Module:WDfetch

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

local p = {}

-- Function to fetch the value of a specified Wikidata property from an entity.
-- 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
        return "Error: No property ID provided."
    end

    -- Get the Q-ID.
    local qid = args.qid
    if not qid then
        return "Error: No Qid provided."
    end

    -- Retrieve the full entity object using the Lua interface.
    local entity = mw.ext.UnlinkedWikibase.getEntity(qid)
    if not entity then
        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
        return nil
    end

    -- Extract the first claim's value.
    local claim = propertyClaims[1]
    if not (claim and claim.mainsnak and claim.mainsnak.datavalue) then
        return nil
    end
    local datavalue = claim.mainsnak.datavalue
    local value = datavalue.value

    -- If the value is a table, handle common cases.
    if type(value) == "table" then
        -- For linked entities, return the entity id.
        if value.id then
            value = value.id
        -- For monolingual text, return the text field.
        elseif value.text then
            value = value.text
        else
            value = tostring(value)
        end
    end

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

    return value
end

return p