fetch.js

/**
 * Sample React Native App
 * https://github.com/facebook/react-native
 * @flow
 */

import React, { Component } from 'react';
import {
  AppRegistry,
  StyleSheet,
  Text,
  View,
  TextInput,
  TouchableOpacity
} from 'react-native'

import RNFetchBlob from 'react-native-fetch-blob'

export default class blob extends Component {

  constructor(props) {
    super(props);
    this.state = {
      url: '',
      path: null
    }
  }

  download = () => {
    const {url} = this.state

    const filename = 'video.mp4'
    const path = RNFetchBlob.fs.dirs.DocumentDir + '/' + filename

    console.log(path)
    console.log(' [ + ] Start Downloading')

    RNFetchBlob
    .config({
      fileCache: true,
      path
    })
    .fetch('GET', url)
    .then((res) => {
      this.setState({ path: res.path() })
      console.log('[ + ] File is downloaded on ', res)
    }, e => {
      console.log(e)
    })
  }

  openfile = () => {
    RNFetchBlob.ios.openDocument(this.state.path).then(r => r, e => e)
  }

  render() {
    return (
      <View style={styles.container}>
        <TextInput
          value={this.state.url}
          onChangeText={(url) => this.setState({url})}
          placeholder='enter url'
          style={{ width: 300, height: 30 }} />

        <TouchableOpacity onPress={this.download}>
          <Text>Download</Text>
        </TouchableOpacity>

        {
          this.state.path != null &&
          <View style={{ marginTop: 40 }}>
            <TouchableOpacity onPress={this.openfile}>
              <Text>Open { this.state.path }</Text>
            </TouchableOpacity>
          </View>
        }
      </View>
    );
  }
}

const styles = StyleSheet.create({
  container: {
    flex: 1,
    marginTop: 100,
    backgroundColor: '#F5FCFF',
  }
});

AppRegistry.registerComponent('blob', () => blob);