libs/LibStub/LibStub.lua

   1 -- LibStub is a simple versioning stub meant for use in Libraries.  http://www.wowace.com/wiki/LibStub for more info
   2 -- LibStub is hereby placed in the Public Domain Credits: Kaelten, Cladhaire, ckknight, Mikk, Ammo, Nevcairiel, joshborke
   3 local LIBSTUB_MAJOR, LIBSTUB_MINOR = "LibStub", 2  -- NEVER MAKE THIS AN SVN REVISION! IT NEEDS TO BE USABLE IN ALL REPOS!
   4 local LibStub = _G[LIBSTUB_MAJOR]
   5
   6 if not LibStub or LibStub.minor < LIBSTUB_MINOR then
   7         LibStub = LibStub or {libs = {}, minors = {} }
   8         _G[LIBSTUB_MAJOR] = LibStub
   9         LibStub.minor = LIBSTUB_MINOR
  10
  11         function LibStub:NewLibrary(major, minor)
  12                 assert(type(major) == "string", "Bad argument #2 to `NewLibrary' (string expected)")
  13                 minor = assert(tonumber(strmatch(minor, "%d+")), "Minor version must either be a number or contain a number.")
  14
  15                 local oldminor = self.minors[major]
  16                 if oldminor and oldminor >= minor then return nil end
  17                 self.minors[major], self.libs[major] = minor, self.libs[major] or {}
  18                 return self.libs[major], oldminor
  19         end
  20
  21         function LibStub:GetLibrary(major, silent)
  22                 if not self.libs[major] and not silent then
  23                         error(("Cannot find a library instance of %q."):format(tostring(major)), 2)
  24                 end
  25                 return self.libs[major], self.minors[major]
  26         end
  27
  28         function LibStub:IterateLibraries() return pairs(self.libs) end
  29         setmetatable(LibStub, { __call = LibStub.GetLibrary })
  30 end