Overview¶

Model¶

Suppose your models.py looks something like this:

class Book(models.Model):
    name = models.CharField(max_length=100)
    binding = models.CharField(max_length=2, choices=BINDING_CHOICES)
    authors = models.ManyToManyField(Author)
    genre = models.ForeignKey(Genre)
    price = models.DecimalField(max_digits=6, decimal_places=2)
    date_published = models.DateField()

(with BINDING_CHOICES, Author and Genre omitted for brevity).

View¶

You might want to present a list of Book objects, allowing the user to filter on the various fields. Your views.py would be something like this:

from django.shortcuts import render

from myapp.models import Book

def booklist(request):
    books = Book.objects.all()
    return render(request, "booklist.html", {'books': books})

URLs¶

And you’d need to add a pattern to your URL conf:

url(r'^booklist/$', views.booklist)

Template¶

And the template:

<ul>
    {% for book in books %}
       <li>{{ book }}</li>
    {% endfor %}
</ul>

Create a Filterset¶

So far, you have simple set-up that lists all the Book objects.

To add the filters, in views.py add a FilterSet subclass and change the view code as follows:

from django.shortcuts import render
from django_easyfilters import FilterSet

from myapp.models import Book

class BookFilterSet(FilterSet):
    fields = [
        'binding',
        'authors',
        'genre',
        'price',
        ]

def booklist(request):
    books = Book.objects.all()
    booksfilter = BookFilterSet(books, request.GET)
    return render(request, "booklist.html", {'books': booksfilter.qs,
                                             'booksfilter': booksfilter})

Notice that the books item put in the context has been replaced by bookfilter.qs, so that the QuerySet passed to the template has filtering applied to it, as defined by BookFilterSet and the information from the query string (request.GET).

The booksfilter item has been added to the context in order for the filters to be displayed on the template.

Change the template¶

Just add {{ booksfilter }} to the template:

{{ booksfilter }}

<ul>
    {% for book in books %}
       <li>{{ book }}</li>
    {% endfor %}
</ul>

Pagination¶

You can also use pagination, for example using django-pagination:

{% load pagination_tags %}

{% autopaginate books 20 %}

{{ booksfilter }}

{% paginate %}

<ul>
    {% for book in books %}
       <li>{{ book }}</li>
    {% endfor %}
</ul>

FilterSet `title` attribute¶

The FilterSet also provides a ‘title’ attribute that can be used to provide a simple summary of what filters are currently being applied. It is made up of a comma-separated list of chosen fields. For example, if the user has selected genre ‘Classics’ and binding ‘Hardback’ in the example above, you would get the following:

>>> books = Book.objects.all()
>>> booksfilter = BookFilterSet(books, request.GET)
>>> booksfilter.title
u"Hardback, Classics"

The fields used for the title attribute, and the order they are used, can be customised by adding a title_fields attribute to your FilterSet:

class BookFilterSet(FilterSet):
    fields = [
        'binding',
        'authors',
        'genre',
        'price',
        ]

    title_fields = ['genre', 'binding']

Customisation of the filters can be done in various ways - see the FilterSet documentation for how to do this, and the Filters documentation for options that can be specified.

Example¶

A full example can be found in django_easyfilters/tests which is included in the source distribution. See the books view in views.py:

https://bitbucket.org/spookylukey/django-easyfilters/src/default/django_easyfilters/tests/views.py

The book_search view gives an example of how to integrate with other searching and filtering. Remember to check the templates:

https://bitbucket.org/spookylukey/django-easyfilters/src/default/django_easyfilters/tests/templates/

See the development documentation if you want to run this example code as a demo.