Module:WikidataIB

Documentation for this module may be created at Module:WikidataIB/doc

-- Module to implement use of a blacklist and whitelist for infobox fields
-- Can take a named parameter |qid which is the Wikidata ID for the article
-- if not supplied, it will use the Wikidata ID associated with the current page.
-- Fields in blacklist are never to be displayed, i.e. module must return nil in all circumstances
-- Fields in whitelist return local value if it exists or the Wikidata value otherwise
-- The name of the field that this function is called from is passed in named parameter |name
-- The name is compulsory when blacklist or whitelist is used,
-- so the module returns nil if it is not supplied.
-- blacklist is passed in named parameter |suppressfields (or |spf)
-- whitelist is passed in named parameter |fetchwikidata (or |fwd)

local p = {}

local i18n =
{
	["errors"] =
	{
		["property-not-found"] = "Property not found.",
		["No property supplied"] = "No property supplied",
		["entity-not-found"] = "Wikidata entity not found.",
		["unknown-claim-type"] = "Unknown claim type.",
		["unknown-entity-type"] = "Unknown entity type.",
		["qualifier-not-found"] = "Qualifier not found.",
		["site-not-found"] = "Wikimedia project not found.",
		["unknown-datetime-format"] = "Unknown datetime format.",
		["local-article-not-found"] = "Article is available on Wikidata, but not on Wikipedia",
		["dab-page"] = " (dab)",
	},
	["months"] =
	{
		"January", "February", "March", "April", "May", "June", "July",
		"August", "September", "October", "November", "December"
	},
	["century"] = "century",
	["BC"] = "BC",
	["BCE"] = "BCE",
	["ordinal"] =
	{
		[1] = "st",
		[2] = "nd",
		[3] = "rd",
		["default"] = "th"
	},
	["filespace"] = "File",
	["Unknown"] = "Unknown",
	["NaN"] = "Not a number",
	["editonwikidata"] = "Edit this on Wikidata",
	["latestdatequalifier"] = function (date) return "before " .. date end,
	-- some languages, e.g. Bosnian use a period as a suffix after each number in a date
	["datenumbersuffix"] = "",
	["list separator"] = ", ",
	["abbr"] =
	{
		["Q828224"]  = "km",
		["Q11573"]   = "m",
		["Q174728"]  = "cm",
		["Q174789"]  = "mm",
		["Q712226"]  = "sq km",
		["Q11570"]   = "kg",
		["Q41803"]   = "g",
		["Q3241121"] = "mg",
		["Q2332346"] = "ml",
		["Q7727"]    = "min",
		["Q11574"]   = "s",
	},
}
-- This allows a internationisation module to override the above table
require("Module:i18n").loadI18n("Module:WikidataIB/i18n", i18n)

-- This piece of html implements a collapsible container. Check the classes exist on your wiki.
local collapsediv = '<div class="mw-collapsible mw-collapsed" style="width:100%; overflow:auto;" data-expandtext="{{int:show}}" data-collapsetext="{{int:hide}}">'

-------------------------------------------------------------------------------
-- Private functions
-------------------------------------------------------------------------------
--
-------------------------------------------------------------------------------
-- makeOrdinal needs to be internationalised along with the above:
-- takes cardinal numer as a numeric and returns the ordinal as a string
-- we need three exceptions in English for 1st, 2nd, 3rd, 21st, .. 31st, etc.
-------------------------------------------------------------------------------
local function makeOrdinal(cardinal)
	local ordsuffix = i18n.ordinal.default
	if cardinal % 10 == 1 then
		ordsuffix = i18n.ordinal[1]
	elseif cardinal % 10 == 2 then
		ordsuffix = i18n.ordinal[2]
	elseif cardinal % 10 == 3 then
		ordsuffix = i18n.ordinal[3]
	end
	-- In English, 1, 21, 31, etc. use 'st', but 11, 111, etc. use 'th'
	-- similarly for 12 and 13, etc.
	if (cardinal % 100 == 11) or (cardinal % 100 == 12) or (cardinal % 100 == 13) then
		ordsuffix = i18n.ordinal.default
	end
	return tostring(cardinal) .. ordsuffix
end


-------------------------------------------------------------------------------
-- findLang takes a "langcode" parameter if supplied
-- otherwise it tries to create it from the user's set language ({{int:lang}})
-- failing that it uses the wiki's content language.
-- It returns a language object
-------------------------------------------------------------------------------
local function findLang(langcode)
	local langobj
	if not langcode or langcode == "" then
		langcode = mw.getCurrentFrame():preprocess( '{{int:lang}}' )
	end
	if mw.language.isKnownLanguageTag(langcode) then
		langobj = mw.language.new( langcode )
	else
		langobj = mw.language.getContentLanguage()
	end
	return langobj
end


-------------------------------------------------------------------------------
-- roundto takes a positive number (x)
-- and returns it rounded to (sf) significant figures
-------------------------------------------------------------------------------
local function roundto(x, sf)
	if x == 0 then return 0 end
	x = math.abs(x)
	if sf < 1 then sf = 1 end
	local e = math.floor(math.log10(x)) - sf + 1
	local m = math.floor(x / 10^e + 0.5)
	x = m * 10^e
	-- if it's integral, cast to an integer:
	if  x == math.floor(x) then x = math.floor(x) end
	return x
end


-------------------------------------------------------------------------------
-- decimalToDMS takes a decimal degrees (x) with precision (p)
-- and returns degrees/minutes/seconds according to the precision
-------------------------------------------------------------------------------
local function decimalToDMS(x, p)
	-- if p is not supplied, use a precision around 0.1 seconds
	if not tonumber(p) then p = 1e-4 end
	local d = math.floor(x)
	local ms = (x - d) * 60
	if p > 0.5 then -- precision is > 1/2 a degree
		if ms > 30 then d = d + 1 end
		ms = 0
	end
	local m = math.floor(ms)
	local s = (ms - m) * 60
	if p > 0.008 then -- precision is > 1/2 a minute
		if s > 30 then m = m +1 end
		s = 0
	elseif p > 0.00014 then -- precision is > 1/2 a second
		s = math.floor(s + 0.5)
	elseif p > 0.000014 then -- precision is > 1/20 second
		s = math.floor(10 * s + 0.5) / 10
	elseif p > 0.0000014 then -- precision is > 1/200 second
		s = math.floor(100 * s + 0.5) / 100
	else -- cap it at 3 dec places for now
		s = math.floor(1000 * s + 0.5) / 1000
	end
	return d, m, s
end


