What user need will be met by this feature?

User can grab code from their source code file when they want to use the source code as reference.

What is the technical design for the change?

Since source code are not in xml form usually. We need to use java code to pull the content into <codeblock>. Either we can use java extension to do that in xslt code or to use a java module to resolve coderef. Since using java extension in xslt will disable xslt file if java class is not in classpath, we prefer to use separate java module or disable coderef resolution in xslt when java class is not available. As coderef resolution does not affect any DITA semantics, it can be put to anywhere after debug&filter module. Although adding it to main transformation will brings java dependency, it will also reduce the effort in genlist to generate another coderef list and prevent preprocessing from being too long.

What sections of the toolkit will be impacted by the change?

dita2xhtml, genlist