web3.md

Web3

• 1. Connecting to a Network
  • 1.1 Web3

1. Connecting to a Network

Every transaction you make using Web3 is required to take place on a designated ethereum network. This is how addresses on the network can send funds to one-another.

In the example below, we show how to initialize a connection.

import { Web3 } from "web3-react-native";

(async () => {
  await Web3('https://ropsten.infura.io/v3/<your-token>');
})();

The network url dictates where all of your transactions will take place. In this documentation, we'll frequently be using the Ropsten test network, which ensures that all of the transactions we perform will be made using test ether.

However, with a simple switch it's easy to start using the same code to make transactions using real ether, with real monetary value.

In the example below, we demonstrate one way of how we could dynamically swap between production and test networks:

import { Web3 } from "web3-react-native";

(async () => {
  const test = 'https://ropsten.infura.io/v3/<your-token>';
  const production = '';
  await Web3(__DEV__ ? test : production);
})();

⚠️ This kind of implementation is not recommended, because developers often switch between development and production bundler modes to test certain features and may not necessarily wish to use real currency. You should make ethereum network urls a function of environment config to prevent mistakes or misuse. You can find a demonstration of this in the example application.

It is also possible to instantiate multiple simultaneous connections. These are guaranteed not to interfere with one-another:

import { Web3 } from "web3-react-native";

(async () => {
  const [...connections] = await Promise.all([
    Web3('https://ropsten.infura.io/v3/<your-token>'),
    Web3('https://ropsten.infura.io/v3/<another-token>'),
  ]);
})();

1.1 web3(url:String)

url:String

The address of the ethereum network you'd like to make the transaction. In the previous example, we use the Ropsten test network. The structure of this call allows the same Wallet instance to be reused across different ethereum networks.

A successful invocation of Web3() will resolve with a Promise which returns the functionality of web3-react-native scoped to the specified url.

In the example below, we show how to access the Wallet and Keystore objects:

import { Web3 } from "web3-react-native";

(async () => {
  const { Wallet, Keystore } = await Web3('https://ropsten.infura.io/v3/<your-token>');
})();