-- Functions for use in retrieving Wikidata for use in templates that deal with identifiers
-- getIdentifierQualifier returns the value of a qualifier for an Identifier
p = {}
-- getIdentifierQualifier returns the value of a qualifier for an Identifier
-- such as 'Art UK artist ID', P1367
-- the assumption is that one value exists for the property
-- and only one qualifier exists for that value
-- Constraint violations for P1367 are at:
-- https://www.wikidata.org/wiki/Wikidata:Database_reports/Constraint_violations/P1367#Single_value
p.getIdentifierQualifier = function(frame)
local propertyID = mw.text.trim(frame.args[1] or "")
-- The PropertyID of the qualifier
-- whose value is to be returned is passed in named parameter |qual=
local qualifierID = frame.args.qual
-- Can take a named parameter |qid which is the Wikidata ID for the article.
-- This will not normally be used because it's an expensive call.
local qid = frame.args.qid
if qid and (#qid == 0) then qid = nil end
local entity = mw.wikibase.getEntityObject(qid)
local props
if entity and entity.claims then
props = entity.claims[propertyID]
end
if props then
-- Check that the first value of the property is an external id
if props[1].mainsnak.datatype == "external-id" then
-- get any qualifiers of the first value of the property
local quals = props[1].qualifiers
if quals and quals[qualifierID] then
-- check what the dataype of the first qualifier value is
-- if it's quantity return the amount
if quals[qualifierID][1].datatype == "quantity" then
return tonumber(quals[qualifierID][1].datavalue.value.amount)
end
-- checks for other datatypes go here:
end
end
end
end
return p
