0xdAC17F958D2ee523a2206206994597C13D831ec7, ERC20 mainnet, [
{"constant":false,"inputs":[{"name":"_spender","type":"address"},{"name":"_value","type":"uint256"}],"name":"approve","outputs":[],"payable":false,"stateMutability":"nonpayable","type":"function"}
],
If the error is happening from the smart contract then only this require statement could cause that error.
require(!((_value != 0) && (allowed[msg.sender][_spender] != 0)));
Try checking the allowance of the addresses using the allowance function. This should not be equal to 0, to complete the approve function.
Please Iâm new to it, please can you run me a sample code of what the line of code should look like, so I could try it out? Thank you for helping.
This is the code to check the allowance of addresses. You need to update the params with the correct addresses.
const options = {
chain: 'eth',
address: "0xdAC17F958D2ee523a2206206994597C13D831ec7",
function_name: "allowance",
abi: [{"constant":true,"inputs":[{"name":"_owner","type":"address"},{"name":"_spender","type":"address"}],"name":"allowance","outputs":[{"name":"remaining","type":"uint256"}],"payable":false,"stateMutability":"view","type":"function"}],
params: {
_owner: "ownerAddressHere",
_spender: "SpenderAddressHere"
}
};
const result = await Moralis.Web3API.native.runContractFunction(options);
console.log(result)
For the âownerAddressHereâ, please how can I change it from a specific address to any signed in users address?
Should I replace it with the abi inputs name _owner?
You can get the loggedin user address using Moralis.User.current().get('ethAddress')
Is that what you are looking for?
You donât have to edit the ABI. Only addresses in params need to be updated.
Yea, I was asking if I was to edit the ownerAddressHere in params with _owner?
_owner address will be the wallet address who owns the tokens
_spender address will be the address of the wallet or contract who can spend the tokens from _owner address.
add the details accordingly
const options = {
chain: 'eth',
address: "0xdAC17F958D2ee523a2206206994597C13D831ec7",
function_name: "allowance",
abi: [{"constant":true,"inputs":[{"name":"_owner","type":"address"},{"name":"_spender","type":"address"}],"name":"allowance","outputs":[{"name":"remaining","type":"uint256"}],"payable":false,"stateMutability":"view","type":"function"}],
params: {
_owner: Moralis.User.current().get('ethAddress'),
_spender: "0x016A2eaE0185af599cF770fe20a2Ad0e9Fc3BfFb"
}
};
const result = await Moralis.Web3API.native.runContractFunction(options);
console.log(result);
if(!isAuthenticated && !user) {
console.log(user);
please hereâs the edited code
1 Like
sorry on my questions, iâm still a beginner.
your code look right. try running it and see what happens.
It looks like you are using react so try using the code from here with react syntax.
https://docs.moralis.io/moralis-dapp/web3-api/native#runcontractfunction
await should be inside an async function.
In react you can get user object data from useMoralis hook. Moralis.User.current() only works when authenticated with vanilla js code
const { user } = useMoralis();
// replace Moralis.User.current() with user
_owner: user.get('ethAddress'),
i then added Moralis.start() to my .env.local file where my Moralis server and appId is, but the error kept up showing.
You donât need to add Moralis.start() in the .env.local file. Make sure you have the appId and itâs value set in your MoralisProvider params which is in the index.js file. If you got it in your .env.local, makre sure itâs set properly there too having it starting with REACT_APP_... if youâre using react and process.env.REACT_APP_...