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建立你自己的完全链上 DAO 来投资 NFT

为您的 NFT 持有者构建 DAO

什么是 DAO？​

DAO 代表去中心化自治组织。您可以将 DAO 视为类似于现实世界中的公司。从本质上讲，DAO 允许成员创建治理决策并对其进行投票。

在传统公司中，当需要做出决定时，公司的董事会或高管负责做出该决定。然而，在 DAO 中，这个过程是民主化的，任何成员都可以创建提案，所有其他成员都可以对其进行投票。创建的每个提案都有一个投票截止日期，在截止日期之后做出有利于投票结果的决定（是或否）。

DAO 的成员资格通常受到 ERC20 代币所有权或 NFT 所有权的限制。成员资格和投票权与您拥有的代币数量成正比的 DAO 示例包括 Uniswap 和 ENS。基于 NFT 的 DAO 示例包括 Meebits DAO。

构建我们的 DAO​

你想为你的 CryptoDevs NFT 的持有者启动一个 DAO。从通过 ICO 获得的 ETH 中，你建立了一个 DAO 库。 DAO 现在有很多 ETH，但目前什么也没做。

您希望允许您的 NFT 持有者创建并投票使用该 ETH 从 NFT 市场购买其他 NFT 的提案，并推测价格。也许将来当你卖回 NFT 时，你会将利润分配给 DAO 的所有成员。

要求​

  • 任何拥有 CryptoDevs NFT 的人都可以创建从 NFT 市场购买不同 NFT 的提案
  • 每个拥有 CryptoDevs NFT 的人都可以投票支持或反对活跃的提案
  • 每个 NFT 计为每个提案的一票
  • 投票者不能对具有相同 NFT 的同一个提案多次投票
  • 如果在截止日期前多数选民投票支持该提案，NFT 购买将自动执行

我们将做什么​

  • 为了能够在提案通过时自动购买 NFT，您需要一个可以调用 purchase() 函数的链上 NFT 市场。那里有很多 NFT 市场，但为了避免过于复杂，我们将为本教程创建一个简化的假 NFT 市场，因为重点是 DAO。
  • 我们还将使用 Hardhat 制作实际的 DAO 智能合约。
  • 我们将使用 Next.js 制作网站，以允许用户创建和对提案进行投票

先决条件​

  • 你已经完成了之前的 NFT Collection 教程。
  • 你必须有一些 ETH 给 DAO 财政部

构建​

智能合约开发​

我们将从创建智能合约开始。我们将制作两个智能合约：

  • FakeNFTMarketplace.sol
  • CryptoDevsDAO.sol

为此，我们将使用我们在过去几个教程中一直使用的 Hardhat 开发框架。

为这个项目创建一个名为 DAO-Tutorial 的文件夹，并在该文件夹中打开一个终端窗口。

通过在终端中运行以下命令来设置新的安全帽项目：

mkdir hardhat-tutorial
cd hardhat-tutorial
npm init --yes
npm install --save-dev hardhat

现在您已经安装了 Hardhat，我们可以设置一个项目。在终端中执行以下命令。

在安装 Hardhat 的同一目录中运行：

npx hardhat

确保选择创建 Javascript 项目，然后按照终端中的步骤完成安全帽设置。

现在，让我们从 NPM 安装 @openzeppelin/contracts 包，因为我们将使用 OpenZeppelin 的 Ownable Contract 作为 DAO 合约。

npm install @openzeppelin/contracts

首先，让我们做一个简单的 Fake NFT Marketplace。在 hardhat-tutorial 中的 contracts 目录下创建一个名为 FakeNFTMarketplace.sol 的文件，并添加以下代码。

// SPDX-License-Identifier: MIT
pragma solidity ^0.8.0;

contract FakeNFTMarketplace {
    /// @dev Maintain a mapping of Fake TokenID to Owner addresses
    mapping(uint256 => address) public tokens;
    /// @dev Set the purchase price for each Fake NFT
    uint256 nftPrice = 0.1 ether;

