Expo

Overview

The RUM React Native SDK supports Expo and Expo Go. To use it, install expo-datadog and @datadog/mobile-react-native.

expo-datadog supports Expo starting from SDK 45 and the plugin’s versions follow Expo versions. For example, if you use Expo SDK 45, use expo-datadog version 45.x.x. Datadog recommends using Expo SDK 45 as a minimum version; previous versions may require manual steps.

Setup

To install with NPM, run:

npm install expo-datadog @datadog/mobile-react-native

To install with Yarn, run:

yarn add expo-datadog @datadog/mobile-react-native

Usage

Add expo-datadog to your plugins in the app.json file:

{
    "expo": {
        "plugins": ["expo-datadog"]
    }
}

Run eas secret:create to set DATADOG_API_KEY to your Datadog API key, and DATADOG_SITE to the host of your Datadog site, for example: datadoghq.com.

Initialize the library with application context

Add the following code snippet to your initialization file:

import { DdSdkReactNative, DdSdkReactNativeConfiguration } from 'expo-datadog';

const config = new DdSdkReactNativeConfiguration(
    '<CLIENT_TOKEN>',
    '<ENVIRONMENT_NAME>',
    '<RUM_APPLICATION_ID>',
    true, // track user interactions such as tapping on a button. You can use the 'accessibilityLabel' element property to give the tap action a name, otherwise the element type is reported.
    true, // track XHR resources.
    true // track errors.
);
// Optional: Select your Datadog website ("US1", "US3", "US5", EU1", or "US1_FED"). Default is "US1".
config.site = 'US1';
// Optional: Enable or disable native crash reports.
config.nativeCrashReportEnabled = true;
// Optional: Sample RUM sessions, for example: 80% of sessions are sent to Datadog. Default is 100%.
config.sessionSamplingRate = 80;
// Optional: Sample tracing integrations for network calls between your app and your backend, for example: 80% of calls to your instrumented backend are linked from the RUM view to the APM view. Default is 20%.
// You need to specify the hosts of your backends to enable tracing with these backends.
config.resourceTracingSamplingRate = 80;
config.firstPartyHosts = ['example.com']; // Matches 'example.com' and subdomains like 'api.example.com'.
// Optional: Let the Datadog SDK print internal logs above or equal to the provided level. Default is undefined, which means no logs.
config.verbosity = SdkVerbosity.WARN;

await DdSdkReactNative.initialize(config);

// Once the Datadog SDK is initialized, you need to setup view tracking in order to see data in the RUM dashboard.

Add the config plugin

If you have not enabled Crash Reporting, you can skip this step.

Add expo-datadog to your plugins in the app.json file:

{
    "expo": {
        "plugins": ["expo-datadog"]
    }
}

This plugin takes care of uploading the dSYMs, source maps and Proguard mapping files on every EAS build.

Add @datadog/datadog-ci as a development dependency. This package contains scripts to upload the source maps. You can install it with NPM:

npm install @datadog/datadog-ci --save-dev

or with Yarn:

yarn add -D @datadog/datadog-ci

Run eas secret:create to set DATADOG_API_KEY to your Datadog API key.

For information about tracking Expo crashes, see Expo Crash Reporting and Error Tracking.

Expo Go

If you are using Expo Go, switch to development builds (recommended), or keep using Expo Go without Datadog while having it run on your standalone application (not recommended).

Switch from Expo Go to development builds

Your application’s development builds are debug builds that contain the expo-dev-client package.

  1. Enable the custom native code to run with expo run:android and expo run:ios.
  2. To start using your development application, run expo install expo-dev-client and expo start --dev-client. This installs and starts the expo-dev-client package to execute the added native code in dev mode.

Develop with Expo Go

When your application runs inside of Expo Go, you are unable to add any custom native code that is not part of the Expo Go application. Because the RUM React Native SDK relies on some custom native code to run, you can develop your application inside Expo Go without Datadog, and use Datadog in your standalone builds.

Your application crashes in Expo Go when some native code (that is not included) is called. To use Datadog with your standalone application and continue using Expo Go in development, add the following TypeScript file to your project:

// mockDatadog.ts
// Datadog does not recommend this approach, consider moving to Expo development builds instead.
// This file is not officially maintained and might not be up-to-date with new releases.

import { DdLogs, DdTrace, DdRum, DdSdkReactNative } from 'expo-datadog';

if (__DEV__) {
    const emptyAsyncFunction = () => new Promise<void>(resolve => resolve());

    DdLogs.debug = emptyAsyncFunction;
    DdLogs.info = emptyAsyncFunction;
    DdLogs.warn = emptyAsyncFunction;
    DdLogs.error = emptyAsyncFunction;

    DdTrace.startSpan = () =>
        new Promise<string>(resolve => resolve('fakeSpanId'));
    DdTrace.finishSpan = emptyAsyncFunction;
    DdRum.startView = emptyAsyncFunction;
    DdRum.stopView = emptyAsyncFunction;
    DdRum.startAction = emptyAsyncFunction;
    DdRum.stopAction = emptyAsyncFunction;
    DdRum.addAction = emptyAsyncFunction;
    DdRum.startResource = emptyAsyncFunction;
    DdRum.stopResource = emptyAsyncFunction;
    DdRum.addError = emptyAsyncFunction;
    DdRum.addTiming = emptyAsyncFunction;

    DdSdkReactNative.initialize = emptyAsyncFunction;
    DdSdkReactNative.setUser = emptyAsyncFunction;
    DdSdkReactNative.setAttributes = emptyAsyncFunction;
    DdSdkReactNative.setTrackingConsent = emptyAsyncFunction;
}

Then, import it before initializing the Datadog React Native SDK:

import './mockDatadog';
import { DdSdkReactNative } from 'expo-datadog';

const config = new DdSdkReactNativeConfiguration(/* your config */);
DdSdkReactNative.initialize(config);

Further reading