source: Dev/branches/rest-dojo-ui/client/dojox/rpc/Client.js @ 256

define("dojox/rpc/Client", ["dojo", "dojox"], function(dojo, dojox) {

        dojo.getObject("rpc.Client", true, dojox);

        // Provide extra headers for robust client and server communication

        dojo._defaultXhr = dojo.xhr;
        dojo.xhr = function(method,args){
                var headers = args.headers = args.headers || {};
                // set the client id, this can be used by servers to maintain state information with the
                // a specific client. Many servers rely on sessions for this, but sessions are shared
                // between tabs/windows, so this is not appropriate for application state, it
                // really only useful for storing user authentication
                headers["Client-Id"] = dojox.rpc.Client.clientId;
                // set the sequence id. HTTP is non-deterministic, message can arrive at the server
                // out of order. In complex Ajax applications, it may be more to ensure that messages
                // can be properly sequenced deterministically. This applies a sequency id to each
                // XHR request so that the server can order them.
                headers["Seq-Id"] = dojox._reqSeqId = (dojox._reqSeqId||0)+1;
                return dojo._defaultXhr.apply(dojo,arguments);
        }

        // initiate the client id to a good random number
        dojox.rpc.Client.clientId = (Math.random() + '').substring(2,14) + (new Date().getTime() + '').substring(8,13);

        return dojox.rpc.Client;

});