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SPL Exceptions#

The Standard PHP Library (SPL) provides some exceptions that should be used whenever possible.

Custom Exceptions#

Do not use wcf\system\exception\SystemException anymore, use specific exception classes!

The following table contains a list of custom exceptions that are commonly used. All of the exceptions are found in the wcf\system\exception namespace.

Class name (examples) when to use
IllegalLinkException access to a page that belongs to a non-existing object, executing actions on specific non-existing objects (is shown as http 404 error to the user)
ImplementationException a class does not implement an expected interface
InvalidObjectArgument 5.4+ API method support generic objects but specific implementation requires objects of specific (sub)class and different object is given
InvalidObjectTypeException object type is not of an expected object type definition
InvalidSecurityTokenException given security token does not match the security token of the active user's session
ParentClassException a class does not extend an expected (parent) class
PermissionDeniedException page access without permission, action execution without permission (is shown as http 403 error to the user)
UserInputException user input does not pass validation

Last update: 2021-01-12