docs/php/exceptions.md

   1 # Exceptions
   2
   3 ## SPL Exceptions
   4
   5 The [Standard PHP Library (SPL)](https://secure.php.net/manual/en/book.spl.php) provides some [exceptions](https://secure.php.net/manual/en/spl.exceptions.php) that should be used whenever possible.
   6
   7
   8 ## Custom Exceptions
   9
  10 !!! warning "Do not use `wcf\system\exception\SystemException` anymore, use specific exception classes!"
  11
  12 The following table contains a list of custom exceptions that are commonly used.
  13
  14 | exception | (examples) when to use |
  15 |-----------|------------------------|
  16 | `wcf\system\exception\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) |
  17 | `wcf\system\exception\ImplementationException` | a class does not implement an expected interface |
  18 | `wcf\system\exception\InvalidObjectTypeException` | object type is not of an expected object type definition |
  19 | `wcf\system\exception\InvalidSecurityTokenException` | given security token does not match the security token of the active user's session |
  20 | `wcf\system\exception\ParentClassException` | a class does not extend an expected (parent) class |
  21 | `wcf\system\exception\PermissionDeniedException` | page access without permission, action execution without permission (is shown as http 403 error to the user) |
  22 | `wcf\system\exception\UserInputException` | user input does not pass validation |