    /// @dev purchase() accepts ETH and marks the owner of the given tokenId as the caller address
    /// @param _tokenId - the fake NFT token Id to purchase
    function purchase(uint256 _tokenId) external payable {
        require(msg.value == nftPrice, "This NFT costs 0.1 ether");
        tokens[_tokenId] = msg.sender;
    }

    /// @dev getPrice() returns the price of one NFT
    function getPrice() external view returns (uint256) {
        return nftPrice;
    }

    /// @dev available() checks whether the given tokenId has already been sold or not
    /// @param _tokenId - the tokenId to check for
    function available(uint256 _tokenId) external view returns (bool) {
        // address(0) = 0x0000000000000000000000000000000000000000
        // This is the default value for addresses in Solidity
        if (tokens[_tokenId] == address(0)) {
            return true;
        }
        return false;
    }
}

FakeNFTMarketplace 公开了一些基本功能，如果提案获得通过，我们将从 DAO 合约中使用这些功能来购买 NFT。 真正的 NFT 市场会更加复杂——因为并非所有 NFT 的价格都相同。

在开始编写 DAO 合约之前，让我们确保一切都编译好。 在终端的 hardhat-tutorial 文件夹中运行以下命令。

npx hardhat compile

并确保没有编译错误。

现在，我们将开始编写 CryptoDevsDAO 合约。 由于这主要是一个完全自定义的合约，并且比我们目前所做的相对复杂，所以我们将一点一点地解释这一点。 首先，让我们为合约编写样板代码。 在 hardhat-tutorial 的 contracts 目录下创建一个名为 CryptoDevsDAO.sol 的新文件，并将以下代码添加到其中。

// SPDX-License-Identifier: MIT
pragma solidity ^0.8.0;

import "@openzeppelin/contracts/access/Ownable.sol";

// We will add the Interfaces here

contract CryptoDevsDAO is Ownable {
    // We will write contract code here
}

现在，我们需要调用 FakeNFTMarketplace 合约以及您之前部署的 CryptoDevs NFT 合约的函数。 回想一下高级 Solidity 主题教程，我们需要为这些合约提供一个接口，因此该合约知道哪些函数可以调用，它们将什么作为参数以及它们返回什么。

通过添加以下代码将以下两个接口添加到您的代码中

/**
 * Interface for the FakeNFTMarketplace
 */
interface IFakeNFTMarketplace {
    /// @dev getPrice() returns the price of an NFT from the FakeNFTMarketplace
    /// @return Returns the price in Wei for an NFT
    function getPrice() external view returns (uint256);

    /// @dev available() returns whether or not the given _tokenId has already been purchased
    /// @return Returns a boolean value - true if available, false if not
    function available(uint256 _tokenId) external view returns (bool);

    /// @dev purchase() purchases an NFT from the FakeNFTMarketplace
    /// @param _tokenId - the fake NFT tokenID to purchase
    function purchase(uint256 _tokenId) external payable;
}

/**
 * Minimal interface for CryptoDevsNFT containing only two functions
 * that we are interested in
 */
interface ICryptoDevsNFT {
    /// @dev balanceOf returns the number of NFTs owned by the given address
    /// @param owner - address to fetch number of NFTs for
    /// @return Returns the number of NFTs owned
    function balanceOf(address owner) external view returns (uint256);

    /// @dev tokenOfOwnerByIndex returns a tokenID at given index for owner
    /// @param owner - address to fetch the NFT TokenID for
    /// @param index - index of NFT in owned tokens array to fetch
    /// @return Returns the TokenID of the NFT
    function tokenOfOwnerByIndex(address owner, uint256 index)
        external
        view
        returns (uint256);
}

现在，让我们考虑一下我们在 DAO 合约中需要哪些功能。

  • 以合约状态存储已创建的提案
  • 允许 CryptoDevs NFT 的持有者创建新提案
  • 允许 CryptoDevs NFT 的持有者对提案进行投票，因为他们尚未投票，并且提案尚未通过其截止日期
  • 允许 CryptoDevs NFT 的持有者在超过截止日期后执行提案，以在提案通过时触发 NFT 购买

