Setting Min Zoom without base map using ArcGIS API for JavaScript?

Question

How do I set min zoom for map without defining base map(User can't zoom out beyond that label)?

Set min zoom with base map is working fine.

For example:

map = new Map("map", {
                        basemap : "streets",
                        center : [ 78.00, 21.00 ],
                        sliderPosition : "top-right",
                        maxZoom : 10,
                        minZoom: 5,                             
                    });

But when i am trying minZoom without base map, it's not working

basemap : ""

My main motive is use the min zoom option without base map.

Something like this in the ArcGIS API for JavaScript Sandbox.

Answer 1

You can set minScale instead. The layer in your example has a Min Scale of 500000000, so you could set the the map's minScale to a smaller value which will disable zooming out beyond that scale.

map = new Map("map", {                            
    center : [ 78.00, 21.00 ],
    sliderPosition : "top-right",
    minScale: 490000000                       
});

You will notice when you don't have a basemap, the map's zoom property is -1, since the zoom value corresponds to the various levels of the basemap. However, the map's scale value increases when you zoom out, and decreases when you zoom in.

Answer 2

Since you're not setting a basemap, the map doesn't have any zoom levels defined (which are derived from a tiled basemap). You'll want to use the minScale and maxScale properties instead.

Make this change to your sample to see it working

var map = new Map("map", {
  extent: bounds,
  maxScale: 10000000,
  minScale: 100000000
});