Lido Example

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Hello Lido!

If you are ready to explore further, the Lido component serves as an excellent fully-fledged example, as it demonstrates how to interact with a smart contract deployed on the Ethereum mainnet.

info

Ethers.js

This component uses the [Ethers JavaScript](https://ethers.org) library to interact with Ethereum smart contracts. Follow [this link](https://docs.ethers.org/v6/) for the official `ethers.js` documentation.

info

Web3 connect

The Lido example uses the [Web3Connect component](https://near.org/near/widget/ComponentDetailsPage?src=a_liutiev.near/widget/button_web3connect) to provide a [WalletConnect modal](https://github.com/WalletConnect/web3modal) so the user can connect with any Web3 Ethereum wallet like Ledger or MetaMask.

Fork the component

Navigate to the component
Select Fork
Feel free to make any changes
Click on Save to deploy the component

note

To deploy the component, you’ll need to sign in with a NEAR account and to make a deposit of a small amount of NEAR for the storage cost. This is because the components are stored in the NEAR network.

Source code

if (
  state.chainId === undefined &&
  ethers !== undefined &&
  Ethers.send("eth_requestAccounts", [])[0]
) {
  Ethers.provider()
    .getNetwork()
    .then((chainIdData) => {
      if (chainIdData?.chainId) {
        State.update({ chainId: chainIdData.chainId });
      }
    });
}
if (state.chainId !== undefined && state.chainId !== 1) {
  return <p>Switch to Ethereum Mainnet</p>;
}

// FETCH LIDO ABI

const lidoContract = "0xae7ab96520de3a18e5e111b5eaab095312d7fe84";
const tokenDecimals = 18;

const lidoAbi = fetch(
  "https://raw.githubusercontent.com/lidofinance/lido-subgraph/master/abis/Lido.json"
);
if (!lidoAbi.ok) {
  return "Loading";
}

const iface = new ethers.utils.Interface(lidoAbi.body);

// FETCH LIDO STAKING APR

if (state.lidoArp === undefined) {
  const apr = fetch(
    "https://api.allorigins.win/get?url=https://stake.lido.fi/api/sma-steth-apr"
  );
  if (!apr) return;
  State.update({ lidoArp: JSON.parse(apr?.body?.contents) ?? "..." });
}

// HELPER FUNCTIONS

const getStakedBalance = (receiver) => {
  const encodedData = iface.encodeFunctionData("balanceOf", [receiver]);

  return Ethers.provider()
    .call({
      to: lidoContract,
      data: encodedData,
    })
    .then((rawBalance) => {
      const receiverBalanceHex = iface.decodeFunctionResult(
        "balanceOf",
        rawBalance
      );

      return Big(receiverBalanceHex.toString())
        .div(Big(10).pow(tokenDecimals))
        .toFixed(2)
        .replace(/d(?=(d{3})+.)/g, "$&,");
    });
};

const submitEthers = (strEther, _referral) => {
  if (!strEther) {
    return console.log("Amount is missing");
  }
  const erc20 = new ethers.Contract(
    lidoContract,
    lidoAbi.body,
    Ethers.provider().getSigner()
  );

  let amount = ethers.utils.parseUnits(strEther, tokenDecimals).toHexString();

  erc20.submit(lidoContract, { value: amount }).then((transactionHash) => {
    console.log("transactionHash is " + transactionHash);
  });
};

// DETECT SENDER

if (state.sender === undefined) {
  const accounts = Ethers.send("eth_requestAccounts", []);
  if (accounts.length) {
    State.update({ sender: accounts[0] });
    console.log("set sender", accounts[0]);
  }
}

//if (!state.sender)  return "Please login first";

// FETCH SENDER BALANCE

if (state.balance === undefined && state.sender) {
  Ethers.provider()
    .getBalance(state.sender)
    .then((balance) => {
      State.update({ balance: Big(balance).div(Big(10).pow(18)).toFixed(2) });
    });
}

// FETCH SENDER STETH BALANCE

if (state.stakedBalance === undefined && state.sender) {
  getStakedBalance(state.sender).then((stakedBalance) => {
    State.update({ stakedBalance });
  });
}

// FETCH TX COST

if (state.txCost === undefined) {
  const gasEstimate = ethers.BigNumber.from(1875000);
  const gasPrice = ethers.BigNumber.from(1500000000);

  const gasCostInWei = gasEstimate.mul(gasPrice);
  const gasCostInEth = ethers.utils.formatEther(gasCostInWei);

  let responseGql = fetch(
    "https://api.thegraph.com/subgraphs/name/uniswap/uniswap-v2",
    {
      method: "POST",
      headers: { "Content-Type": "application/json" },
      body: JSON.stringify({
        query: `{
          bundle(            ethPrice
          }
        }`,
      }),
    }
  );

  if (!responseGql) return "";

  const ethPriceInUsd = responseGql.body.data.bundle.ethPrice;

  const txCost = Number(gasCostInEth) * Number(ethPriceInUsd);

  State.update({ txCost: `$${txCost.toFixed(2)}` });
}

// FETCH CSS

const cssFont = fetch(
  "https://fonts.googleapis.com/css2?family=Manrope:wght@200;300;400;500;600;700;800"
).body;
const css = fetch(
  "https://pluminite.mypinata.cloud/ipfs/Qmboz8aoSvVXLeP5pZbRtNKtDD3kX5D9DEnfMn2ZGSJWtP"
).body;

if (!cssFont || !css) return "";

if (!state.theme) {
  State.update({
    theme: styled.div`
    font-family: Manrope, -apple-system, BlinkMacSystemFont, Segoe UI, Roboto, Oxygen, Ubuntu, Cantarell, Fira Sans, Droid Sans, Helvetica Neue, sans-serif;
    ${cssFont}
    ${css}
`,
  });
}
const Theme = state.theme;

