Find solution for missing $resource in Translation\DatabaseLoader.php

[maschmann]

The MessageCatalogue in DatabaseLoader still has no $resource set when created. So the caching will not be triggered to refresh the translations cachefile.
Since this is complete file-based at the moment (symfony-wise), the resource is a file resource and sf watches for changes in timestamp.
A few thoughts:

• Since dumping the database content is acceptably fast, we might want to refresh the translations at specific time intervals? But what happens if people use files AND database (vendor translations...)?
• If history is completed, we could dump as soon as there's a change in the history table. Therefore we'd need a new type of resource object.
• Completely ignore? In my specific case here, we're deploying symfony and every time there's a complete cache build, so all translations are dumped.

Resolution:

• Implement new resource class "DatabaseResource"
• Add resource factory service(?) or possibly use existing one
• save updated-date from latest database entry as resource "filetime" and compare to latest entry on next call

This should keep translation MessageCatalogue in cache as consistent and current as the file-based checks.