172 lines
4.9 KiB
JavaScript
172 lines
4.9 KiB
JavaScript
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/*
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Copyright (c) 2004-2006, The Dojo Foundation
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All Rights Reserved.
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Licensed under the Academic Free License version 2.1 or above OR the
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modified BSD license. For more information on Dojo licensing, see:
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http://dojotoolkit.org/community/licensing.shtml
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*/
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dojo.provide("dojo.io.ShortBusIO");
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dojo.require("dojo.io"); // io.js provides setIFrameSrc
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// FIXME: determine if we can use XMLHTTP to make x-domain posts despite not
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// being able to hear back about the result
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dojo.require("dojo.io.IframeIO"); // for posting across domains
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dojo.require("dojo.io.cookie"); // for peering
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dojo.require("dojo.event.*");
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/*
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* this file defines a "forever-frame" style Comet client. It passes opaque
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* JSON data structures to/from the client. Both styles of request provide a
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* topic for the event to be sent to and a payload object to be acted upon.
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*
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* All outbound events are sent via dojo.io.bind() and all inbound requests are
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* processed by Dojo topic dispatch.
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*
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* ShortBusIO packets have the basic format:
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*
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* {
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* topic: "/destination/topic/name",
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* body: {
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* // ...
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* }
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* }
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*
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* Packets bound for the event router (not one of it's clients) or generated
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* from it are prefixed with the special "/meta" topic. Meta-topic events
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* either inform the client to take an action or inform the server of a system
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* event.
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*
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* Upon tunnel creation, the server might therefore send the following meta
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* topic packet to the client to inform the client of it's assigned identity:
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*
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* // client <-- server
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* {
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* topic: "/meta",
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* body: {
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* action: "setClientId",
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* clientId: "fooBar23",
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* tunnelId: "fooBarTunnel4",
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* tunnelExpiration: "...", // some date in the future
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* }
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* }
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*
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* The client may then respond with a confirmation:
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*
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* // client --> server
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* {
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* topic: "/meta",
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* body: {
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* action: "confirmClientId",
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* from: "fooBar23"
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* }
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* }
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*
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* The client must implement a basic vocabulary of /meta topic verbs in order
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* to participate as a ShortBus endpoint. These are TBD.
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*
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* NOTE: this example elides any authentication or authorization steps the
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* client and server may have undertaken prior to tunnel setup.
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*/
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// TODO: unlike repubsubio we don't handle any sort of connection
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// subscription/publishing backlog. Should we?
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dojo.io.ShortBusTransport = new function(){
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var initialized = false;
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var connected = false;
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// this class is similar to RepubsubIO save that we don't have the
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// externalized protocol handler code. Our messages are simpler so our code
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// can be as well.
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this.rcvNode = null;
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this.rcvNodeName = "";
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this.topicRoot = null;
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this.getRandStr = function(){
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return Math.random().toString().substring(2, 10);
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}
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this.widenDomain = function(domainStr){
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// allow us to make reqests to the TLD
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var cd = domainStr||document.domain;
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if(cd.indexOf(".")==-1){ return; } // probably file:/// or localhost
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var dps = cd.split(".");
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if(dps.length<=2){ return; } // probably file:/// or an RFC 1918 address
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dps = dps.slice(dps.length-2);
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document.domain = dps.join(".");
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}
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this.canHandle = function(kwArgs){
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return (
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(connected) &&
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(kwArgs["topic"]) &&
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(! // async only!
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((kwArgs["sync"])&&(kwArgs["sync"] == true))
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)
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);
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}
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this.buildConnection = function(){
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// NOTE: we require the server to cooperate by hosting
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// ShortBusInit.html at the designated endpoint
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this.rcvNodeName = "ShortBusRcv_"+this.getRandStr();
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// the "forever frame" approach
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if(dojo.render.html.ie){
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// use the "htmlfile hack" to prevent the background click junk
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this.rcvNode = new ActiveXObject("htmlfile");
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this.rcvNode.open();
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this.rcvNode.write("<html>");
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this.rcvNode.write("<script>document.domain = '"+document.domain+"'");
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this.rcvNode.write("</html>");
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this.rcvNode.close();
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var ifrDiv = this.rcvNode.createElement("div");
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this.rcvNode.appendChild(ifrDiv);
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this.rcvNode.parentWindow.dojo = dojo;
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ifrDiv.innerHTML = "<iframe src='"+this.topicRoot+"/?tunntelType=htmlfile'></iframe>"
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// and we're ready to go!
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connected = true;
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}else{
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this.rcvNode = dojo.io.createIFrame(this.rcvNodeName);
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dojo.io.setIFrameSrc(this.rcvNode, this.topicRoot+"/?tunnelType=iframe");
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// we're still waiting on this one to call back up and advertise
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// that it's been initialized
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}
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}
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this.iframeConnectionInit = function(){
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connected = true;
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}
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this.dispatchServerEvent = function(eObj){
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// FIXME: implement basic /meta topic semantics here!
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}
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this.init = function(){
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if(initialized){
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return;
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}
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initialized = true;
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this.widenDomain();
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// we want to set up a connection to the designated server. Grab the
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// server location out of djConfig.
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this.topicRoot = djConfig["ShortBusRoot"];
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if(!this.topicRoot){
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dojo.debug("no topic root specified in djConfig.ShortBusRoot");
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return;
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}
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}
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this.dispatch = function(evt){
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// dipatch events along the specified path
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}
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dojo.io.transports.addTransport("ShortBusTransport");
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}
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