Module:Convert/wikidata
-- Functions to access Wikidata for Module:Convert.
local Collection = {} Collection.__index = Collection do function Collection:add(item) if item ~= nil then self.n = self.n + 1 self[self.n] = item end end function Collection:join(sep) return table.concat(self, sep) end function Collection:remove(pos) if self.n > 0 and (pos == nil or (0 < pos and pos <= self.n)) then self.n = self.n - 1 return table.remove(self, pos) end end function Collection:sort(comp) table.sort(self, comp) end function Collection.new() return setmetatable({n = 0}, Collection) 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 frequency_unit(value, unit_table) -- For use when converting m to Hz. -- Return true, s where s = name of unit's default output unit, -- or return false, t where t is an error message table. -- However, for simplicity a valid result is always returned. local unit if unit_table._symbol == 'm' then -- c = speed of light in a vacuum = 299792458 m/s -- frequency = c / wavelength local w = value * (unit_table.scale or 1) local f = 299792458 / w -- if w == 0, f = math.huge which works here if f >= 1e12 then unit = 'THz' elseif f >= 1e9 then unit = 'GHz' elseif f >= 1e6 then unit = 'MHz' elseif f >= 1e3 then unit = 'kHz' else unit = 'Hz' end end return true, unit or 'Hz' end
local function wavelength_unit(value, unit_table) -- Like frequency_unit but for use when converting Hz to m. local unit if unit_table._symbol == 'Hz' then -- Using 0.9993 rather than 1 avoids rounding which would give results -- like converting 300 MHz to 100 cm instead of 1 m. local w = 1 / (value * (unit_table.scale or 1)) -- Hz scale is inverted if w >= 0.9993e6 then unit = 'Mm' elseif w >= 0.9993e3 then unit = 'km' elseif w >= 0.9993 then unit = 'm' elseif w >= 0.9993e-2 then unit = 'cm' elseif w >= 0.9993e-3 then unit = 'mm' else unit = 'um' end end return true, unit or 'm' end
local specials = { frequency = { frequency_unit }, wavelength = { wavelength_unit }, -------------------------------------------------------------------------------- -- Following is a removed experiment to show two values as a range -- using '-' as the separator. -- frequencyrange = { frequency_unit, '-' }, -- wavelengthrange = { wavelength_unit, '-' }, }
local function make_unit(units, parms, uid) -- Return a unit code for convert or nil if unit unknown. -- If necessary, add a dummy unit to parms so convert will use it -- for the input without attempting a conversion since nothing -- useful is available (for example, with unit volt). local unit = units[uid] if type(unit) ~= 'table' then return nil end local ucode = unit.ucode if ucode and not unit.si then return ucode -- a unit known to convert end parms.opt_ignore_error = true ucode = ucode or unit._ucode -- must be a non-empty string local ukey, utable if unit.si then local base = units[unit.si] ukey = base.symbol -- must be a non-empty string local n1 = base.name1 local n2 = base.name2 if not n1 then n1 = ukey n2 = n2 or n1 -- do not append 's' end utable = { _symbol = ukey, _name1 = n1, _name2 = n2, link = unit.link or base.link, utype = n1, prefixes = 1, } else ukey = ucode utable = { symbol = ucode, -- must be a non-empty string name1 = unit.name1, -- if nil, uses symbol name2 = unit.name2, -- if nil, uses name1..'s' link = unit.link, -- if nil, uses name1 utype = unit.name1 or ucode, } end utable.scale = 1 utable.default = utable.defkey = utable.linkey = utable.bad_mcode = parms.unittable = { [ukey] = utable } return ucode end
local function matches_qualifier(statement, qual) -- Return: -- false, nil : if statement does not match specification -- true, nil : if matches, and statement has no qualifier -- true, sq : if matches, where sq is the statement's qualifier -- A match means that no qualifier was specified (qual == nil), or that -- the statement has a qualifier matching the specification. -- If a match occurs, the caller needs the statement's qualifier (if any) -- so statements that duplicate the qualifier are not used, after the first. -- Then, if convert is showing all values for a property such as the diameter -- of a telescope's mirror (diameters of primary and secondary mirrors), it -- will not show alternative values that could in principle be present for the -- same item (telescope) and property (diameter) and qualifier (primary/secondary). local target = (statement.qualifiers or {}).P518 -- P518 is "applies to part" if type(target) == 'table' then for _, q in ipairs(target) do if type(q) == 'table' then local value = (q.datavalue or {}).value if value then if qual == nil or qual == value.id then return true, value.id end end end end end if qual == nil then return true, nil -- only occurs if statement has no qualifier end return false, nil -- statement's qualifier is not relevant because statement will be skipped end
