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71 lines
2.4 KiB
71 lines
2.4 KiB
from __future__ import absolute_import
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from pydispatch import dispatcher
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from scrapy.utils import signal as _signal
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class SignalManager(object):
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def __init__(self, sender=dispatcher.Anonymous):
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self.sender = sender
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def connect(self, receiver, signal, **kwargs):
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"""
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Connect a receiver function to a signal.
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The signal can be any object, although Scrapy comes with some
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predefined signals that are documented in the :ref:`topics-signals`
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section.
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:param receiver: the function to be connected
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:type receiver: callable
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:param signal: the signal to connect to
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:type signal: object
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"""
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kwargs.setdefault('sender', self.sender)
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return dispatcher.connect(receiver, signal, **kwargs)
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def disconnect(self, receiver, signal, **kwargs):
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"""
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Disconnect a receiver function from a signal. This has the
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opposite effect of the :meth:`connect` method, and the arguments
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are the same.
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"""
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kwargs.setdefault('sender', self.sender)
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return dispatcher.disconnect(receiver, signal, **kwargs)
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def send_catch_log(self, signal, **kwargs):
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"""
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Send a signal, catch exceptions and log them.
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The keyword arguments are passed to the signal handlers (connected
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through the :meth:`connect` method).
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"""
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kwargs.setdefault('sender', self.sender)
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return _signal.send_catch_log(signal, **kwargs)
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def send_catch_log_deferred(self, signal, **kwargs):
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"""
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Like :meth:`send_catch_log` but supports returning `deferreds`_ from
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signal handlers.
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Returns a Deferred that gets fired once all signal handlers
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deferreds were fired. Send a signal, catch exceptions and log them.
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The keyword arguments are passed to the signal handlers (connected
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through the :meth:`connect` method).
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.. _deferreds: https://twistedmatrix.com/documents/current/core/howto/defer.html
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"""
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kwargs.setdefault('sender', self.sender)
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return _signal.send_catch_log_deferred(signal, **kwargs)
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def disconnect_all(self, signal, **kwargs):
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"""
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Disconnect all receivers from the given signal.
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:param signal: the signal to disconnect from
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:type signal: object
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"""
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kwargs.setdefault('sender', self.sender)
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return _signal.disconnect_all(signal, **kwargs)
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