Webhook for IoT events in IOT Protocols - Interactive Code Practice

Practice - 5 Tasks

1fill in blank

easy

Complete the code to define the HTTP method used for the webhook.

IOT Protocols

webhook_config = {"method": "[1]", "url": "http://example.com/iot"}

Drag options to blanks, or click blank then click option'

AGET

BPUT

CPOST

DDELETE

Attempts:

3 left

💡 Hint

Common Mistakes

Using GET instead of POST

Using DELETE which removes data

The POST method is commonly used to send data to a webhook endpoint.

2fill in blank

medium

Complete the code to specify the content type header for JSON data.

IOT Protocols

headers = {"Content-Type": "[1]"}

Drag options to blanks, or click blank then click option'

Aapplication/json

Btext/plain

Capplication/xml

Dmultipart/form-data

Attempts:

3 left

💡 Hint

Common Mistakes

Using text/plain which is plain text

Using application/xml which is XML format

Webhooks sending IoT data usually use JSON format, so the content type is application/json.

3fill in blank

hard

Fix the error in the webhook URL by completing the missing protocol.

IOT Protocols

webhook_url = "[1]://iot.example.com/events"

Drag options to blanks, or click blank then click option'

Asmtp

Bhttp

Cftp

Dfile

Attempts:

3 left

💡 Hint

Common Mistakes

Using ftp which is for file transfer

Using smtp which is for email

The HTTP protocol is used for webhooks to send data over the web.

4fill in blank

hard

Fill both blanks to create a dictionary comprehension filtering IoT events with temperature above 25.

IOT Protocols

filtered_events = {device: data[1] for device, data in events.items() if data['temperature'] [2] 25}

Drag options to blanks, or click blank then click option'

A.copy()

B>

C<

D.items()

Attempts:

3 left

💡 Hint

Common Mistakes

Using < instead of >

Using .items() which returns key-value pairs

We copy the data dictionary for each device and filter where temperature is greater than 25.

5fill in blank

hard

Fill all three blanks to build a JSON payload with device ID, event type, and timestamp.

IOT Protocols

payload = {"device_id": [1], "event": [2], "timestamp": [3]

Drag options to blanks, or click blank then click option'

A"sensor_01"

B"temperature_reading"

Cint(time.time())

D"humidity_reading"

Attempts:

3 left

💡 Hint

Common Mistakes

Using humidity_reading instead of temperature_reading

Not converting time to int

The payload includes the device ID as a string, the event type as a string, and the current timestamp as an integer.

Practice

1. What is the main purpose of a webhook in IoT event handling?

easy

A. To automatically send event data to another service using HTTP POST

B. To store IoT data locally on the device

C. To manually request data from IoT devices

D. To encrypt IoT device firmware updates

Solution

1. Step 1: Understand webhook function

   A webhook sends data automatically when an event happens, without manual requests.

2. Step 2: Identify how webhooks send data

   They use HTTP POST requests to push JSON data to another service in real time.

3. Final Answer:

   To automatically send event data to another service using HTTP POST -> Option A

4. Quick Check:

   Webhook = automatic HTTP POST data send [OK]

Hint: Webhooks push data automatically via HTTP POST [OK]

Common Mistakes:

• Thinking webhooks store data locally
• Confusing webhooks with manual data requests
• Assuming webhooks handle encryption

2. Which HTTP method is typically used by webhooks to send IoT event data?

easy

A. GET

B. PUT

C. POST

D. DELETE

Solution

1. Step 1: Recall HTTP methods for data sending

   GET requests retrieve data, POST requests send data to a server.

2. Step 2: Identify webhook method

   Webhooks send event data, so they use POST to push JSON payloads.

3. Final Answer:

   POST -> Option C

4. Quick Check:

   Webhook HTTP method = POST [OK]

Hint: Webhooks send data with POST, not GET [OK]

Common Mistakes:

• Choosing GET which only retrieves data
• Confusing PUT with POST
• Using DELETE which removes data

3. Given this webhook payload snippet sent from an IoT device:

{"temperature": 22.5, "humidity": 60}

What is the expected content type header in the HTTP POST request?

medium

A. application/xml

B. text/plain

C. multipart/form-data

D. application/json

Solution

1. Step 1: Identify payload format

   The payload is JSON format with keys and values inside curly braces.

2. Step 2: Match content type header

   JSON data requires the header 'application/json' to inform the receiver.

3. Final Answer:

   application/json -> Option D

4. Quick Check:

   JSON payload uses application/json header [OK]

Hint: JSON payloads need application/json header [OK]

Common Mistakes:

• Choosing XML header for JSON data
• Using text/plain which is generic
• Selecting multipart/form-data which is for files

4. You set up a webhook URL for IoT events but receive a 404 error when the device sends data. What is the most likely cause?

medium

A. The webhook URL is incorrect or not reachable

B. The IoT device is offline

C. The device is sending data with GET instead of POST

D. The JSON payload is missing temperature data

Solution

1. Step 1: Understand 404 error meaning

   404 means the server could not find the requested URL or resource.

2. Step 2: Identify webhook URL issue

   If the webhook URL is wrong or unreachable, the server returns 404 when device sends data.

3. Final Answer:

   The webhook URL is incorrect or not reachable -> Option A

4. Quick Check:

   404 error = wrong or unreachable URL [OK]

Hint: 404 means URL not found or unreachable [OK]

Common Mistakes:

• Assuming device offline causes 404
• Confusing HTTP method errors with 404
• Thinking missing JSON fields cause 404

5. You want to trigger an alert in your app whenever an IoT device reports temperature above 30°C using a webhook. Which approach is best?

hard

A. Send all events to the webhook and filter temperature > 30°C in the app

B. Configure the IoT device to only send webhook events when temperature > 30°C

C. Use GET requests to poll the device temperature every minute

D. Send webhook events with XML payloads for better filtering

Solution

1. Step 1: Understand efficient event triggering

   Filtering on the device reduces unnecessary data sent and processing load.

2. Step 2: Compare options

   Configure the IoT device to only send webhook events when temperature > 30°C sends only relevant events, saving bandwidth and simplifying app logic.

3. Final Answer:

   Configure the IoT device to only send webhook events when temperature > 30°C -> Option B

4. Quick Check:

   Filter events at source for efficiency [OK]

Hint: Filter events on device to reduce data sent [OK]

Common Mistakes:

• Sending all data and filtering later wastes resources
• Using GET polling instead of webhooks
• Choosing XML which is less common for IoT webhooks