For example, we have some of our own filters in a "Webready" class structure so we have:

Zend_Filter::addDefaultNamespaces( array('Webready_Filter', 'Zend_Filter') );

but this causes an error if the filter only exists in the zend library:

$filtered = Zend_Filter::filterStatic( 'testTest', 'Word_CamelCaseToUnderscore' ) );

ERROR: include(Webready/Filter/Word/CamelCaseToUnderscore.php): failed to open stream: No such file or directory Zend/Loader.php:83 Zend/Loader.php:83 Zend/Loader/Autoloader.php:474 Zend/Loader/Autoloader.php:130 Zend/Filter.php:172

The above error is "valid" since it's true that the file doesn't exist in our library but it does in Zend.

The problem is two fold. First Zend_Filter::filterStatic has:

if (!class_exists($className)) { try { Zend_Loader::loadClass($className); } catch (Zend_Exception $ze) { continue; } }

The class_exists needs a false as the second argument otherwise class exists invokes the autoloader.

Second, if you add false, the loadClass still attempts to load the file without checking if it exists first:

Error: include(Webready/Filter/Word/CamelCaseToUnderscore.php): failed to open stream: No such file or directory Zend/Loader.php:83 Zend/Loader.php:83 Zend/Filter.php:174