Coding an UbiFunction

Runtimes

UbiFunctions accept NodeJS or Python, which means you can use these languages to write the required logic to extract, transform, and analyze data.

Entrypoint

Regardless of the chosen runtime, the UbiFunction must define a main function. This function serves as the entrypoint, meaning it is the first function called when a request is made to the UbiFunction.

UbiFunction arguments

UbiFunctions require a JSON payload to be sent in the body of the HTTP request. This payload is passed to the main function as a dictionary object named args. The args object contains all the parameters sent in the request, making them accessible within your function for further usage.

For UbiFunctions configured with the GET method, the args object instead contains the query parameters passed in the URL.

Additionally, when an X-Auth-Token header is included in the request, its value is automatically injected into args as args["token"], regardless of whether the request is made via GET or POST.

NodeJS

async function main(args) {
  var ubidots_token = args?.token;
  var device_label = args.device;
}

Python

def main(args):
    token = args.get('token', None)
    device = args.get('device', None)

Object	Description
args	Any payload sent to the function will be contained by the args object.
args.token	When an x-auth-token header is included in an HTTP invokation request, the args.token key will be included.

Behavior of the `args` object according to HTTP methods

GET

GET /prv/your_user/function_name?device=my_device&limit=10 HTTP/1.1
Host: parse.ubidots.com
X-Auth-Token: BBUS-abcdef0987654321

// Args within the UbiFunction
{
   "device": "my_device",
   "limit": "10",
   "token": "BBUS-abcdef0987654321\
}

POST

POST /prv/your_user/function_name HTTP/1.1
Host: parse.ubidots.com
Content-Type: application/json
X-Auth-Token: BBFF-1234567890abcdef

{
  "temperature": 22.5,
  "location": "lab"
}


// Args within the UbiFunction
//{
//  "temperature": 22.5,
//  "location": "lab",
//  "token": "BBFF-1234567890abcdef"
//}

Code

By default, every new UbiFunction has a sample code that uses input data (token, device, and a variable value) to make a request to Ubidots API. Here are the default examples for your reference:

NodeJS

const axios = require('axios');

// Main function - runs every time the function is executed.
// "args" is a dictionary containing both the URL params and the HTTP body (for POST requests).
async function main(args) {

  // Grab the token and device label from URL parameters, then erase them from the args dictionary
  var ubidots_token = args.token;
  var device_label = args.device;
  delete args['token'];
  delete args['device'];

  // Use the remaining parameters as payload
  var payload = args;

  // Log the payload to the console, for debugging purposes. You may access the function's logs using
  // the option in the above header.
  console.log(payload);

  // Send the payload to Ubidots
  var response = await ubidots_request(ubidots_token, device_label, payload);

  // Log Ubidots response to the console
  console.log(response);

  // Pass Ubidots' API response as the function's reponse
  return response;
}

// This function builds an HTTP POST request to Ubidots
async function ubidots_request(token, label, body) {
  let config = {
    method: 'post',
    url: 'https://industrial.api.ubidots.com/api/v1.6/devices/' + label,
    data: body,
    headers: {
      'Content-Type': 'application/json',
      'X-Auth-Token': token
    }
  }
  const response = await axios.request(config);
  return response.data;
}

Python

import requests
import time

BASE_URL = "https://industrial.api.ubidots.com"

REQUESTS_FUNCTIONS = {"get": requests.get, "post": requests.post}

def main(args):
    '''
    Main function - runs every time the function is executed.
    "args" is a dictionary containing both the URL params and the HTTP body (for POST requests).
    '''
    token = args.get('token', None)
    device = args.get('device', None)

    if token is None or device is None:
        print("[ERROR] Please send your Ubidots Token and device label to update in your args")
        return {"status": "error"}
    
    del args['token']
    del args['device']

    # Log the payload to the console, for debugging purposes. You may access the function's logs using
    # the option in the above header.

    print("[INFO] Payload to send: {}".format(args))

    # Use the remaining parameters as payload
    req = update_device(device, args, token)

    # Prints the request result

    print("[INFO] Request result:")
    print(req.text)

    return {"status": "Ok", "result": req.json()}

def update_device(device, payload, token):
    """
    updates a variable with a single dot
    """

    url = "{}/api/v1.6/devices/{}".format(BASE_URL, device)
    headers = {"X-Auth-Token": token, "Content-Type": "application/json"}

    req = create_request(url, headers, payload, attempts=5, request_type="post")
    
    return req

def create_request(url, headers, data, attempts, request_type):
    """
    Function to create a request to the server
    """

    request_func = REQUESTS_FUNCTIONS.get(request_type)

    kwargs = {"url": url, "headers": headers}

    if request_type == "post":
        kwargs["json"] = data

    try:
        req = request_func(**kwargs)
        print("[INFO] Request result: {}".format(req.text))
        status_code = req.status_code
        time.sleep(1)

        while status_code >= 400 and attempts < 5:
            req = request_func(**kwargs)
            print("[INFO] Request result: {}".format(req.text))
            status_code = req.status_code
            attempts += 1
            time.sleep(1)

        return req
    except Exception as e:
        print("[ERROR] There was an error with the request, details:")
        print(e)
        return None

Output Response

The output of an UbiFunction must be a JSON object. By default, the status code will be 200, but this could be changed using Raw Functions.

NodeJS

function main(args) {
    return {'temperature' : 56}
}

Python

def main():
    return {'temperature' : 56}