WCS Vendor Parameters

WCS vendor parameters are non-standard request parameters that are defined by an implementation to provide enhanced capabilities.

General Vendor Options

These vendor options are available for all operations.

content-disposition

The content-disposition parameter directs how a web browser directed to handle returned content. The syntax is:

content-disposition=<disposition>

Where content-disposition =attachment to direct the browser to save the content to disk.

Where content-disposition=inline asks the browser to display the content. Note this may present performance issues when asked to display very large content.

filename

The filename parameter provides a suggested filename when a browser saves a file (e.g. to Downloads folder). The syntax is:

filename=<file>

An example of filename use is:

filename=features.json

When service output is saved as a file, the vendor-option filename is used to provide the file name used.

GetCoverage Request

namespace

Requests to the WCS GetCapabilities operation can be filtered to only return layers corresponding to a particular namespace.

Sample code:

http://example.com/geoserver/wcs?
   service=wcs&
   version=1.0.0&
   request=GetCapabilities&
   namespace=topp

Using an invalid namespace prefix will not cause any errors, but the document returned will not contain information on any layers.

cql_filter

The cql_filter parameter is similar to same named WMS parameter, and allows expressing a filter using ECQL (Extended Common Query Language). The filter is sent down into readers exposing a Filter read parameter.

For example, assume a image mosaic has a tile index with a cloudCover percentage attribute, then it’s possible to mosaic only granules with a cloud cover less than 10% using:

cql_filter=cloudCover < 10

For full details see the ECQL Reference and CQL and ECQL tutorial.

sortBy

The sortBy parameter allows to control the order of granules being mosaicked, using the same syntax as WFS 1.0, that is:

  • &sortBy=att1 A|D,att2 A|D, ...

This maps to a “SORTING” read parameter that the coverage reader might expose (image mosaic exposes such parameter).

In image mosaic, this causes the first granule found in the sorting will display on top, and then the others will follow.

Thus, to sort a scattered mosaic of satellite images so that the most recent image shows on top, and assuming the time attribute is called ingestion in the mosaic index, the specification will be &sortBy=ingestion D.

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