django-namedid

Django field that automatically combines multiple fields into a unique identifier with collision handling.

Purpose

Create unique identifiers by combining multiple model fields (e.g., name, id, date) with automatic collision resolution.

Installation

pip install django-namedid

Quick Start

Using NamedIDField directly

from django.db import models
from namedid import NamedIDField

class Product(models.Model):
    name = models.CharField(max_length=100)
    code = models.IntegerField()
    created_date = models.DateField()
    
    named_id = NamedIDField(
        source_fields=["name", "code", "created_date"],
        max_length=200,
    )

Custom generator

The base value is built by generate_namedid(instance, source_fields, separator). Pass generator to replace that function. It must use the same signature and return a string. Collision suffixes are still applied by the field.

# myapp/generators.py
from namedid import generate_namedid

def custom_namedid(instance, source_fields, separator):
    base = generate_namedid(instance, source_fields, separator)
    return f"org{separator}{base}" if base else base

named_id = NamedIDField(
    source_fields=["name"],
    generator="myapp.generators.custom_namedid",
    max_length=200,
)

generator also accepts the callable itself. A dotted path is the form migrations can store unchanged.

Using the decorator

from django.db import models
from namedid import add_namedid

@add_namedid(named_id=["title", "id"], slug=["title", "category"])
class Article(models.Model):
    title = models.CharField(max_length=200)
    category = models.CharField(max_length=50)
    content = models.TextField()

Features

• Automatic generation: Values are generated automatically before saving
• Collision handling: Automatically appends numeric suffix if value exists (e.g., name-1-2023, name-1-2023-1, name-1-2023-2)
• Type formatting: Automatically formats dates, numbers, booleans
• Unique and required: Fields are always unique and cannot be empty
• Read-only: Fields are automatically set to read-only

Field Properties

• unique=True: Always unique
• editable=False: Always read-only
• blank=False: Cannot be empty
• null=False: Cannot be NULL

Development

./service.py dev install-dev
./service.py dev test

License

MIT