Answered How to send an automatic email-notification when the cache is cleared by someone?

Can anybody tell me where I have to add code-lines to send an email to me when somebody clears the cache (either directly or by saving/updating a resource/chunk or snippet)? In 'System Events' of Plugins I found OnBeforeCacheUpdate, OnBeforeSaveWebPageCache, OnCacheUpdate and OnLoadWebPageCache. Is one of these events maybe proper to realize this?

And can I add informations in the email who has cleared the cache by which action?

Does anybody know this? Would be great!

OnSiteRefresh is, I believe, the event for when the Manager menu item is used. Any plugin using that event could easily enough indicate who did it, in fact that information is available in the manager actions report.

As far as when the cache is cleared automatically, I don't know of a way to detect that. Using On<Whatever>Save wouldn't be very reliable, because the "clear cache on save" checkbox could always have been cleared so the cache wouldn't have been cleared.

There isn't any way for MODX to detect when someone manually deletes the cache. That would have to be done by some kind of server script, such as iWatch http://iwatch.sourceforge.net/documentation.html

Hi Susan,
maybe I can add some code-lines to the snippet which empties the cache (to send me an email on emptying the cache)? Do you know which snippet/file empties the cache?

There are also system events for a user deleting folders and files using the Manager's file browser - OnFileManagerDirRemove and OnFileManagerFileRemove.

It would be easy to do, but you'll get an email every time a resource, TV, Template, Chunk, Snippet, or Plugin is saved in the Manager and your code could be overwritten when you upgrade MODX.

There is a System Event called OnBeforeCacheUpdate. I think it only fires when the user clears the cache manually, but I'm not sure. You could connect a plugin to it that sent and email (or for a quick check, just writes to a chunk or file) and find out.

Create a chunk called 'CacheUpdates'.

Put this code in a plugin attached to OnBeforeCacheUpdate:




You can look a the chunk and see how often the cache was cleared. If it does what you want, send an email in the plugin code instead of writing to the chunk.

Examining the modcachemanager.class.php file, it has this at the very end

So it looks like a plugin using onCacheUpdate might do something.

However, that would only be for any time MODX is used to clear the cache. Actually deleting files using the File Manager or FTP would require other means. Using the File Manager can be dealt with in the plugin by listening for those two events, but deleting files via FTP or SSH is done without MODX ever being run, so MODX would have no way of monitoring such activity. It is possible for MODX to scan the file system and report changes when it is executed, but that's all it could do. Evolution has a security feature that checks certain key files to report changes to them, displaying the report in a tab in the Welcome page.

No, that event is invoked at the end of the clearCache() function, so it looks like that's only invoked in the case of using the Clear Cache menu item.

So BobRay's solution would have to be used for elements, but you'd need to check to make sure the "Clear Cache on Save" checkbox was checked or you'd possibly get false positives.

Hi Susan and Bob,
thank you so much!