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

144 Part II ■ Programming in World of WarcraftCreating an Addon SkeletonBagBuddy consists of an XML definition of the frames, and a Lua scriptthat defines the behavior and logic of the addon. Start by creating a newdirectory within your Interface\AddOns folder called BagBuddy. Inside thisnew directory create a file called BagBuddy.toc and add the following content:## Interface: 30200## Title: BagBuddy## Notes: A handy helper that allows you to filter your inventoryBagBuddy.luaBagBuddy.xmlNow create BagBuddy.xml, adding just the basic definition of the element that you have seen before:Finally, create an empty file called BagBuddy.lua. You won’t be adding anycode to it for the next few chapters, but creating it now ensures that the WoWclient will recognize the file without needing to be restarted.Creating a FrameThe World of Warcraft user interface is based around the central concept offrames. All textures and font strings must belong to a parent frame. Framescan register for events and receive notification of game events. In addition, theuser can interact with frames, for example by clicking them. As a result, mostaddons begin with a definition of a frame. BagBuddy is no different.In BagBuddy.xml, add the following code inside the element:This code creates a new frame called BagBuddy that is a child of UIParent.The frame is given a width of 384 and a height of 512, and is anchored to thecenter of UIParent, making it appear in the middle of the player’s screen.