Module:WDfetch

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

local p = {}

-- Function to fetch and display the value of a specified Wikidata property
-- from an entity, formatting the output similarly to the infobox display.
-- Requires both a property ID (e.g. P12081) and a Q‑ID (e.g. Q2934).
function p.getvalue(frame)
    -- Collect arguments from the calling frame.
    local args = {}
    for k, v in pairs(frame:getParent().args) do
        if v ~= "" then args[k] = v end
    end
    for k, v in pairs(frame.args) do
        if v ~= "" then args[k] = v end
    end

    -- Get the property ID.
    local propertyId = args[1] or args.pid
    if not propertyId then
        mw.log("p.getvalue: No property ID provided.")
        return "Error: No property ID provided."
    end

    -- Get the Q-ID.
    local qid = args.qid
    if not qid then
        mw.log("p.getvalue: No Qid provided.")
        return "Error: No Qid provided."
    end

    mw.log("p.getvalue: Fetching entity for qid " .. qid)
    -- Retrieve the full entity object using the Lua interface.
    local entity = mw.ext.UnlinkedWikibase.getEntity(qid)
    if not entity then
        mw.log("p.getvalue: Entity not found for qid " .. qid)
        return "Error: Entity not found for Qid " .. qid
    end

    -- Extract claims from the entity.
    local claims = entity.claims or {}
    local propertyClaims = claims[propertyId]
    if not propertyClaims or #propertyClaims == 0 then
        mw.log("p.getvalue: No claims found for property " .. propertyId)
        return nil
    end

    -- Extract the first claim's value.
    local claim = propertyClaims[1]
    if not (claim and claim.mainsnak and claim.mainsnak.datavalue) then
        mw.log("p.getvalue: Claim structure invalid for property " .. propertyId)
        return nil
    end

    local datatype = claim.mainsnak.datatype
    mw.log("p.getvalue: Processing claim for property " .. propertyId .. " with datatype " .. datatype)
    local value

    if datatype == "wikibase-item" then
        value = '{{wdl|' .. claim.mainsnak.datavalue.value.id .. '}}'
    elseif datatype == "monolingualtext" then
        value = claim.mainsnak.datavalue.value.text
    elseif datatype == "commonsMedia" then
        value = '[[File:' .. claim.mainsnak.datavalue.value .. '|300px]]'
    elseif datatype == "time" then
        -- Format the time value using the English date format.
        local timeValue = claim.mainsnak.datavalue.value.time
        local lang = mw.language.getContentLanguage()
        value = lang:formatDate('j F Y', timeValue)
    else
        value = '<small><em>Type ' .. datatype .. ' not handled by Module:Infobox yet.</em></small>'
    end

    -- Capitalize the first letter if the result is a string.
    if type(value) == "string" then
        value = value:gsub("^%l", string.upper)
    end

    mw.log("p.getvalue: Returning value: " .. tostring(value))
    return value
end

return p