The following examples use an open-source library of React hooks built for Ethereum called Wagmi. Please create a new file GreenTokenVaultInterface.json in your project to import the ABI and get started on these code examples 👇

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Depositing into vault

Let’s start with a simple example where we render a component that attempts to deposit 1 token (assuming 18 decimals) to the vault when clicked on.

Note that in order for this to succeed on you must approve the spending amount first on the ERC-20 token for the vault address as the spender. Use depositETH instead if you are integrating with a native token like ETH or Celo
import { ethers } from "ethers";
import {useAccount, useSigner, useContractWrite, usePrepareContractWrite} from "wagmi";
import ImpactVaultInterface from "~/abis/ImpactVaultInterface.json";

export const MyComponent = () => {
  const { address } = useAccount();
  const { signer } = useSigner();

  const { config: depositConfig } = usePrepareContractWrite({
    addressOrName: "",
    contractInterface: ImpactVaultInterface.abi,
    functionName: "deposit",
    signerOrProvider: signer,
    args: [ethers.utils.parseEther("1"), address],
  });

  const { write: deposit } = useContractWrite({
    ...depositConfig,
    onSuccess: async (data: any) => {
      console.log("wallet prompt success");
      const res = await data.wait();
      if (res.status === 1) {
        console.log("txn success");
      } else {
        console.log("txn error");
      }
    },
    onError: error => {
      console.log("wallet prompt error");
    },
  });

  return (

Deposit 1 token

  );
}

​
Reading gToken balance

Great! Now we can also read the gToken balance like any other ERC-20 token contract. Doing this is simple with Wagmi using the useBalance hook.

import { ethers } from "ethers";
import {useAccount, useBalance} from "wagmi";

export const MyComponent = () => {
  const { address } = useAccount();

  const { data: gTokenBalance, refetch: refetchBalance } = useBalance({
    addressOrName: address,
    token: ""
  });

  return (

gToken balance {gTokenBalance.formatted}

  );
}

Let’s merge this with the first snippet so that after we deposit we refetch the user’s gToken balance and see it change!

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Putting it together

import { ethers } from "ethers";
import {useAccount, useSigner, useBalance, useContractWrite, usePrepareContractWrite} from "wagmi";
import ImpactVaultInterface from "~/abis/ImpactVaultInterface.json";

export const MyComponent = () => {
  const { address } = useAccount();
  const { signer } = useSigner();

  const { data: gTokenBalance, refetch: refetchBalance } = useBalance({
    addressOrName: address,
    token: ""
  });

  console.log(`pre-deposit gToken balance: ${gTokenBalance?.formatted}`);

  const { config: depositConfig } = usePrepareContractWrite({
    addressOrName: "",
    contractInterface: ImpactVaultInterface.abi,
    functionName: "deposit",
    signerOrProvider: signer,
    args: [ethers.utils.parseEther("1"), address],
  });

  const { write: deposit } = useContractWrite({
    ...depositConfig,
    onSuccess: async (data: any) => {
      console.log("wallet prompt success");
      const res = await data.wait();
      if (res.status === 1) {
        console.log("txn success");
        await refetchBalance();
        console.log(`post-deposit gToken balance: ${gTokenBalance?.formatted}`);
      } else {
        console.log("txn error");
      }
    },
    onError: error => {
      console.log("wallet prompt error");
    },
  });

  return (

Deposit 1 token

    gToken balance {gTokenBalance.formatted}

  );
}

Woo! Now we have a full end-to-end example of a front-end dapp that deposits an ERC-20 token into the gToken vault and refetches the user’s gToken balance 😤

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