Fixed Application.on_loop_available signal #1739

CHANGES.rst

@@ -2,6 +2,11 @@ Changes
 =======
 
 
+2.0.2 (2017-03-21)
+------------------
+
+- Fixed Application.on_loop_available signal #1739
+
 - Remove debug code
 
 

aiohttp/__init__.py

@@ -1,4 +1,4 @@
-__version__ = '2.0.1'
+__version__ = '2.0.2'
 
 # This relies on each of the submodules having an __all__ variable.
 

aiohttp/signals.py

@@ -40,14 +40,36 @@ def send(self, *args, **kwargs):
         """
         Sends data to all registered receivers.
         """
-        ordinal = None
-        debug = self._app._debug
-        if debug:
-            ordinal = self._pre.ordinal()
-            yield from self._pre.send(ordinal, self._name, *args, **kwargs)
-        yield from self._send(*args, **kwargs)
-        if debug:
-            yield from self._post.send(ordinal, self._name, *args, **kwargs)
+        if self._items:
+            ordinal = None
+            debug = self._app._debug
+            if debug:
+                ordinal = self._pre.ordinal()
+                yield from self._pre.send(
+                    ordinal, self._name, *args, **kwargs)
+            yield from self._send(*args, **kwargs)
+            if debug:
+                yield from self._post.send(
+                    ordinal, self._name, *args, **kwargs)
+
+
+class FuncSignal(BaseSignal):
+    """Callback-based signal implementation.
+
+    To connect a callback to a signal, use any list method.
+
+    Signals are fired using the :meth:`send` method, which takes named
+    arguments.
+    """
+
+    __slots__ = ()
+
+    def send(self, *args, **kwargs):
+        """
+        Sends data to all registered receivers.
+        """
+        for receiver in self._items:
+            receiver(*args, **kwargs)
 
 
 class DebugSignal(BaseSignal):

aiohttp/web.py

@@ -17,7 +17,7 @@
 from .helpers import FrozenList
 from .http import HttpVersion  # noqa
 from .log import access_logger, web_logger
-from .signals import PostSignal, PreSignal, Signal
+from .signals import FuncSignal, PostSignal, PreSignal, Signal
 from .web_exceptions import *  # noqa
 from .web_fileresponse import *  # noqa
 from .web_middlewares import *  # noqa
@@ -67,7 +67,7 @@ def __init__(self, *, logger=web_logger, router=None, middlewares=(),
 
         self._on_pre_signal = PreSignal()
         self._on_post_signal = PostSignal()
-        self._on_loop_available = Signal(self)
+        self._on_loop_available = FuncSignal(self)
         self._on_response_prepare = Signal(self)
         self._on_startup = Signal(self)
         self._on_shutdown = Signal(self)
@@ -113,7 +113,7 @@ def _set_loop(self, loop):
                 "web.Application instance initialized with different loop")
 
         self._loop = loop
-        self._on_loop_available.send()
+        self._on_loop_available.send(self)
 
         # set loop debug
         if self._debug is ...:

tests/test_web_application.py

@@ -45,6 +45,16 @@ def test_set_loop_with_different_loops(loop):
         app._set_loop(loop=object())
 
 
+def test_on_loop_available(loop):
+    app = web.Application()
+
+    cb = mock.Mock()
+    app.on_loop_available.append(cb)
+
+    app._set_loop(loop)
+    cb.assert_called_with(app)
+
+
 @pytest.mark.parametrize('debug', [True, False])
 def test_app_make_handler_debug_exc(loop, mocker, debug):
     app = web.Application(debug=debug)