Re: [xml-dev] Constraining a Schema

[George Bina <george@oxygenxml.com>]

Hi,

Another approach is to implement the restriction not by restricting the 
schema but by restricting the user access to the schema information, if 
the tool that the users are using allow for that. We implemented such an 
approach in oXygen XML Editor - the tool we develop - allowing a 
configuration file to control what elements, attributes and values are 
presented to the user:

https://www.oxygenxml.com/doc/versions/18/ug-editor/topics/configure-elements-attr-cc-individually.html

For example, something like

<elementProposals path="prolog/metadata" insertElements="keywords" 
possibleElements="audience keywords"/>

will automatically insert a 'keywords' element inside a 'metadata' 
element when that is inserted in 'prolog' and then the content 
completion will intersect the offered proposals with {audience, 
keywords}, removing all other elements from the proposed list.

And
<elementProposals path="li" rejectElements="image" />
will not propose 'image' inside a list item 'li' element although that 
may be allowed by the schema or DTD.

We found this very useful as it restricts not what the document may 
contain, but what a specific the user can insert in the document - a 
power users may have full access and be able to insert anything while a 
different user will be able to add only a few elements or attributes.

Best Regards,
George
--
George Cristian Bina
<oXygen/> XML Editor, Schema Editor and XSLT Editor/Debugger
http://www.oxygenxml.com

On 8/16/18 12:25 AM, John Dziurlaj wrote:
> I am working with a schema that is purposely lax (i.e. it may allow too 
> many occurrences, may contain irrelevant elements, etc.) so that it can 
> handle a broad range of customer scenarios. I now have a customer that 
> wants to constrain the schema such that only a subset of the 
> functionality is available. This subset is expected to validate against 
> its larger parent. I’ve come up with a number of different approaches to 
> handle this:
>
>  1. Subset schema using available XML tooling. A standalone derivative
>     will be produced.
>  2. Create a new schema, referencing the old one, but derive all the
>     types by restriction.
>  3. Use XML Assertions
>  4. Use Schematron
>  5. Use CAMV
>
> My preference is to use a XML Schema native approach (1-3), using XSD 
> 1.0 only constructs if possible (1-2), as the actual used XML processor 
> that gets used is outside my control.
>
> Does anyone have ideas on a good approach?
>
> John Dziurlaj
>
> Elections Consultant
>
> Hilton Roscoe LLC
> Cell 330-714-8935 Work/Fax 234-706-6434