v2.x
Web3 Integration
Smart Contract Functions
If you have replaced your web3 provider with Fortmatic provider, nothing needs to be changed for web3 contract transactions to continue working. The following is an example on how to initiate a ERC20 smart contract token transfer.
Web3 Pre-1.0 Stable Versions
Web3 1.0 Beta Version
1
// Initialize provider
2
import Fortmatic from 'fortmatic';
3
import Web3 from 'web3';
4
5
const fm = new Fortmatic('YOUR_API_KEY');
6
window.web3 = new Web3(fm.getProvider());
7
8
// Get the contract ABI from compiled smart contract json
9
const erc20TokenContractAbi = [{"constant":true,"inputs":[],"name":"name","outputs":[{"name":"","type":"string"}],"payable":false,"stateMutability":"view","type":"function"},{"constant":false,"inputs":[{"name":"spender","type":"address"},{"name":"tokens","type":"uint256"}],"name":"approve","outputs":[{"name":"success","type":"bool"}],"payable":false,"stateMutability":"nonpayable","type":"function"},{"constant":true,"inputs":[],"name":"totalSupply","outputs":[{"name":"","type":"uint256"}],"payable":false,"stateMutability":"view","type":"function"},{"constant":false,"inputs":[{"name":"from","type":"address"},{"name":"to","type":"address"},{"name":"tokens","type":"uint256"}],"name":"transferFrom","outputs":[{"name":"success","type":"bool"}],"payable":false,"stateMutability":"nonpayable","type":"function"},{"constant":true,"inputs":[],"name":"decimals","outputs":[{"name":"","type":"uint8"}],"payable":false,"stateMutability":"view","type":"function"},{"constant":false,"inputs":[{"name":"amount","type":"uint256"}],"name":"withdrawEther","outputs":[],"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":"tokenOwner","type":"address"}],"name":"balanceOf","outputs":[{"name":"balance","type":"uint256"}],"payable":false,"stateMutability":"view","type":"function"},{"constant":false,"inputs":[],"name":"acceptOwnership","outputs":[],"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":true,"inputs":[{"name":"a","type":"uint256"},{"name":"b","type":"uint256"}],"name":"safeSub","outputs":[{"name":"c","type":"uint256"}],"payable":false,"stateMutability":"pure","type":"function"},{"constant":false,"inputs":[{"name":"to","type":"address"},{"name":"tokens","type":"uint256"}],"name":"transfer","outputs":[{"name":"success","type":"bool"}],"payable":false,"stateMutability":"nonpayable","type":"function"},{"constant":true,"inputs":[{"name":"a","type":"uint256"},{"name":"b","type":"uint256"}],"name":"safeDiv","outputs":[{"name":"c","type":"uint256"}],"payable":false,"stateMutability":"pure","type":"function"},{"constant":false,"inputs":[{"name":"spender","type":"address"},{"name":"tokens","type":"uint256"},{"name":"data","type":"bytes"}],"name":"approveAndCall","outputs":[{"name":"success","type":"bool"}],"payable":false,"stateMutability":"nonpayable","type":"function"},{"constant":true,"inputs":[{"name":"a","type":"uint256"},{"name":"b","type":"uint256"}],"name":"safeMul","outputs":[{"name":"c","type":"uint256"}],"payable":false,"stateMutability":"pure","type":"function"},{"constant":true,"inputs":[],"name":"newOwner","outputs":[{"name":"","type":"address"}],"payable":false,"stateMutability":"view","type":"function"},{"constant":false,"inputs":[{"name":"tokenAddress","type":"address"},{"name":"tokens","type":"uint256"}],"name":"transferAnyERC20Token","outputs":[{"name":"success","type":"bool"}],"payable":false,"stateMutability":"nonpayable","type":"function"},{"constant":true,"inputs":[{"name":"tokenOwner","type":"address"},{"name":"spender","type":"address"}],"name":"allowance","outputs":[{"name":"remaining","type":"uint256"}],"payable":false,"stateMutability":"view","type":"function"},{"constant":true