Now its time for you to launch your own NFT collection and store its metadata on IPFS
- There should only exist 10 LearnWeb3 Punk NFT's and each one of them should be unique.
- User's should be able to mint only 1 NFT with one transaction.
- The metadata for the NFT's should be stored on IPFS
- There should be a website for your NFT Collection.
- The NFT contract should be deployed on Mumbai testnet
Lets start building ๐
- You should have completed the IPFS Theory tutorial
-
Now its time for us to upload our files to ipfs
-
We would be using a service called Pinata which will help us to pin content on IPFS
-
Go to Pinata Dashboard and click on
Upload
and then onFolder
-
Download the LW3Punks folder to your computer and then upload to it
Pinata
, name the folderLW3Punks
-
Now you should be able to see a
CID
for your folder, Awesome! -
You can check that it actually got uploaded to IPFS is by opening this up:
https://ipfs.io/ipfs/your-nft-folder-cid
replaceyour-nft-folder-cid
with the CID you recieved from pinata. -
The images for your NFT's have now been uploaded to IPFS but just having images is not enough, each NFT should also have associated metadata
-
We will now upload metadata for each NFT to IPFS, each metadata file will be a
json
file. Example for metadata of NFT1
has been given below:{ "name":"1", "description":"NFT Collection for LearnWeb3 Students", "image":"ipfs://QmQBHarz2WFczTjz5GnhjHrbUPDnB48W5BM2v2h6HbE1rZ/1.png" }
-
Note how "image" has ipfs location in it instead of an
https
url. Also note that because you uploaded a folder, you will also need to specify which file within the folder has the correct image for the given NFT. Thus in our case the correct way to specify the location for an NFT image would beipfs://CID-OF-THE-LW3Punks-Folder/NFT-NAME.png
-
We have pre-generated files for metadata for you, you can download them to your computer from here, upload these files to pinata and name the folder
metadata
-
Now each NFT's metadata has been uploaded to IPFS and pinata should have generated a CID for your metadata folder
-
You can check that it actually got uploaded to IPFS is by opening this up:
https://ipfs.io/ipfs/your-metadata-folder-cid
replaceyour-metadata-folder-cid
with the CID you recieved from pinata. -
Copy this CID and store it on your notepad, you will need this futher down in the tutorial
-
Its time to write our contract ๐ฅณ
-
We will also be using
Ownable.sol
from Openzeppelin which helps you manage theOwnership
of a contract- By default, the owner of an Ownable contract is the account that deployed it, which is usually exactly what you want.
- Ownable also lets you:
- transferOwnership from the owner account to a new one, and
- renounceOwnership for the owner to relinquish this administrative privilege, a common pattern after an initial stage with centralized administration is over.
-
We would also be using an extension of ERC721 known as ERC721 Enumerable
- ERC721 Enumerable is helps you to keep track of all the tokenIds in the contract and also the tokensIds held by an address for a given contract.
- Please have a look at the functions it implements before moving ahead
To build the smart contract we would be using Hardhat. Hardhat is an Ethereum development environment and framework designed for full stack development in Solidity. In simple words you can write your smart contract, deploy them, run tests, and debug your code.
-
To setup a Hardhat project, Open up a terminal and execute these commands
mkdir hardhat-tutorial cd hardhat-tutorial npm init --yes npm install --save-dev hardhat
-
In the same directory where you installed Hardhat run:
npx hardhat
- Select
Create a Javascript project
- Press enter for the already specified
Hardhat Project root
- Press enter for the question on if you want to add a
.gitignore
- Press enter for
Do you want to install this sample project's dependencies with npm (@nomicfoundation/hardhat-toolbox)?
- Select
Now you have a hardhat project ready to go!
If you are not on mac, please do this extra step and install these libraries as well :)
npm install --save-dev @nomicfoundation/hardhat-toolbox
and press enter
for all the questions.