-------------------------------------------------------------------------------
-- decimalPrecision takes a decimal (x) with precision (p)
-- and returns x rounded approximately to the given precision
-- precision should be between 1 and 1e-6, preferably a power of 10.
-------------------------------------------------------------------------------
local function decimalPrecision(x, p)
	-- if p is not supplied, pick an arbitrary precision
	if not tonumber(p) then p = 1e-4 end
	if p > 1 then p = 1 end
	if p < 1e-6 then p = 1e-6 end
	local e = math.floor(math.log10(p))
	local m = math.floor(x / 10^e + 0.5)
	x = m * 10^e
	-- if it's integral, cast to an integer:
	if  x == math.floor(x) then x = math.floor(x) end
	-- if it's less than 1e-4, it will be in exponent form, so return a string with 6dp
	-- 9e-5 becomes 0.000090
	if math.abs(x) < 1e-4 then x = string.format("%f", x) end
	return x
end


-------------------------------------------------------------------------------
-- formatDate takes a datetime of the usual format from mw.wikibase.entity:formatPropertyValues
-- like "1 August 30 BCE" as parameter 1
-- and formats it according to the df (date format) and bc parameters
-- df = ["dmy" / "mdy" / "y"] default will be "dmy"
-- bc = ["BC" / "BCE"] default will be "BCE"
-------------------------------------------------------------------------------
local format_Date = function(datetime, dateformat, bc)
	local datetime = datetime or "1 August 30 BCE" -- in case of nil value
	-- chop off multiple vales and/or any hours, mins, etc.
	-- keep anything before punctuation - we just want a single date:
	local dateval = string.match( datetime, "[%w ]+")

	local dateformat = string.lower(dateformat or "dmy") -- default to dmy

	local bc = string.upper(bc or "") -- can't use nil for bc
	-- we only want to accept two possibilities: BC or default to BCE
	if bc == "BC" then
		bc = "&nbsp;" .. i18n["BC"] -- prepend a non-breaking space.
	else
		bc = "&nbsp;" .. i18n["BCE"]
	end

	local postchrist = true -- start by assuming no BCE
	local dateparts = {}
	for word in string.gmatch(dateval, "%w+") do
		if word == "BCE" or word == "BC" then -- **internationalise later**
			postchrist = false
		else
			-- we'll keep the parts that are not 'BCE' in a table
			dateparts[#dateparts + 1] = word
		end
	end
	if postchrist then bc = "" end -- set AD dates to no suffix **internationalise later**

	local sep = "&nbsp;" -- separator is nbsp
	local fdate = table.concat(dateparts, sep) -- set formatted date to same order as input

	-- if we have day month year, check dateformat
	if #dateparts == 3 then
		if dateformat == "y" then
			fdate = dateparts[3]
		elseif dateformat == "mdy" then
			fdate = dateparts[2] .. sep .. dateparts[1] .. "," .. sep .. dateparts[3]
		end
	elseif #dateparts == 2 and dateformat == "y" then
		fdate = dateparts[2]
	end

	return fdate .. bc
end


-------------------------------------------------------------------------------
-- parseParam takes a (string) parameter, e.g. from the list of frame arguments,
-- and makes "false", "no", and "0" into the (boolean) false
-- it makes the empty string and nil into the (boolean) value passed as default
-- allowing the parameter to be true or false by default.
-------------------------------------------------------------------------------
local parseParam = function(param, default)
	if param and param ~= "" then
		param = param:lower()
		if (param == "false") or (param == "no") or (param == "0") then
			return false
		else
			return true
		end
	else
		return default
	end
end


-------------------------------------------------------------------------------
-- The label in a Wikidata item is subject to vulnerabilities
-- that an attacker might try to exploit.
-- It needs to be 'sanitised' by removing any wikitext before use.
-- If it doesn't exist, return the id for the item
-- a second (boolean) value is also returned, value is true when the label exists
-------------------------------------------------------------------------------
local labelOrId = function (id)
	local label = mw.wikibase.label(id)
	if label then
		return mw.text.nowiki(label), true
	else
		return id, false
	end
end


-------------------------------------------------------------------------------
-- sourced takes a table representing a statement that may or may not have references
-- it counts how many references are sourced to something not containing the word "wikipedia"
-- it returns a boolean = true if there are any sourced references.
-------------------------------------------------------------------------------
local sourced = function(claim)
	if claim.references then
		for kr, vr in pairs(claim.references) do
			local ref = mw.wikibase.renderSnaks(vr.snaks)
			if not ref:find("Wikipedia") then
				return true
			end
		end
	end
end


-------------------------------------------------------------------------------
-- setRanks takes a flag (parameter passed) that requests the values to return
-- "b[est]" returns preferred if available, otherwise normal
-- "p[referred]" returns preferred
-- "n[ormal]" returns normal
-- "d[eprecated]" returns deprecated
-- multiple values are allowed, e.g. "preferred normal" (which is the default)
-- "best" will override the other flags, and set p and n
-------------------------------------------------------------------------------
local function setRanks(rank)
	rank = (rank or ""):lower()
	-- if nothing passed, return preferred and normal
	-- if rank == "" then rank = "p n" end
	local ranks = {}
	for w in string.gmatch(rank, "%a+") do
		w = w:sub(1,1)
		if w == "b" or w == "p" or w == "n" or w == "d" then
			ranks[w] = true
		end
	end
	-- check if "best" is requested or no ranks requested; and if so, set preferred and normal
	if ranks.b or not next(ranks) then
		ranks.p = true
		ranks.n = true
	end
	return ranks
end


-------------------------------------------------------------------------------
-- parseInput processes the Q-id , the blacklist and the whitelist
-- if an input parameter is supplied, it returns that and ends the call.
-- it returns (1) either the qid or nil indicating whether or not the call should continue
-- and (2) a table containing all of the statements for the propertyID and relevant Qid
-- if "best" ranks are requested, it returns those instead of all non-deprecated ranks
-------------------------------------------------------------------------------
local parseInput = function(frame, input_parm, property_id)
	-- There may be a local parameter supplied, if it's blank, set it to nil
	input_parm = mw.text.trim(input_parm or "")
	if input_parm == "" then input_parm = nil end

	local args = frame.args

	-- can take a named parameter |qid which is the Wikidata ID for the article.
	-- if it's not supplied, use the id for the current page
	local qid = args.qid or ""
	if qid == "" then qid = mw.wikibase.getEntityIdForCurrentPage() end
	-- if there's no Wikidata item for the current page return nil
	if not qid then return false, nil end

	-- The blacklist is passed in named parameter |suppressfields
	local blacklist = args.suppressfields or args.spf

	-- The whitelist is passed in named parameter |fetchwikidata
	local whitelist = args.fetchwikidata or args.fwd
	if not whitelist or whitelist == "" then whitelist = "NONE" end

	-- The name of the field that this function is called from is passed in named parameter |name
	local fieldname = args.name or ""

	if blacklist then
		-- The name is compulsory when blacklist is used, so return nil if it is not supplied
		if not fieldname or fieldname == "" then return false, nil end
		-- If this field is on the blacklist, then return nil
		if blacklist:find(fieldname) then return false, nil end
	end

	-- If we got this far then we're not on the blacklist
	-- The blacklist overrides any locally supplied parameter as well
	-- If a non-blank input parameter was supplied return it
	if input_parm then return false, input_parm end

