In Mach-II, inside an event handler, you notify a specific listener to execute a specific method. In Model-Glue, inside an event handler, you simply broadcast a message and any listeners that have been declared for that message are executed automatically by the framework.
Here's the listener declaration in my mach-ii.xml file that shows the message listener:
<parameters>
<parameter name="some.message" value="listenerA.method1,listenerB.method2" />
<parameter name="another.message" value="listenerA.method3" />
</parameters>
</listener>
Here's how you broadcast a message:
Finally, here's the MessageListener.cfc:
<cffunction name="onMissingMethod" returntype="void" access="public" output="false">
<cfargument name="missingMethodName" />
<cfargument name="missingMethodArguments" />
<cfset var listenerList = getParameter(arguments.missingMethodName) />
<cfset var listenerManager = getAppManager().getListenerManager() />
<cfset var listener = 0 />
<cfset var event = 0 />
<cfif structKeyExists(arguments.missingMethodArguments,"event")>
<cfset event = arguments.missingMethodArguments.event />
<cfelse>
<cfset event = arguments.missingMethodArguments[1] />
</cfif>
<cfloop index="listener" list="#listenerList#">
<cfinvoke component="#listenerManager.getListener(listFirst(listener,"."))#"
method="#listLast(listener,'.')#"
returnvariable="result"
event="#event#" />
</cfloop>
</cffunction>
</cfcomponent>
Yes, it relies on ColdFusion 8's onMissingMethod() handler so that the MessageListener can respond to any message (i.e., any method call) and it uses the method name to look up the mapping to listeners and methods to be called.
Perhaps the Mach-II approach is less flexible, but I know exactly which method that I'm invoking.
In Model-Glue - as in my example above - the event handler "broadcasts" a message and the framework looks up which methods in which controllers are declared to listen for that message and calls them.
I tend to recommend messages are named "needFoo", "needBar" so that it emphasizes the distinction between message names and method names (which are often "getFoo" and "getBar").
