[mapserver-users] turning on layers at a particular zoom level
sunny74
sb.ray at hotmail.com
Wed Sep 2 09:04:04 EDT 2009
Hi,
Thanks for ur reply.
1)What is the syntax for send request against a Group?
2)If I just write the name of the group within layer then will it be placed
against the group?
3) What is the syntax for checking the zoom level of a map so that once a
zoom level is reached I can call a group of layers?
Regards.
Rahkonen Jukka wrote:
>
> Hi,
>
> Collect the layers to one GROUP, and send requests against the GROUP
> instead of the original scale dependent layers. Mapfile may have
> something like this inside:
>
> LAYER
> GROUP "group"
> NAME "scale1"
> MAXSCALEDENOM 100000
> .
> .
> .
> END
>
> LAYER
> GROUP "group"
> NAME "scale2"
> TYPE POLYGON
> MAXSCALEDENOM 1000000
> MINSCALEDENOM 100000
> .
> .
> .
> END
>
>
> sunny74 wrote:
>>
>>
>> Hi,
>>
>> Thanks for the reply.
>>
>> 1) Can u tell me how to sandwich all the layers and make one
>> WMS call to the server and request all of the layers in one
>> image/call.
>> Presently I am calling the layers separately as below:
>>
>> function init() {
>>
>> //alert("in init");
>> map = new OpenLayers.Map('<%=map.ClientID%>');
>>
>> //
>> layer = new OpenLayers.Layer.WMS("OpenLayers WMS",
>>
>> "http://172.16.128.173:8085/cgi-bin/mapserv.exe?", { map:
>> 'Shape/newwr1.map', layers: 'STATE', 'format': 'png' });
>>
>> layer1 = new OpenLayers.Layer.WMS("Rail Main",
>>
>> "http://172.16.128.173:8085/cgi-bin/mapserv.exe?", { map:
>> 'Shape/newwr1.map', transparent: 'true', layers: 'Railwayline' });
>>
>> // layer2 = new OpenLayers.Layer.WMS("Rail WaterBody",
>> //
>> "http://172.16.128.173:8085/cgi-bin/mapserv.exe?", { map:
>> 'Shape/newwr1.map', transparent: 'true', layers: 'WaterBody' });
>>
>> // layer3 = new OpenLayers.Layer.WMS("Rail Rail_Buffer",
>> //
>> "http://172.16.128.173:8085/cgi-bin/mapserv.exe?", { map:
>> 'Shape/newwr1.map', transparent: 'true', layers: 'Rail_Buffer' });
>>
>> // layer4 = new OpenLayers.Layer.WMS("Roads",
>> //
>> "http://172.16.128.173:8085/cgi-bin/mapserv.exe?", { map:
>> 'Shape/newwr1.map', transparent: 'true', layers: 'Roads' });
>>
>> // layer5 = new OpenLayers.Layer.WMS("Diversions",
>> //
>> "http://172.16.128.173:8085/cgi-bin/mapserv.exe?", {
>> map: 'Shape/newwr1.map', transparent: 'true', layers: 'Diversions' });
>>
>> // layer6 = new OpenLayers.Layer.WMS("Rail Side_Line",
>> //
>> "http://172.16.128.173:8085/cgi-bin/mapserv.exe?", {
>> map: 'Shape/newwr1.map', transparent: 'true', layers:
>> 'Rail_Side_Line' });
>> // layer7 = new OpenLayers.Layer.WMS("LANDMARKS",
>> //
>> "http://172.16.128.173:8085/cgi-bin/mapserv.exe?", {
>> map: 'Shape/newwr1.map', transparent: 'true', layers: 'LANDMARKS' });
>> layer8 = new OpenLayers.Layer.WMS("RailwayStations",
>>
>> "http://172.16.128.173:8085/cgi-bin/mapserv.exe?", { map:
>> 'Shape/newwr1.map', transparent: 'true', layers: 'RailwayStations' });
>> // layer9 = new OpenLayers.Layer.WMS("Bridges_Minor",
>> //
>> "http://172.16.128.173:8085/cgi-bin/mapserv.exe?", {
>> map: 'Shape/newwr1.map', transparent: 'true', layers:
>> 'Bridges_Minor' });
