Subchapter 125.7

React Native

references/react-native.mdMarkdown44 KBView on GitHub

React Native - Docs

Installation

React Native · Integration Expo · PostHog/skills · Skills Docs

yarn add posthog-react-native @react-native-async-storage/async-storage react-native-device-info react-native-localize
# or
npm i -s posthog-react-native @react-native-async-storage/async-storage react-native-device-info react-native-localize

// App.(js|ts)
import { usePostHog, PostHogProvider } from 'posthog-react-native'
...
export function MyApp() {
    return (
        <PostHogProvider apiKey="<ph_project_token>" options={{
            // usually 'https://us.i.posthog.com' or 'https://eu.i.posthog.com'
            host: 'https://us.i.posthog.com',
        }}>
            <MyComponent />
        </PostHogProvider>
    )
}

import PostHog from 'posthog-react-native'
export const posthog = new PostHog('<ph_project_token>', {
  // usually 'https://us.i.posthog.com' or 'https://eu.i.posthog.com'
  host: 'https://us.i.posthog.com'
})

Attribute	Description
hostType: StringDefault: https://us.i.posthog.com (opens in a new tab)	PostHog API host (usually https://us.i.posthog.com (opens in a new tab) by default or https://eu.i.posthog.com (opens in a new tab)). Host is optional if you use https://us.i.posthog.com (opens in a new tab).
flushAtType: NumberDefault: 20	The number of events to queue before sending to PostHog (flushing).
flushIntervalType: NumberDefault: 10000	The interval in milliseconds between periodic flushes.
maxBatchSizeType: NumberDefault: 100	The maximum number of queued messages to be flushed as part of a single batch (must be higher than flushAt).
maxQueueSizeType: NumberDefault: 1000	The maximum number of cached messages either in memory or on the local storage (must be higher than flushAt).
disabledType: BooleanDefault: false	If set to true, the SDK is essentially disabled (useful for local environments where you don’t want to track anything).
defaultOptInType: BooleanDefault: true	If set to false, the SDK will not track until the optIn() function is called.
sendFeatureFlagEventType: BooleanDefault: true	Whether to track that getFeatureFlag was called (used by experiments).
preloadFeatureFlagsType: BooleanDefault: true	Whether to load feature flags when initialized or not.
bootstrapType: ObjectDefault: {}	An object containing the distinctId, isIdentifiedId, featureFlags, and featureFlagPayloads keys. distinctId is a string, and featureFlags and featureFlagPayloads are objects of key-value pairs. Used to ensure data is available as soon as the SDK loads.
fetchRetryCountType: NumberDefault: 3	How many times HTTP requests will be retried.
fetchRetryDelayType: NumberDefault: 3000	The delay between HTTP request retries.
requestTimeoutType: NumberDefault: 10000	Timeout in milliseconds for any calls.
featureFlagsRequestTimeoutMsType: NumberDefault: 10000	Timeout in milliseconds for feature flag calls.
sessionExpirationTimeSecondsType: NumberDefault: 1800	For session analysis, how long before a session expires (defaults to 30 minutes).
persistenceType: StringDefault: file	Allows you to provide the storage type. file will try to load the best available storage, the provided customStorage, customAsyncStorage, or in-memory storage.
customAppPropertiesType: Object or FunctionDefault: null	Allows you to provide your own implementation of the common information about your App or a function to modify the default App properties generated.
customStorageType: ObjectDefault: null	Allows you to provide a custom asynchronous storage such as async-storage, expo-file-system, or a synchronous storage such as mmkv. If not provided, PostHog will attempt to use the best available storage via optional peer dependencies. If persistence is set to memory, this option is ignored.
captureAppLifecycleEventsType: BooleanDefault: false	Captures app lifecycle events such as Application Installed, Application Updated, Application Opened, Application Became Active, and Application Backgrounded. By default, this is false.
disableGeoipType: BooleanDefault: false	When true, disables automatic GeoIP resolution for events and feature flags.
enableSessionReplayType: BooleanDefault: false	Enable Recording of Session replay for Android and iOS.
sessionReplayConfigType: ObjectDefault: null	Session replay configuration. See the replay install docs (opens in a new tab) for more details.
enablePersistSessionIdAcrossRestartType: BooleanDefault: false	When true, persists the $session_id across app restarts. If false, $session_id always resets on app restart.
evaluationContextsType: Array of StringsDefault: undefined	Evaluation context tags that constrain which feature flags are evaluated. When set, only flags with matching evaluation context tags (or no evaluation context tags) will be returned. This helps reduce unnecessary flag evaluations and improves performance. See evaluation contexts documentation (opens in a new tab) for more details. Available in version 4.8.0+. The legacy parameter evaluationEnvironments (version 4.7.2+) is also supported for backward compatibility.
before_sendType: FunctionDefault: undefined	A callback function that is called before each event is sent to PostHog. You can use it to modify, filter, or suppress events. Return null to drop the event, or return the modified event to send it. See customizing exception capture for details.

