quesalltime/react_native_web3_example

react_native_web3_example

Usage

1. Install dependencies

npm install

2. Run in Android or iOS

react-native run-android
react-native run-ios

Testing (Jest)

1. Setting your wallet private key and password in __tests__/env.js

let env = {
  web3Url: 'https://rinkeby.infura.io',
  privateKey: '<YOUR_WALLET_PRIVATE_KEY>',
  password: '<YOUR_WALLET_PASSWORD>'
};

2. Try it

npm test

How to install web3 in react native

1. Open your react native project

2. Install node-libs-browser and react-native-randombytes

npm install node-libs-browser react-native-randombytes
react-native link

3. Create a file called rn-cli.config.js on the root of the project and add the following code into it:

const extraNodeModules = require('node-libs-browser');

module.exports = {
  extraNodeModules,
};

4. Create a file called global.js on the root of the project and add the following code into it:

// Inject node globals into React Native global scope.
global.Buffer = require('buffer').Buffer;
global.process = require('process');
let randomBytes = require('react-native-randombytes').randomBytes;

if (typeof btoa === 'undefined') {
  global.btoa = function (str) {
    return new Buffer(str, 'binary').toString('base64');
  };
}

if (typeof atob === 'undefined') {
  global.atob = function (b64Encoded) {
    return new Buffer(b64Encoded, 'base64').toString('binary');
  };
}

global.crypto = {
  randomBytes(size, cb) {
    return randomBytes(size, cb);
  }
};

5. Import the global.js file into your App.js file

import './global';

6. Install web3

npm install web3

7. Initialize web3

import Web3 from 'web3';
let web3 = new Web3(Web3.givenProvider || 'https://mainnet.infura.io');

8. Try it

componentWillMount() {
  web3.eth.getBlock('latest').then(console.log).catch(console.error);
}

or

componentWillMount() {
  web3.eth.getBlock('latest', (err, result) => {
    if (err) {
      console.error(err);
    } else {
      console.log(result);
    }
  });
}

or

async componentWillMount() {
  try {
    console.log(await web3.eth.getBlock('latest'));
  } catch (err) {
    console.error(err);
  }
}

ref: How to set up web3.js with CRNA

ref: web3.js - Ethereum JavaScript API