[Webmacro-devel] Directive writing question

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

Hiya,

Does anybody know the best way to enforce that an "RValue" directive arg is 
a Variable?

In my (now working) #newobject directive I have the following optional 
syntax:

#newobject $newobj inherits $baseobj

(Which makes $newobj return properties from $baseobj if the property is not 
defined on $newobj).

Anyway, $baseobject has to be a compatible object type - an RValue but also 
a WebMacroObject or perhaps a java.util.Map. I can enforce this at 
evaluation time with instanceof but at build time, can how do I force that 
it is a Variable and not a literal or inline array?

As separate issue, writing this has made me realising something interesting 
- that I probably shouldn't do... I could make it "inherit" from -any- 
Variable even application-supplied custom objects. This would be a weird 
kind of "runtime inheritance" but only for properties, not method calls.

This would just require that if the property X is not defined on the 
referenced WebMacroObject, it will use introspection to read the property 
from the "ancestor" object if any. i.e. ...using #bean to demonstrate 
custom class in context...:

#bean $mybaseObj "com.mycompany.MyObject"
#set $mybaseObject.SomeProperty = "something"

#newobject $wmObj inherits $mybaseObj

The value is: $wmObj.SomeProperty

......Which would show "something" of course. Not rocket science, but it 
might be a useful facility... effectively applying a property "decorator" 
pattern to objects already in the context, such as adding name properties.

-- 
Marc Palmer (Wangjammer5)
http://www.wangjammers.org
Java Consultants