I am quite new to PHP and now I am trying to add a new file upload page.
When I try to study the OCS codes, I found that HookRegistry::call must be excute first. May I know the purpose of this?
Could you ellobrate by this example?
uploadLayoutVersion function in classes\submission\trackDirector\TrackDirectorAction.inc.php
if ($paperFileManager->uploadedFileExists($fileName) && !HookRegistry::call('TrackDirectorAction::uploadLayoutVersion', array(&$submission))
Sorry for my silly question.