让我们从创建一个表示提案的结构开始。 在您的合约中，添加以下代码：

// Create a struct named Proposal containing all relevant information
struct Proposal {
    // nftTokenId - the tokenID of the NFT to purchase from FakeNFTMarketplace if the proposal passes
    uint256 nftTokenId;
    // deadline - the UNIX timestamp until which this proposal is active. Proposal can be executed after the deadline has been exceeded.
    uint256 deadline;
    // yayVotes - number of yay votes for this proposal
    uint256 yayVotes;
    // nayVotes - number of nay votes for this proposal
    uint256 nayVotes;
    // executed - whether or not this proposal has been executed yet. Cannot be executed before the deadline has been exceeded.
    bool executed;
    // voters - a mapping of CryptoDevsNFT tokenIDs to booleans indicating whether that NFT has already been used to cast a vote or not
    mapping(uint256 => bool) voters;
}

让我们还创建一个从提案 ID 到提案的映射以保存所有创建的提案，以及一个计数器来计算存在的提案数量。

// Create a mapping of ID to Proposal
mapping(uint256 => Proposal) public proposals;
// Number of proposals that have been created
uint256 public numProposals;

现在，由于我们将调用 FakeNFTMarketplace 和 CryptoDevsNFT 合约上的函数，让我们为这些合约初始化变量。

IFakeNFTMarketplace nftMarketplace;
ICryptoDevsNFT cryptoDevsNFT;

创建一个构造函数来初始化这些合约变量，并接受部署者的 ETH 存款以填充 DAO ETH 库。 （在后台，由于我们导入了 Ownable 合约，这也会将合约部署者设置为该合约的所有者）

// Create a payable constructor which initializes the contract
// instances for FakeNFTMarketplace and CryptoDevsNFT
// The payable allows this constructor to accept an ETH deposit when it is being deployed
constructor(address _nftMarketplace, address _cryptoDevsNFT) payable {
    nftMarketplace = IFakeNFTMarketplace(_nftMarketplace);
    cryptoDevsNFT = ICryptoDevsNFT(_cryptoDevsNFT);
}

现在，由于我们希望几乎所有其他函数只能由拥有 CryptoDevs NFT 合约的 NFT 的人调用，因此我们将创建一个修饰符以避免重复代码。

// Create a modifier which only allows a function to be
// called by someone who owns at least 1 CryptoDevsNFT
modifier nftHolderOnly() {
    require(cryptoDevsNFT.balanceOf(msg.sender) > 0, "NOT_A_DAO_MEMBER");
    _;
}

现在，要对提案进行投票，我们要添加一个额外的限制，即被投票的提案不得超过其截止日期。 为此，我们将创建第二个修饰符。

注意这个修饰符是如何接受参数的！

此外，由于投票只能是两个值之一（是或否） - 我们可以创建一个表示可能选项的枚举。

编写 voteOnProposal 函数

/// @dev voteOnProposal allows a CryptoDevsNFT holder to cast their vote on an active proposal
/// @param proposalIndex - the index of the proposal to vote on in the proposals array
/// @param vote - the type of vote they want to cast
function voteOnProposal(uint256 proposalIndex, Vote vote)
    external
    nftHolderOnly
    activeProposalOnly(proposalIndex)
{
    Proposal storage proposal = proposals[proposalIndex];

    uint256 voterNFTBalance = cryptoDevsNFT.balanceOf(msg.sender);
    uint256 numVotes = 0;

    // Calculate how many NFTs are owned by the voter
    // that haven't already been used for voting on this proposal
    for (uint256 i = 0; i < voterNFTBalance; i++) {
        uint256 tokenId = cryptoDevsNFT.tokenOfOwnerByIndex(msg.sender, i);
        if (proposal.voters[tokenId] == false) {
            numVotes++;
            proposal.voters[tokenId] = true;
        }
    }
    require(numVotes > 0, "ALREADY_VOTED");

    if (vote == Vote.YAY) {
        proposal.yayVotes += numVotes;
    } else {
        proposal.nayVotes += numVotes;
    }
}

