topic Re: Setting max and min zoom level for map in ArcGIS JavaScript Maps SDK Questions

Setting max and min zoom level for map

vinayb — Fri, 07 Mar 2014 15:20:07 GMT

HI All,

I wan to set zoom level , that is i want to define maximum level upto which user zoom-out and min level to which user can zoom in .

Re: Setting max and min zoom level for map

JeffPace — Fri, 07 Mar 2014 15:29:38 GMT

This has been requested before (setting absolute min/max levels) but has not been implemented yet. We have been told it is planned for a future release

As of now you can handle this by creating your map with custom LODs. The problem with this is level 5 (for example) is your LOD5, which does not necessarily line up with the common absolute Level 5 of accepted basemap scales.

Re: Setting max and min zoom level for map

vinayb — Fri, 07 Mar 2014 16:01:12 GMT

I just have to zoom in and zoom out for max 2 levels, how can create lod

Re: Setting max and min zoom level for map

JeffPace — Fri, 10 Dec 2021 22:12:46 GMT

var lods =
            [
                {
                    "level": 0,
                    "resolution": 156543.03392800014,
                    "scale": 5.91657527591555E8
                },
                {
                    "level": 1,
                    "resolution": 78271.51696399994,
                    "scale": 2.95828763795777E8
                }
            ];

map = new Map("map", {
                                    basemap: "streets",
                                    autoResize: true,
                                    logo: false,
                                    showAttribution: false,
                                    lods: lods
                                });

Re: Setting max and min zoom level for map

vinayb — Fri, 07 Mar 2014 16:41:12 GMT

can you please give me for level2 too , but thanks it worked great

Re: Setting max and min zoom level for map

JeffPace — Fri, 07 Mar 2014 16:46:47 GMT

THey are available from any rest endpoint

http://server.arcgisonline.com/ArcGIS/rest/services/World_Imagery/MapServer

"lods": [{
                      "level": 0,
                      "resolution": 156543.033928,
                      "scale": 591657527.591555
                    }, {
                      "level": 1,
                      "resolution": 78271.5169639999,
                      "scale": 295828763.795777
                    }, {
                      "level": 2,
                      "resolution": 39135.7584820001,
                      "scale": 147914381.897889
                    }, {
                      "level": 3,
                      "resolution": 19567.8792409999,
                      "scale": 73957190.948944
                    }, {
                      "level": 4,
                      "resolution": 9783.93962049996,
                      "scale": 36978595.474472
                    }, {
                      "level": 5,
                      "resolution": 4891.96981024998,
                      "scale": 18489297.737236
                    }, {
                      "level": 6,
                      "resolution": 2445.98490512499,
                      "scale": 9244648.868618
                    }, {
                      "level": 7,
                      "resolution": 1222.99245256249,
                      "scale": 4622324.434309
                    }, {
                      "level": 8,
                      "resolution": 611.49622628138,
                      "scale": 2311162.217155
                    }, {
                      "level": 9,
                      "resolution": 305.748113140558,
                      "scale": 1155581.108577
                    }, {
                      "level": 10,
                      "resolution": 152.874056570411,
                      "scale": 577790.554289
                    }, {
                      "level": 11,
                      "resolution": 76.4370282850732,
                      "scale": 288895.277144
                    }, {
                      "level": 12,
                      "resolution": 38.2185141425366,
                      "scale": 144447.638572
                    }, {
                      "level": 13,
                      "resolution": 19.1092570712683,
                      "scale": 72223.819286
                    }, {
                      "level": 14,
                      "resolution": 9.55462853563415,
                      "scale": 36111.909643
                    }, {
                      "level": 15,
                      "resolution": 4.77731426794937,
                      "scale": 18055.954822
                    }, {
                      "level": 16,
                      "resolution": 2.38865713397468,
                      "scale": 9027.977411
                    }, {
                      "level": 17,
                      "resolution": 1.19432856685505,
                      "scale": 4513.988705
                    }, {
                      "level": 18,
                      "resolution": 0.597164283559817,
                      "scale": 2256.994353
                    }, {
                      "level": 19,
                      "resolution": 0.298582141647617,
                      "scale": 1128.497176
                    }, {
                      "level": 20,
                      "resolution": 0.149291070823808,
                     "scale": 564.248588
                    }]

Re: Setting max and min zoom level for map

vinayb — Fri, 07 Mar 2014 17:12:58 GMT

but all the levels only zoom in there no levels for zoomout ?

Re: Setting max and min zoom level for map

vinayb — Fri, 07 Mar 2014 17:14:42 GMT

All these levels only zoom in there are no levels for zoom out

Re: Setting max and min zoom level for map

JeffPace — Fri, 07 Mar 2014 17:16:31 GMT

I am not sure what you are asking. You have to pick which levels you want to use.

Re: Setting max and min zoom level for map

vinayb — Fri, 07 Mar 2014 17:24:44 GMT

I userd the Lods that you gave when i used them i was able to zoom in (-) upto 3 levels but i was not able to zoom out i.e using (+) button .

how are these LODS available for my map below is the extent

I dont have TILED MAP

var initExtent = new esri.geometry.Extent({"xmin": -2.0037507067161843E7

,"ymin":-7516889.1782586705

,"xmax":2.0037507067161843E7

,"ymax":1.8398924324645087E7

,"spatialReference":{"wkid":102100}});

how can i find lods for my map

Re: Setting max and min zoom level for map

JeffPace — Fri, 07 Mar 2014 17:30:44 GMT

Ahh, this only works on tiled maps

Unfortunately there is no min/max extent yet.