>> // layer10 = new OpenLayers.Layer.WMS("Bridge_Major",
>> //
>> "http://172.16.128.173:8085/cgi-bin/mapserv.exe?", {
>> map: 'Shape/newwr1.map', transparent: 'true', layers:
>> 'Bridge_Major' });
>> // layer11 = new OpenLayers.Layer.WMS("LC_Gate",
>> //
>> "http://172.16.128.173:8085/cgi-bin/mapserv.exe?", {
>> map: 'Shape/newwr1.map', transparent: 'true', layers: 'LC_Gate' });
>>
>> //
>>
>> highlight = new OpenLayers.Layer.Vector("highlight", { style:
>> vector_style });
>> choice_features = new
>> OpenLayers.Layer.Vector("choice_features", {
>> style: v_style });
>> distline = new OpenLayers.Layer.Vector("distline", { style:
>> vector_style });
>> //GML = new OpenLayers.Layers.GML("GML", { style: v_style });
>>
>> //
>> map.addLayers([layer, layer1, layer8, highlight,distline]);
>> // markers = new OpenLayers.Layer.Markers("markers");
>> // map.addLayer(markers);
>>
>> // map.OpenLayers.Control.PanZoom.destroy();
>> // map.OpenLayers.Control.MouseToolbar.destroy();
>> map.zoomToMaxExtent();
>> map.setCenter(new OpenLayers.LonLat(73.25, 20.35), 7);
>>
>> map.addControl(new OpenLayers.Control.PanZoomBar());
>> //map.addControl(new OpenLayers.Control.MouseToolbar());
>> map.addControl(new OpenLayers.Control.LayerSwitcher());
>> map.addControl(new OpenLayers.Control.MousePosition());
>>
>> map.addControl(new OpenLayers.Control.OverviewMap());
>> map.addControl(new OpenLayers.Control.Scale());
>>
>> }
>>
>> 2) Is there a way by which the layers will load at certain
>> zoom level bec'
>> in case of MAXSCALEDENOM /MINSCALEDENOM the layers are
>> loading at PageLoad while only visible at that zoom level.
>>
>> 3)If I use TileCache layer instead of Wms then will it load faster.
>>
>> Regards.
>>
>> Fawcett, David wrote:
>> >
>> > 1. You can use MINSCALEDENOM and MAXSCALEDENOM at either
>> the layer or
>> > class level (on a current version of MapServer). So, it looks like
>> > they are in an appropriate place. The real test is to use
>> MapServer
>> > to draw the layer for you. Does it turn on and off at the
>> scales that
>> > you want it to?
>> >
>> > 2. Yes, it can apply to both the layer or class
>> properties. I assume
>> > that you looked here:
>> > http://www.mapserver.org/mapfile/class.html#class
>> >
>> > 3. MapServer has nothing to do with when things load. This all
>> > happens on your client. It sounds like you modified your client to
>> > request each layer individually. If you just want to sandwich them
>> > all together, why not just make one WMS call to the server
>> and request
>> > all of the layers in one image/call. This question is really more
>> > appropriate for the OpenLayers list.
>> >
>> > 4. I would consult the TileCache or OpenLayers list for this one.
>> >
>> > David.
>> >
>> >
>> > -----Original Message-----
>> > From: mapserver-users-bounces at lists.osgeo.org
>> > [mailto:mapserver-users-bounces at lists.osgeo.org] On Behalf
>> Of sunny74
>> > Sent: Saturday, August 29, 2009 2:01 AM
>> > To: mapserver-users at lists.osgeo.org
>> > Subject: RE: [mapserver-users] turning on layers at a
>> particular zoom
>> > level
>> >
>> >
>> >
>> > Hi David,
>> >
>> > Thanks for your reply.
