1

There's a number of questions and answers about calling contract methods via web3, but they are either outdated (i.e. for web3 0.x while 1.x has many breaking changes) and/or don't include signing (1, 2, 3). The first steps, as far as I understand, should be these:

import Web3 from "web3"
import { AbiItem } from "web3-utils"

;(async() => {
    const provider = new Web3.providers.HttpProvider(...)
    const web3 = new Web3(provider)


// see https://ethereum.stackexchange.com/a/98149/40080 and https://github.com/ChainSafe/web3.js/issues/3310#issuecomment-997396686
const abi = ... as AbiItem[] // imported from a file
const methodName = ...
const callParameters = [
    ...
]
const contractAddress = ...
const universeContract = new web3.eth.Contract(abi, contractAddress)

const call = universeContract.methods[methodName](callParameters)



})()

but then I also have to sign this with private key and send, and this is what I haven't achieved yet. According to this answer, I should be using eth.accounts.sign(data, privateKey) (since I have to do this without a node), but I have no idea what data I should extract from call and how (and how to further send it). Can somebody show how to do this or at least give some pointers?

YakovL
  • 123
  • 7

1 Answers1

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Assuming you have a proper Web3 instance setup, the below is how I generally make contract calls from the server using a class (or where you have a fixed key that requires no user input). I use an instance of the Hyperledger Besu version of Ethereum, so if you use a different provider it might vary slightly. Also, if you are asking the user to sign the transaction, it's a different process, but from your question it sounded like you are using a fixed key without input.

this.contract = new this.web3.eth.Contract(abi, contractAddress);

let tx = {
   from: fromAddress,
   to: this.contract.options.address,
   gasPrice: gasPrice,
   gas: gasAmount,
   data: await this.contract.methods.methodName(param1, param2, ...).encodeABI()
};


let signedTx = await this.web3.eth.accounts.signTransaction(tx, privateKey);
let result = await this.web3.eth.sendSignedTransaction(signedTx.rawTransaction);
pdmoerman
  • 131
  • 6