title: How to modify a z3c form field in updateWidgets?
body: <p>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.</p>
  
  <p>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 <a href="http://packages.python.org/z3c.form/widget.html" rel="nofollow">http://packages.python.org/z3c.form/widget.html</a> but none of the suggestions have worked.</p>
  
  <pre><code>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)
  </code></pre>
  
  <p>*Update: updateWidget wasn't correctly indented.</p>