WebWork 2 : Webwork reference to OGNL access
This page last changed on Nov 30, 2004 by jcarreira.

Webwork uses a standard naming context to evaluate OGNL expressions. The top level object dealing with OGNL is a map (usually referred as a context map). OGNL has a concept of a root object (in webwork terms, this is the OGNLValueStack). Along with the root, other objects are placed in the context map (referred as in the context) including your session/application/request/attr maps. These objects have nothing to do with the root, they just exist along side it in the context map. So, to access these objects, the # is used telling ognl not to look in the root object, but within the rest of the context 

|             

                     |-- request
                     |
                     |--application
                     |
       context map---|--OgnlValueStack(root)
                     |
                     |--session
                     |
                     |--attr
                     |
                     |--parameters

Note that their are other objects in the context map, I'm just referring to a few for this example. Now, your actions instances are placed in the OGNLValueStack so you can refer to your bean properties without the #.

<ww: property value="myBean.myProperty"/>

for sessions,request, and the rest that lie in the context map
ActionContext.getContext().getSession().put("mySessionPropKey", mySessionObject);
<ww: property value="#session.mySessionPropKey"/> or
<ww: property value="#session['mySessionPropKey']"/>

<ww: property value="#attr.mySessionPropKey"/>
Document generated by Confluence on Dec 14, 2004 16:37