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

126 Part II ■ Programming in World of Warcraft## Author: My Name Here## Notes: This is my sample addonMyAddon.xmlMyAddon.luaEach line beginning with ## contains a definition of some sort of metadata.For example, the ## Title metadata is displayed on the addon selectionscreen, and ## Notes contains a longer description that is displayed when youmouse over the addon in that list. The lines after the directives are simply alist of files to be loaded by the addon.## Interface:## Interface: 30300The interface version directive (## Interface: 30300 in this example)provides a basic versioning mechanism that the client uses for the addonselection screen. The game client uses this number to verify that an addon iscompatible with the current game version. If the version is not compatible, thegame will label it with one of two states:Out of date—This state indicates that there has been a patch to the gameclient since the addon was written. This is strictly just a warning; theaddons may work just fine if you check ‘‘Load out of date AddOns’’ atthe top of the screen. The version number typically only changes whenthere is an actual change to the API, so this warning should be heeded.Incompatible—When a major change happens to the game client (suchas an expansion pack), the addon selection screen will display this statusand will refuse to load the addon. A new version of the addon should bedownloaded to ensure it operates correctly in the new API.Figure 8-1 shows two addons, one flagged as out of date and the otheras incompatible. TinyPad could be loaded by checking the Load out of dateAddOns checkbox, but nothing can force the incompatible addon to load.Figure 8-1: Addon selection screenJust because an addon is listed as out of date doesn’t mean there’s anythingparticularly wrong with it, only that the game client has been patched since the