MinimumResolution ???

Question

With the Silverlight API there is a  Minimum and MaximumResolution Property- http://help.arcgis.com/en/webapi/silverlight/apiref/api_start.htm.  These two numbers dictate how much you can zoom in/out. When my map contains tiled layer, sometimes I like to update the map's Minimum and MaximumResolution.  In Silverlight I could set the MinimumResolution="1.0E-08" and it will allow me to zoom in past the largest cached scale (ex 1:200).

Three questions:
1.  What is the equivalent in Javascript?
2. How is it set...can you point me to the API ref?
3.  Is there a way to search the JS API ref, similar to the search functionality in Silverlight?  If not can it be added?

Thanks

GISProgrammer · Answer

Derek or anyone else on the JavaScript team,

I'm still having trouble with this issue. I took Derek advice: If they're not specified when you create your map, they're created from the first service added to the map.

I created my own cached imagery layer and added that to my map as my first layer.  I then added the Basemap tool using a group I created online (to add more imagery base map options: Esri, Bing, etc.).

When I created my imagery I used the ESRI,GOOGLE,BING tiling schema but I added a few larger scales (1:900, 1:500, 1:250) to zoom in more so I could take advantage of my high res 4inch imagery.

Now I can zoom in further but if I have ESRI or Bing imagery on or any ESRI cached layer; it doesn't show up at my larger scales (1:900, 1:500, 1:250).  This is because the obvious reason...these tiles aren't available and/or weren't created but this might be confusing to my endusers and I really want them to have the bing/ESRI imagery option at larger scales even if it gets pixilated.

Ultimately I would like to have a similar setting, like the silverlight Set Map.MinimumResolution, which would give the developer the ability to override this by explicitly setting it....Understanding it will make the lowest LOD tiles stretch beyond what they were meant for...that way the tiled layer will not turn off when you pass this point, and the dynamic layers will not be the only thing visible after this point.

This makes me think of another point...I'm sure this is very hard but a few years back maybe at a Dev summit two or so years ago I heard the API teams talking about getting the APIs to the same level of functionality.  This doesn't seem to be happening.  This issue and many other like example lack of a clean TOC/GROUP layers for javascript but having it for Silverlight (http://help.arcgis.com/en/webapi/silverlight/samples/start.htm#GroupLayers) and I can go the other way the BaseMapGallary sample is there for Javascript but not for Silverlight (I had to write a hack one but it is there in the silverlight viewer thing).  Anyways I don't mean to sound harsh.  I love your API and ESRI provides a lot of cool tools and stuff but having the same functionality and roll outs would make switching API easier and/or straight up choosing a API.

GISProgrammer · Answer

Derek,

Thanks for the reply.  So if my first service added is a tiled map service and it has 18 levels (0 -18).   I want to use all these level so I'm not setting the LOD but I do want to be able to zoom past level 18...do I somehow make up a new level??? I'm not sure what to do, if a level is not present.

derekswingley1 · Answer

1.  What is the equivalent in Javascript?
2. How is it set...can you point me to the API ref?
3.  Is there a way to search the JS API ref, similar to the search functionality in Silverlight?  If not can it be added?

There isn't really an equivalent in the JS API are the map. To manage zoom levels, use levels of detail or LODs. You can optionally specify these when you create your map. If they're not specified when you create your map, they're created from the first service added to the map.