Working with Device Status

Subscribing to Device Status

subscribeToDeviceStatus() allows the application to recieve real-time notification when devices connect and disconnect from the service. With no parameters provided the method would subscribe to notifications for all devies. Use the typeId and deviceId parameters to control the scope of the subscription. A single client can support multiple subscriptions.

import wiotp.sdk.application

options = wiotp.sdk.application.parseConfigFile("app.conf")
client = wiotp.sdk.application.ApplicationClient(options)

client.connect()

# Subscribing to status updates for all devices
client.subscribeToDeviceStatus()

# Subscribing to status updates for all devices of a specific type
client.subscribeToDeviceStatus(typeId=myDeviceType)

# Subscribing to status updates for two different devices
client.subscribeToDeviceStatus(typeId=myDeviceType, deviceId=myDeviceId)
client.subscribeToDeviceStatus(typeId=myOtherDeviceType, deviceId=myOtherDeviceId)

Handling Device Status

To process the status updates that are received by your subscriptions, you need to register an event callback method. The messages are returned as an instance of the Status class. There are two types of status events, Connect events and Disconnect events. All status events include the following properties:

• clientAddr
• protocol
• clientId
• user
• time
• action
• connectTime
• port

The action property determines whether a status event is of type Connect or Disconnect. Disconnect status events include the following additional properties:

• writeMsg
• readMsg
• reason
• readBytes
• writeBytes

import wiotp.sdk.application

options = wiotp.sdk.application.ParseConfigFile(configFilePath)
client = wiotp.sdk.application.ApplicationClient(options)

def myStatusCallback(status):

  if status.action == "Disconnect":
    str = "%s - device %s - %s (%s)"
    print(str % (status.time.isoformat(), status.device, status.action, status.reason))
    else:
      print("%s - %s - %s" % (status.time.isoformat(), status.device, status.action))

client.connect()
client.deviceStatusCallback = myStatusCallback
client.subscribeToDeviceStstus()