This makes filters more plugginable, becuase with this lang file name, get_string will look for the filter name in filter/myfilter/lang/en_utf8/filter_myfilter.php.
To do this, there is a new function filter_get_name in filterlib that contains the logic.
Also, a new function filter_get_all_installed to replace the logic for getting all filters that was duplicated in three places.
filter_get_name no longer does such a nice fall-back if the name is missing, to encourage people to supply the right string. The fallback now looks like '[[filtername]] (filter/tidy)'.
MDL-18669 get_string refactored to elimiate duplicate code and make it easier to understand.
MDL-17763 parent language not processed correctly when getting a plugin string.
MDL-16181 more intelligent caching to avoid repeated file_exists checks.
MDL-12434 move values to array keys to improve lookup times.
The main part of the refactoring is to create a singleton string_manager class to encapsulate the cached data and the processing, while breaking the code up into more smaller methods.
Other performance improvements include:
* Cache results of plugin name -> locations to search array.
* Cache parent lang lookup.
* Skip eval if the string does not contain $ \ or %.
* Remove the unnecessary sprintf from the eval.
There is a performance testing script in lib/simpletest/getstringperformancetester.php. For now this script has the old get_string implementation copied and pasted to the end, and renamed to old_get_string to allow for comparitive timings.
There are now some unit tests for get_string in lib/simpletest/teststringmanager.php. I think I have managed to cover most of the tricky cases.
Before this change, the full name of the resource type had to be stored in the "resource" namespace (for example in /mod/resource/lang/en_utf8/resource.php).
Now it can be put in the "resource_foo" namespace:
e.g. in /mod/resource/type/foo/lang/en_utf8/resource_foo.php:
<?php
$string['resourcetypefoo'] = 'Link to a Foo Bar document';
?>
