TYPO3 Core

It would be useful to have more control over the link checking.

Requirements:

• make it possible to deactivate external link checking entirely (and e.g. let this be done by external task). Using the cache makes it possible - all external URLs to be checked are written to the cache, but not checked
• do not check for an URL multiple times - store the result and reuse it. (this is currently already done but only within one batch - the result is stored in an array in ExternalLinktype). But when a new checklink task is started, all URLs are rechecked again.

In general there could be 3 different modes:

• default: use URL from cache if not expired. If not in cache, check and write to cache
• noCache: never use cache
• cacheOnly : only use cache. If URL is not in cache, treat it like a valid URL - it is not written to broken links table.

see https://decisions.typo3.org/t/linkvalidator-when-to-do-the-link-checking/653

This would solve a number of other problems:

• more checking could be done on the fly, e.g. when saving a record
• in general, less external link checking would be performed