How to modify a z3c form field in updateWidgets?

Question

I am trying to dynamically update a form field based on a variable that is included in a HTTP get variable. Specifically www.site.com/form?id=name. I want to pull the 'id' field from the url and automatically populate the memberID field of the form.

I have access to the get variable using self.request.get('id'). However I haven't been able to figure out how to update the form field. I examined the widget documentation http://packages.python.org/z3c.form/widget.html but none of the suggestions have worked.

class IUpdateEmailFormSchema(interface.Interface):
    # -*- extra stuff goes here -*-
    """
    """
    memberID = schema.TextLine(title=(u'Member id'))

    email = schema.TextLine(title=(u'Email'), description=(u'The email'))

class updateEmailForm(form.Form):
    fields = field.Fields(IUpdateEmailFormSchema)
    label = _(u'Change Email')
    ignoreContext = True


    @button.buttonAndHandler(u'Update')
    def handleUpdate(self,action):
        data, errors = self.extractData()

        if data.has_key('email'):

            portal_membership = getToolByName(self.context, 'portal_membership')
            member = portal_membership.getMemberById(data['memberID'])

    def updateWidgets(self):
        print "This is update widget \n\n"
        import pdb; pdb.set_trace()
        print self.request.form['id']    #Does not work as specified in http://packages.python.org/z3c.form/widget.html
        #self.widgets["memberID"].value = self.request.get('id').encode('utf-8')
        form.Form.updateWidgets(self)

updateEmailFormView = wrap_form(updateEmailForm)

*Update: updateWidget wasn't correctly indented.

Answer 1

updateWidgets method is the right place to do it. just you shouuld first call "form.Form.updateWidgets" and then do your changes (even better user super() as shown bellow):

def updateWidgets(self):
    super(updateEmailForm, self).updateWidgets()
    id = self.request.get('id', None)
    if id:
        self.widgets["memberID"].value = id.encode('utf-8')

so basically the error was the order

and if there is no request (which is kinda weird and you are probably doing something worng there) then you can get it via:

from zope.globalrequest import getRequest
request = getRequest()

Answer 2

Your updateWigets() won't be called above because it's not inside the body of the form, it's a top level function.

Also, you should use super() to call the parent version of updateWidgets() - in your case, you probably want to call the parent version first and then change the value or whatever.

You may be better off using a default value adapter instead of updateWidgets() too.