New basemap feature - Issues with "hybrid"

[AaronConnolly]

Hi,

I'm curious to know how the "hybrid" basemap layer works at version 3.3.

I'd like to take advantage of the new basemap feature on the map object, however the "hybrid" layer appears to overlay several layers and it doesn't do a great job of it. You can see in the attached image that there are labels from one layer obscuring labels from another, not only are they obscured but they're blurry and redundant. There is also a weird issue with the state borders layer remaining visible as you zoom in /out. The borders that are rendered stay visible while the rest of the map scales nicely as you zoom then, after a second the borders dissapear and then re-appear at the new resolution after the zoom completes. This makes for a weird effect.

Does this "hybrid" layer act as a set of 3 different ArcGISTiledMapServiceLayers that are turned on/off at the same time whenever setBasemap is called on the map object?

To summarize:

1. What layers comprise the "hybrid" basemap layer feature?
2. Why are there redundant labels in this map?
3. Why does the layer with the state borders not zoom nicely like the other layers?
4. Does the "hybrid" layer comprise multiple map service layers? By that I mean for each map tile request are there "N" number of additional requests for each layer in the "hybrid" basemap?

Prior to moving to 3.3 we manage and add our own ArcGISTiledMapServiceLayer objects to the map and for our "hybrid" option we only use the roads and the satellite imagery for performance reasons. We found that our users preferred this to others and therefore we generated double the web traffic on our server by using two ArcGISTiledMapServiceLayers rather than just one. My question in point #4 is meant to understand if this "hybrid" basemap resolves this issue, or not.

Thanks,
- Aaron

[derekswingley1]

I've replied in another thread with additional useful info:  http://forums.arcgis.com/threads/80341-Issues-with-ArcGISTiledMapServiceLayer-in-IE8-and-IE7?p=28362...

Regarding the specifics of the basemaps available, you can see what makes up each basemap by entering this in your browser's dev console:

dojo.toJson(esri.config.defaults.map.basemaps)

That will print out the default names and base map layers for each basemap option.

Here it is, prettified:

{
  "streets": {
    "title": "Streets",
    "baseMapLayers": [{
        "url": "http://services.arcgisonline.com/ArcGIS/rest/services/World_Street_Map/MapServer"
      }
    ]
  },
  "satellite": {
    "title": "Satellite",
    "baseMapLayers": [{
        "url": "http://services.arcgisonline.com/ArcGIS/rest/services/World_Imagery/MapServer"
      }
    ]
  },
  "hybrid": {
    "title": "Imagery with Labels",
    "baseMapLayers": [{
        "url": "http://services.arcgisonline.com/ArcGIS/rest/services/World_Imagery/MapServer"
      }, {
        "url": "http://services.arcgisonline.com/ArcGIS/rest/services/Reference/World_Boundaries_and_Places/MapServer",
        "isReference": true
      }
    ]
  },
  "topo": {
    "title": "Topographic",
    "baseMapLayers": [{
        "url": "http://services.arcgisonline.com/ArcGIS/rest/services/World_Topo_Map/MapServer"
      }
    ]
  },
  "gray": {
    "title": "Light Gray Canvas",
    "baseMapLayers": [{
        "url": "http://services.arcgisonline.com/ArcGIS/rest/services/Canvas/World_Light_Gray_Base/MapServer"
      }, {
        "url": "http://services.arcgisonline.com/ArcGIS/rest/services/Canvas/World_Light_Gray_Reference/MapServer",
        "isReference": true
      }
    ]
  },
  "oceans": {
    "title": "Oceans",
    "baseMapLayers": [{
        "url": "http://services.arcgisonline.com/ArcGIS/rest/services/Ocean_Basemap/MapServer"
      }
    ]
  },
  "national-geographic": {
    "title": "National Geographic",
    "baseMapLayers": [{
        "url": "http://services.arcgisonline.com/ArcGIS/rest/services/NatGeo_World_Map/MapServer"
      }
    ]
  },
  "osm": {
    "title": "OpenStreetMap",
    "baseMapLayers": [{
        "type": "OpenStreetMap"
      }
    ]
  }
}

[JeffPace]

can we modify esri.config.defaults.map.basemaps to remove ones we dont want?

[AaronConnolly]

can we modify esri.config.defaults.map.basemaps to remove ones we dont want?

I would also like to see this added to the API. In-fact if it were available I'd use the "basemap" feature on the map object.