Merge pull request #18 from jek/feature/send-asyncmaster

Adds Signal.send_async for asyncio

Author: @jek

3 files changed, 44 insertions, 0 deletions

diff --git a/blinker/__init__.py b/blinker/__init__.py
index 57e1be8..a3251bd 100644
--- a/blinker/__init__.py
+++ b/blinker/__init__.py
@@ -20,3 +20,8 @@ __all__ = [
 
 
 __version__ = '1.5dev'
+
+try:
+    import blinker._async
+except (ImportError, SyntaxError):
+    pass
diff --git a/blinker/_async.py b/blinker/_async.py
new file mode 100644
index 0000000..2b530e4
--- /dev/null
+++ b/blinker/_async.py
@@ -0,0 +1,28 @@
+import asyncio
+
+from blinker.base import Signal
+
+
+try:
+    schedule = asyncio.create_task
+except AttributeError:
+    schedule = asyncio.ensure_future
+
+
+@asyncio.coroutine
+def _wrap_plain_value(value):
+    """Pass through a coroutine *value* or wrap a plain value."""
+    if asyncio.iscoroutine(value):
+        value = yield from value
+    return value
+
+
+def send_async(self, *sender, **kwargs):
+    return [(receiver, schedule(_wrap_plain_value(value)))
+            for receiver, value
+            in self.send(*sender, **kwargs)]
+
+
+send_async.__doc__ = Signal.send_async.__doc__
+Signal.send_async = send_async
+
diff --git a/blinker/base.py b/blinker/base.py
index b68d8db..a2f22aa 100644
--- a/blinker/base.py
+++ b/blinker/base.py
@@ -271,6 +271,17 @@ class Signal(object):
         return [(receiver, receiver(sender, **kwargs))
                 for receiver in self.receivers_for(sender)]
 
+    def send_async(self, *sender, **kwargs):
+        """Send and collect results from connected functions and coroutines.
+
+        As `Signal.send`, but also schedules any coroutines connected to the
+        signal, and uniformly presents all receiver return values as futures,
+        even if one or more receivers are regular functions.
+
+        Available only if asyncio and `yield from` are present.
+        """
+        raise NotImplementedError("asyncio support unavailable")
+
     def has_receivers_for(self, sender):
         """True if there is probably a receiver for *sender*.