User properties in Firebase - Mini Project: Build & Apply

Firebase User Properties Setup

📖 Scenario: You are building a mobile app that tracks user behavior. To personalize the experience, you want to set user properties in Firebase Analytics. These properties help you understand your users better and tailor content accordingly.

🎯 Goal: Set up Firebase user properties correctly to identify user preferences and demographics.

📋 What You'll Learn

Create a dictionary called user_properties with specific user property keys and values.

Add a configuration variable called max_properties to limit the number of properties.

Write a function called set_user_properties that applies the user properties to Firebase Analytics.

Complete the Firebase configuration by calling the function with the user properties.

💡 Why This Matters

🌍 Real World

Setting user properties in Firebase Analytics helps personalize app experiences and analyze user segments effectively.

💼 Career

Understanding how to configure and manage user properties is essential for roles in mobile app development, analytics, and cloud infrastructure management.

1

Create the user properties dictionary

Create a dictionary called user_properties with these exact entries: 'favorite_color': 'blue', 'subscription_level': 'premium', and 'age_group': '25-34'.

Firebase

# Your code here

Hint

Use a Python dictionary with the exact keys and values given.

2

Add a configuration variable for max properties

Add an integer variable called max_properties and set it to 25 to limit the number of user properties.

Firebase

user_properties = {
    'favorite_color': 'blue',
    'subscription_level': 'premium',
    'age_group': '25-34'
}
# Your code here

Hint

Just create a variable named max_properties and assign it the value 25.

3

Write the function to set user properties

Write a function called set_user_properties that takes a dictionary properties and sets each key-value pair as a user property using firebase.analytics().setUserProperties({key: value}). Use a for loop with variables key and value to iterate over properties.items(). Limit the number of properties set to max_properties.

Firebase

user_properties = {
    'favorite_color': 'blue',
    'subscription_level': 'premium',
    'age_group': '25-34'
}
max_properties = 25

# Your code here

Hint

Use a loop to set each user property and stop when you reach max_properties.

4

Call the function to apply user properties

Call the function set_user_properties with the user_properties dictionary to apply the user properties in Firebase Analytics.

Firebase

user_properties = {
    'favorite_color': 'blue',
    'subscription_level': 'premium',
    'age_group': '25-34'
}
max_properties = 25

def set_user_properties(properties):
    count = 0
    for key, value in properties.items():
        if count >= max_properties:
            break
        firebase.analytics().setUserProperties({key: value})
        count += 1

# Your code here

Hint

Just call set_user_properties with user_properties as the argument.

Practice

1. What is the main purpose of user properties in Firebase Analytics?

easy

A. To store simple information about users for better app insights

B. To authenticate users securely

C. To send push notifications to users

D. To manage database access rules

Solution

1. Step 1: Understand user properties role

   User properties are used to store simple info about users, like preferences or demographics.

2. Step 2: Differentiate from other Firebase features

   Authentication, notifications, and database rules serve different purposes unrelated to user properties.

3. Final Answer:

   To store simple information about users for better app insights -> Option A

4. Quick Check:

   User properties = store user info for insights [OK]

Hint: User properties = user info for insights, not security or messaging [OK]

Common Mistakes:

• Confusing user properties with authentication
• Thinking user properties send notifications
• Mixing user properties with database rules

2. Which of the following is the correct way to set a user property named favorite_color to blue in Firebase Analytics?

easy

A. firebase.analytics().setUserProperty('favorite_color', 'blue');

B. firebase.analytics().setUserProperties('favorite_color', 'blue');

C. firebase.analytics().setUserProperties({favorite_color: 'blue'});

D. firebase.analytics().setUserProperty({favorite_color: 'blue'});

Solution

1. Step 1: Recall correct method signature

   The correct method to set multiple user properties is setUserProperties with an object of key-value pairs.

2. Step 2: Check method usage

   firebase.analytics().setUserProperties({favorite_color: 'blue'}); uses setUserProperties with an object, which is correct. The other options misuse method names or parameters.

