Advanced Usage

This section covers some more advanced features of askhome.

Reusing Appliance Details

If you’re creating a Smart Home Skill for devices from one manufacturer, you probably don’t want to repeat yourself when specifying the details when adding the device with Smarthome.add_appliance. You can set defaults to either Appliance or all devices in the Smarthome like this:

class Door(Appliance):
    class Details:
        model = 'QualityDoor'
        version = '2.0'

home = Smarthome(manufacturer='EvilCorp')
home.add_appliance('door1', Door, name='Front Door')
home.add_appliance('door2', Door, name='Back Door', version='1.0')

Resulting detail value is resolved in this order:

1. Smarthome.add_appliance keyword arguments
2. Appliance.Details inner class
3. Smarthome.__init__ keyword arguments

Smarthome Handlers

The simple skill described in Quick Start has a potential problem in that it needs to know all appliances user has on every request. For example, if you keep the data in a remote database, it’s wasteful to query for every appliance when switching one light on.

This problem can be solved by handling discovery and getting appliances for requests manually:

home = Smarthome()

@home.discover_handler
def discover(request):
    # Query the database here for all available appliances
    home.add_appliance('light1', Light, name='Kitchen Light',
                       additional_details={'type': 'Light'})
    return request.response(home)

@home.get_appliance_handler
def get_appliance(request):
    if request.appliance_details['type'] == 'Light':
        return Light

Here we’ve used the additional_details field the Smart Home API offers. You can save custom data in there during discovery and for every subsequent request you get that data back. This way, we query the database only once during discovery.

User Data

Often you will still need to query for some information about the user that sent the request. For that, there is another Smarthome decorator:

@home.prepare_handler
def prepare(request):
    # Query the database for ip address of the user
    ip = '1.2.3.4'
    request.custom_data = {'user_ip': ip}

The above prepare function gets called before every request is processed. We save our user data to Request.custom_data attribute, which we can use in any of our action methods.