Question

Good day.

I’m building an application for ordering prints and struggles at a part where
the user, apart from selecting from predefined values, can enter her own data for printing.

Consider the following:

class PrintItem(models.Model):
    """ Something printable. Poster, t-shirt, mug, etc """
    name = models.CharField(max_length=20)

class AttributeType(models.Model):
    """ Size,colour, etc """
    name = models.CharField(max_length=20)

class Attribute(models.Model):
    """ Size: A4, A5 | Colour: Violet, Black """
    name = models.CharField(max_length=20)
    type = models.ForeignKey(AttributeType)

# And a join model
class PrintAttribute(models.Model):
    print_item = models.ForeignKey(PrintItem)
    attributes = models.ManyToManyField(Attribute)

# The user adds these to a cart
class Cart(models.Model):
    user = models.ForeignKey(User)

class CartItem(models.Model):
    cart = models.ForeignKey(Cart)
    print_item = models.ForeignKey(PrintItem)

This works all good. The user can select from the predefined attributes, but how and where would you suggest I would implement the user input functionality?
User finds an item to print, chooses from the predefined Attributes (print size, the ink colour) and can enter her own message/slogan to print on the item.

Grateful for any suggestions.

Answer 1

If user’s own slogan/message gets entered only upon adding a print item to the cart, then the slogan/message should be a field of CartItem.