[OpenLayers-Users] transparent param not sent to WMS service

[bartvde at osgis.nl]

Hi,

you should use:

     var CTISwms = new OpenLayers.Layer.WMS( "CTI-S WMS",
         "http://wms.sst-sw.rncan.gc.ca/wms/toporama_en",
         {layers: 'railway_30m', format: 'image/png', transparent: true},
         {isBaseLayer: false, visibility: true,
 transitionEffect: 'resize'});

Please not the 3rd parameter is the layer parameters, which are sent to
the server. The 4rd parameter is the layer options.

Best regards,
Bart

>
> Hello,
>
> If there is something I am doing incorrectly in trying to access the
> railway_30m layer (below) transparently, please let me know. Otherwise, I
> thought this was something I should draw someone's attention to.
>
> Although this item is somewhat related to
> http://n2.nabble.com/WMS-transparent-TRUE-versus-true-td1823416.html#a1823416
> and http://trac.openlayers.org/ticket/678 (which was, I believe, submitted
> to address the problem reported in the first link), I don't believe those
> items dealt with actually trying to set transparency on a WMS layer as
> suggested.
>
> In OpenLayers 2.8, given the following example:
>
>     var options = {
>         projection: "EPSG:4269",
>         maxExtent: new OpenLayers.Bounds(-135, 38, -50, 78),
>     };
>     this.map = new OpenLayers.Map('map', options );
>
>     var CTISwms = new OpenLayers.Layer.WMS( "CTI-S WMS",
>         "http://wms.sst-sw.rncan.gc.ca/wms/toporama_en",
>         {layers: 'railway_30m', format: 'image/png'},
>         {isBaseLayer: false, visibility: true, transitionEffect:
> 'resize'});
>     this.map.addLayers([CTISwms]);
>
>     var CTIS_wms_limits = new OpenLayers.Layer.WMS( "CTI-S WMS, limits",
>          "http://wms.sst-sw.rncan.gc.ca/wms/toporama_en",
>         {layers: 'limits', format: 'image/png'},
>         {isBaseLayer: true, visibility: true, transitionEffect:
> 'resize'});
>     this.map.addLayers([CTIS_wms_limits]);
>
>     this.map.zoomToMaxExtent();
>
>
> I have been unable to set the railway_30m layer to be transparent using
> any
> of the following syntax:
>
>     var CTISwms = new OpenLayers.Layer.WMS( "CTI-S WMS",
>         "http://wms.sst-sw.rncan.gc.ca/wms/toporama_en",
>         {layers: 'railway_30m', format: 'image/png'},
>         {isBaseLayer: false, transparent: true, visibility: true,
> transitionEffect: 'resize'});
>
>     var CTISwms = new OpenLayers.Layer.WMS( "CTI-S WMS",
>         "http://wms.sst-sw.rncan.gc.ca/wms/toporama_en",
>         {layers: 'railway_30m', format: 'image/png'},
>         {isBaseLayer: false, transparent: "true", visibility: true,
> transitionEffect: 'resize'});
>
>     var CTISwms = new OpenLayers.Layer.WMS( "CTI-S WMS",
>         "http://wms.sst-sw.rncan.gc.ca/wms/toporama_en",
>         {layers: 'railway_30m', format: 'image/png'},
>         {isBaseLayer: false, visibility: true, transitionEffect: 'resize',
> params: {TRANSPARENT: true}});
>
>     var CTISwms = new OpenLayers.Layer.WMS( "CTI-S WMS",
>         "http://wms.sst-sw.rncan.gc.ca/wms/toporama_en",
>         {layers: 'railway_30m', format: 'image/png'},
>         {isBaseLayer: false, visibility: true, transitionEffect: 'resize',
> params: {TRANSPARENT: "true"}});
>
>
> None of the above will actually send the TRANSPARENT parameter in the
> request to the WMS service. The only way I was able to get the request to
> be
> sent with that parameter and to get the layer to display transparently was
> as follows:
>
>     var CTISwms = new OpenLayers.Layer.WMS( "CTI-S WMS",
>         "http://wms.sst-sw.rncan.gc.ca/wms/toporama_en?transparent=true",
>         {layers: 'railway_30m', format: 'image/png'},
>         {isBaseLayer: false, visibility: true, transitionEffect:
> 'resize'});
>
>
> Also, I noticed while investigating this that both WMS.js and
> ArcGIS93Rest.js assume that params.TRANSPARENT is a string and do not
> handle
> boolean anymore as suggested by the fix noted above.
>
> --
> View this message in context:
> http://n2.nabble.com/transparent-param-not-sent-to-WMS-service-tp3615475p3615475.html
> Sent from the OpenLayers Users mailing list archive at Nabble.com.
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