MycroftAI · MatthewScholefield · Jul 14, 2017 · Jun 16, 2017 · Jul 12, 2017 · Jul 14, 2017
diff --git a/mycroft/client/speech/main.py b/mycroft/client/speech/main.py
@@ -90,8 +90,8 @@ def mute_and_speak(utterance):
         lock.release()
 
 
-def handle_multi_utterance_intent_failure(event):
-    logger.info("Failed to find intent on multiple intents.")
+def handle_complete_intent_failure(event):
+    logger.info("Failed to find intent.")
     # TODO: Localize
     mute_and_speak("Sorry, I didn't catch that. Please rephrase your request.")
 
@@ -205,9 +205,7 @@ def main():
     loop.on('recognizer_loop:no_internet', handle_no_internet)
     ws.on('open', handle_open)
     ws.on('speak', handle_speak)
-    ws.on(
-        'multi_utterance_intent_failure',
-        handle_multi_utterance_intent_failure)
+    ws.on('complete_intent_failure', handle_complete_intent_failure)
     ws.on('recognizer_loop:sleep', handle_sleep)
     ws.on('recognizer_loop:wake_up', handle_wake_up)
     ws.on('mycroft.mic.mute', handle_mic_mute)

diff --git a/mycroft/skills/core.py b/mycroft/skills/core.py
@@ -14,12 +14,11 @@
 #
 # You should have received a copy of the GNU General Public License
 # along with Mycroft Core.  If not, see <http://www.gnu.org/licenses/>.
-
-
 import abc
 import imp
 import time
 
+import operator
 import os.path
 import re
 import time
@@ -383,3 +382,50 @@ def shutdown(self):
         self.emitter.emit(
             Message("detach_skill", {"skill_name": self.name + ":"}))
         self.stop()
+
+
+class FallbackSkill(MycroftSkill):
+    fallback_handlers = {}
+
+    def __init__(self, name, emitter=None):
+        MycroftSkill.__init__(self, name, emitter)
+
+    @classmethod
+    def make_intent_failure_handler(cls, ws):
+        """Goes through all fallback handlers until one returns true"""
+
+        def handler(message):
+            for _, handler in sorted(cls.fallback_handlers.items(),
+                                     key=operator.itemgetter(0)):
+                try:
+                    if handler(message):
+                        return
+                except Exception as e:
+                    logger.info('Exception in fallback: ' + str(e))
+            ws.emit(Message('complete_intent_failure'))
+            logger.warn('No fallback could handle intent.')
+
+        return handler
+
+    @classmethod
+    def register_fallback(cls, handler, priority):
+        """
+        Register a function to be called as a general info fallback
+        Fallback should receive message and return
+        a boolean (True if succeeded or False if failed)
+
+        Lower priority gets run first
+        0 for high priority 100 for low priority
+        """
+        while priority in cls.fallback_handlers:
+            priority += 1
+
+        cls.fallback_handlers[priority] = handler
+
+    @classmethod
+    def remove_fallback(cls, handler_to_del):
+        for priority, handler in cls.fallback_handlers.items():
+            if handler == handler_to_del:
+                del cls.fallback_handlers[priority]
+                return
+        logger.warn('Could not remove fallback!')
diff --git a/mycroft/skills/intent_service.py b/mycroft/skills/intent_service.py
@@ -63,16 +63,11 @@ def handle_utterance(self, message):
             reply = message.reply(
                 best_intent.get('intent_type'), best_intent)
             self.emitter.emit(reply)
-        elif len(utterances) == 1:
+        else:
             self.emitter.emit(Message("intent_failure", {
                 "utterance": utterances[0],
                 "lang": lang
             }))
-        else:
-            self.emitter.emit(Message("multi_utterance_intent_failure", {
-                "utterances": utterances,
-                "lang": lang
-            }))
 
     def handle_register_vocab(self, message):
         start_concept = message.data.get('start')

diff --git a/mycroft/skills/main.py b/mycroft/skills/main.py
@@ -30,7 +30,7 @@
 from mycroft.messagebus.client.ws import WebsocketClient
 from mycroft.messagebus.message import Message
 from mycroft.skills.core import load_skill, create_skill_descriptor, \
-    MainModule, SKILLS_DIR
+    MainModule, SKILLS_DIR, FallbackSkill
 from mycroft.skills.intent_service import IntentService
 from mycroft.util import connected
 from mycroft.util.log import getLogger
@@ -117,6 +117,8 @@ def _load_skills():
 
     check_connection()
 
+    ws.on('intent_failure', FallbackSkill.make_intent_failure_handler(ws))
+
     # Create skill_manager listener and invoke the first time
     ws.on('skill_manager', skills_manager)
     ws.on('mycroft.internet.connected', install_default_skills)