Dojo中的常规加载图标

I'm giving maintenance to an application that makes several Ajax calls with:

dojo.xhrPost() and  dojo.xhrGet()

and I want to add a generic loading "icon + message" to all the calls on the system.. seance the system i find difficult and low maintainable to add the loadingFunction call to all the load:function of all xhr

so I wander if there is a way to add a listener to all the ajax calls on the system so everytime is made a call show the loading...

I read that I can do that with aspect in 1.7 but the application I'm working on is with the Dojo Version of 1.6

so if you know a way to show a generic message for all the ajax calls.. .

Thanks in advice..

Let's think of you are dojo.xhrGet().Make common method where you can pass your URl and the call function to be called.

var processDialog = new dijit.Dialog({

        title : ""
    }); //make it Global
function sendRequest(requestUrl, sucessFunction, errorFunction) {

        dojo.xhrGet({
        preventCache : "true",
        url : requestUrl,
        load : function (){
                   showProgressDlg(processDialog,true);
               sucessFunction; //Call  showProgressDlg(processDialog,false) once your job done inside this call back method.
                    },
        error : function (){
                   showProgressDlg(processDialog,false);//If Any loading image present
                   errorFunction;
                    },
        handleAs : "json"
    });
}



function showProgressDlg(imgContent /*Pass Your Icon URL*/, isShow) {
    if (isShow == true) {
        processDialog .attr("content", imgContent);
        dojo.body().appendChild(processDialog .domNode);
        processDialog.titleBar.style.display = 'none';
        processDialog.startup();
        processDialog.show();
    } else {
        if (processDialog )
            processDialog.hide();
    }
}

You can achieve this via dojo/topic, namely IO Pipeline Topics, which works since Dojo 1.4.

See working example at jsFiddle: http://jsfiddle.net/phusick/cMHdt/

First of all you have to globally enable IO Pipeline Topics, set ioPublish: true in one of dojoConfig, data-dojo-config or djConfig (depends on which you use).

Then dojo.subscribe() to specific topics, e.g.:

dojo.subscribe("/dojo/io/start", function(e) {
    dojo.style(throbberNode, "display", "block");
});

dojo.subscribe("/dojo/io/stop", function(e) {
    dojo.style(throbberNode, "display", "none");
});

Available topics according to Dojo documentation are:

/dojo/io/start is sent when there are no outstanding IO requests, and a new IO request is started. No arguments are passed with this topic.
/dojo/io/send is sent whenever a new IO request is started. It passes the dojo.Deferred for the request with the topic.
/dojo/io/load is sent whenever an IO request has loaded successfully. It passes the response and the dojo.Deferred for the request with the topic.
/dojo/io/error is sent whenever an IO request has errored. It passes the error and the dojo.Deferred for the request with the topic.
/dojo/io/done is sent whenever an IO request has completed, either by loading or by erroring. It passes the error and the dojo.Deferred for the request with the topic.
/dojo/io/stop is sent when all outstanding IO requests have finished. No arguments are passed with this topic.