	-- Otherwise see if this field is on the whitelist:
	-- needs a bit more logic because find will return its second value = 0 if fieldname=""
	-- but nil if fieldname not found on whitelist
	local _, found = whitelist:find(fieldname)
	found = ((found or 0) > 0)
	if whitelist ~= 'ALL' and (whitelist:upper() == "NONE" or not found) then
		return false, nil
	end

	-- See what's on Wikidata (the call always returns a table, but it may be empty):
	local props = {}
	if args.reqranks.b then
		props = mw.wikibase.getBestStatements(qid, property_id)
	else
		props = mw.wikibase.getAllStatements(qid, property_id)
	end
	if props[1] then
		return qid, props
	end
	-- no property on Wikidata
	return false, nil
end


-------------------------------------------------------------------------------
-- assembleoutput takes the sequence table containing the property values
-- and formats it according to switches given
-- it needs the entityID and propertyID to link from the pen icon
-------------------------------------------------------------------------------
-- Dependencies: parseParam
-------------------------------------------------------------------------------
local function assembleoutput(out, args, entityID, propertyID)

	-- sorted is a boolean passed to enable sorting of the values returned
	-- if nothing or an empty string is passed set it false
	-- if "false" or "no" or "0" is passed set it false
	local sorted = parseParam(args.sorted, false)

	-- noicon is a boolean passed to suppress the trailing "edit at Wikidata" icon
	-- for use when the value is processed further by the infobox
	-- if nothing or an empty string is passed set it false
	-- if "false" or "no" or "0" is passed set it false
	local noic = parseParam(args.noicon, false)

	-- list is the name of a template that a list of multiple values is passed through
	-- examples include "hlist" and "ubl"
	-- setting it to "prose" produces something like "1, 2, 3, and 4"
	local list = args.list or ""

	-- sep is a string that is used to separate multiple returned values
	-- if nothing or an empty string is passed set it to the default
	-- any double-quotes " are stripped out, so that spaces may be passed
	-- e.g. |sep=" - "
	local sepdefault = i18n["list separator"]
	local separator = args.sep or ""
	separator = string.gsub(separator, '"', '')
	if separator == "" then
		separator = sepdefault
	end

	-- collapse is a number that determines the maximum number of returned values
	-- before the output is collapsed.
	-- Zero or not a number result in no collapsing (default becomes 0).
	local collapse = tonumber(args.collapse) or 0

	-- if there's anything to return, then return a list
	-- comma-separated by default, but may be specified by the sep parameter
	-- optionally specify a hlist or ubl or a prose list, etc.
	local strout
	if #out > 0 then
		if sorted then table.sort(out) end
		-- if a pen icon is wanted add it the end of the last value
		if not noic then
			local icon = "&nbsp;[[" .. i18n["filespace"]
			icon = icon .. ":Blue pencil.svg |frameless |text-top |10px |alt="
			icon = icon .. i18n["editonwikidata"]
			icon = icon .. "|link=https://www.wikidata.org/wiki/" .. entityID
			icon = icon .. "?uselang=" .. args.langobj.code
			icon = icon .. "#" .. propertyID .. "|" .. i18n["editonwikidata"] .. "]]"
			out[#out] = out[#out] .. icon
		end
		if list == "" then
			strout = table.concat(out, separator)
		elseif list:lower() == "prose" then
			strout = mw.text.listToText( out )
		else
			strout = mw.getCurrentFrame():expandTemplate{title = list, args = out}
		end
		if collapse >0 and #out > collapse then
			strout = collapsediv .. strout .. "</div>"
		end
	else
		strout = nil -- no items had valid reference
	end
	return strout
end


-------------------------------------------------------------------------------
-- propertyvalueandquals takes a property object, the arguments passed from frame,
-- and a qualifier propertyID.
-- It returns a sequence (table) of values representing the values of that property
-- and qualifiers that match the qualifierID if supplied.
-------------------------------------------------------------------------------
-- Dependencies: parseParam; sourced; labelOrId; i18n.latestdatequalifier; format_Date;
-- makeOrdinal; roundto; decimalPrecision; decimalToDMS; assembleoutput;
-------------------------------------------------------------------------------
local function propertyvalueandquals(objproperty, args, qualID)

	-- onlysourced is a boolean passed to return only values sourced to other than Wikipedia
	-- if nothing or an empty string is passed set it true
	local onlysrc = parseParam(args.onlysourced or args.osd, true)

	-- linked is a a boolean that enables the link to a local page via sitelink
	-- if nothing or an empty string is passed set it true
	local linked = parseParam(args.linked, true)

	-- prefix is a string that may be nil, empty (""), or a string of characters
	-- this is prefixed to each value
	-- useful when when multiple values are returned
	-- any double-quotes " are stripped out, so that spaces may be passed
	local prefix = (args.prefix or ""):gsub('"', '')

	-- postfix is a string that may be nil, empty (""), or a string of characters
	-- this is postfixed to each value
	-- useful when when multiple values are returned
	-- any double-quotes " are stripped out, so that spaces may be passed
	local postfix = (args.postfix or ""):gsub('"', '')

	-- linkprefix is a string that may be nil, empty (""), or a string of characters
	-- this creates a link and is then prefixed to each value
	-- useful when when multiple values are returned and indirect links are needed
	-- any double-quotes " are stripped out, so that spaces may be passed
	local lprefix = (args.linkprefix or ""):gsub('"', '')

	-- linkpostfix is a string that may be nil, empty (""), or a string of characters
	-- this is postfixed to each value when linking is enabled with lprefix
	-- useful when when multiple values are returned
	-- any double-quotes " are stripped out, so that spaces may be passed
	local lpostfix = (args.linkpostfix or ""):gsub('"', '')

	-- wdlinks is a boolean passed to enable links to Wikidata when no article exists
	-- if nothing or an empty string is passed set it false
	local wdl = parseParam(args.wdlinks or args.wdl, false)

	-- unitabbr is a boolean passed to enable unit abbreviations for common units
	-- if nothing or an empty string is passed set it false
	local uabbr = parseParam(args.unitabbr, false)

	-- maxvals is a string that may be nil, empty (""), or a number
	-- this determines how many items may be returned when multiple values are available
	-- setting it = 1 is useful where the returned string is used within another call, e.g. image
	local maxvals = tonumber(args.maxvals) or 0

