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I am using web3@0.20.7 and infura to connect Ropsten testing network. I haven't opened my website(using ethereum) for a while. Today I restarted my website, and I can not connect to ethereum with Infura. Here's code

var express = require('express');
var router = express.Router();
var Web3 = require('web3');
const testnet = 'https://ropsten.infura.io/';
const web3 = new Web3(new Web3.providers.HttpProvider(testnet));
var contractAddress = '0x72682d0d54c7ED7cdDdAa66E6DD7171f2B9c626C';
var contractABI =[{"constant":false,"inputs":[{"name":"CopyMatch","type..........
var contract = web3.eth.contract(contractABI).at(contractAddress);

Variable "contract" cannot get anything. How can I revise it? Thanks.

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  • 1
    At least your web3 version is ancient. I suggest you update. – Lauri Peltonen Mar 9 '20 at 16:33
  • Please elaborate on I can not connect to ethereum with Infura, and please explain what does Variable "contract" cannot get anything even mean. – goodvibration Mar 9 '20 at 18:58
  • Please check what is there in your contract, console.log it. I think it is not able to create an instance for you contract. – vteja711 Mar 10 '20 at 10:31
  • And also please upgrade your web3 and use the new method web3.eth.Contract(<<contract_abi>>, <<contract_address>>); – vteja711 Mar 10 '20 at 10:32
  • Also I think you might just have a promise in your contract. So use await and check – vteja711 Mar 10 '20 at 10:35
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I am able to connect to your contract. Try this. I got your abi from etherscan.

