Django - Usecases for Formset and Inline Formset?

Question

I'm really in doubt about which one to use(Formset or Inline Formset).

I've an on-line delivery request form to reserve bicycles. There are more than one type of bicycles and because of that I've two models "DeliveryRequests" and "DeliveryRequestBikes".

class DeliveryRequests(models.Model):
    pickup_date = models.DateField()
    return_date = models.DateField()
    pickup_hour = models.TimeField()
    return_hour = models.TimeField()
    name = models.CharField(max_length=100, null=False, blank=False)
    email = models.EmailField(null=False, blank=False)
    phone = models.CharField(max_length=25, null=False, blank=False)
    location_name = models.CharField(max_length=100, null=False, blank=False)
    address_to_delivery = models.CharField(max_length=200, null=False, blank=False)
    message = models.TextField(null=True, blank=True)
    deliveryrequeststatus = models.ForeignKey(DeliveryRequestStatus, null=False, blank=False)
    comment = models.TextField(null=True, blank=True)
    date_insert = models.DateTimeField(auto_now_add=True)
    date_last_modification = models.DateTimeField(auto_now=True)  

    def __unicode__(self):
        return self.name

    class Meta: # To order in the admin by name of the section
        ordering = ['-id']   


class DeliveryRequestBikes(models.Model):
    deliveryrequest = models.ForeignKey(DeliveryRequests, null=False, blank=False)
    biketype = models.ForeignKey(BikeTypes, null=False, blank=False)
    units = models.IntegerField(null=False, blank=False)
    date_insert = models.DateTimeField(auto_now_add=True)
    date_last_modification = models.DateTimeField(auto_now=True) 

    def __unicode__(self):
        return self.deliveryrequest

    class Meta: # To order in the admin by name of the section
        ordering = ['biketype']  

I forgot to explicitly say that this is a front end form. I need to be able to insert for one "DeliveryRequests" register one or more "DeliveryRequestBikes"

Which one should I use, a Formset or a Inline Formset?

Please give some advice.

Best Regards,

Answer 1

Inline formsets is a small abstraction layer on top of model formsets. These simplify the case of working with related objects via a foreign key.

It seems that inline formsets are exactly what you want. Optionally you can specify how many DeliveryRequestBikes you want to allow for a DeliveryRequests.

Give them a try with:

from django.forms.models import inlineformset_factory
DeliveryRequestBikesFormSet = inlineformset_factory(DeliveryRequests, DeliveryRequestBikes, fk_name="deliveryrequest")