local function get_statements(parms, pid) -- Get specified item and return a list of tables with each statement for property pid. -- Each table is of form {statqual=sq, stmt=statement} where sq = statement qualifier (nil if none). -- Statements are in Wikidata's order except that those with preferred rank -- are first, then normal rank. Any other rank is ignored. local stored = {} -- qualifiers of statements that are first for the qualifier, and will be returned local qid = strip_to_nil(parms.qid) -- nil for current page's item, or an item id (expensive) local qual = strip_to_nil(parms.qual) -- nil or id of wanted P518 (applies to part) item in qualifiers local result = Collection.new() local entity = mw.wikibase.getEntity(qid) if type(entity) == 'table' then local statements = (entity.claims or {})[pid] if type(statements) == 'table' then for _, rank in ipairs({ 'preferred', 'normal' }) do for _, statement in ipairs(statements) do if type(statement) == 'table' and rank == statement.rank then local is_match, statqual = matches_qualifier(statement, qual) if is_match then result:add({ statqual = statqual, stmt = statement }) end end end end end end return result end
local function input_from_property(tdata, parms, pid) -- Given that pid is a Wikidata property identifier like 'P123', -- return a collection of {amount, ucode} pairs (two strings) -- for each matching item/property, or return nothing. -------------------------------------------------------------------------------- -- There appear to be few restrictions on how Wikidata is organized so it is -- very likely that any decision a module makes about how to handle data -- will be wrong for some cases at some time. This meets current requirements. -- For each qualifier (or if no qualitifer), if there are any preferred -- statements, use them and ignore any normal statements. -- For each qualifier, for the preferred statements if any, or for -- the normal statements (but not both): -- * Accept each statement if it has no qualifier (this will not occur -- if qual=x is specified because other code already ensures that in that -- case, only statements with a qualifier matching x are considered). -- * Ignore any statements after the first if it has a qualifier. -- The rationale is that for the diameter at South Pole Telescope, want -- convert to show the diameters for both the primary and secondary mirrors -- if the convert does not specify which diameter is wanted. -- However, if convert is given the wanted qualifier, only one value -- (_the_ diameter) is wanted. For simplicity/consistency, that is also done -- even if no qual=x is specified. Unclear what should happen. -- For the wavelength at Nançay Radio Telescope, want to show all three -- values, and the values have no qualifiers. -------------------------------------------------------------------------------- local result = Collection.new() local done = {} local skip_normal for _, t in ipairs(get_statements(parms, pid)) do local statement = t.stmt if statement.mainsnak and statement.mainsnak.datatype == 'quantity' then local value = (statement.mainsnak.datavalue or {}).value if value then local amount = value.amount if amount then amount = tostring(amount) -- in case amount is ever a number if amount:sub(1, 1) == '+' then amount = amount:sub(2) end local unit = value.unit if type(unit) == 'string' then unit = unit:match('Q%d+$') -- unit item id is at end of URL local ucode = make_unit(tdata.wikidata_units, parms, unit) if ucode then local skip if t.statqual then if done[t.statqual] then skip = true else done[t.statqual] = true end else if statement.rank == 'preferred' then skip_normal = true elseif skip_normal then skip = true end end if not skip then result:add({ amount, ucode }) end end end end end end end return result end
local function input_from_text(tdata, parms, text, insert2) -- Given string should be of form "<value><space><unit>" or -- "<value1><space>ft<space><value2><space>in" for a special case (feet and inches). -- Return true if values/units were extracted and inserted, or return nothing. text = text:gsub(' ', ' '):gsub('%s+', ' ') local pos = text:find(' ', 1, true) if pos then -- Leave checking of value to convert which can handle fractions. local value = text:sub(1, pos - 1) local uid = text:sub(pos + 1) if uid:sub(1, 3) == 'ft ' and uid:sub(-3) == ' in' then -- Special case for enwiki to allow Page Template:Fraction/styles.css has no content.5 feet 10+1⁄2 inches (1.791 m) insert2(uid:sub(4, -4), 'in') insert2(value, 'ft') else insert2(value, make_unit(tdata.wikidata_units, parms, uid) or uid) end return true end end