So your only option is to write an on(extent-change) event that checks the extent, sees if it is beyond where you want to be, and reverts.

sorry for the confusion.

Re: Setting max and min zoom level for map

vinayb — Fri, 07 Mar 2014 17:34:52 GMT

How can i set extent of map to revert back ( using map.setExtent i think this is deprected ) i am using 3.6 api ?

Re: Setting max and min zoom level for map

LloydBronn — Fri, 10 Dec 2021 22:12:48 GMT

Reviving this old thread. I'm trying to set max and min zooms in my map. I want the initial (max) extent to be zoom level 3, and I don't want to be able to zoom in any further than level 15 or so (min extent). I found a snippet of JS that works for the first part, and I'm trying to adapt it to work for the second. I think my issue is how I'm trying to set the minimum extent. I only want a lat/lon center point for the maximum (initial) extent. Here is the code snippet. The first if statement works but the else if does not.

map = new Map("map", {
            basemap: "streets",
               center: [-105, 45],
            zoom: 3
          });
            
            //set max extent to inital extent
        dojo.connect(map, "onLoad", function(){
         maxExtent = map.extent;
         minExtent = ("map", {
            zoom: 15
          });
        });

        //check to see if map is within max extent when its extent changes.  If not, roll back to the max
        //extent that we set above
        dojo.connect(map, "onExtentChange", function(extent){
          if((map.extent.xmin < maxExtent.xmin) ||
            (map.extent.ymin < maxExtent.ymin)  ||
            (map.extent.xmax > maxExtent.xmax) ||
            (map.extent.ymax > maxExtent.ymax) 
            ) {
            map.setExtent(maxExtent);
          }
            else if((map.extent.xmin > minExtent.xmin) ||
            (map.extent.ymin > minExtent.ymin)  ||
            (map.extent.xmax < minExtent.xmax) ||
            (map.extent.ymax < minExtent.ymax) 
            ) {
            map.setExtent(minExtent);
          }
        
      });‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍

Re: Setting max and min zoom level for map

RobertScheitlin__GISP — Fri, 28 Oct 2016 00:51:49 GMT

Lloyd,

A couple of things. Number 1 do not get in the habit of use the depreciated dojo.connect. What you should use is on

map.on("load", function(){

and

map.on("extent-change", function(extent){

Next if you are using an tiled/cached basemap then you get set the LODs you want to use to limit the zoom in and zoom out like discussed about. If you are not using a tiled/cached basemap then use your method.

Re: Setting max and min zoom level for map

LloydBronn — Mon, 31 Oct 2016 13:25:24 GMT

Thanks Robert. I realized that I won't be able to use this method because it's returning to the default center in addition to the zoom. If there is a feature located outside of the default extent, I can't navigate to it.

How would I use a cached basemap if I'm hosting on an ArcGIS server? I can't upload basemaps as part of a map service.

Re: Setting max and min zoom level for map

RobertScheitlin__GISP — Mon, 31 Oct 2016 13:35:19 GMT

Lloyd,

Sorry your question is not making any sense to me:

How would I use a cached basemap if I'm hosting on an ArcGIS server? I can't upload basemaps as part of a map service.

Can you clarify what you are wanting to do?

Re: Setting max and min zoom level for map

LloydBronn — Mon, 31 Oct 2016 13:52:11 GMT

What I'm saying is that my map is not tiled/cached. What I'm trying to do is just restrict the minimum and maximum zoom levels. Earlier in this thread someone said the API does not have this functionality. I tried using this method to revert to the initial extent if someone tries to zoom out too far, but I didn't take into account that this would also send them back to the default center point. If there are any features outside of that level (to the east or west), they can't be accessed.

Re: Setting max and min zoom level for map

RobertScheitlin__GISP — Fri, 10 Dec 2021 22:12:51 GMT

Lloyd,

OK now I see. So ignore all the LOD stuff mentioned then and lets get back to your minExtent var.

So you are using:

minExtent = ("map", {
  zoom: 15
});‍‍‍

and as you mentioned earlier that you thought this was the issue, well it absolutely is. You can not get a valid extent with that code. You need to build a true extent class and set the minExtent to that.

So the issue of the extent re-centering at the initial value can be over come using the Extent classes centerAt method:

Extent | API Reference | ArcGIS API for JavaScript 3.18 | centerAt

map.setExtent(maxExtent.centerAt(map.extent.getCenter());‍

Re: Setting max and min zoom level for map

LloydBronn — Fri, 10 Dec 2021 22:12:53 GMT

I just figured out how to restrict only the zoom levels. I only need the centerpoint for the initial extent. Map | API Reference | ArcGIS API for JavaScript 3.18

map = new Map("map", {
            basemap: "streets",
               center: [-96.8, 38.5],
               maxZoom: 15,
               minZoom: 4
          });‍‍‍‍‍‍‍‍‍‍‍‍