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API Reference

AppLoading

expo-app-loading tells expo-splash-screen to keep the splash screen visible while the AppLoading component is mounted.
This is useful to download and cache fonts, logos, icon images and other assets that you want to be sure the user has on their device for an optimal experience.

Platform Compatibility

Android DeviceAndroid EmulatoriOS DeviceiOS SimulatorWeb

Installation

expo install expo-app-loading

If you're installing this in a bare React Native app, you should also follow these additional installation instructions.

Usage

import React from 'react';
import { Image, Text, View } from 'react-native';
import { Asset } from 'expo-asset';
import AppLoading from 'expo-app-loading';

export default class App extends React.Component {
  state = {
    isReady: false,
  };

  render() {
    if (!this.state.isReady) {
      return (
        <AppLoading
          startAsync={this._cacheResourcesAsync}
          onFinish={() => this.setState({ isReady: true })}
          onError={console.warn}
        />
      ); }

    return (
      <View style={{ flex: 1 }}>
        <Image source={require('./assets/snack-icon.png')} />
      </View>
    );
  }

  async _cacheResourcesAsync() {
    const images = [require('./assets/snack-icon.png')];

    const cacheImages = images.map(image => {
      return Asset.fromModule(image).downloadAsync();
    }); 
    return Promise.all(cacheImages);
  }
}

API

import AppLoading from 'expo-app-loading';

Components

AppLoading

Type: Component<AppLoadingProps>

Props

  • autoHideSplash

    Optional • Type: boolean

    Whether to hide the native splash screen as soon as you unmount the AppLoading component. Auto-hiding is enabled by default. See SplashScreen module for an example.

  • onError

    Type: (error: Error) => void

    Deprecated

    If startAsync throws an error, it is caught and passed into the function provided to onError.

  • onFinish

    Type: () => void

    Deprecated

    (Required if you provide startAsync). Called when startAsync resolves or rejects. This should be used to set state and unmount the AppLoading component.

  • startAsync

    Type: () => Promise<void>

    Deprecated

    A function that returns a Promise, and the Promise should fulfil when the app is done loading required data and assets. You can do this process manually if you prefer. This is mainly for backwards compatibility and it is not recommended.

    When provided, requires providing onError prop as well.