Better asyncio handling in Python <3.7 using threading (#364)

apprise/py3compat/asyncio.py

@@ -72,11 +72,20 @@ def notify(coroutines, debug=False):
 
     else:
         #
-        # The depricated way
+        # The Deprecated Way (<= Python v3.6)
         #
 
-        # acquire access to our event loop
-        loop = asyncio.get_event_loop()
+        try:
+            # acquire access to our event loop
+            loop = asyncio.get_event_loop()
+
+        except RuntimeError:
+            # This happens if we're inside a thread of another application
+            # where there is no running event_loop().  Pythong v3.7 and higher
+            # automatically take care of this case for us.  But for the lower
+            # versions we need to do the following:
+            loop = asyncio.new_event_loop()
+            asyncio.set_event_loop(loop)
 
         if debug:
             # Enable debug mode

test/test_asyncio.py

@@ -0,0 +1,108 @@
+# -*- coding: utf-8 -*-
+#
+# Copyright (C) 2021 Chris Caron <lead2gold@gmail.com>
+# All rights reserved.
+#
+# This code is licensed under the MIT License.
+#
+# Permission is hereby granted, free of charge, to any person obtaining a copy
+# of this software and associated documentation files(the "Software"), to deal
+# in the Software without restriction, including without limitation the rights
+# to use, copy, modify, merge, publish, distribute, sublicense, and / or sell
+# copies of the Software, and to permit persons to whom the Software is
+# furnished to do so, subject to the following conditions :
+#
+# The above copyright notice and this permission notice shall be included in
+# all copies or substantial portions of the Software.
+#
+# THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND, EXPRESS OR
+# IMPLIED, INCLUDING BUT NOT LIMITED TO THE WARRANTIES OF MERCHANTABILITY,
+# FITNESS FOR A PARTICULAR PURPOSE AND NONINFRINGEMENT.IN NO EVENT SHALL THE
+# AUTHORS OR COPYRIGHT HOLDERS BE LIABLE FOR ANY CLAIM, DAMAGES OR OTHER
+# LIABILITY, WHETHER IN AN ACTION OF CONTRACT, TORT OR OTHERWISE, ARISING FROM,
+# OUT OF OR IN CONNECTION WITH THE SOFTWARE OR THE USE OR OTHER DEALINGS IN
+# THE SOFTWARE.
+
+from __future__ import print_function
+import sys
+import pytest
+from apprise import Apprise
+from apprise import NotifyBase
+from apprise import NotifyFormat
+
+from apprise.plugins import SCHEMA_MAP
+
+# Disable logging for a cleaner testing output
+import logging
+logging.disable(logging.CRITICAL)
+
+
+@pytest.mark.skipif(sys.version_info.major <= 2 or sys.version_info >= (3, 7),
+                    reason="Requires Python 3.0 to 3.6")
+def test_apprise_asyncio_runtime_error():
+    """
+    API: Apprise() AsyncIO RuntimeError handling
+
+    """
+    class GoodNotification(NotifyBase):
+        def __init__(self, **kwargs):
+            super(GoodNotification, self).__init__(
+                notify_format=NotifyFormat.HTML, **kwargs)
+
+        def url(self):
+            # Support URL
+            return ''
+
+        def send(self, **kwargs):
+            # Pretend everything is okay
+            return True
+
+        @staticmethod
+        def parse_url(url, *args, **kwargs):
+            # always parseable
+            return NotifyBase.parse_url(url, verify_host=False)
+
+    # Store our good notification in our schema map
+    SCHEMA_MAP['good'] = GoodNotification
+
+    # Create ourselves an Apprise object
+    a = Apprise()
+
+    # Add a few entries
+    for _ in range(25):
+        a.add('good://')
+
+    # Python v3.6 and lower can't handle situations gracefully when an
+    # event_loop isn't already established(). Test that Apprise can handle
+    # these situations
+    import asyncio
+
+    # Get our event loop
+    loop = asyncio.get_event_loop()
+
+    # Adjust out event loop to not point at anything
+    asyncio.set_event_loop(None)
+
+    # With the event loop inactive, we'll fail trying to get the active loop
+    with pytest.raises(RuntimeError):
+        asyncio.get_event_loop()
+
+    try:
+        # Below, we internally will throw a RuntimeError() since there will
+        # be no active event_loop in place. However internally it will be smart
+        # enough to create a new event loop and continue...
+        assert a.notify(title="title", body="body") is True
+
+        # Verify we have an active event loop
+        new_loop = asyncio.get_event_loop()
+
+        # We didn't throw an exception above; thus we have an event loop at
+        # this point
+        assert new_loop
+
+        # Close off the internal loop created inside a.notify()
+        new_loop.close()
+
+    finally:
+        # Restore our event loop (in the event the above test failed)
+        asyncio.set_event_loop(loop)