// App.(js|ts)
import { PostHogProvider } from 'posthog-react-native'
import { NavigationContainer } from '@react-navigation/native'
export function App() {
    return (
        <NavigationContainer>
            <PostHogProvider apiKey="<ph_project_token>" autocapture>
                {/* Rest of app */}
            </PostHogProvider>
        </NavigationContainer>
    )
}

// App.(js|ts)
import { PostHogProvider } from 'posthog-react-native'
import { NavigationContainer } from '@react-navigation/native'
// Using `PostHogProvider` is optional, but needed if you want to capture touch events automatically with the `captureTouches` option.
export function App() {
    return (
        <NavigationContainer>
            <PostHogProvider apiKey="<ph_project_token>" autocapture={{
              captureScreens: false, // Screen events are handled differently for v7 and higher
              captureTouches: true,
            }}>
                {/* Rest of app */}
            </PostHogProvider>
        </NavigationContainer>
    )
}

const posthog = usePostHog() // use the usePostHog hook if using the PostHogProvider or your own custom posthog instance
// you can read the params from `getCurrentRoute()`
posthog.screen(currentRouteName, params)

import PostHog, { PostHogProvider } from 'posthog-react-native'
import { Navigation } from 'react-native-navigation';
export const posthog = new PostHog('<ph_project_token>');
export const SharedPostHogProvider = (props: any) => {
  return (
    <PostHogProvider client={posthog} autocapture={{
      captureScreens: false, // Screen events are handled differently for react-native-navigation
      captureTouches: true,
    }}>
      {props.children}
    </PostHogProvider>
  );
};

export const MyScreen = () => {
  return (
    <SharedPostHogProvider>
      <View>
        ...
      </View>
    </SharedPostHogProvider>
  );
};
Navigation.registerComponent('Screen', () => MyScreen);
Navigation.events().registerAppLaunchedListener(async () => {
  posthog.initReactNativeNavigation({
    navigation: {
      // (Optional) Set the name based on the route. Defaults to the route name.
      routeToName: (name, properties) => name,
      // (Optional) Tracks all passProps as properties. Defaults to undefined
      routeToProperties: (name, properties) => properties,
    },
    captureScreens: true,
  });
});

<PostHogProvider apiKey="<ph_project_token>" autocapture={{
    captureTouches: true,
    captureScreens: true,
    ignoreLabels: [], // Any labels here will be ignored from the stack in touch events
    customLabelProp: "ph-label",
    maxElementsCaptured: 20,
    noCaptureProp: "ph-no-capture",
    propsToCapture: ["testID"], // Limit which props are captured. By default, identifiers and text content are captured.
    navigation: {
        // By default, only the screen name is tracked but it is possible to track the
        // params or modify the name by intercepting the autocapture like so
        routeToName: (name, params) => {
            if (params.id) return `${name}/${params.id}`
            return name
        },
        routeToProperties: (name, params) => {
            if (name === "SensitiveScreen") return undefined
            return params
        },
    },
}}>
    ...
</PostHogProvider>

import { useFeatureFlag } from 'posthog-react-native'
const MyComponent = () => {
    const booleanFlag = useFeatureFlag('key-for-your-boolean-flag')
    if (booleanFlag === undefined) {
        // the response is undefined if the flags are being loaded
        return null
    }
    // Optional use the 'useFeatureFlagWithPayload' hook for fetching the feature flag payload
    return booleanFlag ? <Text>Testing feature 😄</Text> : <Text>Not Testing feature 😢</Text>
}

import { useFeatureFlag } from 'posthog-react-native'
const MyComponent = () => {
    const multiVariantFeature = useFeatureFlag('key-for-your-multivariate-flag')
    if (multiVariantFeature === undefined) {
        // the response is undefined if the flags are being loaded
        return null
    } else if (multiVariantFeature === 'variant-name') { // replace 'variant-name' with the name of your variant
      // Do something
    }
    // Optional use the 'useFeatureFlagWithPayload' hook for fetching the feature flag payload
    return <div/>
}

// Defaults to undefined if not loaded yet or if there was a problem loading
posthog.isFeatureEnabled('key-for-your-boolean-flag')
// Defaults to undefined if not loaded yet or if there was a problem loading
posthog.getFeatureFlag('key-for-your-boolean-flag')
// Multivariant feature flags are returned as a string
posthog.getFeatureFlag('key-for-your-multivariate-flag')
// Optional fetch the payload returns 'JsonType' or undefined if not loaded yet or if there was a problem loading
posthog.getFeatureFlagPayload('key-for-your-multivariate-flag')

export const posthog = new PostHog('<ph_project_token>', {
  // usually 'https://us.i.posthog.com' or 'https://eu.i.posthog.com'
  host: 'https://us.i.posthog.com',
  featureFlagsRequestTimeoutMs: 10000 // Time in milliseconds. Default is 10000 (10 seconds).
})

function handleFeatureFlag(client, flagKey, distinctId) {
    try {
        const isEnabled = client.isFeatureEnabled(flagKey, distinctId);
        console.log(`Feature flag '${flagKey}' for user '${distinctId}' is ${isEnabled ? 'enabled' : 'disabled'}`);
        return isEnabled;
    } catch (error) {
        console.error(`Error fetching feature flag '${flagKey}': ${error.message}`);
        // Optionally, you can return a default value or throw the error
        // return false; // Default to disabled
        throw error;
    }
}
// Usage example
try {
    const flagEnabled = handleFeatureFlag(client, 'new-feature', 'user-123');
    if (flagEnabled) {
        // Implement new feature logic
    } else {
        // Implement old feature logic
    }
} catch (error) {
    // Handle the error at a higher level
    console.error('Feature flag check failed, using default behavior');
    // Implement fallback logic
}

