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Mistral Custom Actions ~ With Mixins (Usage)
import base
class MyCustomAction(base.Action):
def run(self):
return "I ran"
class MyAsyncAction(base.AsyncMixin, base.Action):
def run(self):
return "I have the is_sync method: %s" % hasattr(self, "is_sync")
class MyContextAction(base.ContextMixin, base.Action):
def run(self):
return "I have a context: %s" % self.context
# extensibiltiy scenario: an asynchronous action that requires a context
# note using this scenario differs from the base class scenario as it does not
# require you to redefine is_sync. Net result is cleaner extensibility with
# mixins.
class AsyncContextAction(base.ContextMixin, base.AsyncMixin, base.Action):
def run(self):
return "I have the is_sync method: %s and I have a context: %s" % (
hasattr(self, "is_sync"),
# basic custom action
a = MyCustomAction()
# asynchronous action
b = MyAsyncAction()
# current test in mistral for is_sync tests for is_sync.
# The new example remains backwards compatible.
is_sync = b.is_sync()
# alternate tests for the AsyncMixin
# 1) class inheritance. (Is-A)
# The following wouldn't require the presence of the is_sync method and could
# be tested against all actions, regardless of base type
is_sync = not isinstance(b, "AsyncMixin")
# 2) function existence
# this line tests for presence of the method and is likely considered more "pythonic"
# this would also make more sense if the method on the AsyncMixin was named "is_async"
is_sync = callable(getattr(b, 'is_sync', None))
# run to stay complete with the other examples
context = {"name": "someval"}
c = MyContextAction()
# Current actions in Mistral would be unharmed and backwards compatible
# we would simply add the following block to ensure new actions would
# get the context as needed
if isinstance(c, "ContextMixin"):
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Toure commented Mar 9, 2017

Are you relying on the user to provide the context or would oslo.context be used?

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