	-- all proper values of a Wikidata property will be the same type as the first
	-- qualifiers don't have a mainsnak, properties do
	local datatype = objproperty[1].datatype or objproperty[1].mainsnak.datatype
	-- out holds the values for this property
	-- mtl holds the language code if the datatype is monolingual text
	local out = {}
	local mtl = {}
	for k, v in pairs(objproperty) do
		local snak = v.mainsnak or v
		local datavalue = snak.datavalue
		datavalue = datavalue and datavalue.value
		if onlysrc and not sourced(v) then
			-- nothing added to 'out': it isn't sourced when onlysourced=true
			------------------------------------
		elseif v.rank and not args.reqranks[v.rank:sub(1, 1)] then
			-- nothing added to 'out': value has a rank that isn't requested
		elseif snak.snaktype == "somevalue" then -- value is unknown
			out[#out + 1] = i18n["Unknown"]
			------------------------------------
		elseif snak.snaktype == "novalue" then -- value is none
			-- out[#out + 1] = "No value" -- don't return anything
			------------------------------------
		elseif datatype == "wikibase-item" then -- data type is a wikibase item:
			-- it's wiki-linked value, so output as link if enabled and possible
			local qnumber = datavalue.id
			local sitelink = mw.wikibase.sitelink(qnumber)
			local label, islabel = labelOrId(qnumber)
			if linked then
				if sitelink then
					-- Check which Wiki we're on
					local site = mw.site.siteName
					-- we could also check other wikis that prefer to use label:
					if site ~= "Wikimedia Commons" then
						-- strip any namespace or dab from the sitelink
						-- and use that as label
						local pos = sitelink:find(":") or 0
						label = sitelink:sub(pos+1):gsub("%s%(.+%)$", ""):gsub(",.+$", "")
					end
					out[#out + 1] = "[[" .. lprefix .. sitelink .. lpostfix .. "|" .. label .. "]]"
				elseif islabel then
					-- no sitelink, label exists
					-- examine what an article with a title the same as the label would be
					local artitle = mw.title.new(label, 0)
					if artitle and artitle.redirectTarget then
						-- there's a redirect with the same title as the label
						-- let's link to that
						out[#out + 1] = "[[".. lprefix .. label .. lpostfix
						out[#out] = out[#out] .. "|" .. label .. "]]"
					else
						-- no sitelink, label exists, not a redirect
						-- output the plain label (optionally with Wikidata link)
						if wdl then
							-- show that there's a Wikidata entry available
							local wd = "[[:d:" .. qnumber .. "|" .. label
							wd = wd .. "]]&nbsp;<span title='"
							wd = wd .. i18n["errors"]["local-article-not-found"]
							wd = wd .. "'>[[File:Wikidata-logo.svg|16px|alt=|link=]]</span>"
							out[#out + 1] = wd
						else
							-- no wikidata links required, so just give the plain label
							out[#out + 1] = label
						end -- test if wikdata link display required
					end -- test if article title exists as redirect on current Wiki
				else
					-- no sitelink and no label
					out[#out + 1] = qnumber
				end -- test for sitelink exists
			else -- no link wanted so test for lang code
				local lang = args.lang or ""
				if lang ~= "" then
					-- there's a language code given, so look for label and sanitise it
					label = mw.text.nowiki( mw.wikibase.getLabelByLang(qnumber, lang) or label )
				end
				-- add the plain label
				out[#out + 1] = label
			end -- test for link required
			-- If the property has a qualifier of latest date, add that in all cases:
			if v.qualifiers then
				local quals = v.qualifiers["P1326"] -- latest date qualifier
				if quals then
					local ldq = i18n.latestdatequalifier(mw.wikibase.renderSnaks(quals))
					out[#out] = out[#out] .. " (" .. ldq .. ")"
				end
			end
			------------------------------------
		elseif datatype == "time" then -- data type is time:
			-- it's a date value, so output according to formatting preferences
			local timestamp = datavalue.time
			-- A year can be stored like this: "+1872-00-00T00:00:00Z",
			-- which is processed here as if it were the day before "+1872-01-01T00:00:00Z",
			-- and that's the last day of 1871, so the year is wrong.
			-- So fix the month 0, day 0 timestamp to become 1 January instead:
			timestamp = timestamp:gsub("%-00%-00T", "-01-01T")
			local dateprecision = datavalue.precision
			local fpvdate = tonumber(timestamp:sub(2, 5))
			local fdate
			if dateprecision >= 9 then -- precision is year or shorter
				local dateformat = "y"
				if dateprecision >= 10 then -- prepend month
					fpvdate = i18n.months[tonumber(timestamp:sub(7, 8))] .. " " .. fpvdate
					dateformat = args.df
					if dateprecision >= 11 then -- prepend day
							fpvdate = tonumber(timestamp:sub(10, 11)) .. " " .. fpvdate
					end
				end
				if timestamp:sub(1, 1) == "-" then
					fpvdate = fpvdate .. " BCE"
				end
				fdate = format_Date(fpvdate, dateformat, args.bc)
				-- testing the ability to add "circa" from P1480 "sourcing circumstances"
				-- just testing on years for now
				if dateprecision == 9 and v.qualifiers then
					local sc = v.qualifiers.P1480
					if sc then
						local circa = ""
						for k1, v1 in pairs(sc) do
							if v1.datavalue.value.id == "Q5727902" then
								circa = '<abbr title="circa">c.</abbr>&nbsp;'
								break
							end
						end
						fdate = circa .. fdate
					end
				end
			elseif dateprecision == 7 then -- century
				local century = math.floor((fpvdate - 1) / 100) + 1
				fdate = makeOrdinal(century) .. "&nbsp;" .. i18n["century"]
				if timestamp:sub(1, 1) == "-" then -- date is BC
					local bc = string.upper(args.bc or "") -- can't use nil for bc
					-- we only want to accept two possibilities: BC or default to BCE
					if bc == "BC" then
						fdate = fdate .. "&nbsp;" .. i18n["BC"] -- use non-breaking space.
					else
						fdate = fdate .. "&nbsp;" .. i18n["BCE"]
					end
				end
			else
				-- date precisions 0 to 6 (billion years to millenium) TODO:
				--
			end
			out[#out+1] = fdate
			------------------------------------
		-- data types which are strings:
		elseif datatype == "commonsMedia" or datatype == "external-id" or datatype == "string" or datatype == "url" then
			-- commonsMedia or external-id or string or url
			-- all have mainsnak.datavalue.value as string
			if lprefix == "" and lpostfix == "" then
				out[#out+1] = prefix .. datavalue .. postfix
			else
				out[#out+1] = "[[" .. lprefix .. datavalue .. lpostfix
				out[#out] = out[#out] .. "|" .. prefix .. datavalue .. postfix .. "]]"
			end -- check for link requested (i.e. either linkprefix or linkpostfix exists)
			------------------------------------
		-- data types which are quantities:
		elseif datatype == "quantity" then
			-- quantities have mainsnak.datavalue.value.amount and mainsnak.datavalue.value.unit
			-- the unit is of the form http://www.wikidata.org/entity/Q829073
			--
			-- get the language object as 'lang' to format the numerical value
			local lang = args.langobj
			--
			-- implement a switch to turn on/off numerical formatting later
			local fnum = true
			-- convert amount to a number
			local amount = tonumber(datavalue.amount) or i18n["NaN"]
			-- check if upper and/or lower bounds are given and significant
			local upb = tonumber(datavalue.upperBound)
			local lowb = tonumber(datavalue.lowerBound)
			if upb and lowb then
				-- differences rounded to 2 sig fig:
				local posdif = roundto(upb - amount, 2)
				local negdif = roundto(amount - lowb, 2)
				if fnum then amount = lang:formatNum( amount ) end
				if posdif ~= negdif then
					-- non-symmetrical
					amount = amount .. " +" .. posdif .. " -" .. negdif
				elseif posdif ~= 0 then
					-- symmetrical and significant
					amount = amount .. " ±" .. posdif
				else
				-- otherwise range is zero, so leave it off: amount = amount
				end
			else
				if fnum then amount = lang:formatNum( amount ) end
			end
			-- extract the qid in the form 'Qnnn' from the value.unit url
			-- and then fetch the label from that
			local unit = ""
			local unitqid = string.match( datavalue.unit, "(Q%d+)" )
			if unitqid then
				if uabbr and i18n.abbr[unitqid] then
					-- it's on the list of common abbreviations, so use that
					unit = "&nbsp;" .. i18n.abbr[unitqid]
				else
					-- otherwise use the label (i.e. unit name) if it exists
					local uname = mw.wikibase.label( unitqid )
					if uname then unit = " " .. uname end
				end
			end
			out[#out+1] = amount .. unit
			------------------------------------
		-- datatypes which are global coordinates:
		elseif datatype == "globe-coordinate" then
			-- 'display' parameter defaults to "inline, title" *** unused for now ***
			-- local disp = args.display or ""
			-- if disp == "" then disp = "inline, title" end
			--
			-- format parameter switches from deg/min/sec to decimal degrees
			-- default is deg/min/sec -- decimal degrees needs |format = dec
			local form = (args.format or ""):lower():sub(1,3)
			if form ~= "dec" then form = "dms" end
			--
			-- show parameter allows just the latitude or longitude to be shown
			local show = (args.show or ""):lower()
			if show ~= "longlat" then show = show:sub(1,3) end
			--
			local lat, long, prec = datavalue.latitude, datavalue.longitude, datavalue.precision
			if show == "lat" then
				out[#out+1] = decimalPrecision(lat, prec)
			elseif show == "lon" then
				out[#out+1] = decimalPrecision(long, prec)
			elseif show == "longlat" then
				out[#out+1] = decimalPrecision(long, prec) .. ", " .. decimalPrecision(lat, prec)
			else
				local ns = "N"
				local ew = "E"
				if lat < 0 then
					ns = "S"
					lat = - lat
				end
				if long < 0 then
					ew = "W"
					long = - long
				end
				if form == "dec" then
					lat = decimalPrecision(lat, prec)
					long = decimalPrecision(long, prec)
					out[#out+1] = lat .. "°" .. ns .. " " .. long ..  "°" .. ew
				else
					local latdeg, latmin, latsec = decimalToDMS(lat, prec)
					local longdeg, longmin, longsec = decimalToDMS(long, prec)