,"inputs":[{"name":"a","type":"uint256"},{"name":"b","type":"uint256"}],"name":"safeAdd","outputs":[{"name":"c","type":"uint256"}],"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"},{"payable":true,"stateMutability":"payable","type":"fallback"},{"anonymous":false,"inputs":[{"indexed":true,"name":"_from","type":"address"},{"indexed":true,"name":"_to","type":"address"}],"name":"OwnershipTransferred","type":"event"},{"anonymous":false,"inputs":[{"indexed":true,"name":"from","type":"address"},{"indexed":true,"name":"to","type":"address"},{"indexed":false,"name":"tokens","type":"uint256"}],"name":"Transfer","type":"event"},{"anonymous":false,"inputs":[{"indexed":true,"name":"tokenOwner","type":"address"},{"indexed":true,"name":"spender","type":"address"},{"indexed":false,"name":"tokens","type":"uint256"}],"name":"Approval","type":"event"}];
10
11
// Create contract object
12
const tokenContract = web3.eth.contract(erc20TokenContractAbi);
13
// Instantiate contract
14
const tokenContractInstance = tokenContract.at('0x8EBC7785b83506AaA295Bd9174e6A7Ad5681fb80');
15
16
const toAddress = '0xE0cef4417a772512E6C95cEf366403839b0D6D6D';
17
// Calculate contract compatible value for transfer with proper decimal points using BigNumber
18
const tokenDecimals = web3.toBigNumber(18);
19
const tokenAmountToTransfer = web3.toBigNumber(100);
20
const calculatedTransferValue = web3.toHex(tokenAmountToTransfer.mul(web3.toBigNumber(10).pow(tokenDecimals)));
21
22
// Call contract function (non-state altering) to get total token supply
23
tokenContractInstance.totalSupply.call(function(error, result) {
24
if (error) throw error;
25
console.log(result);
26
});
27
28
// Get user account wallet address first
29
web3.eth.getAccounts(function(error, accounts) {
30
if (error) throw error;
31
// Send ERC20 transaction with web3
32
tokenContractInstance.transfer.sendTransaction(toAddress, calculatedTransferValue, {from: accounts[0]}, (error, txnHash) => {
33
if (error) throw error;
34
console.log(txnHash);
35
});
36
});
Copied!
1
// Initialize provider
2
import Fortmatic from 'fortmatic';
3
import Web3 from 'web3';
4
5
const fm = new Fortmatic('YOUR_API_KEY');
6
window.web3 = new Web3(fm.getProvider());
7
8
// Get the contract ABI from compiled smart contract json
9
const erc20TokenContractAbi = [{"constant":true,"inputs":[],"name":"name","outputs":[{"name":"","type":"string"}],"payable":false,"stateMutability":"view","type":"function"},{"constant":false,"inputs":[{"name":"spender","type":"address"},{"name":"tokens","type":"uint256"}],"name":"approve","outputs":[{"name":"success","type":"bool"}],"payable":false,"stateMutability":"nonpayable","type":"function"},{"constant":true,"inputs":[],"name":"totalSupply","outputs":[{"name":"","type":"uint256"}],"payable":false,"stateMutability":"view","type":"function"},{"constant":false,"inputs":[{"name":"from","type":"address"},{"name":"to","type":"address"},{"name":"tokens","type":"uint256"}],"name":"transferFrom","outputs":[{"name":"success","type":"bool"}],"payable":false,"stateMutability":"nonpayable","type":"function"},{"constant":true,"inputs":[],"name":"decimals","outputs":[{"name":"","type":"uint8"}],"payable":false,"stateMutability":"view","type":"function"},{"constant":false,"inputs":[{"name":"amount","type":"uint256"}],"name":"withdrawEther","outputs":[],"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":"tokenOwner","type":"address"}],"name":"balanceOf","outputs":[{"name":"balance","type":"uint256"}],"payable":false,"stateMutability":"view","type":"function"},{"constant":false,"inputs":[],"name":"acceptOwnership","outputs":[],"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":true,"inputs":[{"name":"a","type