[mapserver-users] querying with mode=tile

[Mr. Puneet Kishor]

I am still struggling with querying with mode=tile. 

My layer definition is

  LAYER
    CLASSITEM "foo"
    CONNECTION "host=localhost port=5432 dbname=db user=user password=password"
    CONNECTIONTYPE POSTGIS
    PROCESSING "CLOSE_CONNECTION=DEFER"
    DATA "the_geom FROM a_view USING UNIQUE gid USING srid=4326"
    NAME "layer"

    PROJECTION
      "init=epsg:4326"
    END

    STATUS ON
    TYPE POLYGON
    TEMPLATE '/path/to/template.json'

     # lots of CLASS definitions
    CLASS
      ..
    END
  END # LAYER "layer"

The "template.json" file looks like so

  // mapserver template
  [resultset layer=layer]
  {
    "type": "FeatureCollection",
    "features": [
      [feature trimlast=',']
      {
        "attrib1": "[attrib1]",
        "attrib2": "[attrib2]",
        "attrib3": "[attrib3]"
      },
      [/feature]
    ]
  }
  [/resultset]

My query looks like so

  http://localhost/cgi-bin/app?layers=layer&mode=query&img.x=430&img.y=375&imgext=59.781131+96.2920453+69.171756+91.588920

Issue 1: I really do have a feature at the point I clicked, yet I get no result. It is likely my query is ill-formed. Truth be told, I don't know the complete list of params that `mode=query` takes, and I can't really find a single place in the documentation where this information is available. One, could someone tell me what is wrong with my query above? Two, point me to the relevant documentation. Maybe I just don't know how to find the correct documentation.

Issue 2: Because MapServer finds no result, it reports back as "msQueryByPoint(): Search returned no results. No matching record(s) found." Well, no... what I really want is an empty JSON stream.

In reality, I am sending the above query via Google Maps (which is why it is likely I have the wrong params, or wrong value for the right params) in my query. Once again, I would really appreciate hearing from someone who has solved this problem already. Specifically, I need to query from Google Maps API v3 to a MapServer backend running `mode=tile`

Oh, and I still want to know if I can run the MapServer backend as a MapScript using `mode=tile` instead of CGI.

Sadly, if I am unable to solve this, I will have to abandon MapServer and look at other options for this project, but I hope it won't come to that.

Many thanks,

Puneet.