Multiple web3 instances on a Single Page

Question

Is it normal/possible to use 2 instances of the web3 object?

In my app, a user can

• trigger the deployment of new contracts by clicking a button on the UI. The gas comes from a wallet that belongs to the app
• send ether to the deployed contract on the same page (made simple via a button on the page, contract then sends tokens to user)

In this scenario, is it recommended to have 2 web3 instances,

1. one using the web3 belonging to the app
2. one injected by the user's browser (eg: Metamask)

If so, is there a naming convention for the 2 web3 instances, like web3App and web3Browser?

Is this also an unusual scenario?

Answer 1

Yes it is possible to run 2 instances of web3.js. I am not aware of any naming convention for each web3 instance.

On the readme of web3 on github (https://github.com/ethereum/web3.js/blob/develop/README.md), there are some instructions to run several instances of web3:

web3.js version 0.14.0 supports multiple instances of web3 object. To migrate to this version, please follow the guide:

var Web3 = require('web3');
var web3 = new Web3();