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

Appendix B ■ Utilizing Addon Libraries 1333or a lower minor version, the initialization process can safely returnimmediately.3. If a version exists but the minor version of the existing instance is lessthan the one being loaded, then this instance should replace (or upgrade)the existing instance with itself.4. If the major version does not already exist, the library should simply beloaded.Using embedded libraries, multiple copies of the library may be loaded andthen thrown away, which can increase load times. This would only happen inthe situation where addons loaded in a specific order had increasing minorversions of the same library. In addition, the library author needs to be sensitiveto the potential upgrade process, and should test the library thoroughly beforereleasing a minor version update to a library.Manually Versioning an Embedded LibraryThe code to manage the versioning of your library can be as simple as thefollowing:local minor_version = 501if MyLibraryName and minor_version < MyLibraryName.minor then-- This version is old, so don’t load itreturnend-- Library definition hereMyLibraryName = {}function MyLibraryName.createDebugFunc(prefix)return function(...)local succ, message = pcall(string.format, ...)if succ thenprint(“|cffff1100“ .. prefix .. “: |r“, message)elseprint(“|cffff1100“ .. prefix .. “: |r“, tostringall(...))endendendendIn this case the major version name is MyLibraryName, and the minor versionis 501. The code first checks to see if the major version exists and, if it does,compares the two minor versions. If the minor version being loaded is lessthan the one that already exists, the code returns.