In MapGuide Open Source, I've defined 10 layers, along with a theme for each. As I understand it, a theme represents how different data values are represented. For each theme, I picked two colors and created a gradient from the lowest data value to the highest.
On my map, I use WMS to render the layers. They render properly, with theming visible. However, I'd also like to generate a legend graphic for the theme.
I've tried this request:
/mapguide/mapagent/mapagent.fcgi?version=1.0.0&operation=getlegendimage&THEMECATEGORY=-1&TYPE=-1&format=image/PNG&SCALE=44076.203877482876&layerdefinition=Library://OneOfMyLayers.LayerDefinition. However, that only returns a 16x16 pixel representation of a single point.
Instead, I want a graphic that displays the theme gradient. This is a standard WMS function, yet I haven't found any way to do it out of MapGuide Open Source.
Is there any way to generate such a theme gradient legend with MapGuide Open Source?