我们快完成了！ 要执行已超过截止日期的提案，我们将创建最终修改器。

// Create a modifier which only allows a function to be
// called if the given proposals' deadline HAS been exceeded
// and if the proposal has not yet been executed
modifier inactiveProposalOnly(uint256 proposalIndex) {
    require(
        proposals[proposalIndex].deadline <= block.timestamp,
        "DEADLINE_NOT_EXCEEDED"
    );
    require(
        proposals[proposalIndex].executed == false,
        "PROPOSAL_ALREADY_EXECUTED"
    );
    _;
}

注意这个修饰符也需要一个参数！

让我们编写 executeProposal 的代码

/// @dev executeProposal allows any CryptoDevsNFT holder to execute a proposal after it's deadline has been exceeded
/// @param proposalIndex - the index of the proposal to execute in the proposals array
function executeProposal(uint256 proposalIndex)
    external
    nftHolderOnly
    inactiveProposalOnly(proposalIndex)
{
    Proposal storage proposal = proposals[proposalIndex];

    // If the proposal has more YAY votes than NAY votes
    // purchase the NFT from the FakeNFTMarketplace
    if (proposal.yayVotes > proposal.nayVotes) {
        uint256 nftPrice = nftMarketplace.getPrice();
        require(address(this).balance >= nftPrice, "NOT_ENOUGH_FUNDS");
        nftMarketplace.purchase{value: nftPrice}(proposal.nftTokenId);
    }
    proposal.executed = true;
}

至此，我们已经实现了所有核心功能。 但是，我们可以并且应该实现一些附加功能。

  • 如果需要，允许合约所有者从 DAO 中提取 ETH
  • 允许合约接受更多的 ETH 存款

我们继承的 Ownable 合约包含一个修饰符 onlyOwner，它将函数限制为只能由合约所有者调用。 让我们使用该修饰符来实现 withdrawEther。

/// @dev withdrawEther allows the contract owner (deployer) to withdraw the ETH from the contract
function withdrawEther() external onlyOwner {
    payable(owner()).transfer(address(this).balance);
}

这会将合约的全部 ETH 余额转移到所有者地址

最后，为了允许向 DAO 库中添加更多 ETH 存款，需要添加一些特殊功能。 通常，合约地址不能接受发送给他们的 ETH，除非是通过支付功能。 但是我们不希望用户调用函数只是为了存钱，他们应该能够直接从他们的钱包中转移 ETH。 为此，让我们添加这两个函数：

// The following two functions allow the contract to accept ETH deposits
// directly from a wallet without calling a function
receive() external payable {}

fallback() external payable {}

智能合约部署​

创建 .env 配置，并安装 dotenv 依赖​

QUICKNODE_HTTP_URL 从 Quicknode 中获取。PRIVATE_KEY 从钱包中获取。

QUICKNODE_HTTP_URL="add-quicknode-http-provider-url-here"
PRIVATE_KEY="add-the-private-key-here"

添加部署代码​

scripts/deploy.js

const { ethers } = require("hardhat");
const { CRYPTODEVS_NFT_CONTRACT_ADDRESS } = require("../constants");

async function main() {
  // Deploy the FakeNFTMarketplace contract first
  const FakeNFTMarketplace = await ethers.getContractFactory(
    "FakeNFTMarketplace"
  );
  const fakeNftMarketplace = await FakeNFTMarketplace.deploy();
  await fakeNftMarketplace.deployed();

  console.log("FakeNFTMarketplace deployed to: ", fakeNftMarketplace.address);

