[Zope-dev] z3c.form SequenceWIdget extract

[Mat Lehmann]

Hi,

I am using z3c.form, which is complicated but a lot more flexible than 
the old zope.formlib. Thanks for building it.


Currently, I am having a problem with the SequenceWidget. Let me 
illustrate the scenario:
I have a search-form with batching of the results - the links for the 
pages of the search contain the search parameters and the action-key as 
GET-parameters like this 
search.html?form.widgets.text=fooform.buttons.search=1.


With normal Widgets, this works perfectly well. But when my 
search-form contains a SequenceWidget, this approach breaks, because 
SequenceWidget depends on zope-functionality in some other place, which 
transforms paramters with a key-postfix of :list to a list of values 
(the postfix is appended to the parameter-name by the template).


The part of my application, that builds the query-string for the batch 
does however not have any knowledge about the widget-type of the 
parameters (that's intentionally to limit the dependencies to the form 
implementation).


This problem would not exist, if the extract-method of SequenceWidget 
would contain two additional lines of code:


def extract(self, default=interfaces.NOVALUE):
   See z3c.form.interfaces.IWidget.
   if (self.name not in self.request and
   self.name+'-empty-marker' in self.request):
   return []
   value = self.request.get(self.name, default)
   if value != default:
   if not isinstance(value, (list, tuple)):
  value = [value]   
  for token in value:

   if token == self.noValueToken:
   continue
   try:
   self.terms.getTermByToken(token)
   except LookupError:
   return default
   return value

I (hope I) can work around this problem by  subclassing SequenceWidget 
and overwrite the extract method, but I wonder, if this fix introduces 
some unknown problems and whether it can be included in the standard 
implementation.


Thanks,

Mat

--
Dipl. Inf. Matthias Lehmann
Software- und Web-Development
Käthe-Kollwitz-Straße 6
99734 Nordhausen

fon:   +49 3631 470652
mobil: +49 170 5176774
eMail: [EMAIL PROTECTED]
web:   http://www.matlehmann.de

___
Zope-Dev maillist  -  Zope-Dev@zope.org
http://mail.zope.org/mailman/listinfo/zope-dev
**  No cross posts or HTML encoding!  **
(Related lists - 
http://mail.zope.org/mailman/listinfo/zope-announce

http://mail.zope.org/mailman/listinfo/zope )

Re: AW: [Zope-dev] z3c.form SequenceWIdget extract

[Mat Lehmann]

Roger Ineichen schrieb:

Hi Mat
  
Can you give a smaple ot the search string which you are using

if it contains a sequence widget? I guess this string is wrong
and this ends in none sequence data at the server side.
If I'm right, now you are trying to convert this simple data
string into a sequence, right?

Try to build a sequence of values as:

search.html?text=footext=bar

that's the right way to send sequence data and will give you 
the result:


text = ['foo', 'bar']

at the server side.
  


Hi Roger,

I am sorry, but I was not clear enough with my description:

In my search-form, I have a simple single-select-widget (i.e. a 
dropdown). My problem is not to transmit multiple values for a single 
widget over a GET-paramter-string - for this, your solution should work.
But I want to use the key and value of this dropdown-widget just the 
same way as for input-widgets:

I want to be able to build a query-string like

search.html?form.widgets.dropdown=foo

and have the SequenceWidget accept this single value. Currently, 
SequenceWidget depends on the fact, that in the templates for 
sequence-widgets, the name of the widget gets a postfix of :list (so 
form.widgets.dropdown is now form.widgets.dropdown:list) and because 
of that, the value is transformed to a list by 
zope.publisher.browser.BrowserRequest.


But because the method in my application that builds the query-string 
has no knowledge about the widget-types - it simple has key-value-pairs 
- it can not append the :list postfix to the paramter name, thus the 
value is not transformed to a list and SequenceWidget disregards the 
value altogether.


With the two additional lines, SequenceWidget does not assume anymore, 
that value has already been transformed to a list (a bold assumtion as I 
think, since it depends on the default templates) and it will accept 
query-strings of the given form.


Regards,

Mat
___
Zope-Dev maillist  -  Zope-Dev@zope.org
http://mail.zope.org/mailman/listinfo/zope-dev
**  No cross posts or HTML encoding!  **
(Related lists - 
http://mail.zope.org/mailman/listinfo/zope-announce

http://mail.zope.org/mailman/listinfo/zope )