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Copyright © 2009 Open Geospatial Consortium, Inc.Copyright © 2009 Open Geospatial Consortium, Inc.
a the interface of the workflow see section 5.1 b the initial request based on a
However, there are three different patterns for obtaining the result, which will be elaborated in the following sub sections.
5.3.1 Raw Data result
The data is delivered back as plain raw data. This pattern is related to Section 5.2.2.1 but is more strict in a sense that the data is delivered without any interface specific overhead.
For instance, if a Geotiff image is requested, the image is delivered in binary format and not wrapped into other message structures.
For instance, WPS or WMS offer explicitly the option for delivering raw data but this concept can be used beyond these interfaces. In the OWS-6 testbed, this was especially
useful for WPS delivering binary data, since the binary data had not to be encoded e.g. as base64 data. However, only one result can be delivered at a time.
5.3.2 Referenced Result
This pattern delivers only a reference to the data back in the meaning of section 5.2.2.2. In the OWS-6 testbed, this pattern was successfully combined with the previously
described pattern: The raw data is referenced and only the reference is delivered back to the requestor. This has the advantage that multiple results could be returned back at once.
5.3.3 Encapsulated Result
Another option is to explicitly wrap the data in an interface specific encoding. For instance, gml features could be encapsulated in a wfs:FeatureCollection or in a
ExecuteResponse document. This could be especially useful if the workflow is exposed via a known interface and only the specific interface response encoding is understood by
the client.
In the OWS-6 testbed, the final workflow partner was a data providing service WCS-T. The workflow engine stored all relevant results as new layers in that service and returned
only a reference to the newly added layers. In other words, the results were encapsulated as WCS layers inside of the workflow and the requests and response message to fetch the
data had to be according to this interface description.
5.4 Architectural Style Independent Workflows
Development Environment
