Removed links and added action cancellation

Author: jtc42

webthing/action.py

@@ -1,5 +1,6 @@
 """High-level Action base class implementation."""
 
+from copy import deepcopy
 import uuid
 import asyncio
 from .utils import timestamp
@@ -17,6 +18,8 @@ def __init__(self, thing, name, target, input_):
         name -- name of the action
         input_ -- any action inputs
         """
+        self._task = None
+
         self.id = uuid.uuid4().hex
         self.thing = thing
         self.name = name
@@ -102,23 +105,29 @@ async def start(self):
         self.thing.action_notify(self)
         # If the action function is async
         if asyncio.iscoroutinefunction(self.target_function):
-            # Await the action function
-            self.output = await self.target_function(self.input)
+            self._task = asyncio.ensure_future(self.target_function(self.input))
         # If the action function is not async
         else:
             # Run in the default ThreadPoolExecutor
-            self.output = await asyncio.get_event_loop().run_in_executor(
+            self._task = asyncio.get_event_loop().run_in_executor(
                 None, self.target_function, self.input
             )
-        self.finish()
+        self._task.add_done_callback(self.finish)
 
     def cancel(self):
-        # TODO: Implement coroutine cancellation
-        pass
+        if self._task:
+            self._task.cancel()
 
-    def finish(self):
+    def finish(self, future):
         """Finish performing the action."""
-        self.status = "completed"
+        try:
+            self.output = future.result()
+            self.status = "completed"
+        except asyncio.CancelledError:
+            self.status = "cancelled"
+        except Exception as e:
+            self.output = str(e)
+            self.status = "error"
         self.time_completed = timestamp()
         self.thing.action_notify(self)
 
@@ -137,6 +146,28 @@ def __init__(self, thing, name, invokeaction=None, metadata=None):
 
         self.queue = []
 
+    def as_action_description(self):
+        """
+        Get the action description.
+
+        Returns a dictionary describing the action.
+        """
+        description = deepcopy(self.metadata)
+
+        # Create forms
+        if "forms" not in description:
+            description["forms"] = []
+
+        description["forms"].append(
+            {
+                "op": "invokeaction",
+                "href": self.href_prefix + self.href,
+                "htv:methodName": "POST",
+            }
+        )
+
+        return description
+
     def invokeaction(self, input_):
         action_obj = ActionObject(
             self.thing, self.name, self.invokeaction_forwarder, input_

webthing/property.py

@@ -65,17 +65,6 @@ def as_property_description(self):
         if "readOnly" not in description and self.value.readonly:
             description["readOnly"] = True
 
-        # Create links
-        if "links" not in description:
-            description["links"] = []
-
-        description["links"].append(
-            {
-                "rel": "property",
-                "href": self.href_prefix + self.href,
-            }
-        )
-
         # Create forms
         if "forms" not in description:
             description["forms"] = []

webthing/server.py

@@ -436,7 +436,7 @@ async def get(self):
             self.set_status(404)
             return
 
-        await self.represent_response(self.thing.get_action_descriptions())
+        await self.represent_response(self.thing.get_action_object_descriptions())
 
     async def post(self):
         """
@@ -490,7 +490,7 @@ async def get(self, action_name=None):
             return
 
         await self.represent_response(
-            self.thing.get_action_descriptions(action_name=action_name)
+            self.thing.get_action_object_descriptions(action_name=action_name)
         )
 
     async def post(self, action_name=None):
@@ -541,21 +541,6 @@ async def get(self, action_name=None, action_id=None):
 
         await self.represent_response(action.as_action_description())
 
-    def put(self, action_name=None, action_id=None):
-        """
-        Handle a PUT request.
-
-        TODO: this is not yet defined in the spec
-
-        action_name -- name of the action from the URL path
-        action_id -- the action ID from the URL path
-        """
-        if self.thing is None:
-            self.set_status(404)
-            return
-
-        self.set_status(200)
-
     def delete(self, action_name=None, action_id=None):
         """
         Handle a DELETE request.

webthing/thing.py

@@ -48,7 +48,7 @@ def as_thing_description(self):
             "title": self.title,
             "@context": self.context,
             "properties": self.get_property_descriptions(),
-            "actions": {},
+            "actions": self.get_action_descriptions(),
             "events": {},
             "links": [
                 {
@@ -66,15 +66,6 @@ def as_thing_description(self):
             ],
         }
 
-        for name, action in self.actions.items():
-            thing["actions"][name] = action.metadata
-            thing["actions"][name]["links"] = [
-                {
-                    "rel": "action",
-                    "href": "{}/actions/{}".format(self.href_prefix, name),
-                },
-            ]
-
         for name, event in self.available_events.items():
             thing["events"][name] = event["metadata"]
             thing["events"][name]["links"] = [
@@ -183,7 +174,15 @@ def get_property_descriptions(self):
         """
         return {k: v.as_property_description() for k, v in self.properties.items()}
 
-    def get_action_descriptions(self, action_name=None):
+    def get_action_descriptions(self):
+        """
+        Get the thing's available actions as a dictionary.
+
+        Returns the actions as a dictionary, i.e. name -> description.
+        """
+        return {k: v.as_action_description() for k, v in self.actions.items()}
+
+    def get_action_object_descriptions(self, action_name=None):
         """
         Get the thing's action objects as an array.