":"uint256"},{"name":"b","type":"uint256"}],"name":"safeSub","outputs":[{"name":"c","type":"uint256"}],"payable":false,"stateMutability":"pure","type":"function"},{"constant":false,"inputs":[{"name":"to","type":"address"},{"name":"tokens","type":"uint256"}],"name":"transfer","outputs":[{"name":"success","type":"bool"}],"payable":false,"stateMutability":"nonpayable","type":"function"},{"constant":true,"inputs":[{"name":"a","type":"uint256"},{"name":"b","type":"uint256"}],"name":"safeDiv","outputs":[{"name":"c","type":"uint256"}],"payable":false,"stateMutability":"pure","type":"function"},{"constant":false,"inputs":[{"name":"spender","type":"address"},{"name":"tokens","type":"uint256"},{"name":"data","type":"bytes"}],"name":"approveAndCall","outputs":[{"name":"success","type":"bool"}],"payable":false,"stateMutability":"nonpayable","type":"function"},{"constant":true,"inputs":[{"name":"a","type":"uint256"},{"name":"b","type":"uint256"}],"name":"safeMul","outputs":[{"name":"c","type":"uint256"}],"payable":false,"stateMutability":"pure","type":"function"},{"constant":true,"inputs":[],"name":"newOwner","outputs":[{"name":"","type":"address"}],"payable":false,"stateMutability":"view","type":"function"},{"constant":false,"inputs":[{"name":"tokenAddress","type":"address"},{"name":"tokens","type":"uint256"}],"name":"transferAnyERC20Token","outputs":[{"name":"success","type":"bool"}],"payable":false,"stateMutability":"nonpayable","type":"function"},{"constant":true,"inputs":[{"name":"tokenOwner","type":"address"},{"name":"spender","type":"address"}],"name":"allowance","outputs":[{"name":"remaining","type":"uint256"}],"payable":false,"stateMutability":"view","type":"function"},{"constant":true,"inputs":[{"name":"a","type":"uint256"},{"name":"b","type":"uint256"}],"name":"safeAdd","outputs":[{"name":"c","type":"uint256"}],"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"},{"payable":true,"stateMutability":"payable","type":"fallback"},{"anonymous":false,"inputs":[{"indexed":true,"name":"_from","type":"address"},{"indexed":true,"name":"_to","type":"address"}],"name":"OwnershipTransferred","type":"event"},{"anonymous":false,"inputs":[{"indexed":true,"name":"from","type":"address"},{"indexed":true,"name":"to","type":"address"},{"indexed":false,"name":"tokens","type":"uint256"}],"name":"Transfer","type":"event"},{"anonymous":false,"inputs":[{"indexed":true,"name":"tokenOwner","type":"address"},{"indexed":true,"name":"spender","type":"address"},{"indexed":false,"name":"tokens","type":"uint256"}],"name":"Approval","type":"event"}];
10
11
// Create contract object
12
const tokenContractAddress = '0x8EBC7785b83506AaA295Bd9174e6A7Ad5681fb80';
13
const tokenContract = new web3.eth.Contract(erc20TokenContractAbi, tokenContractAddress);
14
15
const toAddress = '0xE0cef4417a772512E6C95cEf366403839b0D6D6D';
16
// Calculate contract compatible value for transfer with proper decimal points using BigNumber
17
const tokenDecimals = web3.utils.toBN(18);
18
const tokenAmountToTransfer = web3.utils.toBN(100);
19
const calculatedTransferValue = web3.utils.toHex(tokenAmountToTransfer.mul(web3.utils.toBN(10).pow(tokenDecimals)));
20
21
// Call contract function (non-state altering) to get total token supply
22
tokenContract.methods.totalSupply().call().then(console.log);
23
24
// Get user account wallet address first
25
web3.eth.getAccounts().then((accounts) => {
26
// Send ERC20 transaction with web3
27
tokenContract.methods.transfer(
28
toAddress,
29
calculatedTransferValue
30
).send({from: accounts[0]})
31
.once('transactionHash', (hash) => { console.log(hash); })
32
.once('receipt', (receipt) => { console.log(receipt); });
33
});
Copied!
Last modified 2yr ago
Copy link