Example3

This example simulates a driver which snoops on the thermostat of the previous example, and if the temperature becomes too hot, it opens a window, and closes it when the temperature drops:

import asyncio, time

from indipydriver import (IPyServer, IPyDriver, Device,
                          TextVector, TextMember,
                          getProperties, setNumberVector
                         )

# Other vectors, members and events are available, this example only imports those used.

class WindowControl:
    "This is a simulation containing variables only"

    def __init__(self):
        "Set initial value of window"
        self.window = "Open"
        # window should be "Open" or 'Closed'
        self.update_time = time.time()
        # Set whenever a temperature update is requested

    def set_window(self, temperature):
        """Gets new temperature, sets window accordingly"""
        if temperature > 21:
            self.window = "Open"
        if temperature < 18:
            self.window = "Closed"
        self.update_time = time.time()


class WindowDriver(IPyDriver):

    """IPyDriver is subclassed here"""

    async def clientevent(self, event):
        """On receiving data from the client, this is called,
           Only a 'getProperties' is expected."""
        match event:
            case getProperties():
                await event.vector.send_defVector()

    async def hardware(self):
        "Update client with window status"

        # Send an initial getProperties to snoop on Thermostat
        # This is necessary to inform IPyServer that this driver
        # wants copies of data sent from the thermostat
        await self.send_getProperties(devicename="Thermostat",
                                      vectorname="temperaturevector")

        windowcontrol = self.driverdata["windowcontrol"]
        statusvector = self['Window']['windowstatus']
        while True:
            # every ten seconds send an update on window position
            await asyncio.sleep(10)
            now_time = time.time()
            if now_time - windowcontrol.update_time > 20.0:
                # No new temperature has been received for longer than 20 seconds
                # the thermostat could have been disconnected. Send another
                # getProperties just in case it is reconnected
                await self.send_getProperties(devicename="Thermostat",
                                              vectorname="temperaturevector")

            statusvector['status'] = windowcontrol.window
            # and transmit it to the client
            await statusvector.send_setVector(allvalues=False)
            # allvalues=False means that not all values will be sent, only
            # values that have changed, so this avoids unnecessary data
            # being transmitted


    async def snoopevent(self, event):
        """Handle receipt of an event from the Thermostat."""
        windowcontrol = self.driverdata["windowcontrol"]
        match event:
            case setNumberVector(devicename="Thermostat",
                                 vectorname="temperaturevector") if "temperature" in event:
                # A setNumberVector has been sent from the thermostat to the client
                # and this driver has received a copy, and so can read the temperature
                try:
                    temperature = self.indi_number_to_float(event["temperature"])
                except TypeError:
                    # ignore an incoming invalid number
                    return
                # this updates windowcontrol which opens or closes the widow
                # and also updates its update_time
                windowcontrol.set_window(temperature)


def make_driver():
    "Creates the driver"

    # create hardware object
    windowcontrol = WindowControl()

    status = TextMember( name="status",
                         label="Window position",
                         membervalue=windowcontrol.window )
    windowstatus = TextVector( name="windowstatus",
                               label="Window Status",
                               group="Values",
                               perm="ro",
                               state="Ok",
                               textmembers=[status] )

    # create a Device with these vectors
    window = Device( devicename="Window",
                     properties=[windowstatus] )

    # Create the WindowDriver (inherited from IPyDriver) containing this device
    windowdriver = WindowDriver( devices=[window],
                                 windowcontrol=windowcontrol )

    # and return the driver
    return windowdriver


# Assuming the thermostat example is example2.py, these would be run with

if __name__ == "__main__":

    import example2

    thermodriver = example2.make_driver()
    windowdriver = make_driver()

    server = IPyServer([thermodriver, windowdriver])
    asyncio.run(server.asyncrun())