django-bit-category 0.4

What is included in this app

• abstract HierarchicalModel which takes care about the magic with IDs

• abstract BaseCategory which contains the most usual category implementation

• HierarchicalField which you can use for any custom model

• HierarchicalWidget which dynamically (via AJAX) creates / deletes select boxes

• urls.py and views.py which contains AJAX magic for form field working

How to make it work

If you just want to use just one of the abstract models then you don’t need to do anything special. Import the abstract model from bitcategory.models import BaseCategory and inherit from it in your concrete Model. Then make a foreign key in your another model which is going to use categories:

# :file: models.py
from django.db import models
from bitcategory.models import BaseCategory

class MyCategory(BaseCategory):
    # BaseCategory already provides fileds name, slug and path
    class Meta:
        abstract = False

class MyProduct(models.Model):
    # some other fields like price, quantity ....
    category = models.ForeignKey('myproject.MyCategory', verbose_name=_("Category"))

That is all to your Model definition. Now, provided you have a concrete instance of MyCategory in variable category, you can query products within the category and all its subcategories by:

MyProduct.objects.filter(category_id__gte=category.gte, category_id__lt=category.lt)

or to get products only for the category by:

MyProduct.objects.filter(category=category)

However, if you want to have the awesome dynamic select boxes in your forms with category in it, you need to do more

• add the bitcategory into your INSTALLED_APPS

• add bitcategory.urls into your urls and specify your custom hierarchical model. If you didn’t create your custom hierarchical model, then use our pre-built concrete model bitcategory.models.Category. We do that in order to be able to respond to AJAX requests which are sent by the bitcategory.fields.HierarchicalField. The most simple way looks like:

  # :file: urls.py
  from django.conf.urls import patterns, include, url
  from myapp.models import YourHierarchicalModel
  
  urlpatterns = patterns('',
        url('', include('bitcategory.urls'), {"model": YourHierarchicalModel}),
  )

Now you are ready to show your form with categories in it. First, add bitcategory.fields.HierarchicalField in the form. When rendering the form into a page, don’t forget to include {{form.media}} into your template for javascripts.