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

470 Part III ■ Advanced Addon TechniquesThese define the consistent parts of the button behavior. All these menuitems will be spell buttons, and they will cast on the unit whose frame wasclicked to bring up the spell menu. Note that you use the type tag attributeheretosettheframeattributetoavaluewiththeLuatype“boolean“.Add a Scripts section immediately after the Attributes block and beforethe tag:self:GetFontString():SetPoint(“LEFT“, self.icon, “RIGHT“, 2, 1)self:RegisterEvent(“PLAYER_ENTERING_WORLD“)The first line ensures that the button’s text is placed correctly in the button(because the icon texture is created using a key rather than a name, you can’tcurrently refer to it from an XML tag’s relativeTo attribute). The lastline prepares the button to deal with the fact that its spell icon isn’t availablewhen your addon first loads, which is fully addressed in the next handler (addit right before the tag):self.icon:SetTexture(GetSpellTexture(self:GetAttribute(“spell“)))This handler is run in response to the PLAYER_ENTERING_WORLD event, whenthe client has fully loaded spell icons. These icons are actually loaded by theearlier SPELLS_CHANGED event, but that event does not fire when you reload theUI, so the more reliable PLAYER_ENTERING_WORLD is used. Also, if you watchevent traces, you will see that the SPELL_CHANGED event fires quite a numberof times during logging in. Waiting until the PLAYER_ENTERING_WORLD eventhelps you avoid all of these.Paladins use three major groups of beneficial spells, so you’ll create threemenus, one for each. To facilitate that, create a menu template in the same file,right before the tag: