rpc.js

/**
 * This program is distributed under the terms of the MIT license.
 * 
 * Copyright 2011 (c) Pierre Guilleminot <pierre.guilleminot@gmail.com>
 */

/**
 * Jabber-RPC plugin (XEP-0009)
 * Allow the management of RPC
 */
Strophe.addConnectionPlugin("rpc", {

  _connection : undefined,

  _whitelistEnabled : false,

  jidWhiteList : [],
  nodeWhiteList : [],
  domainWhiteList : [],

  /**
   * Plugin init
   * 
   * @param  {Strophe.Connection} connection Strophe connection
   */
  init: function(connection) {

    this._connection = connection;

    this._whitelistEnabled = false;

    this.jidWhiteList    = [];
    this.nodeWhiteList   = [];
    this.domainWhiteList = [];

    Strophe.addNamespace("RPC", "jabber:iq:rpc");

    if (!connection.hasOwnProperty("disco")) {
      Strophe.warn("You need the discovery plugin " +
                   "to have Jabber-RPC fully implemented.");
    }
    else {
      this._connection.disco.addIdentity("automation", "rpc");
      this._connection.disco.addFeature(Strophe.NS.RPC);
    }
  },

  /**
   * Add a jid or an array of jids to
   * the whitelist.
   * It's possible to use wildecards for the domain
   * or the node. ie:
   *   *@*
   *   myname@*
   *   *@jabber.org
   * 
   * @param {String|Array} jid
   */
  addJidToWhiteList: function(jids) {
    if (typeof(jids.sort) !== "function") {
      jids = [jids];
    }

    for (var i = 0; i < jids.length; i++) {
      var jid = jids[i];

      if (jid === "*@*") {
        this._whitelistEnabled = false;
        return;
      }

      var node   = Strophe.getNodeFromJid(jid);
      var domain = Strophe.getDomainFromJid(jid);
      if (jid) {
        if (node === "*") {
          this.domainWhiteList.push(domain);
        } else if (domain === "*") {
          this.nodeWhiteList.push(node);
        } else {
          this.jidWhiteList.push(jid);
        }
        this._whitelistEnabled = true;
      }
    }
  },

  /**
   * Helper to filter out Jid outside of the whitelists
   * 
   * @param  {String} jid Jid to test 
   * @return {Boolean}
   */
  _jidInWhitelist: function(jid) {
    if (!this._whitelistEnabled)
      return true;

    if (jid === this._connection.jid)
      return true;
    
    return (
      this.domainWhiteList.indexOf(Strophe.getDomainFromJid(jid)) !== -1  ||
      this.nodeWhiteList.indexOf(Strophe.getNodeFromJid(jid))     !== -1  ||
      this.jidWhiteList.indexOf(jid) !== -1
    );
  },

  /**
   * Send a request message
   * 
   * @param  {Object} id     ID of the request
   * @param  {String} to     JID of the recipient
   * @param  {String} method name of the method
   * @param  {Array}  params Array of parameters
   */
  sendRequest: function(id, to, method, params) {
    params = (typeof(params.sort) === "function") ? params : [params];

    var element = new Strophe.Builder("methodCall")
      .c("methodName").t(method)
      .up()
      .c("params");
    
    for (var i = 0; i < params.length; i++) {
      element.c("param")
        .cnode(this._convertToXML(params[i]))
        .up().up();
    }

    this.sendXMLElement(id, to, "set", element.tree());
  },

  /**
   * Send a response message
   * 
   * @param  {String} id     ID of the request
   * @param  {String} to     JID of the recipient
   * @param  {Object} result Result of the function call
   */
  sendResponse: function(id, to, result) {
    var element = new Strophe.Builder("methodResponse")
      .c("params")
      .c("param")
      .cnode(this._convertToXML(result));
    
    this.sendXMLElement(id, to, "result", element.tree());
  },

  /**
   * Send an error response (or fault)
   * 
   * @param  {String} id      ID of the faulted request
   * @param  {String} to      JID of the recipient
   * @param  {Number} code    Code of the error
   * @param  {String} message Error message
   */
  sendError: function(id, to, code, message) {
    if (isNaN(code)) {
      Strophe.error(code + " is not a number");
      return;
    }

    var element = new Strophe.Builder("methodResponse")
      .c("fault")
      .cnode(this._convertToXML({
        faultCode: code,
        faultString: String(message)
      }));

    this.sendXMLElement(id, to, "result", element.tree());
  },

  /**
   * Send a XMLElement as the request
   * Does not check whether it is properly formed or not
   * 
   * @param  {String}  id      ID of the request or response 
   * @param  {String}  to      JID of the recipient
   * @param  {String}  type    Type of the request ('set' for a request and 'result' for a response)
   * @param  {Element} element The XMLElement to send
   */
  sendXMLElement: function(id, to, type, element) {
    if (typeof element.tree === 'function') {
      element = element.tree();
    }

    var iq = $iq({type: type, id: id, from: this._connection.jid, to: to})
      .c("query", {xmlns: Strophe.NS.RPC})
      .cnode(element);
    
    this._connection.send(iq.tree());
  },

  _sendForbiddenAccess: function(id, to) {
    var iq = $iq({type: "error", id: id, from: this._connection.jid, to: to})
      .c("error", {code: 403, type: "auth"})
      .c("forbidden", {xmlns: Strophe.NS.STANZAS});
    
    this._connection.send(iq.tree());
  },

  /**
   * Add a request and response handlers
   * 
   * @param {Function} request_h  Request handler
   * @param {Function} response_h Response handler
   * @param {Object} context Context of the handlers
   */
  addHandlers: function(request_h, response_h, context) {
    this.addRequestHandler(request_h, context);
    this.addResponseHandler(response_h, context);
  },

  /**
   * Add a request handler
   * called every time a request is received
   * 
   * @param {Function} handler The handler function
   * @param {Object} context Context of the handler
   */
  addRequestHandler: function(handler, context) {
    this._connection.addHandler(this._filteredRequestHandler(handler, context), Strophe.NS.RPC, "iq", "set");
  },

  /**
   * Add a response handler
   * called every time a response is received
   * 
   * @param {Function} handler The handler function called every time a response is received
   * @param {Object} context Context of the handler
   */
  addResponseHandler: function(handler, context) {
    this._connection.addHandler(this._filteredResponseHandler(handler, context), Strophe.NS.RPC, "iq", "result");
  },

  /**
   * Add a raw XML handler for every RPC message incoming
   * @param {Function} handler The handler function called every time a rpc is received
   * @param {Object} context Context of the handler
   */
  addXMLHandler: function(handler, context) {
    this._connection.addHandler(this._filteredHandler(handler, context), Strophe.NS.RPC, "iq");
  },

  _filter: function(xml) {
    var from = xml.getAttribute("from");
    if (!this._jidInWhitelist(from)) {
      this._sendForbiddenAccess(xml.getAttribute("id"), from);
      return false;
    }
    return true;
  },

  _filteredHandler: function(handler, context) {
    context = context || this;
    var self = this;
    return function(xml) {
      if (self._filter(xml)) {
        return handler.apply(context, arguments);
      }
      return true;
    };
  },

  _filteredResponseHandler: function(handler, context) {
    context = context || this;
    var self = this;
    return function(xml) {
      if (self._filter(xml)) {
        var rpc = self._parseResponseMessage(xml);
        if (rpc.result || rpc.result === null)
          return handler.call(context, rpc.id, rpc.from, rpc.result, false);
        else if (rpc.fault || rpc.fault === null)
          return handler.call(context, rpc.id, rpc.from, rpc.fault, true);
      }
      return true;
    };
  },

  _filteredRequestHandler: function(handler, context) {
    context = context || this;
    var self = this;
    return function(xml) {
      if (self._filter(xml)) {
        var rpc = self._parseRequestMessage(xml);
        return handler.call(context, rpc.id, rpc.from, rpc.method, rpc.params);
      }
      return true;
    };
  },

  /**
   * Helper to transform a Javascript object
   * into its XML representation as described in
   * the XML-RPC spec
   * 
   * @param  {Object} obj The object to convert
   * @return {Element} A <value> element
   */
  _convertToXML: function(obj) {
    var key;

    var xml   = new Strophe.Builder("value");
    var regex = new RegExp("function (.*?)\\(\\) \\{.*");
    var _ref, _ref1;
    var type = (_ref = regex.exec(typeof obj !== "undefined" && obj !== null ? (_ref1 = obj.constructor) != null ? _ref1.toString() : void 0 : void 0)) != null ? _ref[1] : void 0;

    switch (type) {
      case "Number":
        // Numbers can only be sent as integers or doubles.
        var number = (Math.floor(obj) !== obj) ? "double" : "i4";
        xml.c(number).t(obj.toString());
        break;
      case "String":
        xml.c("string").t(obj);
        break;
      case "Boolean":
        xml.c("boolean").t((obj*1).toString());
        break;
      case "Object":
        xml.c("struct");
        for (key in obj) {
          if (obj.hasOwnProperty(key) && typeof(obj[key]) !== "function") {
            xml.c("member").c("name").t(key);
            xml.up().cnode(this._convertToXML(obj[key]));
            xml.up().up();
          }
        }
        break;
      case "Date":
        var datetext = obj.getFullYear() +
                       this._padNumber(obj.getMonth()+1) +
                       this._padNumber(obj.getDate())    + "T" +
                       this._padNumber(obj.getHours())   + ":" +
                       this._padNumber(obj.getMinutes()) + ":" +
                       this._padNumber(obj.getSeconds());
        xml.c("dateTime.iso8601").t(datetext);
        break;
      case "Array":
        xml.c("array").c("data");
        for (key in obj) {
          if (obj.hasOwnProperty(key) && typeof(obj[key]) !== "function") {
            xml.cnode(this._convertToXML(obj[key]));
            xml.up();
          }
        }
        break;
      default:
        break;
    }

    return xml.tree();
  },

  _padNumber: function(num) {
    if (num < 10) {
      num = "0" + num;
    }
    return num;
  },

  _parseRequestMessage: function(iq) {
    var rpc  = {};
    rpc.from = iq.getAttribute("from");
    rpc.id   = iq.getAttribute("id") || null;

    // Method name
    var method = iq.getElementsByTagName("methodName")[0];
    rpc.method = method ? Strophe.getText(method) : null;

    // Parameters
    rpc.params = null;
    try {
      var params = iq.getElementsByTagName("params")[0]
                     .childNodes;
      if (params && params.length > 0) {
        rpc.params = [];
        for (var i = 0; i < params.length; i++) {
          rpc.params.push(this._convertFromXML(params[i].firstChild));
        }
      }
    } catch(e) {
      rpc.params = null;
    }
    return rpc;
  },

  _parseResponseMessage: function(iq) {
    var rpc  = {};
    rpc.from = iq.getAttribute("from");
    rpc.id   = iq.getAttribute("id") || null;

    try {
      var result = iq.getElementsByTagName("methodResponse")[0].firstChild;

      // Response
      var tag = result.tagName;
      if (tag === "params") {
        rpc.result = this._convertFromXML(result.firstChild.firstChild);
      }
      // Error
      else if (tag === "fault") {
        rpc.fault  = this._convertFromXML(result.firstChild);
      }
    } catch(e) {
      rpc.result = null;
    }
    return rpc;
  },

  _convertFromXML: function(obj) {
    if (!obj)
      return null;

    var data;
    var tag = obj.tagName.toLowerCase();

    try {
      switch (tag) {
        case "value":
          return this._convertFromXML(obj.firstChild);
        case "double":
        case "i4":
        case "int":
          var number = Strophe.getText(obj);
          data = number * 1;
          break;
        case "boolean":
          var bool = Strophe.getText(obj);
          data = (bool === "1" || bool === "true") ? true : false;
          break;
        case "datetime.iso8601":
          var date = Strophe.getText(obj);
          data = new Date();
          data.setFullYear(date.substring(0,4), date.substring(4,6) - 1, date.substring(6,8));
          data.setHours(date.substring(9,11), date.substring(12,14), date.substring(15,17));
          break;
        case "array":
          data = [];
          var datatag = obj.firstChild;
          for (var k = 0; k < datatag.childNodes.length; k++) {
            var value = datatag.childNodes[k];
            data.push(this._convertFromXML(value.firstChild));
          }
          break;
        case "struct":
          data = {};
          for (var j = 0; j < obj.childNodes.length; j++) {
            var membername  = Strophe.getText(obj.childNodes[j].getElementsByTagName("name")[0]);
            var membervalue = obj.childNodes[j].getElementsByTagName("value")[0].firstChild;
            data[membername] = membervalue ? this._convertFromXML(membervalue) : null;
          }
          break;
        case "string":
          data = Strophe.getText(obj);
          break;
        default:
          data = null;
          break;
      }
    } catch(e) {
      data = null;
    }
    return data;
  }

});