50 lines
1.5 KiB
Python
50 lines
1.5 KiB
Python
from functools import partial
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from django.db.models.utils import make_model_tuple
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from django.dispatch import Signal
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class_prepared = Signal()
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class ModelSignal(Signal):
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"""
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Signal subclass that allows the sender to be lazily specified as a string
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of the `app_label.ModelName` form.
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"""
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def _lazy_method(self, method, apps, receiver, sender, **kwargs):
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from django.db.models.options import Options
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# This partial takes a single optional argument named "sender".
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partial_method = partial(method, receiver, **kwargs)
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if isinstance(sender, str):
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apps = apps or Options.default_apps
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apps.lazy_model_operation(partial_method, make_model_tuple(sender))
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else:
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return partial_method(sender)
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def connect(self, receiver, sender=None, weak=True, dispatch_uid=None, apps=None):
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self._lazy_method(
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super().connect, apps, receiver, sender,
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weak=weak, dispatch_uid=dispatch_uid,
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)
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def disconnect(self, receiver=None, sender=None, dispatch_uid=None, apps=None):
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return self._lazy_method(
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super().disconnect, apps, receiver, sender, dispatch_uid=dispatch_uid
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)
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pre_init = ModelSignal(use_caching=True)
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post_init = ModelSignal(use_caching=True)
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pre_save = ModelSignal(use_caching=True)
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post_save = ModelSignal(use_caching=True)
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pre_delete = ModelSignal(use_caching=True)
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post_delete = ModelSignal(use_caching=True)
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m2m_changed = ModelSignal(use_caching=True)
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pre_migrate = Signal()
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post_migrate = Signal()
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