Rule syntax and structure in Firebase - Cheat Sheet & Quick Revision

Recall & Review

beginner

What is the basic structure of a Firebase security rule?

A Firebase security rule has a service block, inside which there are match blocks defining paths, and inside those, allow statements that specify read or write permissions.

beginner

What does the match keyword do in Firebase rules?

The match keyword defines a path in your database or storage where rules apply. It scopes the rules to specific data locations.

beginner

Explain the purpose of allow read: if condition; in Firebase rules.

This statement allows read access to data only if the specified condition evaluates to true. It controls who can read data.

intermediate

How do you specify multiple permissions in one rule?

You can list multiple permissions separated by commas, like allow read, write: if condition;, to apply the same condition to both read and write.

intermediate

What is the role of variables in Firebase rule paths?

Variables in paths, like <code>{userId}</code>, act as placeholders that match any value. They let you write flexible rules for dynamic data locations.

What keyword defines the data path in Firebase security rules?

A path

B allow

C service

D match

The match keyword defines the path where rules apply.

Which statement correctly allows both read and write if a condition is true?

A allow read, write: if condition;

B allow read write if condition;

C allow read or write: if condition;

D allow read if condition; allow write if condition;

You list multiple permissions separated by commas in one allow statement.

What does {userId} represent in a Firebase rule path?

A A variable placeholder

B A fixed folder name

C A function call

D A permission type

Curly braces define variables that match any value in that path segment.

Where do you write Firebase security rules for Firestore?

A Inside <code>service cloud.functions</code> block

B Inside <code>service cloud.firestore</code> block

C Inside <code>service firebase.storage</code> block

D Inside <code>service cloud.database</code> block

Firestore rules go inside the service cloud.firestore block.

What happens if no rule matches a request in Firebase security rules?

A The request is queued

B Access is allowed by default

C Access is denied by default

D The request is logged but allowed

Firebase denies access by default if no rule matches.

Describe the main parts of a Firebase security rule and their roles.

Think about how you specify where and when access is allowed.

Explain how variables in rule paths help manage permissions dynamically.

Imagine you want to write one rule for many users.