local socket = require('socket') local url = require('socket.url') local http = require('socket.http') local https = require('ssl.https') local ltn12 = require('ltn12') local JSON = require("JSON") local DEBUG = require("dbg") --[[ -- Query wikipedia using Wikimedia Web API. -- http://en.wikipedia.org/w/api.php?action=query&prop=extracts&format=json&exintro=&explaintext=&redirects=&titles=hello --]] local Wikipedia = { wiki_server = "http://%s.wikipedia.org", wiki_path = "/w/api.php", wiki_params = { action = "query", prop = "extracts", format = "json", exintro = "", explaintext = "", redirects = "", }, default_lang = "en", } function Wikipedia:getWikiServer(lang) return string.format(self.wiki_server, lang or self.default_lang) end --[[ -- return decoded JSON table from Wikipedia --]] function Wikipedia:loadPage(text, lang, intro, plain) local request, sink = {}, {} local query = "" self.wiki_params.exintro = intro and "" or nil self.wiki_params.explaintext = plain and "" or nil for k,v in pairs(self.wiki_params) do query = query .. k .. '=' .. v .. '&' end local parsed = url.parse(self:getWikiServer(lang)) parsed.path = self.wiki_path parsed.query = query .. "titles=" .. url.escape(text) -- HTTP request request['url'] = url.build(parsed) request['method'] = 'GET' request['sink'] = ltn12.sink.table(sink) DEBUG("request", request) http.TIMEOUT, https.TIMEOUT = 10, 10 local httpRequest = parsed.scheme == 'http' and http.request or https.request local code, headers, status = socket.skip(1, httpRequest(request)) -- raise error message when network is unavailable if headers == nil then error("Network is unreachable") end local content = table.concat(sink) if content ~= "" then local ok, result = pcall(JSON.decode, JSON, content) if ok and result then DEBUG("wiki result", result) return result else DEBUG("error:", result) end end end -- extract intro passage in wiki page function Wikipedia:wikintro(text, lang) local result = self:loadPage(text, lang, true, true) if result then local query = result.query if query then return query.pages end end end return Wikipedia