This is one of my action items ...
> 2005-02-17: Asir to review table on how import and include actually work (added by JJM)
For LC75s, we decided to incorporate a table that describes the visibility of XML Schema components in WSDL. On the call, we formulated the names and number of columns and rows in this table; location of the table; etc. I see some problems with LC75s decision. A copy of the first attempt is:
| Directly in WSDL | In schema | |
|---|---|---|
xs:import |
All components from the imported namespace are visible to WSDL (the schema must have an identical targetNamespace). | Components imported by the schema itself are NOT visible to WSDL. |
xs:include |
All components included are visible to WSDL (the included schema must NOT have a namespace already). | All components included by the schema itself are visible to WSDL (the schema included in the schema must NOT have a namespace already). |
wsdl:import |
The embedded schemas contained in the imported WSDL document are NOT visible to WSDL. | n/a |
wsdl:include |
The embedded schemas contained in the included WSDL are visible to WSDL (as long as they share the same targetNamespace). | n/a |
In this table, ...
Two products are involved: WSDL and XML Schema. This table cuts through multiple levels: XML Representation (xs:import, WSDL), Mapping from XML Representation to Components (xs:import-->schema), and Component Model (embedded schema, schema, components ...) I like to emphasize that this cuts through multiple levels in two products.
Other issues are, this table includes information that is beyond visibility. Example: "the schema must have an identical targetNamespace". But, that is a constraint. Most of these constraints are repetition. They are described in other parts of the spec. 'xs:include' is not allowed in WSDL.
Another observation is, the information in this table is beyond the scope of Section 3, say wsdl:import and wsdl:include elements.
WSDL composition model offers four simple possibilities: including description, importing description, importing XML Schema and Embedding XML Schema.
The goal is to describe the visibility of XML Schema components in the WSDL Description component for these four possibilities. In simple terms (recapitulating from different parts of the spec), at the component level (just one level, in one product):
Transcribing this into a table:
|
WSDL Composition |
XML Representation |
Visibility of XML Schema Components |
|---|---|---|
| Including Description | description/include | XML Schema components in the included Description component's {element declarations} and {type definitions} properties are visible |
| Importing Description | description/import | None of the XML Schema Components in the imported Description component are visible |
| Importing XML Schema | description/xs:import | Element Declaration and Type Definition components in the imported namespace are visible |
| Embedded XML Schema | description/types/xs:schema | Element Declaration and Type Definition components in the embedded XML Schema are visible |
Let me frame the questions that we should ask ..