					if latsec == 0 and longsec == 0 then
						if latmin == 0 and longmin == 0 then
							out[#out+1] = latdeg .. "°" .. ns .. " " .. longdeg ..  "°" .. ew
						else
							out[#out+1] = latdeg .. "°" .. latmin .. "′" .. ns .. " "
							out[#out] = out[#out] .. longdeg .. "°".. longmin .. "′" .. ew
						end
					else
						out[#out+1] = latdeg .. "°" .. latmin .. "′" .. latsec .. "″" .. ns .. " "
						out[#out] = out[#out] .. longdeg .. "°" .. longmin .. "′" .. longsec .. "″" .. ew
					end
				end
			end
			------------------------------------
		elseif datatype == "monolingualtext" then -- data type is Monolingual text:
			-- has mainsnak.datavalue.value as a table containing language/text pairs
			-- collect all the values in 'out' and languages in 'mtl' and process them later
			out[#out+1] = prefix .. datavalue.text .. postfix
			mtl[#out] = datavalue.language
			------------------------------------
		else
			-- some other data type so write a specific handler
			out[#out+1] = "unknown data type: " .. datatype
		end -- of datatype/unknown value/sourced check

		-- See if qualifiers are to be returned:
		if v.qualifiers and qualID and snak.snaktype=="value" then
			local qsep = (args.qsep or ""):gsub('"', '')
			local qargs = {
				["osd"]         = "false",
				["linked"]      = tostring(linked),
				["prefix"]      = args.qprefix,
				["postfix"]     = args.qpostfix,
				["linkprefix"]  = args.qlinkprefix,
				["linkpostfix"] = args.qlinkpostfix,
				["wdl"]         = "false",
				["unitabbr"]    = tostring(uabbr),
				["maxvals"]     = 0,
				["sorted"]      = args.qsorted,
				["noicon"]      = "true",
				["list"]        = "",
				["sep"]         = qsep,
				["langobj"]     = args.langobj,
			}
			if qualID == "DATES" then qargs.maxvals = 1 end
			local qlist = {}
			local t1, t2, dsep = "", "", ""
			for k1, v1 in pairs(v.qualifiers) do
				-- look for date range:
				if qualID == "DATES" then
					if k1 == "P580" then -- P580 is "start time"
						t1 = propertyvalueandquals(v1, qargs)[1] or ""
					elseif k1 == "P582" then -- P582 is "end time"
						t2 = propertyvalueandquals(v1, qargs)[1] or ""
					end
				-- check for latest date qualifier:
				elseif k1 == "P1326" then
					-- do nothing - this is handled already
				-- otherwise see if we want this qualifier:
				elseif qualID == "ALL" or qualID == k1 then 
					local ql = propertyvalueandquals(v1, qargs)
					for k2, v2 in ipairs(ql) do
						qlist[#qlist + 1] = v2
					end
				end
			end -- of loop through qualifiers
			local t = t1 .. t2
			-- *** internationalise date separators later ***
			if t:find("%s") or t:find("&nbsp;") then dsep = "  &ndash; " else dsep = "&ndash;" end
			if #qlist > 0 then
				local qstr = assembleoutput(qlist, qargs)
				out[#out] = out[#out] .. " (" .. qstr .. ")"
			elseif t > "" then
				out[#out] = out[#out] .. " (" .. t1 .. dsep .. t2 .. ")"
			end
		end -- of test for qualifiers wanted
		if maxvals > 0 and #out >= maxvals then break end
	end -- of for each value loop

	-- we need to pick one value to return if the datatype was "monolingualtext"
	-- if there's only one value, use that
	-- otherwise look through the fallback languages for a match
	if datatype == "monolingualtext" and #out >1 then
		local langcode = args.langobj.code
		langcode = mw.text.split( langcode, '-', true )[1]
		local fbtbl = mw.language.getFallbacksFor( langcode )
		table.insert( fbtbl, 1, langcode )
		bestval = ""
		found = false
		for idx1, lang1 in ipairs(fbtbl) do
			for idx2, lang2 in ipairs(mtl) do
				if (lang1 == lang2) and not found then
					bestval = out[idx2]
					found = true
					break
				end
			end -- loop through values of property
		end -- loop through fallback languages
		if found then
			-- replace output table with a table containing the best value
			out = { bestval }
		else
			-- more than one value and none of them on the list of fallback languages
			-- sod it, just give them the first one
			out = { out[1] }
		end
	end
	return out
end

