Error: Tried to register widget with id==legendDiv but that id is already registered

Question

Getting the following error when running my app:

Error: Tried to register widget with id==legendDiv but that id is already registered

Not sure how to get rid of it. My javascript for the legend is:

//Add the Legend
      legendLayers.push({
          layer: layer,
          title: ''
      });
      dojo.connect(map, 'onLayersAddResult', function (results) {
          var legend = new esri.dijit.Legend({
              map: map,
              layerInfos: legendLayers
          }, "legendDiv");
          legend.startup();
      });
      map.addLayers([layer]);

      if (layer.loaded) {
          buildLayerList(layer);
      } else {
          dojo.connect(layer, "onLoad", buildLayerList);
      }

and my HTML is:

<div dojoType="dijit.TitlePane" title="Legend" closable="false"  open="false" style="float:right;">
                <div dojoType="dijit.layout.ContentPane" style="width:180px; overflow:auto;">
                <span id="legendDiv"></span>
                </div>
    </div>

Can anybody suggest a workaround or a fix to the error. I've done some searching and it looks like I might need to do a destroy? Not sure how to do that.

Answer 1

Add the legend on map load, the onLayersAddResult is firing multiple times which means it is trying to create more than one legend of the same name. Connect to the onLoad event

dojo.connect(map, 'onLoad', function (results) {

Answer 2

var legend = new esri.dijit.Legend({ map: map, layerInfos: legendLayers }, "legendDiv");

works two times. You must call it only one time. Whatever you can fix the "id is already register" error with dijit's destroy function. For this example

if(legend){ legend.destroy(); }

legend = new esri.dijit.Legend({ map: map, layerInfos: legendLayers }, "legendDiv");