I have some polygons (country borders) and using the query parameter "transparent=true" in my request, I can see what is behind the layer, where no border is. That is great!
On the other hand, I have to style the border and I should not do it on the server side. So I send an SLD with my map request. Styling the borders, filling the polygons with color, that works fine.
Working with requests from the SLD Cookbook like this one
<FeatureTypeStyle> <Rule> <PolygonSymbolizer> <Fill> <CssParameter name="fill">#000080</CssParameter> <CssParameter name="fill-opacity">0</CssParameter> </Fill> <Stroke> <CssParameter name="stroke">#FFFFFF</CssParameter> <CssParameter name="stroke-width">2</CssParameter> </Stroke> </PolygonSymbolizer> </Rule> </FeatureTypeStyle>
do not work for me. I have still the white background.
I also tried to leave
<CssParameter name="fill">#000080</CssParameter> and also the whole fill-part out. But no success.
I also tried to combine the &transparent=true parameter and the SLD. But that was also without success.
Last but not least I tried to find some configuration on the server side. Thought maybe I can set the transparency per default, so If I want to fill the polygon I can explicitly say this with SLD. But as you might already guess...no success.