-------------------------------------------------------------------------------
-------------------------------------------------------------------------------
-- Public functions
-------------------------------------------------------------------------------
-------------------------------------------------------------------------------
-- getValue is used to get the value(s) of a property
-- The property ID is passed as the first unnamed parameter and is required.
-- A locally supplied parameter may optionaly be supplied as the second unnamed parameter.
-- The function will now also return qualifiers if parameter qual is supplied
-------------------------------------------------------------------------------
-- Dependencies: setRanks; parseInput; propertyvalueandquals; assembleoutput; parseParam; sourced; 
-- labelOrId; i18n.latestdatequalifier; format_Date; makeOrdinal; roundto; decimalPrecision; decimalToDMS;
-------------------------------------------------------------------------------
p.getValue = function(frame)
	if not frame.args[1] then
		frame.args = frame:getParent().args
		if not frame.args[1] then return i18n.errors["No property supplied"] end
	end

	local propertyID = mw.text.trim(frame.args[1] or "")

	frame.args.reqranks = setRanks(frame.args.rank)

	local entityid, props = parseInput(frame, frame.args[2], propertyID)

	if not entityid then
		return props -- either the input parameter or nothing
	end
	-- qual is a string containing the property ID of the qualifier(s) to be returned
	-- if qual == "ALL" then all qualifiers returned
	-- if qual == "DATES" then qualifiers P580 (start time) and P582 (end time) returned
	-- if nothing or an empty string is passed set it nil -> no qualifiers returned
	local qualID = mw.text.trim(frame.args.qual or ""):upper()
	if qualID == "" then qualID = nil end

	-- set a language object in the frame.args table
	frame.args.langobj = findLang(frame.args.lang)

	-- table 'out' stores the return value(s):
	local out = propertyvalueandquals(props, frame.args, qualID)

	-- format the table of values and return it as a string:
	return assembleoutput(out, frame.args, entityid, propertyID)
end


-------------------------------------------------------------------------------
-- getPreferredValue is used to get a value,
-- (or a comma separated list of them if multiple values exist).
-- If preferred ranks are set, it will return those values, otherwise values with normal ranks
-- now redundant to getValue with |rank=best
-------------------------------------------------------------------------------
-- Dependencies: p.getValue; setRanks; parseInput; propertyvalueandquals; assembleoutput;
-- parseParam; sourced; labelOrId; i18n.latestdatequalifier; format_Date;
-- makeOrdinal; roundto; decimalPrecision; decimalToDMS;
-------------------------------------------------------------------------------
p.getPreferredValue = function(frame)
	frame.args.rank = "best"
	return p.getValue(frame)
end

-------------------------------------------------------------------------------
-- getCoords is used to get coordinates for display in an infobox
-- whitelist and blacklist are implemented
-- optional 'display' parameter is allowed, defaults to "inline, title"
-------------------------------------------------------------------------------
-- Dependencies: setRanks; parseInput; decimalPrecision;
-------------------------------------------------------------------------------
p.getCoords = function(frame)
	local propertyID = "P625"

	-- if there is a 'display' parameter supplied, use it
	-- otherwise default to "inline, title"
	local disp = frame.args.display or ""
	if disp == "" then
		disp = "inline, title"
	end

	-- there may be a format parameter to switch from deg/min/sec to decimal degrees
	-- default is deg/min/sec
	-- decimal degrees needs |format = dec
	local form = (frame.args.format or ""):lower():sub(1,3)
	if form ~= "dec" then
		form = "dms"
	end

	-- just deal with best values
	frame.args.reqranks = setRanks("best")

	local qid, props = parseInput(frame, frame.args[1], propertyID)
	if not qid then
		return props -- either local parameter or nothing
	else
		dv = props[1].mainsnak.datavalue.value
		local lat, long, prec = dv.latitude, dv.longitude, dv.precision
		lat = decimalPrecision(lat, prec)
		long = decimalPrecision(long, prec)
		local lat_long = { lat, long }
		lat_long["display"] = disp
		lat_long["format"] = form
		-- invoke template Coord with the values stored in the table
		return frame:expandTemplate{title = 'coord', args = lat_long}
	end
end


-------------------------------------------------------------------------------
-- getQualifierValue is used to get a formatted value of a qualifier
--
-- The call needs:	a property (the unnamed parameter or 1=)
-- 					a target value for that property (pval=)
--					a qualifier for that target value (qual=)
-- The usual whitelisting and blacklisting of the property is implemented
-- The boolean onlysourced= parameter can be set to return nothing
-- when the property is unsourced (or only sourced to Wikipedia)
-------------------------------------------------------------------------------
-- Dependencies: parseParam; setRanks; parseInput; sourced; propertyvalueandquals; assembleoutput; labelOrId;
-- i18n.latestdatequalifier; format_Date; findLang; makeOrdinal; roundto; decimalPrecision; decimalToDMS;
-------------------------------------------------------------------------------
p.getQualifierValue = function(frame)

	-- The property ID that will have a qualifier is the first unnamed parameter
	local propertyID = mw.text.trim(frame.args[1] or "")

	-- The value of the property we want to match whose qualifier value is to be returned
	-- is passed in named parameter |pval=
	local propvalue = frame.args.pval

	-- The property ID of the qualifier
	-- whose value is to be returned is passed in named parameter |qual=
	local qualifierID = frame.args.qual

	-- onlysourced is a boolean passed to return qualifiers
	-- only when property values are sourced to something other than Wikipedia
	-- if nothing or an empty string is passed set it true
	-- if "false" or "no" or 0 is passed set it false
	local onlysrc = parseParam(frame.args.onlysourced or frame.args.osd, true)

	-- set a language object in the frame.args table
	frame.args.langobj = findLang(frame.args.lang)

	-- set the requested ranks flags
	frame.args.reqranks = setRanks(frame.args.rank)