// OUTPUT UI

const getSender = () => {
  return !state.sender
    ? ""
    : state.sender.substring(0, 6) +
        "..." +
        state.sender.substring(state.sender.length - 4, state.sender.length);
};

return (
  <Theme>
    <div className="LidoContainer">
      <div className="Header">Stake Ether</div>
      <div className="SubHeader">Stake ETH and receive stETH while staking.</div>

      <div className="LidoForm">
        {state.sender && (
          <>
            <div className="LidoFormTopContainer">
              <div className="LidoFormTopContainerLeft">
                <div className="LidoFormTopContainerLeftContent1">
                  <div className="LidoFormTopContainerLeftContent1Container">
                    <span>Available to stake</span>
                    <div className="LidoFormTopContainerLeftContent1Circle" />
                  </div>
                </div>
                <div className="LidoFormTopContainerLeftContent2">
                  <span>
                    {state.balance ?? (!state.sender ? "0" : "...")}&nbsp;ETH
                  </span>
                </div>
              </div>
              <div className="LidoFormTopContainerRight">
                <div className="LidoFormTopContainerRightContent1">
                  <div className="LidoFormTopContainerRightContent1Text">
                    <span>{getSender()}</span>
                  </div>
                </div>
              </div>
            </div>
            <div className="LidoSplitter" />
          </>
        )}
        <div
          className={
            state.sender ? "LidoFormBottomContainer" : "LidoFormTopContainer"
          }
        >
          <div className="LidoFormTopContainerLeft">
            <div className="LidoFormTopContainerLeftContent1">
              <div className="LidoFormTopContainerLeftContent1Container">
                <span>Staked amount</span>
              </div>
            </div>
            <div className="LidoFormTopContainerLeftContent2">
              <span>
                {state.stakedBalance ?? (!state.sender ? "0" : "...")}
                &nbsp;stETH
              </span>
            </div>
          </div>
          <div className="LidoFormTopContainerRight">
            <div className="LidoAprContainer">
              <div className="LidoAprTitle">Lido APR</div>
              <div className="LidoAprValue">{state.lidoArp ?? "..."}%</div>
            </div>
          </div>
        </div>
      </div>
      <div className="LidoStakeForm">
        <div className="LidoStakeFormInputContainer">
          <span className="LidoStakeFormInputContainerSpan1">
            <svg width="24" height="24" viewBox="0 0 24 24" fill="currentColor">
              <path
                opacity="0.6"
                d="M11.999 3.75v6.098l5.248 2.303-5.248-8.401z"
              ></path>
              <path d="M11.999 3.75L6.75 12.151l5.249-2.303V3.75z"></path>
              <path
                opacity="0.6"
                d="M11.999 16.103v4.143l5.251-7.135L12 16.103z"
              ></path>
              <path d="M11.999 20.246v-4.144L6.75 13.111l5.249 7.135z"></path>
              <path
                opacity="0.2"
                d="M11.999 15.144l5.248-2.993-5.248-2.301v5.294z"
              ></path>
              <path
                opacity="0.6"
                d="M6.75 12.151l5.249 2.993V9.85l-5.249 2.3z"
              ></path>
            </svg>
          </span>
          <span className="LidoStakeFormInputContainerSpan2">
            <input
              disabled={!state.sender}
              className="LidoStakeFormInputContainerSpan2Input"
              value={state.strEther}
              onChange={(e) => State.update({ strEther: e.target.value })}
              placeholder="Amount"
            />
          </span>
          <span
            className="LidoStakeFormInputContainerSpan3"
            onClick={() => {
              State.update({
                strEther: (state.balance > 0.05
                  ? parseFloat(state.balance) - 0.05
                  : 0
                ).toFixed(2),
              });
            }}
          >
            <button
              className="LidoStakeFormInputContainerSpan3Content"
              disabled={!state.sender}
            >
              <span className="LidoStakeFormInputContainerSpan3Max">MAX</span>
            </button>
          </span>
        </div>
        {!!state.sender ? (
          <button
            className="LidoStakeFormSubmitContainer"
            onClick={() => submitEthers(state.strEther, state.sender)}
          >
            <span>Submit</span>
          </button>
        ) : (
          <Web3Connect
            className="LidoStakeFormSubmitContainer"
            connectLabel="Connect with Web3"
          />
        )}

        <div className="LidoFooterContainer">
          {state.sender && (
            <div className="LidoFooterRaw">
              <div className="LidoFooterRawLeft">You will receive</div>
              <div className="LidoFooterRawRight">${state.strEther ?? 0} stETH</div>
            </div>
          )}
          <div className="LidoFooterRaw">
            <div className="LidoFooterRawLeft">Exchange rate</div>
            <div className="LidoFooterRawRight">1 ETH = 1 stETH</div>
          </div>
          {false && (
            <div className="LidoFooterRaw">
              <div className="LidoFooterRawLeft">Transaction cost</div>
              <div className="LidoFooterRawRight">{state.txCost}</div>
            </div>
          )}
          <div className="LidoFooterRaw">
            <div className="LidoFooterRawLeft">Reward fee</div>
            <div className="LidoFooterRawRight">10%</div>
          </div>
        </div>
      </div>
    </div>
  </Theme>
);

Fork the component

Navigate to the component
Select Fork
Feel free to make any changes
Click on Save to deploy the component

note

To deploy the component, you’ll need to sign in with a NEAR account and to make a deposit of a small amount of NEAR for the storage cost. This is because NEAR components are stored in the NEAR network.

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