const express = require('express')
const Web3 = require('web3')
const web3 = new Web3(new Web3.providers.HttpProvider('https://ropsten.infura.io/'));
const abi = [{"constant":false,"inputs":[{"name":"CopyMatch","type":"address"}],"name":"proxy_ActiveStrategy","outputs":[{"name":"","type":"bool"}],"payable":false,"stateMutability":"nonpayable","type":"function"},{"constant":true,"inputs":[],"name":"name","outputs":[{"name":"","type":"string"}],"payable":false,"stateMutability":"view","type":"function"},{"constant":false,"inputs":[{"name":"_spender","type":"address"},{"name":"_value","type":"uint256"}],"name":"approve","outputs":[{"name":"","type":"bool"}],"payable":false,"stateMutability":"nonpayable","type":"function"},{"constant":false,"inputs":[{"name":"_signature","type":"bytes"},{"name":"_to","type":"address"},{"name":"_value","type":"uint256"},{"name":"_fee","type":"uint256"},{"name":"_nonce","type":"uint256"}],"name":"transferPreSigned","outputs":[{"name":"","type":"bool"}],"payable":false,"stateMutability":"nonpayable","type":"function"},{"constant":true,"inputs":[],"name":"totalSupply","outputs":[{"name":"","type":"uint256"}],"payable":false,"stateMutability":"view","type":"function"},{"constant":true,"inputs":[{"name":"hash","type":"bytes32"},{"name":"sig","type":"bytes"}],"name":"recover","outputs":[{"name":"","type":"address"}],"payable":false,"stateMutability":"pure","type":"function"},{"constant":false,"inputs":[{"name":"_from","type":"address"},{"name":"_to","type":"address"},{"name":"_value","type":"uint256"}],"name":"transferFrom","outputs":[{"name":"","type":"bool"}],"payable":false,"stateMutability":"nonpayable","type":"function"},{"constant":true,"inputs":[{"name":"_owner","type":"address"}],"name":"getNonce","outputs":[{"name":"nonce","type":"uint256"}],"payable":false,"stateMutability":"view","type":"function"},{"constant":true,"inputs":[],"name":"decimals","outputs":[{"name":"","type":"uint8"}],"payable":false,"stateMutability":"view","type":"function"},{"constant":false,"inputs":[],"name":"kill","outputs":[],"payable":false,"stateMutability":"nonpayable","type":"function"},{"constant":false,"inputs":[{"name":"CopyMatch","type":"address"}],"name":"proxy_inActiveStrategy","outputs":[{"name":"","type":"bool"}],"payable":false,"stateMutability":"nonpayable","type":"function"},{"constant":false,"inputs":[{"name":"_signature","type":"bytes"},{"name":"_spender","type":"address"},{"name":"_value","type":"uint256"},{"name":"_fee","type":"uint256"},{"name":"_nonce","type":"uint256"}],"name":"approvePreSigned","outputs":[{"name":"","type":"bool"}],"payable":false,"stateMutability":"nonpayable","type":"function"},{"constant":false,"inputs":[{"name":"_spender","type":"address"},{"name":"_subtractedValue","type":"uint256"}],"name":"decreaseApproval","outputs":[{"name":"","type":"bool"}],"payable":false,"stateMutability":"nonpayable","type":"function"},{"constant":true,"inputs":[{"name":"_owner","type":"address"}],"name":"balanceOf","outputs":[{"name":"","type":"uint256"}],"payable":false,"stateMutability":"view","type":"function"},{"constant":true,"inputs":[],"name":"Initial_Supply","outputs":[{"name":"","type":"uint256"}],"payable":false,"stateMutability":"view","type":"function"},{"constant":false,"inputs":[{"name":"CopyMatch","type":"address"},{"name":"addrCopyTrader","type":"address"},{"name":"id","type":"uint256"},{"name":"endAmount","type":"uint256"}],"name":"proxy_endCommit","outputs":[{"name":"","type":"bool"}],"payable":false,"stateMutability":"nonpayable","type":"function"},{"constant":false,"inputs":[{"name":"_signature","type":"bytes"},{"name":"_spender","type":"address"},{"name":"_subtractedValue","type":"uint256"},{"name":"_fee","type":"uint256"},{"name":"_nonce","type":"uint256"}],"name":"decreaseApprovalPreSigned","outputs":[{"name":"","type":"bool"}],"payable":false,"stateMutability":"nonpayable","type":"function"},{"constant":true,"inputs":[],"name":"owner","outputs":[{"name":"","type":"address"}],"payable":false,"stateMutability":"view","type":"function"},{"constant":true,"inputs":[],"name":"symbol","outputs":[{"name":"","type":"string"}],"payable":false,"stateMutability":"view","type":"function"},{"constant":false,"inputs":[{"name":"_to","type":"address"},{"name":"_value","type":"uint256"}],"name":"transfer","outputs":[{"name":"","type":"bool"}],"payable":false,"stateMutability":"nonpayable","type":"function"},{"constant":false,"inputs":[{"name":"_signature