--- /dev/null
+# -*- coding: utf-8 -*-
+"""
+ Implements signals based on blinker if available, otherwise
+ falls silently back to a noop. Shamelessly stolen from flask.signals:
+ https://github.com/mitsuhiko/flask/blob/master/flask/signals.py
+"""
+signals_available = False
+try:
+ from blinker import Namespace
+ signals_available = True
+except ImportError:
+ class Namespace(object):
+ def signal(self, name, doc=None):
+ return _FakeSignal(name, doc)
+
+ class _FakeSignal(object):
+ """If blinker is unavailable, create a fake class with the same
+ interface that allows sending of signals but will fail with an
+ error on anything else. Instead of doing anything on send, it
+ will just ignore the arguments and do nothing instead.
+ """
+
+ def __init__(self, name, doc=None):
+ self.name = name
+ self.__doc__ = doc
+ def _fail(self, *args, **kwargs):
+ raise RuntimeError('signalling support is unavailable '
+ 'because the blinker library is '
+ 'not installed.')
+ send = lambda *a, **kw: None
+ connect = disconnect = has_receivers_for = receivers_for = \
+ temporarily_connected_to = connected_to = _fail
+ del _fail
+
+# The namespace for code signals. If you are not oauthlib code, do
+# not put signals in here. Create your own namespace instead.
+_signals = Namespace()
+
+
+# Core signals.
+scope_changed = _signals.signal('scope-changed')