-- Functions to access Wikidata for Module:Convert.
local function collection()
-- Return a table to hold items.
return {
n = 0,
add = function (self, item)
self.n = self.n + 1
self[self.n] = item
end,
}
end
local function strip_to_nil(text)
-- If text is a non-empty string, return its trimmed content,
-- otherwise return nothing (empty string or not a string).
if type(text) == 'string' then
return text:match('(%S.-)%s*$')
end
end
local function adjustparameters(tdata, parms, pid, index)
-- For Module:Convert, adjust parms (a table of {{convert}} parameters).
-- Return true if successful or return false, t where t is an error message table.
-- Given that pid is a Wikidata property identifier like 'P123',
-- try to find a value and unit for the pid.
-- If successful, replace parms[index] with the value and
-- insert the unit after index.
local units = tdata.wikidata_units
local qid = strip_to_nil(parms.qid) -- nil (item is current page) or requested id (expensive)
local entity = mw.wikibase.getEntity(qid)
local claims = ((entity or {}).claims or {})[pid]
if claims and claims[1] then
local first = claims[1] -- TODO taking the first claim is not adequate
if first.mainsnak and first.mainsnak.datatype == 'quantity' then
local value = (first.mainsnak.datavalue or {}).value
if value then
local amount = value.amount
local unit = units[(value.unit or ''):match('Q%d+$')]
if amount and unit then
if amount:sub(1, 1) == '+' then
amount = amount:sub(2)
end
parms[index] = amount
table.insert(parms, index + 1, unit.ucode)
return true
end
end
end
end
return false, { 'cvt_wd_property', tostring(pid),
qid and (' for item ' .. tostring(qid)) or '' }
end
local function listunits(tdata, ulookup)
-- For Module:Convert, make wikitext to list the built-in Wikidata units.
-- Return true, wikitext if successful or return false, t where t is an
-- error message table. Currently, an error return never occurs.
local units = tdata.wikidata_units
local result = collection()
local function get_unit_name(ucode)
local success, unit_table = ulookup(ucode)
if success then
if unit_table.name1 then
return unit_table.name1
end
return 'Cannot get name of unit; per unit?'
end
return 'ERROR: unknown unit code'
end
local keys, n = {}, 0
for k, v in pairs(units) do
n = n + 1
keys[n] = k
end
table.sort(keys)
for _, qid in ipairs(keys) do
local unit = units[qid]
result:add(string.format('*[[d:%s]] (%s) = %s (%s)',
qid,
unit.label,
unit.ucode,
get_unit_name(unit.ucode))
)
end
return true, table.concat(result, '\n')
end
return { _adjustparameters = adjustparameters, _listunits = listunits }