  // Now deploy the CryptoDevsDAO contract
  const CryptoDevsDAO = await ethers.getContractFactory("CryptoDevsDAO");
  const cryptoDevsDAO = await CryptoDevsDAO.deploy(
    fakeNftMarketplace.address,
    CRYPTODEVS_NFT_CONTRACT_ADDRESS,
    {
      // This assumes your account has at least 1 ETH in it's account
      // Change this value as you want
      value: ethers.utils.parseEther("1"),
    }
  );
  await cryptoDevsDAO.deployed();

  console.log("CryptoDevsDAO deployed to: ", cryptoDevsDAO.address);
}

main()
  .then(() => process.exit(0))
  .catch((error) => {
    console.error(error);
    process.exit(1);
  });

添加部署代码需要的变量​

constants/index.js

// Replace the value with your NFT contract address
const CRYPTODEVS_NFT_CONTRACT_ADDRESS =
  "YOUR_CRYPTODEVS_NFT_CONTRACT_ADDRESS_HERE";

module.exports = { CRYPTODEVS_NFT_CONTRACT_ADDRESS };

修改 hardhat.config.js 配置​

require("@nomicfoundation/hardhat-toolbox");
require("dotenv").config({ path: ".env" });

const QUICKNODE_HTTP_URL = process.env.QUICKNODE_HTTP_URL;
const PRIVATE_KEY = process.env.PRIVATE_KEY;

module.exports = {
  solidity: "0.8.4",
  networks: {
    goerli: {
      url: QUICKNODE_HTTP_URL,
      accounts: [PRIVATE_KEY],
    },
  },
};

编译​

npx hardhat compile

部署​

npx hardhat run scripts/deploy.js --network goerli

保存合约地址​

前端开发​

创建 my-app 项目​

npx create-next-app@latest

安装依赖​

npm install web3modal ethers

修改样式​

my-app/styles/Home.modules.css

.main {
  min-height: 90vh;
  display: flex;
  flex-direction: row;
  justify-content: center;
  align-items: center;
  font-family: "Courier New", Courier, monospace;
}

.footer {
  display: flex;
  padding: 2rem 0;
  border-top: 1px solid #eaeaea;
  justify-content: center;
  align-items: center;
}

.image {
  width: 70%;
  height: 50%;
  margin-left: 20%;
}

.title {
  font-size: 2rem;
  margin: 2rem 0;
}

.description {
  line-height: 1;
  margin: 2rem 0;
  font-size: 1.2rem;
}

.button {
  border-radius: 4px;
  background-color: blue;
  border: none;
  color: #ffffff;
  font-size: 15px;
  padding: 10px;
  width: 200px;
  cursor: pointer;
  margin-right: 2%;
}

.button2 {
  border-radius: 4px;
  background-color: indigo;
  border: none;
  color: #ffffff;
  font-size: 15px;
  padding: 10px;
  cursor: pointer;
  margin-right: 2%;
  margin-top: 1rem;
}

.proposalCard {
  width: fit-content;
  margin-top: 0.25rem;
  border: black 2px solid;
  flex: 1;
  flex-direction: column;
}

.container {
  margin-top: 2rem;
}

.flex {
  flex: 1;
  justify-content: space-between;
}

@media (max-width: 1000px) {
  .main {
    width: 100%;
    flex-direction: column;
    justify-content: center;
    align-items: center;
  }
}

配置合约地址和接口​

该网站还需要从两个智能合约——CryptoDevsDAO 和 CryptoDevsNFT 读取/写入数据。 让我们将他们的合约地址和 ABI 存储在一个常量文件中。 在 my-app 目录中创建一个 constants.js 文件。

constants/index.js

export const CRYPTODEVS_DAO_CONTRACT_ADDRESS = "";
export const CRYPTODEVS_NFT_CONTRACT_ADDRESS = "";

export const CRYPTODEVS_DAO_ABI = [];
export const CRYPTODEVS_NFT_ABI = [];

