Reading Data from Multiple Contracts Using Wagmi and React
As a developer, you are probably familiar with the Wagmi library, which provides an easy-to-use API for interacting with multiple blockchain contracts using Web3.js and Ethers.js. In this article, we will explore how to use Wagmi’s “useReadContracts” hook to retrieve data from multiple Ethereum contracts at once.
Problem
Suppose you have a list of 5 contracts with the same ABI (Application Binary Interface), but each contract has its own implementation. You want to use Wagmi to retrieve all the required data from these contracts, but currently “useReadContracts” only returns information about one contract at a time.
Decision
To solve this problem, we will use Wagmi’s “useGetContractInstance” hook and create an array of instances for each contract. We then pass this array to “useReadContracts” to retrieve data from all contracts at once.
Here are some code examples to get you started:
import { Ether } from 'Ether';
import { useReadContracts } from '@wagmi/wagmi';
const abi = [...]; // Your ABI contract
// Create an array of instances for each contract
const contractInstances = [
{
ID: 1,
Address: '0x...',
Example: ethers.ContractABI.fromWei(abi, ethers.utils.hexToWei('...'))(),
},
{
ID: 2,
Address: '0x...',
Example: ethers.ContractABI.fromWei(abi, ethers.utils.hexToWei('...'))(),
},
// ...
];
// Use useGetContractInstance to get an array of contract instances
const contracts = await useReadContracts(contractInstances);
// Now you can fetch data from all contracts at once using wagmi's useGetContractData hook
async function fetchData() {
const data = [];
for (const contract contract) {
try {
const result = await useGetContractData(contract.address, abi);
data.push(...result.data);
} catch errors {
console.error(error);
}
}
return data;
}
// Use fetchData function when you need to fetch data from multiple contracts
setInterval(fetchData, 1000); // fetch every second
Tips and Variations
- You can pass an object with contract addresses as key-value pairs to useReadContracts.
const contractInstances = [
{
ID: 1,
Address: '0x...',
Example: ethers.ContractABI.fromWei(abi, ethers.utils.hexToWei('...'))(),
},
{
ID: 2,
Address: '0x...',
Example: ethers.ContractABI.fromWei(abi, ethers.utils.hexToWei('...'))(),
},
];
- If you need to get data from a contract in parallel, you can use Wagmi’s useGetContractData hook with an object where the key is the contract address and the value is a function that returns data for each contract.
const contractInstances = [
{
ID: 1,
Address: '0x...',
Example: ethers.ContractABI.fromWei(abi, ethers.utils.hexToWei('...'))(),
},
{
ID: 2,
Address: '0x...',
Example: ethers.ContractABI.fromWei(abi, ethers.utils.hexToWei('...'))(),
},
];
const data = {};
for (const contract contract) {
Data[Contract.Address] = wait useGetContractData(Contract.Address, abi);
}
Hope this helps! Let me know if you have any questions or need further help.