Skip to main content

No project description provided

Project description

Set of custom fields useful to implement the Strategy Pattern with Django models.

The Strategies are displayed in SelectBoxes as standard choice field

This package provides the following custom fields:

  • StrategyField

  • MultipleStrategyField

  • StrategyClassField

  • MultipleStrategyClassField

The StrategyField can be accessed as instance of the model with an attribute context that points to model that ‘owns’ the field (inverse relation). So:

Example

from strategy_field.fields import StrategyField
from django.core.mail.backends.filebased.EmailBackend


class Event(models.Model):
    backend = StrategyField()

Event(sender='django.core.mail.backends.filebased.EmailBackend')

Use case

As example we can imagine an application that manages Events that need to be notified to users. Each Occurrence of Event can be notified using different transport, (email, sms,…). We want to be able to add/change the way we send notification, per event basis, simply using the Django admin panel.

from strategy_field.fields import StrategyField
from strategy_field.registry import Registry

class TransportRegistry(Registry)
    pass

class AbstractStrategy(object):
    def __init__(self, context):
        self.context = context

    def send(self):
        raise NotImplementedError

class EmailStrategy(AbstractTransport):
    def send(self):
        ...

class SMSStrategy(AbstractTransport):
    def send(self):
        ...
registry = TransportRegistry(AbstractStrategy)
registry.register(EmailStrategy)
registry.register(SMSStrategy)

class Event(models.Model):
    sender = StrategyField(registry=registry)

Event.objects.get_or_create(sender=EmailStrategy)
...
...
e = Event.objects.get(sender=EmailStrategy)
e.sender.send() # e.sender.context == e

More examples

Use callable

from strategy_field.fields import StrategyField
from strategy_field.registry import Registry

registry1 = Registry()
registry2 = Registry()

class A(model):
    sender = StrategyField(registry=lambda model: model._registry)
    class Meta:
        abstract = True

class C1(A):
    _registry = registry1
    class Meta:
        abstract = True

class C2(A):
    _registry = registry2
    class Meta:
        abstract = True

Project details


Download files

Download the file for your platform. If you're not sure which to choose, learn more about installing packages.

Source Distribution

django-strategy-field-3.1.0.tar.gz (23.7 kB view details)

Uploaded Source

File details

Details for the file django-strategy-field-3.1.0.tar.gz.

File metadata

  • Download URL: django-strategy-field-3.1.0.tar.gz
  • Upload date:
  • Size: 23.7 kB
  • Tags: Source
  • Uploaded using Trusted Publishing? No
  • Uploaded via: twine/3.1.1 CPython/3.9.2

File hashes

Hashes for django-strategy-field-3.1.0.tar.gz
Algorithm Hash digest
SHA256 a355aa9b944da488644cfb7a0c7e96a155ddf241c65adb22003789df02a1c030
MD5 b1a92ea61ca4d5f0379df40a895c7a6a
BLAKE2b-256 43cd146f06b2d823aba26d0a650ffa78f9a489ea26d0860e82816e781fcf09b5

See more details on using hashes here.

Supported by

AWS AWS Cloud computing and Security Sponsor Datadog Datadog Monitoring Fastly Fastly CDN Google Google Download Analytics Microsoft Microsoft PSF Sponsor Pingdom Pingdom Monitoring Sentry Sentry Error logging StatusPage StatusPage Status page