django-hashids

Django Hashids

django-hashids is a simple and non-intrusive hashids library for Django. It acts as a model field, but it does not touch the database or change the model.

Features

• Proxy the internal model pk field without storing the value in the database.
• Allows lookups and filtering by hashid string.
• Can be used as sort key
• Allows specifying a salt, min_length and alphabet globally
• Supports custom salt, min_length, and alphabet per field
• Supports Django REST Framework Serializers
• Supports exact ID searches in Django Admin when field is specified in search_fields.
• Supports common filtering lookups, such as __iexact, __contains, __icontains, though matching is the same as __exact.
• Supports other lookups: isnull, gt, gte, lt and lte.

Install

pip install django-hashids

django-hashids is tested with Django 1.11, 2.2, 3.0, 3.1, 3.2, 4.0 and python 3.6, 3.7, 3.8, 3.9, 3.10.

Usage

Add HashidsField to any model

from django_hashids import HashidsField

class TestModel(Model):
    hashid = HashidsField(real_field_name="id")

TestModel.hashid field will proxy TestModel.id field but all queries will return and receive hashids strings. TestModel.id will work as before.

Examples

instance = TestModel.objects.create()
instance2 = TestModel.objects.create()
instance.id  # 1
instance2.id  # 2

# Allows access to the field
instance.hashid  # '1Z'
instance2.hashid  # '4x'

# Allows querying by the field
TestModel.objects.get(hashid="1Z")
TestModel.objects.filter(hashid="1Z")
TestModel.objects.filter(hashid__in=["1Z", "4x"])
TestModel.objects.filter(hashid__gt="1Z")  # same as id__gt=1, would return instance 2

# Allows usage in queryset.values
TestModel.objects.values_list("hashid", flat=True) # ["1Z", "4x"]
TestModel.objects.filter(hashid__in=TestModel.objects.values("hashid"))

Config

The folloing attributes can be added in settings file to set default arguments of HashidsField:

• DJANGO_HASHIDS_SALT: default salt
• DJANGO_HASHIDS_MIN_LENGTH: default minimum length
• DJANGO_HASHIDS_ALPHABET: default alphabet

HashidsField does not reqiure any arguments but the followinig arguments can be supplied to modify its behavior.

Name	Description
real_field_name	The proxied field name
hashids_instance	The hashids instance used to encode/decode for this field
salt	The salt used for this field to generate hashids
min_length	The minimum length of hashids generated for this field
alphabet	The alphabet used by this field to generate hashids

The argument hashids_instance is mutually exclusive to salt, min_length and alphabet. See hashids-python for more info about the arguments.

Some common Model arguments such as verbose_name are also supported.