[!NOTE]
Realm is now Atlas Device SDK - Learn More
The Realm Database
Realm is a mobile database that runs directly inside phones, tablets or wearables. This project hosts the JavaScript & TypeScript implementation of Realm. Currently, we support React Native (JSC & Hermes on iOS & Android), Node.js and Electron (on Windows, MacOS and Linux).
What are the Atlas Device SDKs?
The Atlas Device SDKs are a collection of language and platform specific SDKs, each with a suite of app development tools optimized for data access and persistence on mobile and edge devices. Use the SDKs to build data-driven mobile, edge, web, desktop, and IoT apps.
It might help to think of the Realm database as the persistance layer of the Atlas Device SDKs.
Features
Mobile-first: Realm is the first database built from the ground up to run directly inside phones, tablets and wearables.
Simple: Data is directly exposed as objects and queryable by code, removing the need for ORM's riddled with performance & maintenance issues.
Modern: The database supports relationships, generics, and vectorization.
Fast: It is faster than even raw SQLite on common operations, while maintaining an extremely rich feature set.
The Atlas Device SDK for React Native provides persistence of objects and advanced queries for persisted objects. You can have easier integration with React Native by using @realm/react.
Template apps
We have TypeScript templates to help you get started using Realm. Follow the links to your desired template and follow the instructions there to get up and running fast.
Need help with your code?: Look for previous questions on the #realm tag — or ask a new question. You can also check out our Community Forum where general questions about how to do something can be discussed.
Have a bug to report?Open an issue. If possible, include the version of Realm, a full log, the Realm file, and a project that shows the issue.
Have a feature request?Open an issue. Tell us what the feature should do, and why you want the feature.
Realm is not compatible with the legacy Chrome Debugger. The following debugging methods are supported:
Hermes Debugger is the recommended way for debugging modern React Native apps.
Safari also has a similar feature set, but requires some setup and only supports debugging in iOS.
NOTE: For the above methods, it is not necessary to enable Debug with Chrome in the Debug Menu.
Building the SDK
For instructions on building the SDK from the source, see the building.md file.
Troubleshooting missing binary
It's possible after installing and running Realm that one encounters the error Could not find the Realm binary. Here are are some tips to help with this.
Compatibility
Consult our COMPATIBILITY.md to ensure you are running compatible version of realm with the supported versions of node, react-native or expo.
React Native
iOS
Typically this error occurs when the pod dependencies haven't been updating.
Try running the following command:
npx pod-install
If that still doesn't help it's possible there are some caching errors with your build or your pod dependencies. The following commands can be used to safely clear these caches:
Afterwards, reinstall pods and try again. If this still doesn't work, ensure that prebuilds/apple/realm-core.xcframework directory exists and contains a binary for your platform and architecture. If this is missing, try reinstalling the realm npm package and as well as CocoaPods.
Android
This can occur when installing realm and not performing a clean build. The following commands can be used to clear your cache:
cd android
./gradlew clean
Afterwards, try and rebuild for Android. If you are still encountering problems, ensure that node_moduels/realm/react-native/android/src/main/jniLibs contains a realm binary for your architecture. If this is missing, try reinstalling the realm npm package.
Expo
If you are using Expo, a common pitfall is not installing the expo-dev-client and using the Development Client specific scripts to build and run your React Native project in Expo. The Development Client allows you to create a local version of Expo Go which includes 3rd party libraries such as Realm. If you would like to use realm in an Expo project, the following steps can help.
install the expo-dev-client:
npm install expo-dev-client
build the dev client for iOS
npx expo run:ios
build the dev client for Android
npx expo run:android
start the bundler without building
npx expo start --dev-client
Node/Electron
When running npm install realm the realm binaries for the detected architecture are downloaded into node_modules/realm/prebuilds. If this directory is missing or empty, ensure that there weren't any network issues reported on installation.
Analytics
Asynchronously submits install information to Realm.
Why are we doing this? In short, because it helps us build a better product
for you. None of the data personally identifies you, your employer or your
app, but it will help us understand what language you use, what Node.js
versions you target, etc. Having this info will help prioritizing our time,
adding new features and deprecating old features. Collecting an anonymized
application path & anonymized machine identifier is the only way for us to
count actual usage of the other metrics accurately. If we don’t have a way to
deduplicate the info reported, it will be useless, as a single developer
npm install-ing the same app 10 times would report 10 times more than another
developer that only installs once, making the data all but useless.
No one likes sharing data unless it’s necessary, we get it, and we’ve
debated adding this for a long long time. If you truly, absolutely
feel compelled to not send this data back to Realm, then you can set an env
variable named REALM_DISABLE_ANALYTICS.
Currently the following information is reported:
What version of Realm is being installed.
The OS platform and version which is being used.
If a JavaScript framework (currently React Native and Electron) is used and its version.
Which JavaScript engine is being used.
Node.js version number.
