Message bus AttributeError

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1

I created a simple notification skill following the guidelines here. Below is my source code:

from mycroft import MycroftSkill

class WakeWordDetector(MycroftSkill):
    def __init__(self):
        MycroftSkill.__init__(self)
        self.add_event('recognizer_loop:wakeword', self.handle_recognizer_wakeword)

    def handle_recognizer_wakeword(self):
        self.log.info('Wake word detected!')

def create_skill():
    return WakeWordDetector()

When I load this skill, the error below is produced.

Traceback (most recent call last):
File “/home/pi/Project/mycroft-core/mycroft/skills/skill_loader.py”, line 292, in _create_skill_instance
self.instance = skill_module.create_skill()
File “/opt/mycroft/skills/wake-word-detector-skill/init.py”, line 62, in create_skill
return WakeWordDetector()
File “/opt/mycroft/skills/wake-word-detector-skill/init.py”, line 8, in init
self.add_event(‘recognizer_loop:wakeword’, self.handle_recognizer_wakeword)
File “/home/pi/Project/mycroft-core/mycroft/skills/mycroft_skill/mycroft_skill.py”, line 946, in add_event
return self.events.add(name, wrapper, once)
File “/home/pi/Project/mycroft-core/mycroft/skills/mycroft_skill/event_container.py”, line 150, in add
self.bus.on(name, handler)
AttributeError: ‘NoneType’ object has no attribute ‘on’

It seems like it is having difficulty resolveing self.bus.

Does anyone know what the issue is? Thanks in advance!

2

Hey there,

I’d suggest moving the event handler registration to the initialize() method which is called after the Skill class is fully constructed. There’s some detail on the difference here:

Your handler will also receive a message object when it’s called so you need to add at least an optional argument to your handler signature, eg:

class WakeWordDetector(MycroftSkill):
    def __init__(self):
        MycroftSkill.__init__(self)

    def initialize(self):
        self.add_event('recognizer_loop:wakeword', self.handle_recognizer_wakeword)

    def handle_recognizer_wakeword(self, message):
        self.log.info('Wake word detected!')

def create_skill():
    return WakeWordDetector()

That should then log your message when the wake word is detected.

1 Like
3

Thank you so much for the help! Forgot that during __init__ the message bus isn’t available yet.

1 Like