	-- check for locally supplied parameter in second unnamed parameter
	-- success means no local parameter and the property exists
	local qid, props = parseInput(frame, frame.args[2], propertyID)
	if qid then
		local out = {}
		-- Scan through the values of the property
		-- we want something like property is P793, significant event (in propertyID)
		-- whose value is something like Q385378, construction (in propvalue)
		-- then we can return the value(s) of a qualifier such as P580, start time (in qualifierID)
		for k1, v1 in pairs(props) do
			if v1.mainsnak.snaktype == "value" and v1.mainsnak.datavalue.type == "wikibase-entityid" then
				-- It's a wiki-linked value, so check if it's the target (in propvalue)
				-- and if it has qualifiers
				if v1.mainsnak.datavalue.value.id == propvalue and v1.qualifiers then
					if onlysrc == false or sourced(v1) then
						-- if we've got this far, we have a (sourced) claim with qualifiers
						-- which matches the target, so find the value(s) of the qualifier we want
						local quals = v1.qualifiers[qualifierID]
						if quals then
							local vals = propertyvalueandquals(quals, frame.args, qid)
							for k, v in pairs(vals) do
								out[#out + 1] = v
							end
						end
					end -- of check for sourced
				end -- of check for matching required value and has qualifiers
			end -- of check for wikibase entity
		end -- of loop through values of propertyID
		return assembleoutput(out, frame.args, qid, propertyID)
	else
		return props -- either local parameter or nothing
	end -- of test for success
	return nil
end
-------------------------------------------------------------------------------
-- getValueByQual gets the value of a property which has a qualifier with a given entity value
-- The call needs:
--					a property ID (the unnamed parameter or 1=Pxxx)
--					the ID of a qualifier for that property (qualID=Pyyy)
--					the Wikibase-entity ID of a value for that qualifier (qvalue=Qzzz)
-- The usual whitelisting, blacklisting, onlysourced, etc. are implemented
-------------------------------------------------------------------------------
-- Dependencies: _getvaluebyqual; parseParam; setRanks; parseInput; sourced;
-- assembleoutput;
-------------------------------------------------------------------------------
p.getValueByQual = function(frame)
	local qualID = frame.args.qualID
	-- The Q-id of the value for the qualifier we want to match is in named parameter |qvalue=
	local qval = frame.args.qvalue or ""
	if qval == "" then return "no qualifier value supplied" end
	local function checkQID(id)
		return id == qval
	end
	return _getvaluebyqual(frame, qualID, checkQID)
end
-------------------------------------------------------------------------------
-- getValueByLang gets the value of a property which has a qualifier P407
-- ("language of work or name") whose value has the given language code
-- The call needs:
--					a property ID (the unnamed parameter or 1=Pxxx)
--					the MediaWiki language code to match the language (lang=xx[-yy])
--					(if no code is supplied, it uses the default language)
-- The usual whitelisting, blacklisting, onlysourced, etc. are implemented
-------------------------------------------------------------------------------
-- Dependencies: _getvaluebyqual; parseParam; setRanks; parseInput; sourced; assembleoutput;
-------------------------------------------------------------------------------
p.getValueByLang = function(frame)
	
	-- The language code for the qualifier we want to match is in named parameter |lang=
	local langcode = frame.args.lang or ""
	if langcode == "" then
		langcode = frame:callParserFunction{ name = "int", args = "lang" }
	end
	function checkLanguage(id)
		-- id should represent a language like "British English (Q7979)"
		-- it should have string property "Wikimedia language code (P424)"
		-- qlcode will be a table:
		local qlcode = mw.wikibase.getBestStatements(id, "P424")
		if (#qlcode > 0) and (qlcode[1].mainsnak.datavalue.value == langcode) then
			return true
		end
	end
	return _getvaluebyqual(frame, "P407", checkLanguage)
end
-------------------------------------------------------------------------------
-- Common code for p.getValueByQual and p.getValueByLang
-------------------------------------------------------------------------------
-- Dependencies: parseParam; setRanks; parseInput; sourced; assembleoutput;
-------------------------------------------------------------------------------
function _getvaluebyqual(frame, qualID, checkvalue)

	-- The property ID that will have a qualifier is the first unnamed parameter
	local propertyID = mw.text.trim(frame.args[1] or "")
	if propertyID == "" then return "no property supplied" end

	-- The property ID of the qualifier with a particular value is in named parameter |qualID=
	local qualID = frame.args.qualID or ""
	if qualID == "" then return "no qualifier supplied" end

	-- onlysourced is a boolean passed to return property values
	-- only when property values are sourced to something other than Wikipedia
	-- if nothing or an empty string is passed set it true
	-- if "false" or "no" or 0 is passed set it false
	local onlysrc = parseParam(frame.args.onlysourced or frame.args.osd, true)

	-- set the requested ranks flags
	frame.args.reqranks = setRanks(frame.args.rank)

	-- check for locally supplied parameter in second unnamed parameter
	-- success means no local parameter and the property exists
	local qid, props = parseInput(frame, frame.args[2], propertyID)

	if qid then
		local out = {}
		-- Scan through the values of the property
		-- we want something like property is "pronunciation audio (P443)" in propertyID
		-- with a qualifier like "language of work or name (P407)" in qualID
		-- whose value has the required ID, like "British English (Q7979)", in qval
		for k1, v1 in pairs(props) do
			if v1.mainsnak.snaktype == "value" and v1.mainsnak.datavalue.type == "string" then
				-- We'll only deal with returning strings for now
				-- so check if it has the right qualifier
				local v1q = v1.qualifiers
				if v1q and v1q[qualID] then
					if onlysrc == false or sourced(v1) then
						-- if we've got this far, we have a (sourced) claim with qualifiers
						-- so see if matches the required value
						-- We'll only deal with wikibase-items for now
						if v1q[qualID][1].datatype == "wikibase-item" then
							if checkvalue(v1q[qualID][1].datavalue.value.id) then
								out[#out + 1] = v1.mainsnak.datavalue.value
							end
						end
					end -- of check for sourced
				end -- of check for matching required value and has qualifiers
			else
				return "not string"
			end -- of check for string
		end -- of loop through values of propertyID
		return assembleoutput(out, frame.args, qid, propertyID)
	else
		return props -- either local parameter or nothing
	end -- of test for success
	return nil
end

-------------------------------------------------------------------------------
-- getLink has the qid of a Wikidata entity passed as the first unnamed parameter or as |qid=
-- If there is a sitelink to an article on the local Wiki, it returns a link to the article
-- with the Wikidata label as the displayed text.
-- If there is no sitelink, it returns the label as plain text.
-- If there is no label in the local language, it displays the qid instead.
-------------------------------------------------------------------------------
p.getLink = function(frame)
	local itemID = mw.text.trim(frame.args[1] or frame.args.qid or "")
	if itemID == "" then return end
	local sitelink = mw.wikibase.sitelink(itemID)
	local label = labelOrId(itemID)
	if sitelink then
		return "[[" .. sitelink .. "|" .. label .. "]]"
	else
		return label
	end
end


-------------------------------------------------------------------------------
-- getLabel has the qid of a Wikidata entity passed as the first unnamed parameter or as |qid=
-- It returns the Wikidata label for the local language as plain text.
-- If there is no label in the local language, it displays the qid instead.
-------------------------------------------------------------------------------
p.getLabel = function(frame)
	local itemID = mw.text.trim(frame.args[1] or frame.args.qid or "")
	if itemID == "" then return end
	local label = labelOrId(itemID)
	return label
end


