WPS

GRASS based OGC Web Processing Service (WPS) standard implementations

Inside GRASS 7

In GRASS7, the WPS process description can be automatically generated with the option '--wps-process-description'. See announcement.

Example:

 r.external --wps-process-description
     <?xml version="1.0" encoding="UTF-8"?>
     <wps:process_descriptions xmlns:wps="http://www.opengis.net/wps/1.0.0"
     xmlns:ows="http://www.opengis.net/ows/1.1"
     xmlns:xlink="http://www.w3.org/1999/xlink"
     xmlns:xsi="http://www.w3.org/2001/XMLSchema-instance"
     xsi:schemaLocation="http://www.opengis.net/wps/1.0.0
      http://schemas.opengis.net/wps/1.0.0/wpsDescribeProcess_response.xsd"
      service="WPS" version="1.0.0" xml:lang="en-US">
       <process_description wps:processVersion="1" storeSupported="true" statusSupported="true">
                               <ows:Identifier>r.external</ows:Identifier>
                               <ows:Title>Link GDAL supported raster file to a binary raster map layer.</ows:Title>
                               <ows:Abstract>Link GDAL supported raster file to a binary raster map layer.</ows:Abstract>
               <ows:Metadata xlink:title="raster" />
               <ows:Metadata xlink:title="import" />
               <data_inputs>
                       <Input minOccurs="0" maxOccurs="1">
                               <ows:Identifier>input</ows:Identifier>
                               <ows:Title>Raster file to be linked</ows:Title>
                               <ows:Abstract>Raster file to be linked</ows:Abstract>
                               <LiteralData>
                                       <ows:DataType ows:reference="xs:string">string</ows:DataType>
                                       <ows:AnyValue/>
                               </LiteralData>
                       </Input>
                       <Input minOccurs="0" maxOccurs="1">
             [...]
                                               <Format>
                                                       <MimeType>application/grass-raster-binary</MimeType>
                                               </Format>
                                       </Supported>
                               </ComplexOutput>
                       </Output>
               </process_outputs>
       </process_description>
     </wps:process_descriptions>

Linking to other software

There are currently several WPS implementations which use GRASS as GIS backbone:

• PyWPS: http://pywps.wald.intevation.org/
  • Gallery (live examples)
• WPS by 52n: http://52north.org/maven/project-sites/wps/52n-wps-site/
• vtkGRASSBridge: GRASS_and_VTK
• ZOO project - Open OSW Platform: http://www.zoo-project.org/