>> > I wanted to have 3 layers displayed b/w scale of 1.2M and
>> 1.15M and so
>> > I have added set MAXSCALEDENOM /MINSCALEDENOM as follows:
>> >
>> > LAYER
>> > NAME 'WaterBody'
>> > TYPE POLYGON
>> > DATA 'C:\ms4w\Apache\cgi-bin\Shape\WaterBody.shp'
>> > METADATA
>> > 'wms_title' 'WaterBody'
>> > END
>> > STATUS OFF
>> > TRANSPARENCY 100
>> > PROJECTION
>> > 'proj=longlat'
>> > 'ellps=WGS84'
>> > 'datum=WGS84'
>> > 'no_defs'
>> > ''
>> > END
>> > CLASS
>> > NAME 'WaterBody'
>> > MAXSCALEDENOM 2000000
>> > MINSCALEDENOM 1500000
>> > STYLE
>> > SYMBOL 0
>> > SIZE 2
>> > OUTLINECOLOR 0 0 0
>> > COLOR 150 123 90
>> > END
>> > END
>> > END
>> >
>> > 1)Pls tell me whether I hav added the things at the correct place.
>> > 2) Can I also add it within the layer properties?
>> > 3) I find that the layers are being added at PageLoad.This
>> I found out
>> > by looking at the number of items being added at the bottom left
>> > corner of IE. The number of items has nearly doubled due to the
>> > addition of the 3 layers. Is there any way by which I can stop the
>> > layers from being added at PageLoad i.e they should be
>> added only when
>> > the desired scale is reached.
>> >
>> > 4) How to use TileCache or GeoWebCache i.e js code?
>> >
>> > Thanks again.
>> >
>> > Fawcett, David wrote:
>> >>
>> >> I assume the 'M' stands for million.
>> >>
>> >> If you want the layer to be only visible when 'zoomed in' beyond
>> >> 1:2M, I would set a MAXSCALEDENOM of 2000000.
>> >>
>> >> If you want the layer to be only visible when 'zoomed out' beyond
>> >> 1:2M, I would set a MINSCALEDENOM of 2000000.
>> >>
>> >> If you only want the layer to be visible between resolutions of
>> >> 1:100000 and 1:200000, you would set: both MINSCALEDENOM
>> 100000 and
>> >> MAXSCALEDENOM 200000
>> >>
>> >> These values go in either a LAYER or CLASS of LAYER in
>> your MapServer map
>> >> file.
>> >>
>> >>
>> >> -----Original Message-----
>> >> From: mapserver-users-bounces at lists.osgeo.org
>> >> [mailto:mapserver-users-bounces at lists.osgeo.org] On Behalf
>> Of sunny74
>> >> Sent: Friday, August 28, 2009 8:45 AM
>> >> To: mapserver-users at lists.osgeo.org
>> >> Subject: Re: [mapserver-users] turning on layers at a
>> particular zoom
>> >> level
>> >>
>> >>
>> >>
>> >> Hi,
>> >>
>> >> Thanks for your reply.
>> >> I went thru the link and read about
>> MAXSCALEDENOM/MINSCALEDENOM. So
>> >> MINSCALEDENOM is the minimum scale level at which a layer
>> will become
>> >> visible. But I am a bit confused.When the map loads for the first
>> >> time it has a zoom level of 7 as given in the code below.
>> >>
>> >> map.setCenter(new OpenLayers.LonLat(74.25, 20.35), 7);
>> >>
>> >> In terms of scale it is showing 1:3M.
>> >> What is M?
>> >> If I increase the zoom level i.e do zoom in, scale becomes
>> 1:856K and
>> >> 1:256K etc i.e scale decreases. So If want a layer to be
>> visible at a
>> >> scale level of 1:2M what do I write in the mapfile?
>> >>
>> >> How to use TileCache or GeoWebCache?Pls give the js code.
>> >>
>> >>
>> >> Rahkonen Jukka wrote:
>> >>>
>> >>> Hi,
>> >>>
>> >>> Mapserver is somehow documented, about adjusting visibility
>> >>> according to scale, try to find MAXSCALEDENOM/MINSCALEDENOM from
>> >>> http://www.mapserver.org/mapfile/layer.html#index-21
>> >>>
>> >>> Mapserver does not do caching but you can use for examply
>> TileCache
>> >>> or GeoWebCache between your clients and Mapserver.