// set properties for a group
posthog.setGroupPropertiesForFlags({'company': {'property1': 'value', property2: 'value2'}})
// reset properties for all groups:
posthog.resetGroupPropertiesForFlags()

// With the useFeatureFlag hook
import { useFeatureFlag } from 'posthog-react-native'
const MyComponent = () => {
    const variant = useFeatureFlag('experiment-feature-flag-key')
    if (variant === undefined) {
        // the response is undefined if the flags are being loaded
        return null
    }
    if (variant == 'variant-name') {
        // do something
    }
}

import { PostHogProvider, PostHogErrorBoundary } from 'posthog-react-native'
import { View, Text } from 'react-native'
const App = () => {
  return (
    <PostHogProvider apiKey="<ph_project_token>">
      <PostHogErrorBoundary
        fallback={YourFallbackComponent}
        additionalProperties={{ screen: "home" }}
      >
        <YourApp />
      </PostHogErrorBoundary>
    </PostHogProvider>
  )
}
const YourFallbackComponent = ({ error, componentStack }) => {
  return (
    <View>
      <Text>Something went wrong!</Text>
      <Text>{error instanceof Error ? error.message : String(error)}</Text>
    </View>
  )
}

const posthog = new PostHog('<ph_project_token>', {
  host: 'https://us.i.posthog.com',
  before_send: (event) => {
    if (event.event === '$exception') {
      const exceptionList = event.properties?.['$exception_list'] || []
      const exception = exceptionList.length > 0 ? exceptionList[0] : null
      if (exception) {
        // Add custom properties
        event.properties['custom_property'] = 'custom_value'
        // Override fingerprint for custom grouping
        event.properties['$exception_fingerprint'] = 'MyCustomGroup'
      }
      // Suppress specific exception types
      if (exception?.['$exception_type'] === 'IgnoredError') {
        return null // Drop the event
      }
    }
    return event
  },
})

// App.(js|ts)
import { usePostHog, PostHogProvider } from 'posthog-react-native'
...
export function MyApp() {
    return (
        <PostHogProvider apiKey="<ph_project_token>" options={{
            // Disable PostHog in development (or whatever other logic you choose)
            disabled: __DEV__,
        }}>
            <MyComponent />
        </PostHogProvider>
    )
}
const MyComponent = () => {
    const posthog = usePostHog()
    useEffect(() => {
        // Safe to call even when disabled!
        posthog.capture("mycomponent_loaded", { foo: "bar" })
    }, [])
}

// DEPRECATED V1 Setup
import PostHog from 'posthog-react-native'
await PostHog.setup('<ph_project_token>', {
    // usually 'https://us.i.posthog.com' or 'https://eu.i.posthog.com'
    host: 'https://us.i.posthog.com',
    captureApplicationLifecycleEvents: false, // Replaced by 'PostHogProvider'
    captureDeepLinks: false, // No longer supported
    recordScreenViews: false, // Replaced by 'PostHogProvider' supporting @react-navigation/native
    flushInterval: 30, // Stays the same
    flushAt: 20, // Stays the same
    android: {...}, // No longer needed
    iOS: {...}, // No longer needed
})
PostHog.capture("foo")
// V2 Setup difference
import PostHog from 'posthog-react-native'
const posthog = await Posthog.initAsync('<ph_project_token>', {
    // usually 'https://us.i.posthog.com' or 'https://eu.i.posthog.com'
    host: 'https://us.i.posthog.com',
    // Add any other options here.
})
// Use created instance rather than the PostHog class
posthog.capture("foo")
// V3 Setup difference
import PostHog from 'posthog-react-native'
const posthog = new PostHog('<ph_project_token>', {
    // usually 'https://us.i.posthog.com' or 'https://eu.i.posthog.com'
    host: 'https://us.i.posthog.com',
    // Add any other options here.
})
// Use created instance rather than the PostHog class
posthog.capture("foo")
// V4 Setup difference
import PostHog from 'posthog-react-native'
const posthog = new PostHog('<ph_project_token>', {
    // usually 'https://us.i.posthog.com' or 'https://eu.i.posthog.com'
    host: 'https://us.i.posthog.com',
    captureAppLifecycleEvents: true, // instead of `captureNativeAppLifecycleEvents` or `autocapture={{ captureLifecycleEvents: true }}`,
    // captureMode: 'json', // No longer supported
    // maskPhotoLibraryImages: true, // No longer supported
})
posthog.setPersonPropertiesForFlags(...) // instead of `personProperties`
posthog.setGroupPropertiesForFlags(...) // instead of `groupProperties`