Two Bugs with Basemap Gallery

Question

Original User: Steaks

The first bug occurs sometimes while switching between Bing base maps.  If you cycle through them fairly fast the map will stop updating.  Sometimes it happens right away, other times it can take up to a minute of switching the maps until it stops working.  I wish I could narrow it down more and find out how its actually happening. You can test it here http://help.arcgis.com/en/webapi/javascript/arcgis/demos/widget/widget_basemap.html.  Firebug returns this message when it happens.uncaught exception: [Exception... "Component returned failure code: 0x80004003 (NS_ERROR_INVALID_POINTER) [nsIDOMHTMLDivElement.removeChild]" nsresult: "0x80004003 (NS_ERROR_INVALID_POINTER)" location: "JS frame :: http://serverapi.arcgisonline.com/jsapi/arcgis/?v=2.4 :: <TOP_LEVEL> :: line 48" data: no]

The second bug is minor.  While switching the maps programmatically using the select method the orange border around the thumbnails inside the widget does not update.

bug1.jpg

bug2.jpg

BillDaigle · Answer

Here is my latest installment.

I linked to the onClick event of the basemapGallery Nodes:    //Listen for a change of basemap (NIM080755)
    dojo.forEach(dojo.query(".esriBasemapGalleryNode"),function(galleryNode){
      dojo.connect(galleryNode,"onclick",function(){
        _this._basemapButton.closeDropDown();
        _this._disableAllMapFunctionUntilBasemapUpdates();
      });
    });

The following function disables the map until it is done updating://this is a a stopgap measure until ESRI fixes NIM080755  
  _disableAllMapFunctionUntilBasemapUpdates: function(){
    var _this = this;
    //disable the map  it id done updating the basemap 
    var mapStandby = new dojox.widget.Standby({target: _this.map.container});
    document.body.appendChild(mapStandby.domNode);
    mapStandby.startup();
    mapStandby.show();
    
    var mapUpdateEndConnect = dojo.connect(_this.map,"onUpdateEnd",function(){
        mapStandby.destroy();
        dojo.disconnect(mapUpdateEndConnect);
      });    
  }

Finally, if all else fails I give the user an alert so they know something might have gone wrong.  //added to account for errors caused by NIM080755
    window.onerror = function(){
      alert("An error has occured.
You're map will likely continue to function, but you may see inconsistent results.
Refresh your browser to start over.");
    };

Anonymous User · Answer

Original User: bdaigle

Thanks for the suggestion Jeff. I may try something along that line.  The root of the problem seems to be that the basemap needs to completely update before the user updates the map in any way.  The same problem occurs if the user picks one basemap, then quickly changes to another.  Give it a try on the samples if your curious.  I contacted ESRI support and they filed it as a bug (NIM080755).  It doesn't seem to be showing up in their system yet, but I assume it will soon.

I tried the following workaround:dojo.connect(this.basemapGallery,"onSelectionChange",function(){
  
  //disable the map until it done updating the basemap 
  var mapStandby = new dojox.widget.Standby({target: _this.map.container});
  document.body.appendChild(mapStandby.domNode);
  mapStandby.startup();
  mapStandby.show();
  
  var mapUpdateEndConnect = dojo.connect(_this.map,"onUpdateEnd",function(){
      //disconnect the listener
      dojo.disconnect(mapUpdateEndConnect);
      
      //destroy the map standby
      mapStandby.destroy();
    });  
});

It helps, but unfortunately the "onSelectionChange" event is somewhat slow to react, soit's still possible for the user to update that map before the standby widget pops up.  I may try using it in combination with your suggestion and see how that works for me.

JeffPace1 · Answer

Well not at all an accurate solution, you might be able to do some TRIAGE/damage mitigation.

In your showLoading function, you could set a 1000ms timer or so and have it publish an onUpdateEnd event, which would at least trick your app into thinking it was done drawing and hide the icon, even if its not done.

I know this does not fix the error of never properly receiving the onUpdateEnd event, but if you application relies on receiving it to continue at least this way you are stuck refreshing the browser.

Better to have a busted basemap and be able to proceed than eject.