Modul:LuaWiki

--[=[ 2013-05-07 LuaWiki - Support Lua programming in Wiki environment

• .getArg()
• .initVariables()
• .getVariable()
• .isExisting()
• .setFrame()
• .transclude()

]=]

-- Module globals local wikiVariables local LuaWiki = {}

LuaWiki.error = function ( about )

   -- Enclose errorMsg with 
   -- Precondition:
   --     about  -- string
   local r = about
   if type( about ) == "string" then
       if #about == 0 then
           r = "Error in Lua"
       end
   else
       r = tostring( about )
   end
   return ""

end -- LuaWiki.error()

LuaWiki.getArg = function ( arg, assign )

   -- Retrieve template argument
   -- Precondition:
   --     arg     -- string or number; argument identifier
   --     assign  -- any, optional; default value
   -- Uses:
   --     mw.getCurrentFrame()
   local r = mw.getCurrentFrame().args[ arg ]
   if type( r ) ~= "string" then
       if type( assign ) == nil then
           r = "{{{<" .. arg .. ">}}}"
       else
           r = assign
       end
   end
   return r

end -- LuaWiki.getArg()

LuaWiki.getVariable = function ( seek, numeric )

   -- Retrieve item from wikiVariables; populate if not yet present
   -- Precondition:
   --     seek     -- string; name of variable
   --     numeric  -- true: seek is numeric (else string)
   -- Uses:
   --     >< wikiVariables
   --     mw.getCurrentFrame()
   local g, i, n
   local r = false
   if type( wikiVariables ) == "table" then
       n = #wikiVariables
       for i = 1, n do
           g = wikiVariables[ i ]
           if g then
               if g[ 1 ] == seek then
                   r = g[ 2 ]
                   break;
               end
           end
       end -- for i
   else
       wikiVariables = { }
       n = 0
   end
   if not r then
       g = mw.getCurrentFrame():preprocess( "Vorlage:" .. seek .. "" )
       r = mw.ustring.match( g, "^(.*)$" )
       if numeric then
           r = tonumber( g )
       end
       table.insert( wikiVariables,  n + 1,  { seek, r } )
   end
   return r

end -- LuaWiki.getVariable()

LuaWiki.initVariables = function ( request )

   -- Initialize wikiVariables
   -- Precondition:
   --     request  -- table; every element either
   --                        * string; name of variable
   --                        * table; name string and true, if numeric
   -- Uses:
   --      < wikiVariables
   --     mw.getCurrentFrame()
   local g, i, n, s
   local src = "|"
   wikiVariables = { }
   for i = 1, #request do
        s = request[ i ]
        if type( s ) == "table" then
            s = s[ 1 ]
        end
        src = src .. s .. "=Vorlage:" .. s .. "|"
   end -- for i
   src = mw.getCurrentFrame():preprocess( src )
   for i = 1, #request do
       s = request[ i ]
       n = ( type( s ) == "table" )
       if n then
           n = s[ 2 ]
       end
       if n then
           g = "-?%d+"
           s = s[ 1 ]
       else
           g = "[^|]*"
       end
       g = mw.ustring.match( src,  "|" .. s .. "=(" .. g .. ")|" )
       if n then
           g = tonumber( g )
       end
       table.insert( wikiVariables,  i,  { s, g } )
   end -- for i

end -- LuaWiki.initVariables()

LuaWiki.isExisting = function ( seek )

   -- Return true if page exists, else false
   -- Precondition:
   --     seek  -- string; full page name
   -- Uses:
   --     mw.getCurrentFrame()
   local g = mw.getCurrentFrame():callParserFunction( "#ifexist",
                                                      { seek,
                                                        "1",
                                                        "0" } )
   return ( g == "1" )

end -- LuaWiki.isExisting()

LuaWiki.transclude = function ( s, args )

   -- Save transclusion of a page, or error message
   -- Precondition:
   --     s     -- string; page name
   --     args  -- table or nil; arguments
   -- Uses:
   --     mw.getCurrentFrame()
   --     error()
   local r = { s, "1" }
   local frame = mw.getCurrentFrame()
   if frame:callParserFunction( "#ifexist", r ) == "1" then
       if args then
           r = frame:expandTemplate{ title = s, args = args }
       else
           r = frame:expandTemplate{ title = s }
       end
   else
       r = error( "No transclude page '" .. s .. "'" )
   end
   return r

end -- LuaWiki.transclude()

return LuaWiki