Create a Function to Automate the Process

1. Add two new properties to the Thing.

   
   
   Figure 1.

2. Change to the Functions section to create your function.

   
   
   Figure 2.

Functions are divided into two main parts, called Workers and Triggers.

A Worker is the Function itself. It allows to create its custom-base function and enables to subscribe to an “Event Trigger”.

3. Create the function itself (worker) using the following code. Complete the PATH with your own values.
   Note: Add your thing’s Client ID and Secret ID from the Interface tab inside the Thing.

   import time
   import requests
   import json
   
   API_HOST = 'https://api.swx.altairone.com'
   PATH = "/spaces/YourSpaceID/collections/YourCollectionName/things/YpurThingUID/properties/lamp-state"
   CLIENT_ID = "EnterYourValues"
   CLIENT_SECRET = "EnterYourValues"
   
   def get_access_token():
       payload = f'grant_type=client_credentials&' \
                 f'client_id={CLIENT_ID}&' \
                 f'client_secret={CLIENT_SECRET}&' \
                 f'scope=thing.read thing.update'
   
       headers = {'Content-Type': 'application/x-www-form-urlencoded'}
       response = requests.request("POST", API_HOST + "/oauth2/token",
                                   headers=headers, data=payload)
   
       return response.json()['access_token']
       
   def revoke_token(token):
       payload = f'token={token}&' \
                 f'client_id={CLIENT_ID}&' \
                 f'client_secret={CLIENT_SECRET}' 
                 
   
       headers = {'Content-Type': 'application/x-www-form-urlencoded'}
       response = requests.request("POST", API_HOST + "/oauth2/revoke",
                                   headers=headers, data=payload)
      
       return response
       
   def handle(req):
       body = req.body.decode("utf-8")
       body = json.loads(body)
       temperature = body['temperature']
       token=get_access_token()
       if temperature >= 70:
           state = "Warning"
       else:
           state = "Normal"
   
       headers = {"Authorization": "Bearer " + token}
       response = requests.request("PUT", API_HOST + PATH, headers=headers,
                           json={"lamp-state": state})
       
       revoke_token(token)
       return {
       	"body": response.json(),
       	"status_code": response.status_code
       }

4. Add the following event trigger:

   status/yourspaceID/collections/yourcollectionname/things/yourthingUID/properties/temperature

   
   
   Figure 3.

A Trigger is a component that is capable of invoking serverless Functions from an event source. Triggers work as a listener to a particular endpoint, capturing events and messages from different sources and redirecting them to one or more Functions.

5. Create a MQTT trigger to subscribe to the topic entered as Event Trigger in the worker.

   
   
   Figure 4.

   Note: MQTT credentials can be obtained as shown below:

   
   
   Figure 5.

6. Open the MQTT Inspector to track the messages received:

   
   
   Figure 6.

7. Check that the function works as expected:

   
   
   Figure 7.