-------------------------------------------------------------------------------
-- getAT has the qid of a Wikidata entity passed as the first unnamed parameter or as |qid=
-- If there is a sitelink to an article on the local Wiki, it returns the sitelink as plain text.
-- If there is no sitelink, it returns nothing.
-------------------------------------------------------------------------------
p.getAT = function(frame)
	local itemID = mw.text.trim(frame.args[1] or frame.args.qid or "")
	if itemID == "" then return end
	return mw.wikibase.sitelink(itemID)
end


-------------------------------------------------------------------------------
-- getDescription has the qid of a Wikidata entity passed as |qid=
-- (it defaults to the associated qid of the current article if omitted)
-- and a local parameter passed as the first unnamed parameter.
-- Any local parameter passed (other than "Wikidata" or "none") becomes the return value.
-- It returns the article description for the Wikidata entity if the local parameter is "Wikidata".
-- Nothing is returned if the description doesn't exist or "none" is passed as the local parameter.
-------------------------------------------------------------------------------
p.getDescription = function(frame)
	local desc = mw.text.trim(frame.args[1] or "")
	local itemID = mw.text.trim(frame.args.qid or "")
	if itemID == "" then itemID = nil end
	if desc:lower() == 'wikidata' then
		return mw.wikibase.description(itemID)
	elseif desc:lower() == 'none' then
		return nil
	else
		return desc
	end
end


-------------------------------------------------------------------------------
-- pageId returns the page id (entity ID, Qnnn) of the current page
-- returns nothing if the page is not connected to Wikidata
-------------------------------------------------------------------------------
function p.pageId(frame)
	return mw.wikibase.getEntityIdForCurrentPage()
end


-------------------------------------------------------------------------------
-- formatDate is a wrapper to export the private function format_Date
-------------------------------------------------------------------------------
-- Dependencies: format_Date
-------------------------------------------------------------------------------
p.formatDate = function(frame)
	return format_Date(frame.args[1], frame.args.df, frame.args.bc)
end


-------------------------------------------------------------------------------
-- checkBlacklist allows a test to check whether a named field is allowed
-- returns true if the field is not blacklisted (i.e. allowed)
-- returns false if the field is blacklisted (i.e. disallowed)
-- {{#if:{{#invoke:WikidataIB |checkBlacklist |name=Joe |suppressfields=Dave; Joe; Fred}} | not blacklisted | blacklisted}}
-- displays "blacklisted"
-- {{#if:{{#invoke:WikidataIB |checkBlacklist |name=Jim |suppressfields=Dave; Joe; Fred}} | not blacklisted | blacklisted}}
-- displays "not blacklisted"
-------------------------------------------------------------------------------
p.checkBlacklist = function(frame)
	local blacklist = frame.args.suppressfields or frame.args.spf or ""
	local fieldname = frame.args.name or ""
	if blacklist ~= "" and fieldname ~= "" then
		if blacklist:find(fieldname) then
			return false
		else
			return true
		end
	else
		-- one of the fields is missing: let's call that "not on the list"
		return true
	end
end


-------------------------------------------------------------------------------
-- emptyor returns nil if its first unnamed argument is just punctuation, whitespace or html tags
-- otherwise it returns the argument unchanged (including leading/trailing space).
-- If the argument may contain "=", then it must be called explicitly:
-- |1=arg
-- (In that case, leading and trailing spaces are trimmed)
-- It finds use in infoboxes where it can replace tests like:
-- {{#if: {{#invoke:WikidatIB |getvalue |P99 |fwd=ALL}} | <span class="xxx">{{#invoke:WikidatIB |getvalue |P99 |fwd=ALL}}</span> | }}
-- with a form that uses just a single call to Wikidata:
-- {{#invoke |WikidataIB |emptyor |1= <span class="xxx">{{#invoke:WikidataIB |getvalue |P99 |fwd=ALL}}</span> }}
-------------------------------------------------------------------------------
p.emptyor = function(frame)
	local s = frame.args[1] or ""
	if s == "" then return nil end
	local sx = s:gsub("%s", ""):gsub("<[^>]*>", ""):gsub("%p", "")
	if sx == "" then
		return nil
	else
		return s
	end
end


-------------------------------------------------------------------------------
-- labelorid is a public function to expose the output of labelOrId()
-- Pass the Q-number as |qid= or as an unnamed parameter.
-- It returns the Wikidata label for that entity or the qid if no label exists.
-------------------------------------------------------------------------------
-- Dependencies: labelOrId
-------------------------------------------------------------------------------
p.labelorid = function(frame)
	local label = labelOrId( frame.args.qid or frame.args[1] )
	return label
end


-------------------------------------------------------------------------------
-- getLang returns the MediaWiki language code of the current content.
-- If optional parameter |style=full, it returns the language name.
p.getLang = function(frame)
	local style = (frame.args.style or ""):lower()
	local langcode = mw.language.getContentLanguage().code
	if style == "full" then
		return mw.language.fetchLanguageName( langcode )
	end
	return langcode
end


-------------------------------------------------------------------------------
-- getQid returns the qid, if supplied
-- failing that, the Wikidata entity ID of the "category's main topic (P301)", if it exists
-- failing that, the Wikidata entity ID asociated with the curent page, if it exists
-- otherwise, nothing
p.getQid = function(frame)
	local qid = (frame.args.qid or ""):upper()
	-- check if a qid was passed; if so, return it:
	if qid ~= "" then return qid end
	-- check if there's a "category's main topic (P301)":
	local qid = mw.wikibase.getEntityIdForCurrentPage()
	if qid then
		local prop301 = mw.wikibase.getBestStatements(qid, "P301")
		if prop301[1] then
			local mctid = prop301[1].mainsnak.datavalue.value.id
			if mctid then return mctid end
		end
	end
	-- otherwise return the page qid (if any)
	return qid
end


-------------------------------------------------------------------------------
-- formatNumber formats a number according to the the supplied language code ("|lang=")
-- or the default language if not supplied.
-- The number is the first unnamed parameter or "|num="
-------------------------------------------------------------------------------
-- Dependencies: findLang
-------------------------------------------------------------------------------
p.formatNumber = function(frame)
	local lang
	local num = tonumber(frame.args[1] or frame.args.num) or 0
	lang = findLang(frame.args.lang)
	return lang:formatNum( num )
end

-------------------------------------------------------------------------------
-- examine dumps the property (the unnamed parameter) from the item given by the parameter 'qid'
-- or from the item corresponding to the current page if qid is not supplied.
-------------------------------------------------------------------------------
p.examine = function( frame )
	pid = mw.text.trim( frame.args[1] or frame.args.pid or "" )
	if pid == "" then return "No property supplied" end
	qid = frame.args.qid or ""
	if qid == "" then qid = mw.wikibase.getEntityIdForCurrentPage end
	if not qid then return "No item for this page" end
	return mw.dumpObject( mw.wikibase.getAllStatements( qid, pid ) )
end

return p