[Zope3-Users] custom tuple widget

[Marco Mariani]

I'd like to create a custom widget for the "Starbucks problem" - my 
designation - where I need to set an attribute to a path of an external 
tree, which is stored on LDAP or DBMS.

Basically, the content object has an attribute "store" which is a tuple 
of (state, city, store_no) and I would manipulate the tuple as a single 
widget, with three <select> menus.

I'm thinking of declaring it this way:


== interfaces.py ==

class IMyObject(Interface):

    store = Tuple(
        title=u"Store",
        description=u"Store state, city and number",
        required = False,
        min_length = 3,
        max_length = 3,
        value_type=TextLine(title=u"path element")
        )

...



== browser/configure.py ==

  <addform
    label = "New MyObject"
    name = "AddMyObject.html"
    schema = "myapp.interfaces.IMyObject"
    content_factory = "myapp.myobject.MyObject"
    fields = "store"
    permission = "zope.ManageContent">

    <widget field="store" class=".widget.StarbucksWidget" />

  </addform>


...

== browser/widget.py ==

class StarbucksWidget(TupleSequenceWidget):
     ....





The custom widget will then render all the tree in a javascript object 
(dictionary of dictionaries of dictionaries) which will fill and change 
the dropdown menus accordingly. As an improvement, the tree nodes can be 
retrieved by XmlHttp

Before hitting my head too hard, is this doable?


Is it possible to avoid the bunch of javascript by having the widget 
re-submit itself at each menu selection? For instance, I select the 
state, the form resubmits and gives me the choice of cities. How can I 
tell the first two <select> tags to reload the page? Is it enough to 
attach an onchange event that calls submit() ?


Thanks