Custom events in Firebase - Practice Problems & Coding Challenges

Challenge - 5 Problems

❓ service_behavior

intermediate

What happens when a Firebase custom event is logged without a required parameter?

You log a custom event in Firebase Analytics but omit a parameter marked as required in your app's event schema. What is the expected behavior?

Firebase

firebase.analytics().logEvent('purchase', {item_id: '12345'}); // missing 'value' parameter

A The event is logged successfully but the missing parameter is recorded as null.

B The event is rejected and not logged at all.

C The event is logged but flagged as invalid in the Firebase console.

D The event triggers an error in the client app and stops execution.

💡 Hint

Think about how Firebase Analytics handles optional and required parameters in custom events.

Firebase Analytics logs custom events even if some parameters are missing. Missing parameters are recorded as null or simply omitted, but the event itself is still logged.

❓ Configuration

intermediate

Which Firebase configuration is required to enable custom event tracking?

To track custom events in a Firebase app, which configuration step is mandatory?

A Add a custom event schema JSON file to the app source code.

B Enable Google Analytics in the Firebase project settings.

C Create a Cloud Function to listen for custom events.

D Set up a Firebase Realtime Database trigger for events.

💡 Hint

Consider what Firebase requires to collect and process analytics data.

Google Analytics must be enabled in the Firebase project to collect and view custom event data. Other options are unrelated to basic custom event tracking.

❓ Architecture

advanced

How to architect a Firebase system to react to custom events in real-time?

You want your Firebase app to perform actions immediately after a custom event is logged. Which architecture best supports this?

A Log events to Firestore and use Firestore triggers in Cloud Functions.

B Use Firebase Analytics to log events and Cloud Functions triggered by Analytics events.

C Send events to Firebase Realtime Database and poll for changes every minute.

D Use Firebase Hosting to serve a webhook endpoint that listens for events.

💡 Hint

Think about which Firebase services support real-time triggers on data changes.

Firebase Analytics events cannot directly trigger Cloud Functions. Logging events to Firestore allows Cloud Functions to react immediately to data changes via Firestore triggers.

❓ security

advanced

What is the best practice to secure custom event data sent from client apps?

To prevent malicious users from sending fake custom events to Firebase Analytics, what security measure should you implement?

A Validate event data on the client before sending and rely on Firebase security.

B Restrict event logging to authenticated users only.

C Encrypt event data in the client app before sending to Firebase Analytics.

D Use Firebase App Check to verify requests come from your authentic app instances.

💡 Hint

Consider Firebase's built-in tools to verify app integrity.

Firebase App Check helps ensure that only requests from your genuine app instances are accepted, reducing fake event submissions.

✅ Best Practice

expert

Which approach optimizes custom event naming and parameter usage for Firebase Analytics?

To maximize the usefulness and clarity of custom events in Firebase Analytics, which naming and parameter strategy is best?

A Create unique event names for every user action and avoid parameters to reduce complexity.

B Use event names with spaces and special characters for readability.

C Follow Firebase recommended event names and use typed parameters with clear names.

D Use short, generic event names and include all parameters as strings.

💡 Hint

Think about Firebase Analytics documentation recommendations for event design.

Firebase recommends using predefined event names when possible and using clear, typed parameters to improve analysis and reporting.