just want to share some thoughts on a possble nice addition for the woody forms, feel free to comment
(see http://wiki.cocoondev.org/Wiki.jsp?page=Woody for the miinimal current docs)
the woody forms as of today allow you to define the form-model (woody-definition file, with some validation in there) and have a way to template the defined widgets into an HTML-form frame (woody-template file)
however, filling the form with data comming from your backend needs to be done programmtically (various frm.getWidget(..).setValue (..) calls)
this got me thinking (and thinkering) towards a declarative way for expresiing what I would call 'form-binding'
Using a similar factory/builder pattern as the current woody forms there could be some binding-definition file that gets build into some runtime Binding object that actually performs the trick for you:
Form frm ...;
BindingManager bm = serviceManager.lookup("..");
Binding b = bm.createBinding(source);Object model = BackendService.interact();
b.loadFormFromModel(frm, model);
// and something similar for the way back? b.saveFormToModel(frm,model)?
The actual binding definition file could be filled with:
<bnd:field id="widget-name"
path="xpath expression into model" />and possibly a bit more complex constructs to ease on the typing with context narrowing:
<bnd:context path="xpath to context"> <bnd:field path="relative-path" id="widget-name" /> <bnd:field path="relative-path" id="widget-name" /> </bnd:context>
Thinking about a context like 'address' and fields as 'addressline', 'city', 'zip'
This would call for the Binding object to be in fact a nested tree of binding objects reflecting the widget-tree inside the form. Each of these Binding objects could then narrow the scope of the current context and pass over to the children to continue on the binding. (assuming jxpath usage for inspecting the model)
e.g. for this context-thing:
public void loadFormFromModel(
ContainerWidget c, JXPathContext jxpc){ JXPathContext subContext;
subContext = jxpc.getRelativeContext(
jxpc.getPointer(this.xpath));continueLoadingFromChildren(c, subContext); }
similar there could be binding for repeaters and the new aggregate fields
<bnd:repeater path=".." id=".."> <bnd:field .../> </bnd:repeater>
<bnd:aggregate path=".." id=".."> <bnd:field .../> </bnd:aggregate>
Using JXPath there should be a fairly easy way to have this binding work for a backend producing either javabeans or XML files.
what do people think?
-marc= -- Marc Portier http://outerthought.org/ Outerthought - Open Source, Java & XML Competence Support Center Read my weblog at http://radio.weblogs.com/0116284/ [EMAIL PROTECTED] [EMAIL PROTECTED]
