Added ShadowClearState and adjusted Shadow sample

awsiot/iotshadow.py

@@ -1277,9 +1277,11 @@ def from_payload(cls, payload):
         val = payload.get('desired')
         if val is not None:
             new.desired = val
+
         val = payload.get('reported')
         if val is not None:
             new.reported = val
+
         return new
 
 class ShadowState(awsiot.ModeledClass):
@@ -1329,6 +1331,47 @@ def to_payload(self):
             payload['reported'] = self.reported
         return payload
 
+class ShadowClearState(awsiot.ModeledClass):
+    """
+
+    (Potentially partial) clear state of an AWS IoT thing's shadow.
+
+    Used to clear all of the desired and/or reported state properties of an AWS IoT thing's shadow.
+    All attributes are None by default and may be set by keyword in the constructor.
+
+    Keyword Args:
+        clear_desired (bool): Whether to clear the desired shadow state (defaults to false)
+        clear_reported (bool): Whether to clear the reported shadow state (defaults to false)
+
+    Attributes:
+        clear_desired (bool): Whether to clear the desired shadow state (defaults to false)
+        clear_reported (bool): Whether to clear the reported shadow state (defaults to false)
+    """
+
+    __slots__ = ['clear_desired', 'clear_reported']
+
+    def __init__(self, *args, **kwargs):
+        self.clear_desired = kwargs.get('clear_desired')
+        self.clear_reported = kwargs.get('clear_reported')
+
+    @classmethod
+    def from_payload(cls, payload):
+        # type: (typing.Dict[str, typing.Any]) -> ShadowState
+        new = cls()
+        # nothing to do here - shouldn't occur
+        return new
+
+    def to_payload(self):
+        # type: () -> typing.Dict[str, typing.Any]
+        payload = {} # type: typing.Dict[str, typing.Any]
+        if self.clear_desired is not None:
+            if self.clear_desired == True:
+                payload['desired'] = None
+        if self.clear_reported is not None:
+            if self.clear_reported == True:
+                payload['reported'] = None
+        return payload
+
 class ShadowStateWithDelta(awsiot.ModeledClass):
     """
 

samples/shadow.py

@@ -192,7 +192,10 @@ def on_update_shadow_accepted(response):
                 return
 
         try:
-            print("Finished updating reported shadow value to '{}'.".format(response.state.reported[shadow_property])) # type: ignore
+            if (response.state.reported != None):
+                print("Finished updating reported shadow value to '{}'.".format(response.state.reported[shadow_property])) # type: ignore
+            else:
+                print ("Shadow states cleared.")
             print("Enter desired value: ") # remind user they can input new values
         except:
             exit("Updated shadow is missing the target property.")
@@ -238,14 +241,31 @@ def change_shadow_value(value):
         # any "response" messages received on the /accepted and /rejected topics
         token = str(uuid4())
 
-        request = iotshadow.UpdateShadowRequest(
-            thing_name=thing_name,
-            state=iotshadow.ShadowState(
-                reported={ shadow_property: value },
-                desired={ shadow_property: value },
-            ),
-            client_token=token,
-        )
+        # if the value is "clear_shadow" then send a ShadowClearState to clear the shadow state document
+        if (value == "clear_shadow"):
+            request = iotshadow.UpdateShadowRequest(
+                thing_name=thing_name,
+                state=iotshadow.ShadowClearState(
+                    clear_reported=True,
+                    clear_desired=True
+                ),
+                client_token=token,
+            )
+        # otherwise, send a ShadowState to update the shadow state document
+        else:
+            # if the user types none, then clear the property by setting the value to a None type
+            if (value == "none"):
+                value = None
+
+            request = iotshadow.UpdateShadowRequest(
+                thing_name=thing_name,
+                state=iotshadow.ShadowState(
+                    reported={ shadow_property: value},
+                    desired={ shadow_property: value},
+                ),
+                client_token=token,
+            )
+
         future = shadow_client.publish_update_shadow(request, mqtt.QoS.AT_LEAST_ONCE)
 
         locked_data.request_tokens.add(token)