source: Dev/branches/rest-dojo-ui/client/dojox/cometd/longPollTransportJsonEncoded.js @ 256

dojo.provide("dojox.cometd.longPollTransportJsonEncoded");
dojo.require("dojox.cometd._base");

dojox.cometd.longPollTransportJsonEncoded = new function(){
        // This is an alternative implementation to that provided in logPollTransportFormEncoded.js
        // that sends messages as text/json rather than form encoding them.
        
        this._connectionType="long-polling";
        this._cometd=null;

        this.check = function(types, version, xdomain){
                return ((!xdomain)&&(dojo.indexOf(types, "long-polling") >= 0));
        }

        this.tunnelInit = function(){
                var message = {
                        channel:        "/meta/connect",
                        clientId:       this._cometd.clientId,
                        connectionType: this._connectionType,
                        id:     ""+this._cometd.messageId++
                };
                message=this._cometd._extendOut(message);
                this.openTunnelWith([message]);
        }

        this.tunnelCollapse = function(){
                // TODO handle transport specific advice
                
                if(!this._cometd._initialized){ return; }
                        
                if(this._cometd._advice && this._cometd._advice["reconnect"]=="none"){
                        return;
                }
                if (this._cometd._status=="connected") {
                        setTimeout(dojo.hitch(this,function(){this._connect();}),this._cometd._interval());
                }else{
                        setTimeout(dojo.hitch(this._cometd,function(){this.init(this.url,this._props);}),this._cometd._interval());
                }
        }

        this._connect = function(){
                if(!this._cometd._initialized){ return; }
                if(this._cometd._polling) {
                        return;
                }
                        
                if((this._cometd._advice) && (this._cometd._advice["reconnect"]=="handshake")){
                        this._cometd._status="unconnected";
                        this._initialized = false;
                        this._cometd.init(this._cometd.url,this._cometd._props);
                }else if(this._cometd._status=="connected"){
                        var message={
                                channel:        "/meta/connect",
                                connectionType: this._connectionType,
                                clientId:       this._cometd.clientId,
                                id:     ""+this._cometd.messageId++
                        };
                        if (this._cometd.connectTimeout>=this._cometd.expectedNetworkDelay){
                                message.advice={timeout:(this._cometd.connectTimeout-this._cometd.expectedNetworkDelay)};
                        }
                        message=this._cometd._extendOut(message);
                        this.openTunnelWith([message]);
                }
        }

        this.deliver = function(message){
                // Nothing to do
        }

        this.openTunnelWith = function(messages, url){
                this._cometd._polling = true;
                var post = {
                        url: (url||this._cometd.url),
                        postData: dojo.toJson(messages),
                        contentType: "text/json;charset=UTF-8",
                        handleAs: this._cometd.handleAs,
                        load: dojo.hitch(this, function(data){
                                this._cometd._polling=false;
                                this._cometd.deliver(data);
                                this._cometd._backon();
                                this.tunnelCollapse();
                        }),
                        error: dojo.hitch(this, function(err){
                                this._cometd._polling=false;
                                var metaMsg = {
                                        failure: true,
                                        error: err,
                                        advice: this._cometd._advice
                                };
                                this._cometd._publishMeta("connect",false, metaMsg);
                                this._cometd._backoff();
                                this.tunnelCollapse();
                        })
                };

                var connectTimeout=this._cometd._connectTimeout();
                if (connectTimeout>0) {
                        post.timeout=connectTimeout;
                }

                this._poll = dojo.rawXhrPost(post);
        }

        this.sendMessages = function(messages){
                for(var i=0; i<messages.length; i++){
                        messages[i].clientId = this._cometd.clientId;
                        messages[i].id = ""+this._cometd.messageId++;
                        messages[i]=this._cometd._extendOut(messages[i]);
                }
                return dojo.rawXhrPost({
                        url: this._cometd.url||dojo.config["cometdRoot"],
                        handleAs: this._cometd.handleAs,
                        load: dojo.hitch(this._cometd, "deliver"),
                        postData: dojo.toJson(messages),
                        contentType: "text/json;charset=UTF-8",
                        error: dojo.hitch(this, function(err){
                                this._cometd._publishMeta("publish",false,{messages:messages});
                        }),
                        timeout: this._cometd.expectedNetworkDelay
                });
        }

        this.startup = function(handshakeData){
                if(this._cometd._status=="connected"){ return; }
                this.tunnelInit();
        }

        this.disconnect = function(){
                var message = {
                        channel: "/meta/disconnect",
                        clientId: this._cometd.clientId,
                        id:     "" + this._cometd.messageId++
                };
                message = this._cometd._extendOut(message);
                dojo.rawXhrPost({
                        url: this._cometd.url || dojo.config["cometdRoot"],
                        handleAs: this._cometd.handleAs,
                        postData: dojo.toJson([message]),
                        contentType: "text/json;charset=UTF-8"
                });
        }

        this.cancelConnect = function(){
                if(this._poll){
                        this._poll.cancel();
                        this._cometd._polling=false;
                        this._cometd._publishMeta("connect",false,{cancel:true});
                        this._cometd._backoff();
                        this.disconnect();
                        this.tunnelCollapse();
                }
        }
}

dojox.cometd.longPollTransport = dojox.cometd.longPollTransportJsonEncoded;

dojox.cometd.connectionTypes.register("long-polling", dojox.cometd.longPollTransport.check, dojox.cometd.longPollTransportJsonEncoded);
dojox.cometd.connectionTypes.register("long-polling-json-encoded", dojox.cometd.longPollTransport.check, dojox.cometd.longPollTransportJsonEncoded);