app.js

var l          = require("nlogger").logger(module),
    config     = require('./config'),
    ifttt      = require("./models/ifttt"),
    Client     = require("../../irkit-client/"),
    irkit      = new Client({
        apikey : config.apikey
    }),
    async      = require("async")
;

// ifttt servers actually request us like following:
// 2015-02-15 05:28:45.796 deserialized: mt.supportedMethods ([0])
// 2015-02-15 05:28:46.203 deserialized: metaWeblog.getRecentPosts ([0,"o.masakazu@gmail.com","password",1])
// 2015-02-15 05:28:46.415 deserialized: metaWeblog.getRecentPosts ([0,"o.masakazu@gmail.com","password",1])
// 2015-02-15 05:28:46.816 deserialized: mt.supportedMethods ([0])
// 2015-02-15 05:28:47.217 deserialized: metaWeblog.getRecentPosts ([0,"o.masakazu@gmail.com","password",1])
// 2015-02-15 05:28:47.417 deserialized: metaWeblog.getRecentPosts ([0,"o.masakazu@gmail.com","password",1])

ifttt.setDelegate({
    getRecentPosts: function(username, password, callback) {
        // always success
        callback();
    },
    newPost: function(username, password, post, callback) {
        // ignore username and password
        var clientkey = post.title;
        var signal;
        try {
            signal = JSON.parse(post.description);
        } catch (e) {
            l.info("JSON.parse failed: ", e, post.description);
            callback(400);
            return;
        };
        var deviceids = post.categories;
        async.map(deviceids,
                  function(deviceid, cb) {
                      irkit.messages.create(clientkey, signal, deviceid, cb);
                  },
                  function(err, results) {
                      callback(err);
                  });
    }
});

module.exports = ifttt;

ifttt.js

var http         = require("http"),
    Deserializer = require("xmlrpc/lib/deserializer"),
    Serializer   = require("xmlrpc/lib/serializer"),
    l            = require("nlogger").logger(module),
    HTTPStatus   = require("http-status")
;

// thanks to https://github.com/femto113/node-ifttt-webhook
var server = http.createServer(function (request, response) {
    var deserializer = new Deserializer();
    deserializer.deserializeMethodCall(request, function(error, methodName, params) {
        var xml = null,
            username,
            password,
            post;
        if (!error) {
            l.info("deserialized: "+methodName+" ("+JSON.stringify(params)+")");
            switch (methodName) {
            case 'mt.supportedMethods': // codex.wordpress.org/XML-RPC_MovableType_API#mt.supportedMethods
                // this is used by IFTTT to verify the site is actually a wordpress blog ;-)
                server.writeSuccess(response, ['metaWeblog.getRecentPosts', 'metaWeblog.newPost']);
                break;
            case 'metaWeblog.getRecentPosts': // codex.wordpress.org/XML-RPC_MetaWeblog_API#metaWeblog.getRecentPosts
                {
                    // this is the authentication request from IFTTT
                    // send a blank blog response
                    // this also makes sure that the channel is never triggered

                    params.shift();
                    username = params.shift();
                    password = params.shift();

                    server.delegate.getRecentPosts(username, password, function(err) {
                        if (err) {
                            l.info(err);
                            if (typeof err === "number") {
                                server.writeError(response, err, HTTPStatus[err]);
                            }
                            else {
                                server.writeError(response, 401, "Unauthorized");
                            }
                        }
                        else {
                            server.writeSuccess(response, []);
                        }
                    });
                }
                break;
            case 'metaWeblog.newPost': // codex.wordpress.org/XML-RPC_WordPress_API/Posts#wp.newPost
                {
                    // This is the actual webhook.  Parameters are provided via fields in IFTTT's GUI.  By convention
                    // we put the target URL in the Tags field (passed as mt_keywords).  e.g. params
                    // [0, "user", "password", {"title":"...","description":"...","categories":[...],mt_keywords":[webhook url]}]
                    params.shift();  // blogid? 
                    username = params.shift();
                    password = params.shift();
                    post     = params.shift();

                    server.delegate.newPost(username, password, post, function(err) {
                        if (err) {
                            l.info(err);
                            if (typeof err === "number") {
                                server.writeError(response, err, HTTPStatus[err]);
                            }
                            else {
                                server.writeError(response, 500, "Internal Server Error");
                            }
                        }
                        else {
                            // a "postid", presumably ignored by IFTTT
                            server.writeSuccess(response, Date.now().toString(32));
                        }
                    });
                }
                break;
            default:
                server.writeError(response, 400, "Invalid Request. Method Not Found");
                break;
            }
        }
    });
});
server.writeSuccess = function (response, object) {
    var xml = Serializer.serializeMethodResponse(object);
    this.writeXML(response, xml);
};
server.writeError = function (response, faultCode, faultString) {
    var xml = Serializer.serializeFault({
        faultCode: faultCode,
        faultString: faultString
    });
    this.writeXML(response, xml);
};
server.writeXML = function (response, xml) {
    response.writeHead(200, {
        'Content-Type': 'text/xml', 'Content-Length': xml.length
    });
    response.end(xml);
};
server.setDelegate = function (delegate) {
    if (typeof delegate.getRecentPosts !== "function") {
        throw("delegate.getRecentPosts function required");
    }
    if (typeof delegate.newPost !== "function") {
        throw("delegate.newPost function required");
    }
    server.delegate = delegate;
};

module.exports = server;