> 
> "Chris Lieb" wrote:
> 
> > I am new to XML Schema and am running into a bit of a snag.  I have
> > defined an XML-based scripting language for an updater program that I
> > am working on.  I would like to make a schema for this language since
> > malformed XML documents break the updater.  (I did not have time to add
> > good error-handling code, so run-time errors can abound if the document
> > is malformed.)
> > 
> > A sample doc might look something like this:
> > 
> > <manifest>
> >   <version major="1" minor="0" revision="1" base="1.0.1\files\"
> > doprevious="true">
> >     <file action="copy" name="text.doc"/>
> >     <folder action="create" name="temp"/>
> >     <updater>
> >       <file name="update.exe"/>
> >       <file name="updaterlib.dll"/>
> >     </updater>
> >   </version>
> >   <version major="1" minor="0" revision="0" base="1.0.0\files\"
> > doprevious="false">
> >     <dll action="register" name="updaterlib.dll"/>
> >     <cmd location="server" command="patch.bat">
> >       <file name="patch.dat"/>
> >       <file name="patch.bat"/>
> >     </cmd>
> >   </version>
> > </manifest>
> > 
> > Problem is that the second version element in the document, the updater
> > element, the dll element, and the cmd element all get flagged as
> > invalid.  I guess that this stems from using a sequence in the complex
> > type.  What should I use to allow all children elements of version
> > (file, folder, dll, msi, cmd, updater) to appear in any order and in
> > whatever quantity (except updater, which can only appear once)?
> > 
> > 'all' looks like it comes close since it allows you to use elements in
> > any order, except my reading tells me that it only allows each element
> > to be used once and forces you to use all elements.  'choice' also
> > appears to come close since it allows you to choose which element you
> > want, but it only lets you choose one element from the set.
> > 
> 
> Are you certain you need to allow for all possible combinations of all 
> elements in any order...if you can whittle down the possible combinations to 
> only those combinations that should be allowed to occur you can use 
> xs:sequence embedded inside of xs:choice, like:
> 
>       <xs:choice>
>         <xs:sequence>
>           <xs:element ref="dll"/>
>           <xs:element ref="cmd"/>
>         </xs:sequence>
>         <xs:sequence>
>           <xs:element ref="file"/>
>           <xs:element ref="folder"/>
>           <xs:element ref="updater"/>
>         </xs:sequence>
>       </xs:choice>
>  
> If indeed all possible combinations are possible, then the above is not a 
> very attractive solution.
> 

The above is not a good way in retrospect...look at mavis's post of 5/31/06. 
 Put all possible sub-elements of version into a <xs:choise 
maxOccurs="unbounded">.

mavis suggests the XML processor may be a long time doing such validation, 
but that may not be of concern to you in your application.