using-one-wallet-with-smart-contracts.md

Using One Wallet with Smart Contracts

Add the following lines to your src/init.js

import initializeContract from './contract';
import userWallet from './userWallet';

let but = document.getElementById("inputtButton");

but.addEventListener("click",initWallet);

async function initWallet(){
    const wallet = new userWallet();
    await wallet.signin();
    const contract = await initializeContract();
    console.log(contract)
    const result = await contract.methods.getCount().call()
    console.log(result.toString())
}

In you src/hmy.js file, add the following lines of code

const { Harmony } = require('@harmony-js/core');
const { ChainType } = require('@harmony-js/utils');

export default new Harmony(
  // let's assume we deploy smart contract to this end-point URL
  'https://api.s0.b.hmny.io',
  {
    chainType: ChainType.Harmony,
    chainId: 2,
  },
);

Now add the following lines of code to src/contract.js

import hmy from './hmy';
import fs from 'fs';

const initializeContract = async (wallet)=>{
    let contract = fs.readFileSync("../build/contracts/Counter.json" , { encoding: "UTF-8" });
    contract = JSON.parse(contract)
    const abi = contract.abi;
    const contractAddress = contract.networks['2'].address;
    const contractInstance = hmy.contracts.createContract(abi,contractAddress);
    return contractInstance    
}

export default initializeContract;

To sign the transactions when calling send method on a smart contract, add the following lines to wallet class in src/userWallet.js

      signTransaction(txn) {
        if (this.isOneWallet) {
          return this.onewallet.signTransaction(txn);
        }
      }

      attachToContract(contract) {
        if(this.onewallet){
          contract.wallet.signTransaction = async (tx)=>{
            tx.from = this.address;
            const signTx = await this.signTransaction(tx);
            console.log(signTx);
            return signTx;
          }
        }
        return contract
      }

We assume that you are using the same setup structure throughout the documentation. If not, change the path of Counter.json to your desired location.

That's It !!

Now call "view" methods on smart contracts like this:

  const value = await contract.methods.getMoneyStored().call();

Call "payable" methods like this.

    const one = new BN('1')
    let options = {
		gasPrice: 1000000000,
		gasLimit: 210000,
		value: toWei(one, hmy.utils.Units.one),
    };
    
    const increment = await contract.methods.addMoney().send(options)

Congratulations you have now connected your one wallet, and completed writing code for it to interact with the harmony blockchain.