topic Failed to add an operational layer. in ArcGIS JavaScript Maps SDK Questions

Failed to add an operational layer.

ShaningYu — Fri, 24 Jan 2014 16:08:35 GMT

I created a mayservice (containing only 1 layer) a couple of days ago, and I could add it as a operational layer by:
var operationalLayer = new esri.layers.ArcGISDynamicMapServiceLayer(serverURL, { "opacity": 0.5 } );
...
map.addLayers([basemap, operationalLayer, featureLayer]);
After I updated the mapservice to hold multiple layers. Then I revised the code as
var operationalLayer = new esri.layers.ArcGISDynamicMapServiceLayer(serverURL + "/0", { "opacity": 0.5 } );
where the '/0' points to the layer to be added. However, in this way, the operational layer is not added or displayed. What's wrong I did here? Thanks if you can point out.

Re: Failed to add an operational layer.

KenBuja — Fri, 24 Jan 2014 16:15:42 GMT

To show some of the layers for a ArcGISDynamicMapServiceLayer, you have to use the setVisibleLayers method. Using the "/0" at the end of the URL is for FeatureLayers.

var operationalLayer = new esri.layers.ArcGISDynamicMapServiceLayer(serverURL, { "opacity": 0.5 } ); operationalLayer.setVisibleLayers([0]);

Re: Failed to add an operational layer.

ShaningYu — Fri, 24 Jan 2014 16:59:22 GMT

kenbuja: Thanks for your response. Your answer has been credited. However, I also got another solution by loading the TOC component sourced from http://gmaps-utility-gis.googlecode.com/svn/tags/agsjs/2.04/examples/toc.html

Re: Failed to add an operational layer.

KenBuja — Fri, 24 Jan 2014 17:48:41 GMT

The TOC is a remarkable tool and I salute NLui for developing it.

However, when using Dynamic Layers, you'll always have to set the visible layers somehow, either with setVisibleLayers or a tool like this. If you delve into the code for NLui's TOC or Matt Driscoll's Layer Legend Widget, you'll see that they use setVisibleLayers.