>> >>>
>> >>> -Jukka Rahkonen-
>> >>>
>> >>>
>> >>>
>> >>>> -----Alkuperäinen viesti-----
>> >>>> Lähettäjä: mapserver-users-bounces at lists.osgeo.org
>> >>>> [mailto:mapserver-users-bounces at lists.osgeo.org] Puolesta sunny74
>> >>>> Lähetetty: 28. elokuuta 2009 14:53
>> >>>> Vastaanottaja: mapserver-users at lists.osgeo.org
>> >>>> Aihe: [mapserver-users] turning on layers at a particular zoom
>> >>>> level
>> >>>>
>> >>>>
>> >>>> DEar Friends,
>> >>>>
>> >>>> I have 12 layers in my map and it is taking tooooo long to
>> >>>> load.Therefore I decided to turn on only 2 layers at Page Load.
>> >>>>
>> >>>> Rest of the layers I want to turn on at a particular zoom
>> >>>> level.How can I check the zoom level and turn on these layers.
>> >>>>
>> >>>> How can make the map load faster especially on page
>> reload? Is it
>> >>>> possible to cache the map or is there some other technique?
>> >>>>
>> >>>> Thanks for ur reply.
>> >>>>
>> >>>> --
>> >>>> View this message in context:
>> >>>> http://n2.nabble.com/turning-on-layers-at-a-particular-zoom-le
>> >>>> vel-tp3534156p3534156.html
>> >>>> Sent from the Mapserver - User mailing list archive at
>> Nabble.com.
>> >>>> _______________________________________________
>> >>>> mapserver-users mailing list mapserver-users at lists.osgeo.org
>> >>>> http://lists.osgeo.org/mailman/listinfo/mapserver-users
>> >>>>
>> >>> _______________________________________________
>> >>> mapserver-users mailing list
>> >>> mapserver-users at lists.osgeo.org
>> >>> http://lists.osgeo.org/mailman/listinfo/mapserver-users
>> >>>
>> >>>
>> >>
>> >> --
>> >> View this message in context:
>> >>
>> http://n2.nabble.com/turning-on-layers-at-a-particular-zoom-level-tp3
>> >> 534156p3534743.html Sent from the Mapserver - User mailing list
>> >> archive at Nabble.com.
>> >> _______________________________________________
>> >> mapserver-users mailing list
>> >> mapserver-users at lists.osgeo.org
>> >> http://lists.osgeo.org/mailman/listinfo/mapserver-users
>> >> _______________________________________________
>> >> mapserver-users mailing list
>> >> mapserver-users at lists.osgeo.org
>> >> http://lists.osgeo.org/mailman/listinfo/mapserver-users
>> >>
>> >>
>> >
>> > --
>> > View this message in context:
>> >
>> http://n2.nabble.com/turning-on-layers-at-a-particular-zoom-level-tp35
>> > 34156p3540787.html Sent from the Mapserver - User mailing
>> list archive
>> > at Nabble.com.
>> > _______________________________________________
>> > mapserver-users mailing list
>> > mapserver-users at lists.osgeo.org
>> > http://lists.osgeo.org/mailman/listinfo/mapserver-users
>> > _______________________________________________
>> > mapserver-users mailing list
>> > mapserver-users at lists.osgeo.org
>> > http://lists.osgeo.org/mailman/listinfo/mapserver-users
>> >
>> >
>>
>> --
>> View this message in context:
>> http://n2.nabble.com/turning-on-layers-at-a-particular-zoom-le
>> vel-tp3534156p3566414.html
>> Sent from the Mapserver - User mailing list archive at Nabble.com.
>> _______________________________________________
>> mapserver-users mailing list
>> mapserver-users at lists.osgeo.org
>> http://lists.osgeo.org/mailman/listinfo/mapserver-users
>>
> _______________________________________________
> mapserver-users mailing list
> mapserver-users at lists.osgeo.org
> http://lists.osgeo.org/mailman/listinfo/mapserver-users
>
>
--
View this message in context: http://n2.nabble.com/turning-on-layers-at-a-particular-zoom-level-tp3534156p3566575.html
Sent from the Mapserver - User mailing list archive at Nabble.com.
More information about the mapserver-users
mailing list