Update features with StreamLayer

ChristineBrunner — Mon, 04 Nov 2013 12:06:57 GMT

I'm using the StreamLayer to show data from GeoEventProcessor on my map. Like in the sample I use a FeatureCollection to initialize the layer:

layerDefinition = {
        "geometryType": "esriGeometryPoint",
        "fields": [{
            name: "OBJECTID",
            type: "esriFieldTypeOID"
          },
          {
            name: "id",
            type: "esriFieldTypeDouble"
          },
          {
            name: "name",
            type: "esriFieldTypeString"
          }
        ]};
var featureCollection = {
            "layerDefinition": null,
            "featureSet": {
              "features": [],
              "geometryType": "esriGeometryPoint"}
            };
featureCollection.layerDefinition = layerDefinition;
var layer = new StreamLayer(featureCollection, {
              socketUrl: "<url>",
              purgeOptions : { displayCount: 1000 },
          infoTemplate : new esri.InfoTemplate("${name}")
            });

At first glance everything is ok. The data is shown on the map and by clicking on a feature, you can see the attributes. However for each event a new feature is added to the map by the StreamLayer. This is ok for sources like Twitter messages. But I want to show moving features (trains) in my application. Is it possible to mark one of the fields of the FeatureCollection as ID field, so features are updated?

Thanks, Christine

Re: Update features with StreamLayer

CarisaSmith — Thu, 08 May 2014 16:51:02 GMT

If you still haven't found a solution for this, I had the same issue and received a response back from ESRI with a work around until they incorporate the TrackId field to replace old messages coming thru the StreamLayer WebSocket. I'll attach their example.

topic Update features with StreamLayer in ArcGIS JavaScript Maps SDK Questions

Update features with StreamLayer

Re: Update features with StreamLayer