Modify tiles-defs.xml and Related Files
This is somewhat involved (not too bad, but more so than the other major steps), so I'll organize this a bit.
Step 1. First, you'll need to break up the
tiles-defs.xml into multiple files, in the same way you
did with the struts-config.xml file. I broke mine into
tiles-defs.xml (default module),
tiles-defs-articles.xml, and
tiles-defs-software.xml. In slightly more detail, this
means that definitions that are specific to a given module go in that
module's tiles-defs-xxx.xml file. Shared definitions
just go in the default module's tiles-defs.xml file,
where they can be imported by other modules in a way to be described
in just a bit.
IMPORTANT: There's an important disanalogy between the way one modularizes the Struts config and the way one modularizes the Tiles config. With the Struts config, the action paths are understood to be relative to the module, which is consistent with the standard understanding of what a module is. With the Tiles config, on the other hand, the paths to the JSPs are not relativized to the module directories. Not sure why this is, and to me (and apparently others) this seems to break the "module" semantics, but that's the way it works. The punchline is this: just move the Tiles defs to the right file; don't modify the JSP paths.
Step 2. Now go into your various
struts-config.xml files, and modify the
TilesPlugin definition in each one. There are two changes
you'll need:
Step 2.1. Change
<set-property property="definitions-config" value="/WEB-INF/tiles-defs.xml"/>
to something along the lines
<set-property property="definitions-config"
value="/WEB-INF/tiles-defs.xml,/WEB-INF/tiles-defs-articles.xml"/>
The list of Tiles definition files you include depends on whether
your module's Tiles config references definitions contained in
another config file. The most common case of this would be that your
tiles-defs.xml config contains a bunch of shared layout
definitions, and your non-default modules want to use them. Anyway,
you need to include all directly and indirectly referenced files in
the comma-separated list.
(In the special case of the default Struts config file, you
probably won't need anything other than
/WEB-INF/tiles-defs.xml.)
Step 2.2. Add the following to the TilesPlugin
definition:
<set-property property="moduleAware" value="true"/>
This tells Struts to create a separate Tiles factory for each module, which you want since you're modularizing the Tiles config files. IMPORTANT: Don't forget to add this to the default module as well!
Step 3. Cross your fingers and fire it up.
That's how to do it. Good luck!
