Topic-based messaging in Firebase - Interactive Code Practice

Practice - 5 Tasks

1fill in blank

easy

Complete the code to subscribe a device to a topic.

Firebase

firebase.messaging().subscribeToTopic(token, [1]);

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

AtopicName

Btoken

C'news'

D'user123'

Attempts:

3 left

💡 Hint

Common Mistakes

Passing the token instead of the topic name.

Not using quotes around the topic name.

The subscribeToTopic method requires the topic name as a string. Here, 'news' is the topic.

2fill in blank

medium

Complete the code to send a message to a topic.

Firebase

admin.messaging().send({ topic: [1], notification: { title: 'Hello', body: 'World' } });

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

A'news'

Btoken

C'user123'

D'deviceToken'

Attempts:

3 left

💡 Hint

Common Mistakes

Using a device token instead of a topic name.

Omitting quotes around the topic name.

The topic field must be the topic name string, such as 'news', to send messages to all subscribers.

3fill in blank

hard

Fix the error in the code to unsubscribe from a topic.

Firebase

firebase.messaging().[1](token, 'news');

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

AsubscribeToTopic

BunsubscribeFromTopic

CsendToTopic

DsendMessage

Attempts:

3 left

💡 Hint

Common Mistakes

Using subscribeToTopic instead of unsubscribeFromTopic.

Using sendToTopic which is for sending messages.

To unsubscribe a device from a topic, use unsubscribeFromTopic method.

4fill in blank

hard

Fill both blanks to create a message payload for topic messaging with a data payload.

Firebase

const message = { topic: [1], data: { [2]: 'value' } };

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

A'sports'

B'score'

C'news'

D'title'

Attempts:

3 left

💡 Hint

Common Mistakes

Using a data key that is not a string.

Mixing topic and data keys.

The topic is set to 'sports' and the data key is 'score' with a value.

5fill in blank

hard

Fill all three blanks to send a notification message with a topic and a condition.

Firebase

const message = { [1]: 'weather', notification: { [2]: 'Alert', [3]: 'Rain expected' }, condition: "'weather' in topics || 'news' in topics" };

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

Atopic

Btitle

Cbody

Ddata

Attempts:

3 left

💡 Hint

Common Mistakes

Using 'data' instead of 'topic' for the topic key.

Mixing up title and body keys.

The message uses topic to specify the topic, and title and body for notification content.