[Users] How to create legend panel using OpenLayers.Layer.MapServer layer...

[Andreas Hocevar]

stela anders wrote:
> Hello Andreas...
> 
> All sublayers is with status ON, they are draw on map, but in my legend 
> I got ONLY "Layer1" label printed...
> My layers:
>                OpenLayers.Layer.WMS("Layer1",
>                 mycgi, {
>                     map: mymapfile,
>                     layers: ['Sublayer11','Sublayer12', 'Sublayer13'],
>                     format: "image/png",
>                     transparent: "true"
>                 }, {
>                     isBaseLayer: true,                   
>                     visibility: true
>                 }),

The above should cause three GetFeatureInfo requests to be issued: one 
for each of your sublayers. If you just see the label, then MapServer 
does not send you an image on the GetFeatureInfo request. Here is what 
you can try: enable the Net panel on firebug and look at the 
GetFeatureInfo request that the browser issues. Copy them, open them in 
a browser window/tab, and fix your mapfile until they work (more help 
available in mapserver docs/lists).

> 
>                OpenLayers.Layer.WMS("Layer2",
>                 mycgi, {
>                     map: mymapfile,
>                     layers: ['Sublayer21','Sublayer22', 'Sublayer23'],
>                     format: "image/png",
>                     transparent: "true"
>                 }, {
>                     isBaseLayer: false,
>                     displayInLayerSwitcher: false,
>                     visibility: true
>                 }),

This won't display anything, because you have set 
"displayInLayerSwitcher" to false.

> So, What is your suggestion in building a legend to Map with GeoExt 
> sublayers? I need all sublayers appears on my legend (each one has 
> different images...)

The LegendPanel does exactly that. It requests one image per sublayer 
(now that you provided a code snippet and I finally know what you meant 
by "sublayer"). My suggestion is: fix your mapfile so Mapserver can 
answer GetFeatureInfo requests correctly.

Regards,
Andreas.

-- 
Andreas Hocevar
OpenGeo - http://opengeo.org/
Expert service straight from the developers.