npm react-native-fetch-blob - "RNFetchBlob.fetch is not a function" - node.js

Question

I am using the npm package react-native-fetch-blob.
I have followed all the steps from the git repository to use the package.
I then imported the package using the following line:
var RNFetchBlob = require('react-native-fetch-blob');
I am trying to request a BLOB containing an image from the a server.
This is my main method.
fetchAttachment: function(attachment_uri) {
var authToken = 'youWillNeverGetThis!'
var deviceId = '123';
var xAuthToken = deviceId+'#'+authToken
//Authorization : 'Bearer access-token...',
// send http request in a new thread (using native code)
RNFetchBlob.fetch('GET', config.apiRoot+'/app/'+attachment_uri, {
'Origin': 'http://10.0.1.23:8081',
'X-AuthToken': xAuthToken
})
// when response status code is 200
.then((res) => {
// the conversion is done in native code
let base64Str = res.base64()
// the following conversions are done in js, it's SYNC
let text = res.text()
let json = res.json()
})
// Status code is not 200
.catch((errorMessage, statusCode) => {
// error handling
});
}
I keep receiving the following error:
"Possible Unhandled Promise Refection(id: 0): TypeError: RNFetchBlob.fetch is not a function".
Any ideas?

Answer 1

The issue is you are using ES5 style require statements with a library written against ES6/ES2015. You have two options:
ES5:
var RNFetchBlob = require('react-native-fetch-blob').default
ES6:
import RNFetchBlob from 'react-native-fetch-blob'

Answer 2

My import looks like this : import RNFetchBlob from 'rn-fetch-blob';
but I'v got an error : TypeError: RNFetchBlob.scanFile is not a function
My code:
const downloadAudio = async () => {
const { config, fs } = RNFetchBlob;
const meditationFilesPath =
Platform.OS == 'android'
? `${fs.dirs.DownloadDir}/meditations/${id}`
: `${fs.dirs.DocumentDir}/meditations/${id}`;
let audio_URL = track;
let options = {
fileCache: true,
path: meditationFilesPath + `/${id}.mp3`,
addAndroidDownloads: {
// Related to the Android only
useDownloadManager: true,
notification: true,
path: meditationFilesPath + `/${id}.mp3`,
description: 'Audio',
},
};
try {
const resAudio = await config(options).fetch('GET', audio_URL.uri);
if (resAudio) {
const audio = await RNFetchBlob.fs.scanFile([
{ path: resAudio.path(), mime: 'audio/mpeg' },
]);
console.log('res -> ', audio);
Alert.alert('Audio Downloaded Successfully.');
}
} catch (error) {
console.error('error from downloadAudio', error);
}
};