","type":"bytes"},{"name":"_spender","type":"address"},{"name":"_addedValue","type":"uint256"},{"name":"_fee","type":"uint256"},{"name":"_nonce","type":"uint256"}],"name":"increaseApprovalPreSigned","outputs":[{"name":"","type":"bool"}],"payable":false,"stateMutability":"nonpayable","type":"function"},{"constant":false,"inputs":[{"name":"_signature","type":"bytes"},{"name":"_to","type":"address"},{"name":"_controlId","type":"uint256"},{"name":"_fee","type":"uint256"},{"name":"_nonce","type":"uint256"},{"name":"CopyMatch","type":"address"},{"name":"addrCopyTrader","type":"address"},{"name":"id","type":"uint256"},{"name":"amount","type":"uint256"},{"name":"otherData","type":"string"},{"name":"endAmount","type":"uint256"}],"name":"controlPreSigned","outputs":[{"name":"","type":"bool"}],"payable":false,"stateMutability":"nonpayable","type":"function"},{"constant":false,"inputs":[{"name":"CopyMatch","type":"address"},{"name":"addrCopyTrader","type":"address"},{"name":"id","type":"uint256"},{"name":"amount","type":"uint256"},{"name":"otherData","type":"string"}],"name":"proxy_createCommit","outputs":[{"name":"","type":"bool"}],"payable":false,"stateMutability":"nonpayable","type":"function"},{"constant":false,"inputs":[{"name":"_spender","type":"address"},{"name":"_addedValue","type":"uint256"}],"name":"increaseApproval","outputs":[{"name":"","type":"bool"}],"payable":false,"stateMutability":"nonpayable","type":"function"},{"constant":true,"inputs":[{"name":"_owner","type":"address"},{"name":"_spender","type":"address"}],"name":"allowance","outputs":[{"name":"","type":"uint256"}],"payable":false,"stateMutability":"view","type":"function"},{"constant":true,"inputs":[{"name":"_token","type":"address"},{"name":"_functionSig","type":"bytes4"},{"name":"_spender","type":"address"},{"name":"_value","type":"uint256"},{"name":"_fee","type":"uint256"},{"name":"_nonce","type":"uint256"}],"name":"recoverPreSignedHash","outputs":[{"name":"","type":"bytes32"}],"payable":false,"stateMutability":"pure","type":"function"},{"constant":false,"inputs":[{"name":"newOwner","type":"address"}],"name":"transferOwnership","outputs":[],"payable":false,"stateMutability":"nonpayable","type":"function"},{"inputs":[],"payable":false,"stateMutability":"nonpayable","type":"constructor"},{"anonymous":false,"inputs":[{"indexed":true,"name":"from","type":"address"},{"indexed":true,"name":"to","type":"address"},{"indexed":false,"name":"value","type":"uint256"}],"name":"ControlPreSigned_Transfer_Fee","type":"event"},{"anonymous":false,"inputs":[{"indexed":true,"name":"from","type":"address"},{"indexed":true,"name":"to","type":"address"},{"indexed":true,"name":"delegate","type":"address"},{"indexed":false,"name":"_controlId","type":"uint256"},{"indexed":false,"name":"amount","type":"uint256"},{"indexed":false,"name":"fee","type":"uint256"}],"name":"ControlPreSigned","type":"event"},{"anonymous":false,"inputs":[{"indexed":true,"name":"from","type":"address"},{"indexed":true,"name":"to","type":"address"},{"indexed":false,"name":"value","type":"uint256"}],"name":"TransferPreSigned_Transfer_Fee","type":"event"},{"anonymous":false,"inputs":[{"indexed":true,"name":"from","type":"address"},{"indexed":true,"name":"to","type":"address"},{"indexed":true,"name":"delegate","type":"address"},{"indexed":false,"name":"amount","type":"uint256"},{"indexed":false,"name":"fee","type":"uint256"}],"name":"TransferPreSigned","type":"event"},{"anonymous":false,"inputs":[{"indexed":true,"name":"from","type":"address"},{"indexed":true,"name":"to","type":"address"},{"indexed":true,"name":"delegate","type":"address"},{"indexed":false,"name":"amount","type":"uint256"},{"indexed":false,"name":"fee","type":"uint256"}],"name":"ApprovalPreSigned","type":"event"},{"anonymous":false,"inputs":[{"indexed":true,"name":"existingOwner","type":"address"},{"indexed":true,"name":"newOwner","type":"address"}],"name":"transferOwner","type":"event"},{"anonymous":false,"inputs":[{"indexed":true,"name":"owner","type":"address"},{"indexed":true,"name":"spender","type":"address"},{"indexed":false,"name":"value","type":"uint256"}],"name":"Approval","type":"event"},{"anonymous":false,"inputs":[{"indexed":true,"name":"from","type":"address"},{"indexed":true,"name":"to","type":"address"},{"indexed":false,"name":"value","type":"uint256"}],"name":"Transfer","type":"event"}];
const app = express();
var contractAddress = '0x72682d0d54c7ED7cdDdAa66E6DD7171f2B9c626C';
const name = '';

