Custom events in Firebase - Cheat Sheet & Quick Revision

Recall & Review

beginner

What is a custom event in Firebase Analytics?

A custom event is a user-defined action that you can log to track specific behaviors or interactions in your app that are not covered by default events.

beginner

How do you log a custom event in Firebase Analytics?

You use the logEvent method with a unique event name and optional parameters to send data about the event to Firebase Analytics.

intermediate

Why should custom event names be descriptive and consistent?

Descriptive and consistent names help you easily understand and analyze the events later in reports, making data clearer and more useful.

intermediate

What is the maximum number of custom event names you can register in Firebase Analytics?

Firebase Analytics allows up to 500 unique event names per project, including both default and custom events.

beginner

Can custom events include parameters? If yes, why?

Yes, custom events can include parameters to provide more details about the event, such as item names, categories, or values, which helps in deeper analysis.

What method is used to send a custom event in Firebase Analytics?

A trackEvent

B sendEvent

C logEvent

D createEvent

The logEvent method is the correct way to send custom events in Firebase Analytics.

How many unique event names can Firebase Analytics handle per project?

A Unlimited

B 100

C 1000

D 500

Firebase Analytics supports up to 500 unique event names per project.

Why add parameters to custom events?

A To provide extra details about the event

B To increase event count

C To reduce data usage

D To change event names

Parameters add extra details to events, helping with better analysis.

Which of these is a good practice for naming custom events?

A Use random numbers

B Use descriptive and consistent names

C Use very long names

D Use special characters

Descriptive and consistent names make event data easier to understand.

Custom events in Firebase Analytics are used to:

A Track specific user actions not covered by default events

B Track default app crashes

C Send push notifications

D Manage user authentication

Custom events track user actions that default events do not cover.

Explain what a custom event is in Firebase Analytics and why you might use one.

Think about how you track special actions users take in your app.

Describe how to properly name and use parameters with custom events for better analytics.

Consider how clear names and extra details help you understand user behavior.

Practice

1. What is the main purpose of custom events in Firebase Analytics?

easy

A. To replace default events with simpler ones

B. To automatically collect user location data

C. To track specific user actions not covered by default events

D. To send notifications to users

Solution

1. Step 1: Understand default vs custom events

   Default events cover common actions, but some user actions need custom tracking.

2. Step 2: Identify the role of custom events

   Custom events let you track specific actions unique to your app that default events don't cover.

3. Final Answer:

   To track specific user actions not covered by default events -> Option C

4. Quick Check:

   Custom events = track unique user actions [OK]

Hint: Custom events track unique actions default events miss [OK]

Common Mistakes:

• Thinking custom events replace default events
• Assuming custom events send notifications
• Believing custom events collect location automatically

2. Which Firebase function is used to log a custom event with parameters?

easy

A. firebase.analytics().logEvent(eventName, params)

B. firebase.analytics().trackEvent(eventName, params)

C. firebase.analytics().sendEvent(eventName, params)

D. firebase.analytics().createEvent(eventName, params)

Solution

1. Step 1: Recall Firebase Analytics API for events

   The correct method to log events is logEvent.

2. Step 2: Confirm method signature

   logEvent takes the event name and optional parameters as arguments.

3. Final Answer:

   firebase.analytics().logEvent(eventName, params) -> Option A

4. Quick Check:

   logEvent = log custom events [OK]

Hint: Use logEvent to send custom events with parameters [OK]

Common Mistakes:

• Using trackEvent instead of logEvent
• Using sendEvent or createEvent which don't exist
• Confusing parameter order or names

3. What will happen if you run this code snippet?

firebase.analytics().logEvent('purchase', {item: 'book', price: 15});

medium

A. Throws a syntax error due to incorrect parameter format

B. Logs a custom event named 'purchase' with item and price parameters

C. Logs a default event ignoring parameters

D. Sends an error because 'purchase' is a reserved event name

Solution

1. Step 1: Analyze the logEvent call

   The code calls logEvent with event name 'purchase' and parameters object.

2. Step 2: Check if 'purchase' is valid and parameters are correct

   'purchase' is a valid event name and parameters are passed as an object correctly.

3. Final Answer:

   Logs a custom event named 'purchase' with item and price parameters -> Option B

4. Quick Check:

   logEvent('purchase', params) = logs event with params [OK]

Hint: logEvent with name and object logs event with parameters [OK]

Common Mistakes:

• Thinking 'purchase' is reserved and causes error
• Assuming parameters must be strings only
• Confusing syntax causing error

4. Identify the error in this Firebase custom event logging code:

firebase.analytics().logEvent('level_up', 'level', 5);

medium

A. Incorrect parameter format; parameters must be in an object

B. Event name must be uppercase

C. logEvent requires only one argument

D. The event name 'level_up' is invalid

Solution

1. Step 1: Review logEvent parameter requirements

   logEvent expects the second argument as an object containing key-value pairs.

2. Step 2: Identify the mistake in argument passing

   The code passes parameters as separate arguments instead of a single object.

3. Final Answer:

   Incorrect parameter format; parameters must be in an object -> Option A

4. Quick Check:

   Parameters must be an object, not separate arguments [OK]

Hint: Pass parameters as one object, not separate arguments [OK]

Common Mistakes:

• Passing parameters as multiple arguments
• Assuming event name case matters
• Thinking logEvent takes only one argument

5. You want to track when users complete a tutorial step with step number and success status. Which is the best way to log this custom event in Firebase?

hard

A. firebase.analytics().logEvent('tutorial_complete', {step: stepNumber, success: isSuccess});

B. firebase.analytics().logEvent('tutorial_complete', stepNumber, isSuccess);

C. firebase.analytics().logEvent('tutorialComplete', {stepNumber, isSuccess});

D. firebase.analytics().logEvent('tutorial_complete', {stepNumber: stepNumber, success: isSuccess});

Solution

1. Step 1: Check event name format

   Firebase recommends lowercase with underscores for event names, so 'tutorial_complete' is correct.

2. Step 2: Verify parameters object keys and values

   Parameters should be an object with clear keys. firebase.analytics().logEvent('tutorial_complete', {stepNumber: stepNumber, success: isSuccess}); uses keys 'stepNumber' and 'success' with values from variables.

3. Step 3: Compare options for best practice

   firebase.analytics().logEvent('tutorial_complete', {step: stepNumber, success: isSuccess}); uses 'step' key which is less descriptive than 'stepNumber'. firebase.analytics().logEvent('tutorialComplete', {stepNumber, isSuccess}); uses camelCase event name which is less recommended. firebase.analytics().logEvent('tutorial_complete', stepNumber, isSuccess); passes parameters incorrectly.

4. Final Answer:

   firebase.analytics().logEvent('tutorial_complete', {stepNumber: stepNumber, success: isSuccess}); -> Option D

5. Quick Check:

   Use descriptive keys and correct event name format [OK]

Hint: Use descriptive keys and underscore event names [OK]

Common Mistakes:

• Passing parameters as separate arguments
• Using camelCase event names instead of underscores
• Using unclear parameter keys