Examples¶

Minimal configuration¶

This example shows the absolute minimum information needed to configure a layer in GeoWebCache, as well as the assumptions that will be made.

At the very least, GeoWebCache needs to know only two things to be able to cache a layer:

1. The URL of a to the WMS server
2. The name of the layer as known to the WMS

<gwcConfiguration>
  <!-- ... -->
  <layers>
    <!-- ... -->
    <wmsLayer>
      <name>topp:states</name>
      <wmsUrl><string>http://demo.opengeo.org/geoserver/wms</string></wmsUrl>
    </wmsLayer>
    <!-- ... -->
  </layers>
</gwcConfiguration>

In this case the following will be assumed:

1. WMS version 1.1.1 will be used (version=1.1.1)
2. The layer will be valid for EPSG:4326 and EPSG:900913, with world extent (srs=EPSG:4326, srs=EPSG:900913)
3. The layer name on the WMS will be identical to the name of the layer as specified here (layers=topp:states)
4. The image formate supported will be PNG (image/png) and JPEG (image/jpeg) (format=image/png, format=image/jpeg)
5. The default style will be used (styles=)
6. Exceptions will reported inside images (exceptions=application/vnd.ogc.se_inimage)
7. Requests using OpenLayers will be made with transparent=true

Simple configuration¶

The following is a more realistic but still simple example for configuring a layer in GeoWebCache.

In this case, the following are our requirements:

1. Combine two layers from a WMS, (nurc:Img_Sample and topp:states)
2. Name the layer img states (note the space in the name)
3. Set the projection to EPSG:4326
4. Limit the extent to the continental United States
5. Support only GIF
6. Draw the background color (where there is no data) in a shade of blue
7. Set the transparency to false

The resulting configuration would look like:

<gwcConfiguration>
  <!-- ... -->
  <layers>
    <!-- ... -->
      <wmsLayer>
        <name>img states</name>
        <metaInformation>
          <title>Nicer title for Image States</title>
          <description>This is a description. Fascinating.</description>
        </metaInformation>
        <mimeFormats><string>image/gif</string></mimeFormats>
        <gridSubsets>
          <gridSubset>
            <gridSetName>EPSG:4326</gridSetName>
            <extent>
              <coords>
                <double>-129.6</double>
                <double>3.45</double>
                <double>-62.1</double>
                <double>70.9</double>
              </coords>
            </extent>
          </gridSubset>
        </gridSubsets>
        <wmsUrl>
          <string>http://demo.opengeo.org/geoserver/wms</string>
        </wmsUrl>
        <wmsLayers>nurc:Img_Sample,topp:states</wmsLayers>
        <transparent>false</transparent>
        <bgColor>0x0066FF</bgColor>
      </wmsLayer>
    <!-- ... -->
  </layers>
</gwcConfiguration>