Managing Cloud Data in React Native

Introduction to Cloud Data Management

As a React Native developer, you may need to access your device’s file system to perform certain operations, such as creating, saving, and editing files, or uploading and downloading files from the cloud. This is where the react-native-fs and react-native-blob-util packages come in.

What is a Blob?

A blob (Binary Large Object) is a data type that holds multimedia objects like images and videos, GIFs, and audio. It stores binary data as a single entity.

Creating and Saving Files with react-native-fs

To create a file with react-native-fs, you can use the writeFile method. This method allows you to write your files to a file path.

import { DocumentDirectoryPath, writeFile } from 'react-native-fs';

const filePath = `${DocumentDirectoryPath}/test.txt`;
const content = 'Hello, World!';

writeFile(filePath, content, 'utf8')
  .then((success) => {
    console.log('File created successfully!');
  })
  .catch((error) => {
    console.log('Error creating file:', error);
  });

Reading Files with readDir and readFile

To read the contents of a directory, you can use the readDir method. This method returns a promise that contains an array of objects with properties.

import { readDir } from 'react-native-fs';

readDir(DocumentDirectoryPath)
  .then((files) => {
    console.log('Files in directory:', files);
  })
  .catch((error) => {
    console.log('Error reading directory:', error);
  });

Uploading and Downloading Files

To upload and download files, you can use the react-native-blob-util package. This package provides methods for uploading and downloading files from the cloud.

import { Blob } from 'react-native-blob-util';

const file = new Blob(['Hello, World!'], { type: 'text/plain' });

// Upload file
fetch('https://example.com/upload', {
  method: 'POST',
  body: file,
})
  .then((response) => response.json())
  .then((data) => console.log(data))
  .catch((error) => console.error(error));

// Download file
fetch('undefinedexample.com/download')
  .then((response) => response.blob())
  .then((blob) => console.log(blob))
  .catch((error) => console.error(error));