TypeScript version if used.
An anonymous machine identifier and hashed application name to aggregate the other information on.
Moreover, we unconditionally write various constants to a file which we might use at runtime.
The callback for SyncSession.addProgressNotification taking transferred and transferable arguments is deprecated and will be removed. See Enhancements below for the new callback supporting both Flexible Sync and Partition-Based Sync. (#6743)
AppConfiguration.app is no longer used by Atlas Device Sync. It will be removed in future SDK releases and should not be used. (#6785)
Enhancements
Added support for "bridgeless" React Native on iOS and Android, a part of the "new architecture". (#6737)
Added progress notifications support for Flexible Sync using an estimate as the new callback argument. The estimate is roughly equivalent to an estimated value of transferred / transferable in the deprecated Partition-Based Sync callback. (#6743)
It is no longer an error to set a base url for an App with a trailing slash - for example, https://services.cloud.mongodb.com/ instead of https://services.cloud.mongodb.com - before this change that would result in a 404 error from the server. (realm/realm-core#7791)
Performance has been improved for range queries on integers and timestamps when using the BETWEEN operator. (realm/realm-core#7785)
On Windows devices Device Sync will additionally look up SSL certificates in the Windows Trusted Root Certification Authorities certificate store when establishing a connection. (realm/realm-core#7882)
Role and permissions changes no longer require a client reset to update the Realm on-device. (realm/realm-core#7440)
Fixed
Opening an Flexible Sync Realm asynchronously may not wait to download all data. (realm/realm-core#7720, since v10.12.0)
Clearing a list of mixed in an upgraded file would lead to an assertion failing. (realm/realm-core#7771, since 12.7.0-rc.0)
Sync client can crash if a session is resumed while the session is being suspended. (realm/realm-core#7860, since v10.18.0)
If a sync session is interrupted by a disconnect or restart while downloading a bootstrap, stale data from the previous bootstrap may be included when the session reconnects and downloads the bootstrap. This can lead to objects stored in the database that do not match the actual state of the server and potentially leading to compensating writes. (realm/realm-core#7827, since v10.18.0)
Fixed unnecessary server roundtrips when there is no download to acknowledge. (realm/realm-core#2129, since v12.10.0)
Realm.App.Sync.SyncSession#uploadAllLocalChanges() was inconsistent in how it handled commits which did not produce any changesets to upload. Previously it would sometimes complete immediately if all commits waiting to be uploaded were empty, and at other times it would wait for a server roundtrip. It will now always complete immediately. (realm/realm-core#7796)
Realm#writeCopyTo() on an encrypted Realm without explicitly specifying a new encryption key would only work if the old key happened to be a valid nul-terminated string. (realm/realm-core#7842, since v12.10.0).
You could get unexpected merge results when assigning to a nested collection. (realm/realm-core#7809, since v12.7.0-rc.0)
When mapTo is used to have an alias for a property name, Realm.Results#sorted() doesn't recognize the alias leading to errors like Cannot sort on key path 'NAME': property 'PersonObject.NAME' does not exist. (#6779, since v11.2.0)
A mixed property with a collection could sometimes end up with a combination of values assigned by different clients. (realm/realm-core#7809, since v12.9.0)
Fixed removing backlinks from the wrong objects if the link came from a nested list, nested dictionary, top-level dictionary, or list of mixed, and the source table had more than 256 objects. This could manifest as array_backlink.cpp:112: Assertion failed: int64_t(value >> 1) == key.value when removing an object. (realm/realm-core#7594, since v10.6.0)
Fixed a bug when removing an object from a nested collection could lead to an assert with the message array.cpp:319: Array::move() Assertion failed: begin <= end [2, 1]. (realm/realm-core#7839, since v12.9.0)
Compatibility
React Native >= v0.71.4
Realm Studio v15.0.0.
File format: generates Realms with format v24 (reads and upgrades file format v10).
Internal
Adding a CallInvoker-based scheduler for Core on React Native and removing the "flush ui queue" workaround. (#6791)
Refactors throwing uncaught exceptions from callbacks dispatched onto the event loop from C++ on React Native. (#6772)
Upgraded Realm Core from v14.10.0 to v14.11.0. (#6744)
Realm by MongoDB is an offline-first mobile database: an alternative to SQLite and key-value stores
The npm package realm receives a total of 30,631 weekly downloads. As such, realm popularity was classified as popular.
We found that realm demonstrated a healthy version release cadence and project activity because the last version was released less than a year ago.It has 0 open source maintainers collaborating on the project.
Package last updated on 23 Jul 2024
Did you know?
Socket for GitHub automatically highlights issues in each pull request and monitors the health of all your open source dependencies. Discover the contents of your packages and block harmful activity before you install or update your dependencies.
Ransomware payment rates hit an all-time low in 2024 as law enforcement crackdowns, stronger defenses, and shifting policies make attacks riskier and less profitable.