Currently, XINS 2.2 supports XML-type parameters with the _xml type; that is excellent. While with other types of parameters (such as _list or _set) it is possible to create more specific subtypes (e.g. with <list> or <set> elements inside a .typ file), the same does not apply to XML-type parameters.
I propose adding the possibliity to have types that are effectively specializations of the _xml type, but with an assigned XSD for validating the structure of the XML.
For example the following could be in a .fnc file:
<param name="model" required="true" type="Model" />
Then this could be in the Model.typ file:
<xml xsd="Model.xsd" />
Then the Model.xsd file would be a regular XML Schema definition file, which would be checked by the server- and by the client-framework.
The generated specification documentation (xins specdocs) should be updated so that it can show the XSD, preferrably in a nicely formatted manner.
@Anthony: Do you think this is a good idea? If so, do you want to do a proposed implementation or shall I do it?