[jboss-jira] [JBoss JIRA] Updated: (JBAS-460) Make *-service.xml 'validable'

Make *-service.xml 'validable' ------------------------------ Key: JBAS-460 URL: http://jira.jboss.com/jira/browse/JBAS-460 Project: JBoss Application Server Issue Type: Feature Request Security Level: Public(Everyone can see) Components: MicroContainer bus Affects Versions: JBossAS-4.0.0 Final Reporter: SourceForge User Assigned To: Scott M Stark Priority: Minor Fix For: JBoss-4.2.1.CR1 SourceForge Submitter: hanming . A little while back, I reported this bug: https://sourceforge.net/tracker/?func=detail&atid=376685&aid=7156... It brought jboss-service_3_2.dtd closer to what David Jencks has in mind: "we do not have a dtd for *-service files because attributes can have xml element values. AFAIK the only way to cater to this is with namespaces and xml schema. We may need to do this for jboss 4. basically... <depends optional-attribute-name="foo">[object name or another mbean dd]</depends> and <depends-list optional-attribute-name="bar"> <depends-list-element>[o-n or mbean dd]</depends-list-element> <depends-list-element>[o-n or mbean dd]</depends-list-element> ... </depends-list>" jboss-service_3_2.dtd is as good a DTD as in reflecting what David has in mind but it has a major problem: it can never be used to validate any *-service.xml file. This is because XML 1.0 can never have this kind of construct (represented here as using DTD language, as opposed to Schema because it cannot be represented using the latter): <!ELEMENT depends (#PCDATA | mbean)> The closest that one can come up with is <!ELEMENT depends (#PCDATA | mbean)*> This is how XML 1.0 (may XML 1.1 changes it, I don't know) deal with a class of SGML problem known as the 'pernicious mixed content". Search Google for more details. http://www.w3.org/TR/REC-xml#sec-mixed-content Summary: --------------- I know it's too late to change anything for 3.2 but I have suggestions for 4.0 1. Don't use mixed content, if possible. It's easy to get it wrong in different level: API, parsing and writing of DTDs/Schemas. 2. The easiest local workaround for the element <depends> is to use Element wrapper pattern, e.g: <!ELEMENT depends-content (#PCDATA)> <!ELEMENT depends (depends-content | mbean)> But that might not be a good overall solution. 3. Bear in mind that XML Schema in designed to work with XML 1.0, hence the closest one can use Schema to constraint <depends> is: <xs:element name="depends"> <xs:complexType mixed="true"> <xs:choice> <xs:element ref="mbean"/> </xs:choice> <xs:attribute name="optional-attribute-name" type="xs:string"/> </xs:complexType> </xs:element> which is not really what David's original intention is. Thank you, Han Ming