UTFGrid driver doesn't specify GetMap format application/json in Capabilities

[AxxL]

I have implemented a simple service with some points and specified an UTFGrid. Problem is, the output-format "application/json" is not specified in the Capabilities. A client can not determine if the service supports UTFGrid or not. I can send a WMS Request with FORMAT="application/json" although it's like a shot in the dark. My proposal: If I define a driver UTFGrid in my mapfile, the corresponding mimetype should be placed in the GetMap Formats section of the capabilities.

Steps to reproduce

I have defined a service with a UTF-Grid output.

OUTPUTFORMAT                                                                                                                                                                                                                                 
    NAME 'UTFGrid'                                                                                                                                                                                                                           
    DRIVER 'UTFGrid'                                                                                                                                                                                                                         
    FORMATOPTION "UTFRESOLUTION=4"                                                                                                                                                                                                           
    FORMATOPTION "DUPLICATES=false"   
END

[...]

LAYER                                                                                                                                                                                                                                        
    NAME "Kundenpunkte"                                                                                                                                                                                                                      
[...]                                                                                                                                                                                                                                             
    UTFITEM   "id"                                                                                                                                                                                                                           
    UTFDATA   "{\"id\":\"[id]\",\"name\":\"[name_k]\"}"    
[...]

Works, if I use my internal example request. I get an UTF-Grid and everythings fine.

Observed problem

This outputformat application/json is not part of the WMS Capabilities:

<WMS_Capabilities>
  <Capability>
    <Request>
      <GetMap>
        <Format>image/png</Format>
        <Format>image/jpeg</Format>
        <Format>image/png; mode=8bit</Format>
        <Format>application/x-pdf</Format>
        <Format>image/svg+xml</Format>
        <Format>image/tiff</Format>
[...]

Therefore I can't determine if a service supports UTFGrid or not and if I can ask as a client for the format application/json.

What I expect to happen and how I workaround at it

I expect to have this definition of the output-format application/json in the GetMap section of my Capabilities:

<GetMap>
  [...]
  <Format>application/json</Format>
  [...]

Right now I get this by defining the output-formats by hand in the WEB-METADATA section of my mapfile:

wms_getmap_formatlist" "image/png,image/jpeg,image/png; mode=8bit,application/x-pdf,image/svg+xml,image/tiff,application/json"     

Proposal

I expect it to happen automatically if I define the driver. You can even define the mimetype for yourself. Which could be also part of the Capabilities.