John L. Clark wrote: > I was wondering if it is possible to write XXE configurations in such a > way that they can "transparently" support users with either the Standard > or the Professional version. For example, suppose our organization > developed an XML language called WowML, with both an XML Schema and a > DTD which could validate WowML documents. We would like to be able to > create an XXE configuration in such a way that an XXE Standard user > could use the configuration with the more limited feature set (DTD > validation, no namespace support, etc.), while XXE Pro users would > automatically get the advanced features. > > Does this simply require two independent configurations? Is there any > way that they could be installed together and not conflict (that is, > does XXE Standard silently ignore any configuration features only > supported in XXE Pro (such as XML Schema support))?
--> This requires two independent configurations, but there is currently no way to specify: * when you open document "mydoc.wow" using Standard Edition, use configuration "WOW DTD"; * and when you open *same* document "mydoc.wow" using Professional Edition (for example, a Standard Edition user gives an XML file to a Professional Edition user), use configuration "WOW Schema". --> The two independent configurations can be installed together and not conflict. For that, you need to write a <detect> configuration element which can make the difference between the DTD-based configuration and the schema-based configuration. There are 2 possible cases: [1] Easy case: your W3C XML Schema has a targetNamespace. (Example: XHTML DTD versus XHTML W3C XML Schema or RELAX NG) Use the <rootElementNamespace> configuration element to make a difference. This works because documents conforming to a DTD are never namespace-aware. [2] Tricky case: your W3C XML Schema has no targetNamespace. (Example: DocBook DTD versus DocBook W3C XML Schema or RELAX NG) The trick is to use the <schemaType> element of the <detect> configuration element. [a] Template conforming to a DTD: --- <?xml version="1.0"?> <!DOCTYPE wow PUBLIC "WOW DTD" "http://wow.com/dtd/wow.dtd";> <wow/> --- Associated <detect> configuration element: --- <detect> <dtdPublicId>WOW DTD</dtdPublicId> </detect> --- [b] Template conforming to a W3C XML Schema: --- <?xml version="1.0"?> <!DOCTYPE wow [ <!ENTITY % symbols PUBLIC "WOW Symbols" "http://wow.com/dtd/wow.ent";> %symbols; ]> <wow xmlns:xsi="http://www.w3.org/2001/XMLSchema-instance"; xsi:noNamespaceSchemaLocation="http://wow.com/wxs/wow.xsd"/> --- (Using a <!DOCTYPE> for character entities is OK.) Associated <detect> configuration element: --- <detect> <and> <schemaType>schema</schemaType> <rootElementLocalName>wow</rootElementLocalName> </and> </detect> --- --> Other components in the configuration * The CSS can be always shared by both configurations. Using a CSS like this for the schema-based configuration (if this configuration uses namespace "http://wow.com/ns";) is not required, but will improve the speed of matching elements with their CSS rules. --- @namespace "http://wow.com/ns";; @import url(../wow_dtd/wow.css); --- * You'll have to duplicate all macro-commands and other configuration elements such as <documentResources> if the schema-based configuration uses a namespace. * If your configuration uses DocBook or XHTML tables, you can use the table editing commands in both the DTD-based configuration and the schema-based configuration, because the table editing commands ignore the namespaces and work by looking at the local names (tbody, row, entry, tr, th, td, etc).
