers, you can also use more general cache identifiers like "pages" (to clear the cache for all pages), cache tags, or any other value that can be used with TCEMAIN.clearCacheCmd.