Performance issue with Layer.Refresh

DaveSouthern — Tue, 18 Feb 2014 18:28:00 GMT

We have a simple prototype application that shows a map and allows the user to draw polygons on the map. The polygon that is drawn is saved to an arcGis server. I'll show what I think are the relevant snippets of code below with a brief description of what I believe is going on:

The section that allows for the drawing of the polygon looks like this:

        function digitizeShape(evt) {


            //initialiaze the toolbar, if not found
            if (!drawToolbar) { InitToolbar() }

            //set the map to the digitize state
            map.disableMapNavigation;
            drawToolbar.activate(esri.toolbars.Draw.POLYGON);

        }

Once the user is finished digitizing the polygon, this code is called to save it to the server:

        function addToMap(evt) {



            //get the name
            var buildingName = document.getElementById('BuildingNameBox').value;

            //get the polygon coordinates
            var polyString = dojo.toJson(evt.geographicGeometry.toJson());
            // polyString = '';

            //also commit to the server
            var requestText = "facno=" + buildingName + "&shape=" + polyString;
            httpAddRequest = new XMLHttpRequest();
            httpAddRequest.open("POST", "../ajax/postfacility.aspx?type=IHB", true);
            httpAddRequest.setRequestHeader("Content-type", "application/x-www-form-urlencoded");
            httpAddRequest.onreadystatechange = evalAddResult;
            httpAddRequest.send(requestText);

            //restore the map navigation state
            map.enableMapNavigation;
            drawToolbar.deactivate();

        }

Finally, once the postback is complete, we refresh the map:

        function evalAddResult(args) {

            if (httpAddRequest.readyState == 4 /* complete */) {
                if (httpAddRequest.status == 200) {

                    //see if the add was successful
                    if (httpAddRequest.getResponseHeader("ERROR") == null) {

                        //success: refresh the map
                        var ihbLayer = map._layers['buildings'];
                        ihbLayer.refresh();

                    }
                    else {

                        //TODO: show the error when we get jquery messaging sorted out
                        //ShowMessage(httpAddRequest.getResponseHeader("ERROR"), "Add Failed");
                        window.alert(httpAddRequest.getResponseHeader("ERROR"));
                    }

                }
            }

        }

All this works good except for one exception: The refreshing of the map takes about 5 seconds. So I'm wondering... Are we doing this correctly? Is Layer.Refresh the most efficient way to refresh the map, or is there another way that would work better?

Or... Is the problem really just a performance issue with our server? Right now we're just trying out azurewebsites.net. Maybe there's too much running on our server?

Any insight would be helpful.

topic Performance issue with Layer.Refresh in ArcGIS JavaScript Maps SDK Questions

Performance issue with Layer.Refresh