please read! - planned change that might break Barracuda apps with simple fix...

Hi everyone,

A recent change that I made to the DefaultDOMLoader may break your code, 
but there is a very simple fix which requires absolutely no changes to your 
existing code, nor does it even require recompilation.

If you update to the latest CVS (as of May 28th, 2003), you will notice 
that if you don't explicitly set a DOMFactory implementation to the 
DefaultDOMLoader, your code will fail as soon as DefaultDOMWriter#getDOM() 
is called.  The reason for this is that I removed the default DOMFactory 
that DefaultDOMLoader was using.  It was creating a compile-time dependency 
upon XMLC which, in turn, created a compile-time dependency on XMLC for the 
DefaultApplicationAssembler (because it gets a DOMLoader instance by doing 
DefaultDOMLoader.getGlobalInstance()).  This was reported by James Carnegie 
who doesn't use the View part of the application asembler, so he didn't 
want a dependency on XMLC.  This is described in the javadoc for 
DefaultDOMLoader#setDefaultDOMFactory(), but I'll spell it out here as well...

What is required is that you either set the DOMFactory programatically via 
or via assembler configuration.  I recommend using the assembler 
configuration as it requires no other change to your code.  All it takes is 
a line such as this....

<dom-loader 
factory="org.enhydra.barracuda.core.util.dom.XMLCDeferredParsingDOMFactory"/>

If you choose to do this programmatically, then do something like the 
following before calling DefaultDOMWriter#getDOM()...

DefaultDOMLoader.getGlobalInstance().setDefaultDOMFactory(new 
XMLCDeferredParsingDOMFactory());


You will find the above <dom-loader> line in Barracuda's event-gateway.xml 
file.  Actually, you will find...

<dom-loader 
factory="org.enhydra.barracuda.core.util.dom.XMLCDeferredParsingDOMFactory">
         <set-property name="servletContext" delegateRuntimeValue="true" />
</dom-loader>

This part is out of the scope of the issue at hand, but I'll explain it 
anyway since it is a cool feature.  The <set-property> actually tells the 
DefaultApplicationAssembler to call the 
XMLCDeferredParsingFactory#setServletContext() method with the current 
runtime ServletContext, allowing access to context init parameters.  More 
information on this can be found in the javadoc for 
DefaultApplicationAssembler and my description of changes in 
A_Changes_History.java.


If you have any comments or questions, please do not hesitate to ask.  I 
want to make sure this is a smooth transition for everyone.

thanks,

Jake