修改页面​

pages/index.js

import { Contract, providers } from "ethers";
import { formatEther } from "ethers/lib/utils";
import Head from "next/head";
import { useEffect, useRef, useState } from "react";
import Web3Modal from "web3modal";
import {
  CRYPTODEVS_DAO_ABI,
  CRYPTODEVS_DAO_CONTRACT_ADDRESS,
  CRYPTODEVS_NFT_ABI,
  CRYPTODEVS_NFT_CONTRACT_ADDRESS,
} from "../constants";
import styles from "../styles/Home.module.css";

export default function Home() {
  // ETH Balance of the DAO contract
  const [treasuryBalance, setTreasuryBalance] = useState("0");
  // Number of proposals created in the DAO
  const [numProposals, setNumProposals] = useState("0");
  // Array of all proposals created in the DAO
  const [proposals, setProposals] = useState([]);
  // User's balance of CryptoDevs NFTs
  const [nftBalance, setNftBalance] = useState(0);
  // Fake NFT Token ID to purchase. Used when creating a proposal.
  const [fakeNftTokenId, setFakeNftTokenId] = useState("");
  // One of "Create Proposal" or "View Proposals"
  const [selectedTab, setSelectedTab] = useState("");
  // True if waiting for a transaction to be mined, false otherwise.
  const [loading, setLoading] = useState(false);
  // True if user has connected their wallet, false otherwise
  const [walletConnected, setWalletConnected] = useState(false);
  const web3ModalRef = useRef();

  // Helper function to connect wallet
  const connectWallet = async () => {
    try {
      await getProviderOrSigner();
      setWalletConnected(true);
    } catch (error) {
      console.error(error);
    }
  };

  // Reads the ETH balance of the DAO contract and sets the `treasuryBalance` state variable
  const getDAOTreasuryBalance = async () => {
    try {
      const provider = await getProviderOrSigner();
      const balance = await provider.getBalance(
        CRYPTODEVS_DAO_CONTRACT_ADDRESS
      );
      setTreasuryBalance(balance.toString());
    } catch (error) {
      console.error(error);
    }
  };

  // Reads the number of proposals in the DAO contract and sets the `numProposals` state variable
  const getNumProposalsInDAO = async () => {
    try {
      const provider = await getProviderOrSigner();
      const contract = getDaoContractInstance(provider);
      const daoNumProposals = await contract.numProposals();
      setNumProposals(daoNumProposals.toString());
    } catch (error) {
      console.error(error);
    }
  };

  // Reads the balance of the user's CryptoDevs NFTs and sets the `nftBalance` state variable
  const getUserNFTBalance = async () => {
    try {
      const signer = await getProviderOrSigner(true);
      const nftContract = getCryptodevsNFTContractInstance(signer);
      const balance = await nftContract.balanceOf(signer.getAddress());
      setNftBalance(parseInt(balance.toString()));
    } catch (error) {
      console.error(error);
    }
  };

  // Calls the `createProposal` function in the contract, using the tokenId from `fakeNftTokenId`
  const createProposal = async () => {
    try {
      const signer = await getProviderOrSigner(true);
      const daoContract = getDaoContractInstance(signer);
      const txn = await daoContract.createProposal(fakeNftTokenId);
      setLoading(true);
      await txn.wait();
      await getNumProposalsInDAO();
      setLoading(false);
    } catch (error) {
      console.error(error);
      window.alert(error.data.message);
    }
  };

  // Helper function to fetch and parse one proposal from the DAO contract
  // Given the Proposal ID
  // and converts the returned data into a Javascript object with values we can use
  const fetchProposalById = async (id) => {
    try {
      const provider = await getProviderOrSigner();
      const daoContract = getDaoContractInstance(provider);
      const proposal = await daoContract.proposals(id);
      const parsedProposal = {
        proposalId: id,
        nftTokenId: proposal.nftTokenId.toString(),
        deadline: new Date(parseInt(proposal.deadline.toString()) * 1000),
        yayVotes: proposal.yayVotes.toString(),
        nayVotes: proposal.nayVotes.toString(),
        executed: proposal.executed,
      };
      return parsedProposal;
    } catch (error) {
      console.error(error);
    }
  };

