How can i get my object id from a generic update views to use in my form in django 1.1

I m using generic view to update object.

I m using form :

class VehiPrepaClientForm(ModelForm):




class Meta:
    model = VehiPrepa
    fields = ('date_dem_prepa','carburant','ty_carburant')



def clean(self):
    cleaned_data = self.cleaned_data
    data = self.cleaned_data['date_dem_prepa']

    vehiprepa = get_object_or_404(VehiPrepa,pk=object_id)
    if data :

        vehiprepa.demande_prepa = 1
        vehiprepa.save()
        date_in = vehiprepa.date_in
        delta = data - date_in
        date_dem = date_in + delta 
        if delta.days < 2 :
            raise forms.ValidationError("Veuillez entrez une date au dela du : %s" %(date_dem) )

        if data.weekday()>= 5 :

            raise forms.ValidationError("La date choisie n'est pas valide, cela tombe un weekend")    

        #test si date demande sup a date_in et si pas samedi, ni dimanche, et si pas plus 32 vehi ce jour la



    return cleaned_data

I m using this generic view :

def vehiprepa_update (request, vehiprepa_id):

user= request.user

login = user.username
vehiprepa = get_object_or_404(VehiPrepa,pk=vehiprepa_id)

url_template_base = "base_client_washtest.html"


    response = create_update.update_object(
            request,
            form_class = VehiPrepaClientForm, 
            object_id = vehiprepa_id,
            post_save_redirect = "/washtest/vehiprepa_list/0/",
            template_name = 'washtest/vehiprepa_update.html',
            template_object_name = 'object',
            extra_context = {"url_template_base":url_template_base,"login":login,"vehiprepa":vehiprepa},)

return response

But i have an error, because object_id on my form is not known.... How can i get my request object id to use in my form clean ?

Thx

EDIT : HEre the error :

global name 'object_id' is not defined

Your error comes from this line:

vehiprepa = get_object_or_404(VehiPrepa,pk=object_id)

In your model form, you don't have a object_id.

To solve this problem, refer to the documentation; which states:

Also, a model form instance bound to a model object will contain a self.instance attribute that gives model form methods access to that specific model instance.

From that we understand that the bound instance is in self.instance. So, in your model form you need

vehiprepa = self.instance

instead of the get_object_or_404 line.