Wiley-World.of.Warcraft.Programming.A.Guide.and.Reference.for.Creating.WoW.Addons

1326 Part V ■ AppendixesEntering | into the Chat Edit BoxBecause World of Warcraft uses the | character in its color codes andhyperlinks, any that are entered in the edit box are automatically escapedto a double ||. This can be problematic when running Lua scripts with the/script and /run commands. You can substitute the sequence \124 instead ofthe actual character to get around this limitation.‘‘Missing’’ FramesWhen you create a frame in your addon you expect it to be visible. If you can’tfind your frame, it may be missing due to not meeting one of the followingrequirements:The frame must have some visual component, such as a texture, backdrop,or text element.The frame must not be set as hidden in the XML file, or the frame’s Show()method must have been called to explicitly show the frame.Each frame that is a parent of the frame must also be shown. This includesthe frame’s parent, the parent’s parent, and so on.The frame must be anchored somewhere within the bounds of the screen.It’s easy to spend time digging through your code only to find later thatyou’ve forgotten to place the frame on the screen.Ignoring Logs\FrameXML.logWhen working on XML, there are two places to check to ensure the file is beingparsed and validated properly:Load the file in some program that can indicate that the file is well-formed.This could include most web browsers or a more complex XML editor/validator.Check the Logs\FrameXML.log file to ensure there weren’t any errorsparsing the file.Not Checking API ReturnsThere are times when the Blizzard API functions may return somethingother than what you’d expect. For example, there’s a small period of timewhere UnitClass(unit) can return nil when you’d expect a class name to bereturned. If you use these function returns in some other computation, such asindexing a table or calling another function, you may get an error somewherealong the line.