KML - Keyhole Markup Language

Keyhole Markup Language (KML) is an XML-based language for managing the display of 3D geospatial data.

Data Access / Connection Method

KML access is available through OGR. See the OGR driver page for specific driver information. Read support was initially added to GDAL/OGR version 1.5.0.

The CONNECTION parameter must include the kml extension, and the DATA parameter should be the name of the layer.

CONNECTIONTYPE ogr
CONNECTION "myplaces.kml"
DATA "layername"

OGRINFO Examples

First you should make sure that your GDAL/OGR build contains the “KML” driver, by using the ‘–formats’ command:

>ogrinfo --formats
   Loaded OGR Format Drivers:
   ...
   -> "GML" (read/write)
   -> "GPX" (read/write)
   -> "KML" (read/write)
   ...

If you don’t have the driver, you might want to try the FWTools or MS4W packages, which include the driver.

Once you have the KML driver you are ready to try an ogrinfo command on your file to get a list of available layers:

>ogrinfo myplaces.kml
   INFO: Open of `myplaces.kml'
   using driver `KML' successful.
   1: Layer #0 (Point)

Now use ogrinfo to get information on the structure of the layer:

>ogrinfo fountains-hotel.kml "Layer #0" -summary
  Had to open data source read-only.
  INFO: Open of `fountains-hotel.kml'
    using driver `KML' successful.

  Layer name: Layer #0
  Geometry: Point
  Feature Count: 1
  Extent: (18.424930, -33.919627) - (18.424930, -33.919627)
  Layer SRS WKT:
  GEOGCS["WGS 84",
      DATUM["WGS_1984",
        SPHEROID["WGS 84",6378137,298.257223563,
          AUTHORITY["EPSG","7030"]],
      AUTHORITY["EPSG","6326"]],
    PRIMEM["Greenwich",0,
      AUTHORITY["EPSG","8901"]],
    UNIT["degree",0.01745329251994328,
      AUTHORITY["EPSG","9122"]],
    AUTHORITY["EPSG","4326"]]
  Name: String (0.0)
  Description: String (0.0)

Mapfile Example

 LAYER
   NAME kml_places
   TYPE POINT
   STATUS DEFAULT
   CONNECTIONTYPE OGR
   CONNECTION "kml/fountains-hotel.kml"
   DATA "Layer #0"
   LABELITEM "NAME"
   CLASS
     NAME "My Places"
     STYLE
       COLOR 250 0 0
       OUTLINECOLOR 255 255 255
       SYMBOL 'circle'
       SIZE 6
     END
   LABEL
     SIZE TINY
     COLOR 0 0 0
     OUTLINECOLOR 255 255 255
     POSITION AUTO
   END
  END
END