The DescribeJoinAbilities operation returns an XML document that identifies all of the spatial frameworks to which data can be joined by the service instance. This description includes information that uniquely identifies each spatial framework, and descriptive information about each framework. This description can be used to automatically build a user interface to identify the spatial framework for which the user would like to obtain attribute data.
|service||Required||Identifies service type. Must be "TJS".|
|request||Required||Identifies service request. Must be "DescribeJoinAbilities".|
|version||Required||Identifies service version. Defaults to the latest available version, currently 1.0.|
|language||Optional||Determines the language of the human-readable content of the response. Value is a two or five character IETF RFC 4646 language identifier.|
HTTP GET method using KVP (mandatory)
All TJS servers shall implement HTTP GET transfer of the DescribeJoinAbilities request, using KVP encoding. The KVP encoding of the DescribeJoinAbilities request shall use the parameters specified above. An example of a DescribeJoinAbilities request via HTTP GET is:
HTTP POST method using XML (optional)
TJS servers may also implement HTTP POST transfer of the DescribeJoinAbilities operation request, using XML encoding only. The request parameters are encoded as XML elements, with their contents identical to those indicated in the parameter table shown above according to the DescribeJoinAbilities request XML schema. The following example indicates the contents and structure of a DescribeJoinAbilities operation request encoded in XML.
<DescribeJoinAbilities service="TJS" version="1.0" language="en"/>
The normal response to a valid DescribeJoinAbilities operation request shall be a JoinAbilities data structure, which contains descriptions of one or more Frameworks to which attribute data can be joined by this service. This document is encoded in XML according to the DescribeJoinAbilities response XML schema.
When a TJS server encounters an error while performing a DescribeJoinAbilities operation, it shall return an exception report message as specified in Clause 8 of [OGC 06-121r3]. The allowed exception codes shall include those listed in Table 5 of Subclause 7.4.1 of [OGC 06-121r3].
For more information on structuring requests, please see the TJS Standard.