struts-dev mailing list archives

Site index · List index
Message view « Date » · « Thread »
Top « Date » · « Thread »
From Don Brown <mr...@twdata.org>
Subject [Proposal] ActionFactory refactoring
Date Fri, 02 Jan 2004 20:44:33 GMT
What if we extracted the creation of Actions and ActionForms (including
DynaActionForms) into an ActionFactory, overridable by the user?

Here's the problem as I see it: there is no simple way for a user to plug
in their own code to manage the creation of actions and action
forms.  The actual creation is handled by static methods in
RequestUtils, obviously not overridable, leaving the only option to
extend RequestProcessor and duplicate a lot of logic.

Why would you want to plug in your own ActionFactory?  My primary purpose
is to better integrate Inversion of Control (IoC), specifically Spring's
IoC, into Struts.  By letting Spring create Struts objects, Spring can
handle any dependencies and configuration they need.  Another use, as
stated in bug #23583
(http://issues.apache.org/bugzilla/show_bug.cgi?id=23583), could be a
factory that creates ActionForms using JavaAssist at runtime.  Finally,
this factory would be an easy way for the user to create their own
DynaActionForms, particularly useful for unit testing.

Impact: This would have no impact on current Struts applications as it is
an internal refactoring and default behavior would remain the same.
Extensions that include custom RequestProcessors or interfere with object
creation might be affected.

Configuration: I'd recommend another attribute in the <controller />
element in struts-config, possibily named "actionFactoryClass", pointing
to the new ActionFactory implementation to use.  If none specified, a
default factory which mimics current behavior would be used.

This is my proposed interface:

public interface ActionFactory {

	public Action createAction(ActionServlet servlet);

	public DynaActionForm createDynaActionForm(ActionServlet servlet,
						   FormBeanConfig config,
					           ActionConfig mapping);

	public ActionForm createDefaultActionForm(ActionServlet,
						  FormBeanConfig config);


        public ActionForm createActionForm(ActionServlet servlet,
                                           FormBeanConfig config,
                                           ActionConfig mapping);

}

Note createActionForm() creates either a DynaActionForm or ActionForm
depending on the config.

Comments?  Obviously, I'd perform the refactorings if this feature was
agreed upon.  Future targets for factories could include config objects:
http://issues.apache.org/bugzilla/show_bug.cgi?id=13638

Don


---------------------------------------------------------------------
To unsubscribe, e-mail: struts-dev-unsubscribe@jakarta.apache.org
For additional commands, e-mail: struts-dev-help@jakarta.apache.org


Mime
View raw message