  // Runs a loop `numProposals` times to fetch all proposals in the DAO
  // and sets the `proposals` state variable
  const fetchAllProposals = async () => {
    try {
      const proposals = [];
      for (let i = 0; i < numProposals; i++) {
        const proposal = await fetchProposalById(i);
        proposals.push(proposal);
      }
      setProposals(proposals);
      return proposals;
    } catch (error) {
      console.error(error);
    }
  };

  // Calls the `voteOnProposal` function in the contract, using the passed
  // proposal ID and Vote
  const voteOnProposal = async (proposalId, _vote) => {
    try {
      const signer = await getProviderOrSigner(true);
      const daoContract = getDaoContractInstance(signer);

      let vote = _vote === "YAY" ? 0 : 1;
      const txn = await daoContract.voteOnProposal(proposalId, vote);
      setLoading(true);
      await txn.wait();
      setLoading(false);
      await fetchAllProposals();
    } catch (error) {
      console.error(error);
      window.alert(error.data.message);
    }
  };

  // Calls the `executeProposal` function in the contract, using
  // the passed proposal ID
  const executeProposal = async (proposalId) => {
    try {
      const signer = await getProviderOrSigner(true);
      const daoContract = getDaoContractInstance(signer);
      const txn = await daoContract.executeProposal(proposalId);
      setLoading(true);
      await txn.wait();
      setLoading(false);
      await fetchAllProposals();
    } catch (error) {
      console.error(error);
      window.alert(error.data.message);
    }
  };

  // Helper function to fetch a Provider/Signer instance from Metamask
  const getProviderOrSigner = async (needSigner = false) => {
    const provider = await web3ModalRef.current.connect();
    const web3Provider = new providers.Web3Provider(provider);

    const { chainId } = await web3Provider.getNetwork();
    if (chainId !== 5) {
      window.alert("Please switch to the Goerli network!");
      throw new Error("Please switch to the Goerli network");
    }

    if (needSigner) {
      const signer = web3Provider.getSigner();
      return signer;
    }
    return web3Provider;
  };

  // Helper function to return a DAO Contract instance
  // given a Provider/Signer
  const getDaoContractInstance = (providerOrSigner) => {
    return new Contract(
      CRYPTODEVS_DAO_CONTRACT_ADDRESS,
      CRYPTODEVS_DAO_ABI,
      providerOrSigner
    );
  };

  // Helper function to return a CryptoDevs NFT Contract instance
  // given a Provider/Signer
  const getCryptodevsNFTContractInstance = (providerOrSigner) => {
    return new Contract(
      CRYPTODEVS_NFT_CONTRACT_ADDRESS,
      CRYPTODEVS_NFT_ABI,
      providerOrSigner
    );
  };

  // piece of code that runs everytime the value of `walletConnected` changes
  // so when a wallet connects or disconnects
  // Prompts user to connect wallet if not connected
  // and then calls helper functions to fetch the
  // DAO Treasury Balance, User NFT Balance, and Number of Proposals in the DAO
  useEffect(() => {
    if (!walletConnected) {
      web3ModalRef.current = new Web3Modal({
        network: "goerli",
        providerOptions: {},
        disableInjectedProvider: false,
      });

      connectWallet().then(() => {
        getDAOTreasuryBalance();
        getUserNFTBalance();
        getNumProposalsInDAO();
      });
    }
  }, [walletConnected]);

  // Piece of code that runs everytime the value of `selectedTab` changes
  // Used to re-fetch all proposals in the DAO when user switches
  // to the 'View Proposals' tab
  useEffect(() => {
    if (selectedTab === "View Proposals") {
      fetchAllProposals();
    }
  }, [selectedTab]);

  // Render the contents of the appropriate tab based on `selectedTab`
  function renderTabs() {
    if (selectedTab === "Create Proposal") {
      return renderCreateProposalTab();
    } else if (selectedTab === "View Proposals") {
      return renderViewProposalsTab();
    }
    return null;
  }

