[WebMacro-user] Changes to WM/Broker

[Marc P. <ma...@an...>]

Hi,

I've just, very easily, got a basic Spring view implementation working
with WebMacro. This means I have successfully used basic test Spring web
applications with either JSP front end using a WM Taglib to use WM within
the JSP, as well as a no-JSP application that only uses WM templates for
the view.

I have yet again run into issues with WM's Broker mechanism. I still
strongly believe this is a major thorn in our sides and it needs to be
removed or reworked.

Basically in the Spring WM view implementation we have access only to our
ServletContext, not the Servlet. All WM + Broker's constructors/factories
need a Servlet if you want to be able to access templates from the
webapp's directories/classpath.

So for example, I have had to create a new "Servlet22BrokerPlus" (because
Servlet22Broker has a private constructor - argh!) and add a new static
getBroker:

public static Broker getBroker (
  ServletContext sc, 
  ClassLoader servletClassLoader,
  Properties additionalProperties) throws InitException

In my view implementation I call this method, and I can pass in
servletClassLoader by doing this.getClass().getClassLoader() on the spring
view. Well, this will only work I believe if the webmacro/webmacro Spring
JAR is not in a shared location such as tomcat/shared or tomcat/common/lib
or endorsed. 

So this in itself is imperfect but better than not being able to access
webapp templates at all. I don't know how we can get to the servlet's
classloader from a Spring view class. (it's the webapp classloader we want
of course - clarifying terminology).

Anyway, I therefore suggest that:

1. We need to add a new constructor to o.w.WM:

   public WM(ServletContext sc, ClassLoader webappClassLoader);

...and as a result also new getBroker(ServletContext, ClassLoader, ...)
methods to Servlet20Broker and Servlet22Broker (or ServletBroker if we can
polymorphize it!)

2. We make these private constructors in ServletXXBroker protected
instead. Private is just such a pain in the ass when you need to do
something like this without tweaking the original WM source.

What say you guys?

My Spring view needs more testing obviously but I'll put it forward soon.


Cheers