Django BaseModel ORM __repr__ Example Custom JSONEncoder

django-base-model.py

import json, re
import dateparser
from django.db import models
from django.forms.models import model_to_dict
from uuid import uuid4, UUID
from datetime import date, datetime
from django.template.defaultfilters import slugify

class ModelEncoder(json.JSONEncoder):
    def default(self, obj):
        if isinstance(obj, UUID):
            return str(obj)
        if isinstance(obj, (datetime, date)):
            return obj.isoformat()
        return json.JSONEncoder.default(self, obj)

class BaseModel(models.Model):
    uuid = models.UUIDField(default=uuid4)
    created_at = models.DateTimeField(auto_now_add=True, null=True)
    updated_at = models.DateTimeField(auto_now=True, null=True)

    @property
    def attributes(self):
        return model_to_dict(self)

    def save(self, *args, **kwargs):
        if hasattr(self, 'slug') and hasattr(self, 'slug_property'):
            self.slug = slugify(self.slug_property)
        super(BaseModel, self).save(*args, **kwargs)

    def __repr__(self):
        return json.dumps(self.attributes, cls=ModelEncoder, indent=4)

    class Meta:
        abstract = True

class User(BaseModel):
    name = models.CharField(max_length=255, null=True)
    email = models.EmailField()
    password = models.CharField(max_length=255, null=True)


class Event(BaseModel):
    title = models.CharField(max_length=255, null=True)
    slug = models.SlugField(unique=True, blank=True)
    description = models.TextField(null=True)
    location = models.CharField(max_length=255, null=True)
    start = models.DateTimeField(null=True)
    stop = models.DateTimeField(null=True)

    def save(self, *args, **kwargs):
        self.start = dateparser.parse(self.__dict__['start'])
        self.stop = dateparser.parse(self.__dict__['stop'])

        super(Event, self).save(*args, **kwargs)

    @property
    def slug_property(self):
        return self.title

class Ticket(BaseModel):
    event = models.ForeignKey(Event, related_name='tickets')
    name = models.CharField(max_length=255, null=True)
    price = models.FloatField(null=True)

    def save(self, *args, **kwargs):
        self.price = float(re.sub(r'[^0-9\.]', '', self.price or '') or 0.0)
        super(Ticket, self).save(*args, **kwargs)

    @property
    def slug_property(self):
        return self.name