  // Renders the 'Create Proposal' tab content
  function renderCreateProposalTab() {
    if (loading) {
      return (
        <div className={styles.description}>
          Loading... Waiting for transaction...
        </div>
      );
    } else if (nftBalance === 0) {
      return (
        <div className={styles.description}>
          You do not own any CryptoDevs NFTs. <br />
          <b>You cannot create or vote on proposals</b>
        </div>
      );
    } else {
      return (
        <div className={styles.container}>
          <label>Fake NFT Token ID to Purchase: </label>
          <input
            placeholder="0"
            type="number"
            onChange={(e) => setFakeNftTokenId(e.target.value)}
          />
          <button className={styles.button2} onClick={createProposal}>
            Create
          </button>
        </div>
      );
    }
  }

  // Renders the 'View Proposals' tab content
  function renderViewProposalsTab() {
    if (loading) {
      return (
        <div className={styles.description}>
          Loading... Waiting for transaction...
        </div>
      );
    } else if (proposals.length === 0) {
      return (
        <div className={styles.description}>No proposals have been created</div>
      );
    } else {
      return (
        <div>
          {proposals.map((p, index) => (
            <div key={index} className={styles.proposalCard}>
              <p>Proposal ID: {p.proposalId}</p>
              <p>Fake NFT to Purchase: {p.nftTokenId}</p>
              <p>Deadline: {p.deadline.toLocaleString()}</p>
              <p>Yay Votes: {p.yayVotes}</p>
              <p>Nay Votes: {p.nayVotes}</p>
              <p>Executed?: {p.executed.toString()}</p>
              {p.deadline.getTime() > Date.now() && !p.executed ? (
                <div className={styles.flex}>
                  <button
                    className={styles.button2}
                    onClick={() => voteOnProposal(p.proposalId, "YAY")}
                  >
                    Vote YAY
                  </button>
                  <button
                    className={styles.button2}
                    onClick={() => voteOnProposal(p.proposalId, "NAY")}
                  >
                    Vote NAY
                  </button>
                </div>
              ) : p.deadline.getTime() < Date.now() && !p.executed ? (
                <div className={styles.flex}>
                  <button
                    className={styles.button2}
                    onClick={() => executeProposal(p.proposalId)}
                  >
                    Execute Proposal{" "}
                    {p.yayVotes > p.nayVotes ? "(YAY)" : "(NAY)"}
                  </button>
                </div>
              ) : (
                <div className={styles.description}>Proposal Executed</div>
              )}
            </div>
          ))}
        </div>
      );
    }
  }

  return (
    <div>
      <Head>
        <title>CryptoDevs DAO</title>
        <meta name="description" content="CryptoDevs DAO" />
        <link rel="icon" href="/favicon.ico" />
      </Head>

      <div className={styles.main}>
        <div>
          <h1 className={styles.title}>Welcome to Crypto Devs!</h1>
          <div className={styles.description}>Welcome to the DAO!</div>
          <div className={styles.description}>
            Your CryptoDevs NFT Balance: {nftBalance}
            <br />
            Treasury Balance: {formatEther(treasuryBalance)} ETH
            <br />
            Total Number of Proposals: {numProposals}
          </div>
          <div className={styles.flex}>
            <button
              className={styles.button}
              onClick={() => setSelectedTab("Create Proposal")}
            >
              Create Proposal
            </button>
            <button
              className={styles.button}
              onClick={() => setSelectedTab("View Proposals")}
            >
              View Proposals
            </button>
          </div>
          {renderTabs()}
        </div>
        <div>
          <img className={styles.image} src="/cryptodevs/0.svg" />
        </div>
      </div>

      <footer className={styles.footer}>
        Made with &#10084; by Crypto Devs
      </footer>
    </div>
  );
}

运行​

pnpm run dev

测试​

  • 创建几个提案
  • 尝试在一个上投 YAY，在另一个上投 NAY
  • 等待 5 分钟让他们的最后期限过去
  • 执行这两个。
  • 由于在执行时购买 NFT 的提案获得通过，DAO 财政部的余额减少了 0.1 ETH。

推送到 github​

部署​