    //Call the blockchain to send the details
    const nid = async() => {
        var contract = new web3.eth.Contract(abi,contractAddress);
        console.log("contract methods:", contract.methods);
    }
    nid();

I am able to log your methods.

contract methods: {
  proxy_ActiveStrategy: [Function: bound _createTxObject],
  '0x06a60e70': [Function: bound _createTxObject],
  'proxy_ActiveStrategy(address)': [Function: bound _createTxObject],
  name: [Function: bound _createTxObject],
  '0x06fdde03': [Function: bound _createTxObject],
  'name()': [Function: bound _createTxObject],
  approve: [Function: bound _createTxObject],
  '0x095ea7b3': [Function: bound _createTxObject],
  'approve(address,uint256)': [Function: bound _createTxObject],
  transferPreSigned: [Function: bound _createTxObject],
  '0x1296830d': [Function: bound _createTxObject],
  'transferPreSigned(bytes,address,uint256,uint256,uint256)': [Function: bound _createTxObject],
  totalSupply: [Function: bound _createTxObject],
  '0x18160ddd': [Function: bound _createTxObject],
  'totalSupply()': [Function: bound _createTxObject],
  recover: [Function: bound _createTxObject],
  '0x19045a25': [Function: bound _createTxObject],
  'recover(bytes32,bytes)': [Function: bound _createTxObject],
  transferFrom: [Function: bound _createTxObject],
  '0x23b872dd': [Function: bound _createTxObject],
  'transferFrom(address,address,uint256)': [Function: bound _createTxObject],
  getNonce: [Function: bound _createTxObject],
  '0x2d0335ab': [Function: bound _createTxObject],
  'getNonce(address)': [Function: bound _createTxObject],
  decimals: [Function: bound _createTxObject],
  '0x313ce567': [Function: bound _createTxObject],
  'decimals()': [Function: bound _createTxObject],
  kill: [Function: bound _createTxObject],
  '0x41c0e1b5': [Function: bound _createTxObject],
  'kill()': [Function: bound _createTxObject],
  proxy_inActiveStrategy: [Function: bound _createTxObject],
  '0x42c1eb38': [Function: bound _createTxObject],
  'proxy_inActiveStrategy(address)': [Function: bound _createTxObject],
  approvePreSigned: [Function: bound _createTxObject],
  '0x617b390b': [Function: bound _createTxObject],
  'approvePreSigned(bytes,address,uint256,uint256,uint256)': [Function: bound _createTxObject],
  decreaseApproval: [Function: bound _createTxObject],
  '0x66188463': [Function: bound _createTxObject],
  'decreaseApproval(address,uint256)': [Function: bound _createTxObject],
  balanceOf: [Function: bound _createTxObject],
  '0x70a08231': [Function: bound _createTxObject],
  'balanceOf(address)': [Function: bound _createTxObject],
  Initial_Supply: [Function: bound _createTxObject],
  '0x7bc14a67': [Function: bound _createTxObject],
  'Initial_Supply()': [Function: bound _createTxObject],
  proxy_endCommit: [Function: bound _createTxObject],
  '0x7f3e4852': [Function: bound _createTxObject],
  'proxy_endCommit(address,address,uint256,uint256)': [Function: bound _createTxObject],
  decreaseApprovalPreSigned: [Function: bound _createTxObject],
  '0x8be52783': [Function: bound _createTxObject],
  'decreaseApprovalPreSigned(bytes,address,uint256,uint256,uint256)': [Function: bound _createTxObject],
  owner: [Function: bound _createTxObject],
  '0x8da5cb5b': [Function: bound _createTxObject],
  'owner()': [Function: bound _createTxObject],
  symbol: [Function: bound _createTxObject],
  '0x95d89b41': [Function: bound _createTxObject],
  'symbol()': [Function: bound _createTxObject],
  transfer: [Function: bound _createTxObject],
  '0xa9059cbb': [Function: bound _createTxObject],
  'transfer(address,uint256)': [Function: bound _createTxObject],
  increaseApprovalPreSigned: [Function: bound _createTxObject],
  '0xadb8249e': [Function: bound _createTxObject],
  'increaseApprovalPreSigned(bytes,address,uint256,uint256,uint256)': [Function: bound _createTxObject],
  controlPreSigned: [Function: bound _createTxObject],
  '0xbe997005': [Function: bound _createTxObject],
  'controlPreSigned(bytes,address,uint256,uint256,uint256,address,address,uint256,uint256,string,uint256)': [Function: bound _createTxObject],
  proxy_createCommit: [Function: bound _createTxObject],
  '0xd5b71241': [Function: bound _createTxObject],
  'proxy_createCommit(address,address,uint256,uint256,string)': [Function: bound _createTxObject],
  increaseApproval: [Function: bound _createTxObject],
  '0xd73dd623': [Function: bound _createTxObject],
  'increaseApproval(address,uint256)': [Function: bound _createTxObject],
  allowance: [Function: bound _createTxObject],
  '0xdd62ed3e': [Function: bound _createTxObject],
  'allowance(address,address)': [Function: bound _createTxObject],
  recoverPreSignedHash: [Function: bound _createTxObject],
  '0xe9024691': [Function: bound _createTxObject],
  'recoverPreSignedHash(address,bytes4,address,uint256,uint256,uint256)': [Function: bound _createTxObject],
  transferOwnership: [Function: bound _createTxObject],
  '0xf2fde38b': [Function: bound _createTxObject],
  'transferOwnership(address)': [Function: bound _createTxObject]
}
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