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:
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')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
from strategy_field.fields import StrategyField
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()
registry.register(EmailStrategy)
registry.register(SMSStrategy)
class Event(models.Model):
sender = StrategyField(registry)
Event.objects.get_or_create(sender=EmailStrategy)
...
...
e = Event.objects.get(sender=EmailStrategy)
e.sender.send() # e.sender.context == e| Stable |  |
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| Development |  |
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| Project home page: | https://github.co | m/saxix/django- | strategy-field |
| Issue tracker: | https://github.co | m/saxix/django- | strategy-field/issues?sort |
| Download: | http://pypi.pytho | n.org/pypi/djan | go-strategy-field/ |