What is the best way to test a feature service url and verify it is responding?

Question

Before I load and begin querying all the feature service layers in my map that I have created with the ArcGIS JavaScript API, I would like to first verify that the service is responding.  What I'm trying to accomplish is to check if any urls are not responding, and if so, skip those feature services and allow my application to keep loading without them. What is the best/recommended way to do this?

kenbuja · Answer

By the way, the array of urls that I pass into the function looks something like this: [ { url: "https://.../MapServer", id: "layerShoreZone", type: "dynamic", name: "ShoreZone Inventory" }, { url: "https://.../MapServer", id: "layerAIS", type: "dynamic", name: "Human Uses: AIS" }, { url: "https://.../MapServer", id: "layerParticipatory", type: "tiled", name: "Human Uses: Participatory Mapping" } ]‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍

mfcallahan · Answer

Thanks for the reply, this is an interesting implementation of a testLayer() function.  I'm giving this a try in my application right now!

mfcallahan · Answer

Thanks for the helpful reply - I've implemented something similar and this appears to be what I need.