[OpenLayers-Users] Implementing a layer for a proprietary WMS-like service

[Bart van den Eijnden (OSGIS)]

Hi Franz,

and have you verified you only have a single tile?

Do you have singleTile: true, ratio: 1 and buffer: 0 in your layer options?

Best regards,
Bart

>  Hi Bart,
>
> I'm almost done with my layer implementation. The only problem: my
> getURLasync() Method gets triggered far too often (about 3x per pan/zoom
> action).
>
> How can I make sure that getURLasync is only triggered once per map
> action?
>
> Franz
>
> 2010/8/3 Bart van den Eijnden (OSGIS) <bartvde at osgis.nl>
>
>> Hi Franz,
>>
>> check out OpenLayers.Tile.Image.
>>
>> Best regards,
>> Bart
>>
>> > Hi Bart,
>> >
>> > thanks for the fast and helpful response!
>> >
>> > One question though: which class actually invokes the methods
>> > OpenLayers.Layer.ArcIMS.getUrl and OpenLayers.Layer.getUrlAsync?
>> >
>> > They seem to be overriden methods, but i couldn't find them in
>> > OpenLayers.Layer.Grid or OpenLayers.Layer.HTTPRequest.
>> >
>> > kind regards,
>> >
>> > Franz
>> >
>> > 2010/8/3 Bart van den Eijnden (OSGIS) <bartvde at osgis.nl>
>> >
>> >> Hi,
>> >>
>> >> I would advise you to look at OpenLayers.Layer.ArcIMS which uses a
>> >> similar
>> >> approach.
>> >>
>> >> Best regards,
>> >> Bart
>> >>
>> >> > Hi,
>> >> >
>> >> > I'm a frontend developer and was programming a web viewer for a
>> >> > proprietary,
>> >> > WMS-like map service.
>> >> > I discovered Openlayers one month ago and I'm really fascinated by
>> its
>> >> > awesome capabilities, so I decided to integrate our map service in
>> >> > OpenLayers.
>> >> >
>> >> > Here is a short description how the map service works:
>> >> >
>> >> > The client sends an AJAX request containing the current map bounds,
>> >> the
>> >> > map
>> >> > id and the pixel size of the map.
>> >> >
>> >>
>> map=22&px=1720&py=833&left=2504400&right=2544000&top=5699500&bottom=5669500&type=0
>> >> >
>> >> > The server responds with the generated map image (url) and the
>> >> corrected
>> >> > bounds:
>> >> > <MapProperties>
>> >> >   <mapLeft>2493227.6110444176</mapLeft>
>> >> >   <mapTop>5699500</mapTop>
>> >> >   <mapRight>2555172.3889555824</mapRight>
>> >> >   <mapBottom>5669500</mapBottom>
>> >> >   <mapType>0</mapType>
>> >> >   <overviewMap>22</overviewMap>
>> >> >   <url>
>> >> http://localhost/cgmCache/41600065-c3d2-4934-9feb-78a32f6668c8.png
>> >> > </url>
>> >> > </MapProperties>
>> >> >
>> >> > The maps are always single-tiled.
>> >> >
>> >> > My first approach was to write a ProprietaryMapLayer, that executes
>> >> the
>> >> > map
>> >> > request and creates an ImageLayer with the result url and its
>> bounds.
>> >> > When the ImageLayer is moved, a new request is performed, the
>> current
>> >> > ImageLayer is destroyed and a new one generated. The disadvantage:
>> >> there
>> >> > are
>> >> > now 2 layers representing one map, which leads to confusion in the
>> >> layer
>> >> > switcher control.
>> >> >
>> >> > I read over the code of Layer.WMS, which inherits from Layer.Grid
>> and
>> >> also
>> >> > makes use of Tile.Image, but it's difficult to derive a solution
>> from
>> >> it,
>> >> > since all the request/response handling is already integrated into
>> the
>> >> > layer. Furthermore, WMS simply responds with tile images, whereas I
>> >> have
>> >> > to
>> >> > deal with an xml response.
>> >> >
>> >> > Any ideas how I could implement my layer?
>> >> >
>> >> > kind regards,
>> >> >
>> >> > Franz
>> >> > _______________________________________________
>> >> > Users mailing list
>> >> > Users at openlayers.org
>> >> > http://openlayers.org/mailman/listinfo/users
>> >> >
>> >>
>> >>
>> >> --
>> >> Looking for flexible support on OpenLayers or GeoExt? Please check
>> out
>> >> http://www.osgis.nl/support.html
>> >>
>> >> Bart van den Eijnden
>> >> OSGIS
>> >> bartvde at osgis.nl
>> >>
>> >>
>> >
>>
>>
>> --
>> Looking for flexible support on OpenLayers or GeoExt? Please check out
>> http://www.osgis.nl/support.html
>>
>> Bart van den Eijnden
>> OSGIS
>> bartvde at osgis.nl
>>
>>
>


-- 
Looking for flexible support on OpenLayers or GeoExt? Please check out
http://www.osgis.nl/support.html

Bart van den Eijnden
OSGIS
bartvde at osgis.nl