mirror of https://github.com/pallets/flask.git
67 lines
2.2 KiB
Python
67 lines
2.2 KiB
Python
# -*- coding: utf-8 -*-
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"""
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flask.signals
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~~~~~~~~~~~~~
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Implements signals based on blinker if available, otherwise
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falls silently back to a noop.
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:copyright: © 2010 by the Pallets team.
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:license: BSD, see LICENSE for more details.
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"""
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signals_available = False
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try:
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from blinker import Namespace
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signals_available = True
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except ImportError:
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class Namespace(object):
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def signal(self, name, doc=None):
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return _FakeSignal(name, doc)
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class _FakeSignal(object):
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"""If blinker is unavailable, create a fake class with the same
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interface that allows sending of signals but will fail with an
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error on anything else. Instead of doing anything on send, it
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will just ignore the arguments and do nothing instead.
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"""
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def __init__(self, name, doc=None):
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self.name = name
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self.__doc__ = doc
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def send(self, *args, **kwargs):
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pass
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def _fail(self, *args, **kwargs):
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raise RuntimeError(
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"Signalling support is unavailable because the blinker"
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" library is not installed."
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)
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connect = connect_via = connected_to = temporarily_connected_to = _fail
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disconnect = _fail
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has_receivers_for = receivers_for = _fail
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del _fail
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# The namespace for code signals. If you are not Flask code, do
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# not put signals in here. Create your own namespace instead.
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_signals = Namespace()
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# Core signals. For usage examples grep the source code or consult
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# the API documentation in docs/api.rst as well as docs/signals.rst
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template_rendered = _signals.signal("template-rendered")
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before_render_template = _signals.signal("before-render-template")
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request_started = _signals.signal("request-started")
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request_finished = _signals.signal("request-finished")
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request_tearing_down = _signals.signal("request-tearing-down")
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got_request_exception = _signals.signal("got-request-exception")
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appcontext_tearing_down = _signals.signal("appcontext-tearing-down")
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appcontext_pushed = _signals.signal("appcontext-pushed")
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appcontext_popped = _signals.signal("appcontext-popped")
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message_flashed = _signals.signal("message-flashed")
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