[WebMacro-user] on WebMacro-Spring integration

[Hai-Chen Tu <hc...@op...>]

Hi,
	I exchanged several email with Sebastian on WebMacro-Spring integration
	issues and here is a summary of our discussion. It happened that
	we have different approaches to implement the integration and I will
	first describe the key parts of our approaches and then present
	some issues I have. You are all welcome to give your views and suggestions.
	Hopefully at the end of discussion we will have a version of integration
	that everyone is	happy to use.

	Sebastian's approach:
		* a CommonsLog class that implements WebMacro's Log interface
			using apache's common log API.
		* a SpringBroker class that extends WebMacro's Broker. It uses
			CommonsLog as the logger and Spring's ResourceLoader
			as the resource loader.
		* The WebMacro engine is created using SpringBroker.
		* rendering output is done through
			template.write(response.getOutputStream(), context);

	My approach:
		* ServletBroker: under the Spring MVC framework, I couldn't find any API
			to access the DispatchServletcan to create a ServletBroker.
			So I wrote a utility that creates a Servlet20Broker/Servlet22Broker
			using the ServletContext retrieved from the Spring application context.
			(There is probably a way to use Sebastian's CommonsLog as
			 the logger for this ServletBroker but I don't know how to do it.)
		* The WebMacro engine is based on WMServlet (which is probably
			a mistake but please read on). Since there is
			no servlet available during init time, I wrap WMServlet
			in a thin subclass and override its initWebMacro() and use
				new WM(broker created from the above mechanism)	
			to create a WM.
		* rendering output is done through
			WMServlet.execute(Template, WebContext)
		* I also recycle WebContext instances

	The reasons I want to use WMServlet are because
		1. I can use error.wm:
		2. I can use #param to set TEMPLATE_OUTPUT_ENCODING and
			TEMPLATE_LOCALE
		3. I can use ContextTools, e.g., $CGI.

	About error.wm, I am not quite sure if it is important to use it.
	I did, however, use it in my applications.

	Sebastian thinks that there is no need to use WMServlet and
	one can still access ContextTools without WMServlet. I think he is
	correct but I think a ServletBroker is still needed to be able to create
	CGI_Impersonator, and probably some other ContextTools. If this
	is the case, we may need to consolidate his SpringBroker and
	ServletBroker.

	On encoding/local setting, if we don't use WMServlet, then we probably
	want to allow developers to specify template encoding/locale
	through Spring's configuration file per WebMacroView  bean (each template
	has a one-one correspondence with a view), which is the mechanism
	Spring-Velocity integration uses.	

Sebastian,
	Could you describe the difference between Spring ResourcLoader
	and default resource loading used by Servlet20Broker/Servlet22Broker?
		
Hai-Chen Tu