# Django Hashids
[![Github Actions](https://github.com/ericls/django-hashids/workflows/test/badge.svg)](https://github.com/ericls/django-hashids/actions)
[![Code Coverage](https://codecov.io/gh/ericls/django-hashids/branch/master/graph/badge.svg)](https://codecov.io/gh/ericls/django-hashids)
[![Python Version](https://img.shields.io/pypi/pyversions/django-hashids.svg)](https://pypi.org/project/django-hashids/)
[![PyPI Package](https://img.shields.io/pypi/v/django-hashids.svg)](https://pypi.org/project/django-hashids/)
[![License](https://img.shields.io/pypi/l/django-hashids.svg)](https://github.com/ericls/django-hashids/blob/master/LICENSE)

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

```bash
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

```python
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

```python
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`:
1. `DJANGO_HASHIDS_SALT`: default salt
2. `DJANGO_HASHIDS_MIN_LENGTH`: default minimum length
3. `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](https://github.com/davidaurelio/hashids-python) for more info about the arguments.

Some common Model arguments such as `verbose_name` are also supported.
