Modul:Autocategories

Moduldokumentasjon
-- module for replicating categories listed at Wikidata
-- © John Erling Blad, Creative Commons by Attribution 3.0

-- don't pollute with globals
require('Module:No globals')

-- @var our exposed table
local Autocategories = {}

-- find the first entry that seems to be a Q-id
-- @param table args argument list from the frame
-- @return string first matching argument
function Autocategories._findQid( args )
	for key, value in ipairs( args ) do
		if value ~= '' and string.match(value, '^Q%d+$') then
			return value
		end
	end
	local entity = mw.wikibase.getEntity()
	if entity then
		return entity['id']
	end
	return nil
end

-- value for all statements
-- @param table statement well-defined structure for a statement
-- @return values for the provided statements
function Autocategories._findValue(statements)
	local values = {}
	for _,statement in pairs(statements) do
		local mainsnak = statement["mainsnak"]
		if mainsnak then
			local datavalue = mainsnak['datavalue']
			if datavalue then
				local value = datavalue['value']
				if value then
					values[1+#values] = value
				end
			end
		end
	end
	return values
end

-- find the P-ids from the argument lists
-- note that this maintain argument sequence
-- @param table vector forwarded from the method call
-- @return table hash of matching arguments
function Autocategories._findPids( pids, args )
	for _,value in pairs( args ) do
		local _,_,action,pid = string.find(value, '^%s*(!?)(P%d+)%s*$')
		if pid then
			pids[pid] =  action == '' and true or nil
		end
	end
	return pids
end

-- load a list of statements and format the entries according to build directive
-- @param string id some entity to load
-- @param string properety id for the property to use
-- @return table
function Autocategories._loadStatements( id, prop )
	local entity = id and mw.wikibase.getEntity( id ) or mw.wikibase.getEntity()
	statements = entity:getBestStatements( prop )
	if not statements then
		return {}
	end
	return statements
end

-- find the P-ids from the frame lists
-- note that this does not maintain argument sequence
-- @param table frames forwarded from the method call
-- @return table hash of matching arguments
function Autocategories.findPids( ... )
	local pids = {}
	for i = 1,arg.n do
		local frame = arg[i]
		pids = Autocategories._findPids( pids, frame.args )
	end
	
	local keys = {}
	for key,_ in pairs( pids ) do
		keys[1+#keys] = key
	end
	return keys
end

-- do all allowable categorizations
-- @param table frame arguments from invoke
-- @return string status report during development, should be an empty string
function Autocategories.run( frame )
	--local qid = Autocategories._findQid( frame.args )
	--first call is when the call is encapsulated in a template
	local pids = frame:getParent() and Autocategories.findPids( frame, frame:getParent() ) or Autocategories.findPids( frame )
	if #pids == 0 then
		return ''
	end
	local entity = mw.wikibase.getEntity()
	if not entity then
		return ''
	end
	for _,pid in pairs(pids) do
		-- local statements = Autocategories._loadStatements( qid, pid )
		local statements = entity:getBestStatements( pid )
		if not statements then
			return ''
		end
		return mw.dumpObject( Autocategories._findValue( statements ) )
	end
	
	--return table.concat( pids, ', ' )
	return mw.dumpObject(pids)
end

-- export the accesspoint
return Autocategories