Module database

firebase_rs_sdk

Module database 

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Expand description

§Firebase Realtime Database module

This module ports core pieces of the Realtime Database from the Firebase JS SDK to Rust.

It wires the Database component into the FirebaseApp, provides an in-memory backend for quick tests, and can fall back to the REST API for basic reads and writes against an emulator or hosted backend.

Live streaming connections and the richer reference/query surface from the JS SDK are still pending.

It includes error handling, configuration options, and integration with Firebase apps.

§Features

  • Component registration and shared get_database resolution
  • Reference CRUD with auto-ID push and path navigation (parent/root)
  • Priority-aware writes plus server value helpers (server_timestamp increment)
  • Snapshot traversal (child, has_child, size, to_json) and value/child listeners
  • Dual backends (in-memory + REST) with unit test coverage

§References to the Firebase JS SDK - firestore module

§Development status as of 14th October 2025

  • Core functionalities: Mostly implemented (see the module’s README.md for details)
  • Testing: 30 tests (passed)
  • Documentation: Most public functions are documented
  • Examples: 2 examples

DISCLAIMER: This is not an official Firebase product, nor it is guaranteed that it has no bugs or that it will work as intended.

§Quick Start Example

use firebase_rs_sdk::app::*;
use firebase_rs_sdk::database::{*, query as compose_query};

use serde_json::json;

fn main() -> Result<(), Box<dyn std::error::Error>> {
    // Point to the Realtime Database emulator or a database URL.
    let options = FirebaseOptions {
        project_id: Some("demo-project".into()),
        database_url: Some("http://127.0.0.1:9000/?ns=demo".into()),
        ..Default::default()
    };
    let app = initialize_app(options, Some(FirebaseAppSettings::default()))?;
    let database = get_database(Some(app))?;

    let messages = database.reference("/messages")?;
    messages.set(json!({ "greeting": "hello" }))?;
    let value = messages.get()?;
    assert_eq!(value, json!({ "greeting": "hello" }));

    let recent = compose_query(
        messages,
        vec![order_by_child("timestamp"), limit_to_last(10)],
    )?;
    let latest = recent.get()?;
    println!("latest snapshot: {latest}");

    Ok(())
}

Modules§

error

Structs§

DataSnapshot
Represents a data snapshot returned to listeners, analogous to the JS DataSnapshot type.
Database
DatabaseQuery
Represents a composable database query, analogous to the JS QueryImpl (packages/database/src/api/Reference_impl.ts).
DatabaseReference
ListenerRegistration
RAII-style listener registration; dropping the handle detaches the underlying listener.
OnDisconnect
Placeholder implementation of the Realtime Database OnDisconnect API.
QueryConstraint
Represents a single constraint produced by helpers such as order_by_child() (packages/database/src/api/Reference_impl.ts).

Functions§

end_at
Mirrors the JS endAt() constraint (Reference_impl.ts).
end_at_with_key
Mirrors the JS endAt(value, name) overload (Reference_impl.ts).
end_before
Mirrors the JS endBefore() constraint (Reference_impl.ts).
end_before_with_key
Mirrors the JS endBefore(value, name) overload (Reference_impl.ts).
equal_to
Mirrors the JS equalTo() constraint (Reference_impl.ts).
equal_to_with_key
Mirrors the JS equalTo(value, name) overload (Reference_impl.ts).
get_database
increment
Port of increment() from packages/database/src/api/ServerValue.ts.
limit_to_first
Mirrors the JS limitToFirst() constraint (Reference_impl.ts).
limit_to_last
Mirrors the JS limitToLast() constraint (Reference_impl.ts).
on_child_added
Registers a child_added listener for the provided reference.
on_child_changed
Registers a child_changed listener for the provided reference.
on_child_removed
Registers a child_removed listener for the provided reference.
order_by_child
Produces a constraint that orders the results by the specified child path. Mirrors orderByChild() from the JS SDK.
order_by_key
Produces a constraint that orders nodes by key (orderByKey() in JS).
order_by_priority
Produces a constraint that orders nodes by priority (orderByPriority() in JS).
order_by_value
Produces a constraint that orders nodes by value (orderByValue() in JS).
push
Generates a child location with an auto-generated push ID.
push_with_value
Generates a child location with an auto-generated push ID and writes the provided value.
query
Creates a derived query by applying the provided constraints, following the semantics of query() in packages/database/src/api/Reference_impl.ts.
register_database_component
run_transaction
Runs a transaction at the provided reference (currently unimplemented).
server_timestamp
Port of serverTimestamp() from packages/database/src/api/ServerValue.ts.
set_priority
Updates the priority for the current location, mirroring the modular setPriority() helper (packages/database/src/api/Reference_impl.ts).
set_with_priority
Writes a value together with a priority, mirroring the modular setWithPriority() helper (packages/database/src/api/Reference_impl.ts).
start_after
Mirrors the JS startAfter() constraint (Reference_impl.ts).
start_after_with_key
Mirrors the JS startAfter(value, name) overload (Reference_impl.ts).
start_at
Mirrors the JS startAt() constraint (Reference_impl.ts).
start_at_with_key
Mirrors the JS startAt(value, name) overload (Reference_impl.ts).

Type Aliases§

DatabaseResult