Get Started

Overview

Django Abstract Relations allows dynamic creation of intermediary models inside many-to-many relationships of abstract (or non-abstract) models. This is possible by using a AbstractManyToManyField in place of original ManyToManyField.

 1
 2
 3
 4
 5
 6
 7
 8
 9
10
11
12
13
14
15
16
17
18
19
from django.db import models

from abstract_relations.models import AbstractManyToManyField


class Category(models.Model):
    name = models.CharField(max_length=100)


class AbstractItemCategoryThrough(models.Model):
    category = models.ForeignKey(Category)
    # the second model foreign key will be automatically added

    class Meta:
        abstract = True

class Pizza(models.Model):
    name = models.CharField(max_length=100)
    categories = AbstractManyToManyField(Category, through=AbstractItemCategoryThrough)

Above code results in creation of following class in the same module where AbstractItemCategoryThrough was defined and usage of that class in place of original Pizza.categories.through:

class PizzaCategory(models.Model):
    category = models.ForeignKey(Category)
    pizza = models.ForeignKey(Pizza)

    # The model with AbstractManyToManyField can be referenced-back with 'self.abstract_item'
    @property
    def abstract_item(self):
        return self.pizza

Installation

  1. Install django_abstract_relations:

    pip install django_abstract_relations

2. Use AbstractManyToManyField instead of ManyToManyField there, wherever you want dynamically created intermediary models!