local function adjustparameters(tdata, parms, index) -- For Module:Convert, adjust parms (a table of [convert: needs a number] parameters). -- Return true if successful or return false, t where t is an error message table. -- This is intended mainly for use in infoboxes where the input might be -- <value><space><unit> or -- <wikidata-property-id> -- If successful, insert values and units in parms, before given index. local text = parms.input -- should be a trimmed, non-empty string local pid = text:match('^P%d+$') local sep = ',' local special = specials[parms[index]] if special then parms.out_unit = special[1] sep = special[2] or sep table.remove(parms, index) end local function quit() return false, pid and { 'cvt_no_output' } or { 'cvt_bad_input', text } end local function insert2(first, second) table.insert(parms, index, second) table.insert(parms, index, first) end if pid then parms.input_text = -- output an empty string if an error occurs local result = input_from_property(tdata, parms, pid) if result.n == 0 then return quit() end local ucode for i, t in ipairs(result) do -- Convert requires each input unit to be identical. if i == 1 then ucode = t[2] elseif ucode ~= t[2] then return quit() end end local item = ucode if item == parms[index] then -- Remove specified output unit if it is the same as the Wikidata unit. -- For example, with property "12 km". table.remove(parms, index) end for i = result.n, 1, -1 do insert2(result[i][1], item) item = sep end return true else if input_from_text(tdata, parms, text, insert2) then return true end end return quit() end
--- List units and check syntax of definitions ---------------------------------
local specifications = { -- seq = sequence in which fields are displayed base = { title = 'SI base units', fields = { symbol = { seq = 2, mandatory = true }, name1 = { seq = 3, mandatory = true }, name2 = { seq = 4 }, link = { seq = 5 }, }, noteseq = 6, header = '{| class="wikitable"\n!si !!symbol !!name1 !!name2 !!link !!note', item = '|-\n|%s ||%s ||%s ||%s ||%s ||%s', footer = '|}', }, alias = { title = 'Aliases for convert', fields = { ucode = { seq = 2, mandatory = true }, si = { seq = 3 }, }, noteseq = 4, header = '{| class="wikitable"\n!alias !!ucode !!base !!note', item = '|-\n|%s ||%s ||%s ||%s', footer = '|}', }, known = { title = 'Units known to convert', fields = { ucode = { seq = 2, mandatory = true }, label = { seq = 3, mandatory = true }, }, noteseq = 4, header = '{| class="wikitable"\n!qid !!ucode !!label !!note', item = '|-\n|%s ||%s ||%s ||%s', footer = '|}', }, unknown = { title = 'Units not known to convert', fields = { _ucode = { seq = 2, mandatory = true }, si = { seq = 3 }, name1 = { seq = 4 }, name2 = { seq = 5 }, link = { seq = 6 }, label = { seq = 7, mandatory = true }, }, noteseq = 8, header = '{| class="wikitable"\n!qid !!_ucode !!base !!name1 !!name2 !!link !!label !!note', item = '|-\n|%s ||%s ||%s ||%s ||%s ||%s ||%s ||%s', footer = '|}', }, }
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.
-- The syntax of each unit definition is checked and a note is added if
-- a problem is detected.
local function safe_cells(t)
-- This is not currently needed, but in case definitions ever use wikitext
-- like 'kg', escape the text so it works in a table cell.
local result = {}
for i, v in ipairs(t) do
if v:find('|', 1, true) then
v = v:gsub('(%[%[[^%[%]]-)|(.-%]%])', '%1\0%2') -- replace pipe in piped link with a zero byte
v = v:gsub('|', '|') -- escape '|'
v = v:gsub('%z', '|') -- restore pipe in piped link
end
result[i] = v:gsub('{', '{') -- escape '{'
end
return unpack(result)
end
local wdunits = tdata.wikidata_units
local speckeys = { 'base', 'alias', 'unknown', 'known' }
for _, sid in ipairs(speckeys) do
specifications[sid].units = Collection.new()
end
local keys = Collection.new()
for k, v in pairs(wdunits) do
keys:add(k)
end
table.sort(keys)
local note_count = 0
for _, key in ipairs(keys) do
local unit = wdunits[key]
local ktext, sid
if key:match('^Q%d+$') then
ktext = '' .. key .. ''
if unit.ucode then
sid = 'known'
else
sid = 'unknown'
end
elseif unit.ucode then
ktext = key
sid = 'alias'
else
ktext = key
sid = 'base'
end
local result = { ktext }
local spec = specifications[sid]
local fields = spec.fields
local note = Collection.new()
for k, v in pairs(unit) do
if fields[k] then
local seq = fields[k].seq
if result[seq] then
note:add('duplicate ' .. k) -- cannot happen since keys are unique
else
result[seq] = v
end
else
note:add('invalid ' .. k)
end
end
for k, v in pairs(fields) do
local value = result[v.seq]
if value then
if k == 'si' and not wdunits[value] then
note:add('need si ' .. value)
end
if k == 'label' then
local wdl = mw.wikibase.label(key)
if wdl ~= value then
note:add('label changed to ' .. tostring(wdl))
end
end
else
result[v.seq] =
if v.mandatory then
note:add('missing ' .. k)
end
end
end
local text
if note.n > 0 then
note_count = note_count + 1
text = '*' .. note:join('
')
end
result[spec.noteseq] = text or
spec.units:add(result)
end
local results = Collection.new()
if note_count > 0 then
local text = note_count .. (note_count == 1 and ' note' or ' notes')
results:add("Search for * to see " .. text .. "\n")
end
for _, sid in ipairs(speckeys) do
local spec = specifications[sid]
results:add("" .. spec.title .. "")
results:add(spec.header)
local fmt = spec.item
for _, unit in ipairs(spec.units) do
results:add(string.format(fmt, safe_cells(unit)))
end
results:add(spec.footer)
end
return true, results:join('\n')
end
return { _adjustparameters = adjustparameters, _listunits = listunits }