3. Final Answer:

   firebase.analytics().setUserProperties({favorite_color: 'blue'}); -> Option C

4. Quick Check:

   Use setUserProperties with object = firebase.analytics().setUserProperties({favorite_color: 'blue'}); [OK]

Hint: Use setUserProperties with an object for key-value pairs [OK]

Common Mistakes:

• Using setUserProperty instead of setUserProperties
• Passing key and value as separate arguments incorrectly
• Passing an object to setUserProperty

3. Consider this code snippet:

firebase.analytics().setUserProperties({membership: 'gold'});
console.log(userProperties.membership);

What will be the output of console.log?

medium

A. 'gold'

B. undefined

C. null

D. Error: userProperties is not defined

Solution

1. Step 1: Analyze variable usage

   The code calls setUserProperties but tries to log userProperties.membership.

2. Step 2: Check if userProperties is defined

   No variable named userProperties is declared or imported, so accessing it causes a ReferenceError.

3. Final Answer:

   Error: userProperties is not defined -> Option D

4. Quick Check:

   Undefined variable access = ReferenceError [OK]

Hint: User properties set in Firebase, not accessible as local variable [OK]

Common Mistakes:

• Assuming userProperties is a local object
• Expecting immediate local access after setUserProperties call
• Confusing Firebase API with local variables

4. You wrote this code to set a user property:

firebase.analytics().setUserProperties('plan', 'premium');

But it does not work. What is the error?

medium

A. The method name should be setUserProperty (singular)

B. setUserProperties expects an object, not two string arguments

C. User property keys cannot be strings

D. Firebase Analytics does not support user properties

Solution

1. Step 1: Review method signature

   setUserProperties requires a single object argument with key-value pairs, not separate strings.

2. Step 2: Identify correct usage

   Passing two strings causes the method to fail because it expects an object like {plan: 'premium'}.

3. Final Answer:

   setUserProperties expects an object, not two string arguments -> Option B

4. Quick Check:

   setUserProperties needs object argument [OK]

Hint: setUserProperties takes one object, not separate strings [OK]

Common Mistakes:

• Passing key and value as separate arguments
• Using wrong method name
• Thinking keys can't be strings

5. You want to track users by their subscription tier and preferred language using user properties. Which code snippet correctly sets both properties at once?

hard

A. firebase.analytics().setUserProperties({subscription: 'premium', language: 'en'});

B. firebase.analytics().setUserProperties('subscription', 'premium');
firebase.analytics().setUserProperties('language', 'en');

C. firebase.analytics().setUserProperty({subscription: 'premium', language: 'en'});

D. firebase.analytics().setUserProperties(['subscription', 'premium'], ['language', 'en']);

Solution

1. Step 1: Understand setting multiple properties

   To set multiple user properties at once, pass a single object with all key-value pairs to setUserProperties.

2. Step 2: Evaluate each option

   firebase.analytics().setUserProperties({subscription: 'premium', language: 'en'}); correctly uses an object with both properties. firebase.analytics().setUserProperties('subscription', 'premium'); firebase.analytics().setUserProperties('language', 'en'); incorrectly calls the method twice with wrong argument types. firebase.analytics().setUserProperty({subscription: 'premium', language: 'en'}); uses wrong method name. firebase.analytics().setUserProperties(['subscription', 'premium'], ['language', 'en']); passes arrays instead of an object.

3. Final Answer:

   firebase.analytics().setUserProperties({subscription: 'premium', language: 'en'}); -> Option A

4. Quick Check:

   One object with all properties = firebase.analytics().setUserProperties({subscription: 'premium', language: 'en'}); [OK]

Hint: Set multiple properties in one object with setUserProperties [OK]

Common Mistakes:

• Calling setUserProperties multiple times with wrong args
• Using setUserProperty instead of setUserProperties
• Passing arrays instead of an object