Remove arguments that pass before_start, before_stop, after_start, after_stop functions, instead use decorators.

Results in cleaner API.

sanic/sanic.py

@@ -20,6 +20,7 @@ from .static import register as static_register
 
 
 class Sanic:
+
     def __init__(self, name=None, router=None,
                  error_handler=None):
         # Only set up a default log handler if the
@@ -45,6 +46,10 @@ class Sanic:
         self.debug = None
         self.sock = None
         self.processes = None
+        self._before_start_callbacks = []
+        self._after_start_callbacks = []
+        self._before_stop_callbacks = []
+        self._after_stop_callbacks = []
 
         # Register alternative method names
         self.go_fast = self.run
@@ -53,6 +58,27 @@ class Sanic:
     # Registration
     # -------------------------------------------------------------------- #
 
+    # Decorator
+    def before_start(self, func):
+        """Decorates a function to be executed before the server starts accepting connections"""
+        self._before_start_callbacks.append(func)
+
+    # Decorator
+    def after_start(self, func):
+        """Decorates a function to be executed after the server starts accepting connections"""
+        self._after_start_callbacks.append(func)
+
+    # Decorator
+    def after_stop(self, func):
+        """Decorates a function to be executed when all requests are complete"""
+        self._after_stop_callbacks.append(func)
+
+    # Decorator
+    def before_stop(self, func):
+        """Decorates a function to be executed when a stop signal is received before it is respected"""
+        self._before_stop_callbacks.append(func)
+
+
     # Decorator
     def route(self, uri, methods=frozenset({'GET'}), host=None):
         """
@@ -367,8 +393,7 @@ class Sanic:
     # Execution
     # -------------------------------------------------------------------- #
 
-    def run(self, host="127.0.0.1", port=8000, debug=False, before_start=None,
-            after_start=None, before_stop=None, after_stop=None, ssl=None,
+    def run(self, host="127.0.0.1", port=8000, debug=False, ssl=None,
             sock=None, workers=1, loop=None, protocol=HttpProtocol,
             backlog=100, stop_event=None, register_sys_signals=True):
         """
@@ -378,14 +403,6 @@ class Sanic:
         :param host: Address to host on
         :param port: Port to host on
         :param debug: Enables debug output (slows server)
-        :param before_start: Functions to be executed before the server starts
-                             accepting connections
-        :param after_start: Functions to be executed after the server starts
-                            accepting connections
-        :param before_stop: Functions to be executed when a stop signal is
-                            received before it is respected
-        :param after_stop: Functions to be executed when all requests are
-                           complete
         :param ssl: SSLContext for SSL encryption of worker(s)
         :param sock: Socket for the server to accept connections from
         :param workers: Number of processes
@@ -397,12 +414,9 @@ class Sanic:
         :param protocol: Subclass of asyncio protocol class
         :return: Nothing
         """
-        server_settings = self._helper(
-            host=host, port=port, debug=debug, before_start=before_start,
-            after_start=after_start, before_stop=before_stop,
-            after_stop=after_stop, ssl=ssl, sock=sock, workers=workers,
-            loop=loop, protocol=protocol, backlog=backlog,
-            stop_event=stop_event, register_sys_signals=register_sys_signals)
+        server_settings = self._helper(host=host, port=port, debug=debug, ssl=ssl, sock=sock, workers=workers,
+                                       loop=loop, protocol=protocol, backlog=backlog, stop_event=stop_event,
+                                       register_sys_signals=register_sys_signals)
         try:
             if workers == 1:
                 serve(**server_settings)
@@ -417,20 +431,13 @@ class Sanic:
         """This kills the Sanic"""
         get_event_loop().stop()
 
-    async def create_server(self, host="127.0.0.1", port=8000, debug=False,
-                            before_start=None, after_start=None,
-                            before_stop=None, after_stop=None, ssl=None,
-                            sock=None, loop=None, protocol=HttpProtocol,
-                            backlog=100, stop_event=None):
+    async def create_server(self, host="127.0.0.1", port=8000, debug=False, ssl=None, sock=None, loop=None,
+                            protocol=HttpProtocol, backlog=100, stop_event=None):
         """
         Asynchronous version of `run`.
         """
-        server_settings = self._helper(
-            host=host, port=port, debug=debug, before_start=before_start,
-            after_start=after_start, before_stop=before_stop,
-            after_stop=after_stop, ssl=ssl, sock=sock, loop=loop,
-            protocol=protocol, backlog=backlog, stop_event=stop_event,
-            run_async=True)
+        server_settings = self._helper(host=host, port=port, debug=debug, ssl=ssl, sock=sock, loop=loop,
+                                       protocol=protocol, backlog=backlog, stop_event=stop_event, run_async=True)
 
         # Serve
         proto = "http"
@@ -440,11 +447,8 @@ class Sanic:
 
         return await serve(**server_settings)
 
-    def _helper(self, host="127.0.0.1", port=8000, debug=False,
-                before_start=None, after_start=None, before_stop=None,
-                after_stop=None, ssl=None, sock=None, workers=1, loop=None,
-                protocol=HttpProtocol, backlog=100, stop_event=None,
-                register_sys_signals=True, run_async=False):
+    def _helper(self, host="127.0.0.1", port=8000, debug=False, ssl=None, sock=None, workers=1, loop=None,
+                protocol=HttpProtocol, backlog=100, stop_event=None, register_sys_signals=True, run_async=False):
         """
         Helper function used by `run` and `create_server`.
         """
@@ -482,10 +486,10 @@ class Sanic:
         # -------------------------------------------- #
 
         for event_name, settings_name, args, reverse in (
-                ("before_server_start", "before_start", before_start, False),
-                ("after_server_start", "after_start", after_start, False),
-                ("before_server_stop", "before_stop", before_stop, True),
-                ("after_server_stop", "after_stop", after_stop, True),
+                ("before_server_start", "before_start", self._before_start_callbacks, False),
+                ("after_server_start", "after_start", self._after_start_callbacks, False),
+                ("before_server_stop", "before_stop", self._before_stop_callbacks, True),
+                ("after_server_stop", "after_stop", self._after_stop_callbacks, True),
         ):
             listeners = []
             for blueprint in self.blueprints.values():
@@ -493,7 +497,7 @@ class Sanic:
             if args:
                 if callable(args):
                     args = [args]
-                listeners += args
+                listeners.extend(args)
             if reverse:
                 listeners.reverse()
             # Prepend sanic to the arguments when listeners are triggered