Using the web3.js APIs
we shall create a folder named web3projects to store the web3.js
APIs. In Terminal, type the following commands:
$ cd ~
$ mkdir web3projects
$ cd web3projects
Before you download the web3.js APIs, you want to create an empty Node.js project:
$ npm init –yes
The preceding command creates a file named package.json. This file contains the dependencies required by a Node.js application. To download the web3.js APIs, type the following command:
$ npm install web3@0.20.7 --save
The --save option informs npm to modify the package.json file and add the web3.js
as a dependency for the application.
Create a text
file named TestWeb3.html and save it in the web3projects folder.
Populate it as follows:
<!DOCTYPE html>
<html lang=“en”>
<script src=“./node_modules/web3/dist/web3.min.js”></script>
<body>
<script>
if (typeof web3!== ‘undefined’) {
// this statement is executed if you are using
// MetaMask
async function enableAccounts() {await ethereum.enable();
.then((account) => {
alert(“Account: “ + account + “\n” + “Provider Name: “ + web3.currentProvider.constructor.name);
})
}
enableAccounts();
} else {
// set the provider you want from Web3.providers web3 = new Web3(
new Web3.providers.HttpProvider(“http://localhost:8545”));
alert(“Account: “ + web3.eth.accounts[0] + “\n” + “Provider Name: “ + web3.currentProvider.constructor.name);
}
</script>
</body>
</html>
In Terminal, type the following command:
$ npm install -g serve
In the web3projects folder, type the following command:
$ serve
Using the Chrome browser (with MetaMask installed), load the following URL: http://localhost:5000/TestWeb3.html.
Click Connect
You need to give permission to the page to allow it to access your
MetaMask account(s)
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