-
In the same terminal now install
@openzeppelin/contracts
as we would be importing Openzeppelin's ERC721Enumerable Contract in ourLW3Punks
contract.npm install @openzeppelin/contracts
-
Now lets create a new file inside the
contracts
directory and call itLW3Punks.sol
// SPDX-License-Identifier: MIT pragma solidity ^0.8.4; import "@openzeppelin/contracts/token/ERC721/extensions/ERC721Enumerable.sol"; import "@openzeppelin/contracts/access/Ownable.sol"; import "@openzeppelin/contracts/utils/Strings.sol"; contract LW3Punks is ERC721Enumerable, Ownable { using Strings for uint256; /** * @dev _baseTokenURI for computing {tokenURI}. If set, the resulting URI for each * token will be the concatenation of the `baseURI` and the `tokenId`. */ string _baseTokenURI; // _price is the price of one LW3Punks NFT uint256 public _price = 0.01 ether; // _paused is used to pause the contract in case of an emergency bool public _paused; // max number of LW3Punks uint256 public maxTokenIds = 10; // total number of tokenIds minted uint256 public tokenIds; modifier onlyWhenNotPaused { require(!_paused, "Contract currently paused"); _; } /** * @dev ERC721 constructor takes in a `name` and a `symbol` to the token collection. * name in our case is `LW3Punks` and symbol is `LW3P`. * Constructor for LW3P takes in the baseURI to set _baseTokenURI for the collection. */ constructor (string memory baseURI) ERC721("LW3Punks", "LW3P") { _baseTokenURI = baseURI; } /** * @dev mint allows an user to mint 1 NFT per transaction. */ function mint() public payable onlyWhenNotPaused { require(tokenIds < maxTokenIds, "Exceed maximum LW3Punks supply"); require(msg.value >= _price, "Ether sent is not correct"); tokenIds += 1; _safeMint(msg.sender, tokenIds); } /** * @dev _baseURI overides the Openzeppelin's ERC721 implementation which by default * returned an empty string for the baseURI */ function _baseURI() internal view virtual override returns (string memory) { return _baseTokenURI; } /** * @dev tokenURI overides the Openzeppelin's ERC721 implementation for tokenURI function * This function returns the URI from where we can extract the metadata for a given tokenId */ function tokenURI(uint256 tokenId) public view virtual override returns (string memory) { require(_exists(tokenId), "ERC721Metadata: URI query for nonexistent token"); string memory baseURI = _baseURI(); // Here it checks if the length of the baseURI is greater than 0, if it is return the baseURI and attach // the tokenId and `.json` to it so that it knows the location of the metadata json file for a given // tokenId stored on IPFS // If baseURI is empty return an empty string return bytes(baseURI).length > 0 ? string(abi.encodePacked(baseURI, tokenId.toString(), ".json")) : ""; } /** * @dev setPaused makes the contract paused or unpaused */ function setPaused(bool val) public onlyOwner { _paused = val; } /** * @dev withdraw sends all the ether in the contract * to the owner of the contract */ function withdraw() public onlyOwner { address _owner = owner(); uint256 amount = address(this).balance; (bool sent, ) = _owner.call{value: amount}(""); require(sent, "Failed to send Ether"); } // Function to receive Ether. msg.data must be empty receive() external payable {} // Fallback function is called when msg.data is not empty fallback() external payable {} }
-
Now we would install
dotenv
package to be able to import the env file and use it in our config. Open up a terminal pointing athardhat-tutorial
directory and execute this commandnpm install dotenv
-
Now create a
.env
file in thehardhat-tutorial
folder and add the following lines, use the instructions in the comments to get yourALCHEMY_API_KEY_URL
andMUMBAI_PRIVATE_KEY
.If you dont have Mumbai on MetaMask, you can follow this to add it to your MetaMask, make sure that the account from which you get your mumbai private key is funded with mumbai matic, you can get some from here.// Go to https://www.alchemyapi.io, sign up, create // a new App in its dashboard and select the chain as Polygon and network as Mumbai, and replace "add-the-alchemy-key-url-here" with its key url ALCHEMY_API_KEY_URL="add-the-alchemy-key-url-here" // Replace this private key with your MUMBAI account private key // To export your private key from Metamask, open Metamask and // go to Account Details > Export Private Key // Be aware of NEVER putting real Ether into testing accounts MUMBAI_PRIVATE_KEY="add-the-mumbai-private-key-here"
-
Lets deploy the contract to
mumbai
network. Create a new file, or replace the existing default one, nameddeploy.js
under thescripts
folder. Remember to replaceYOUR-METADATA-CID
with the CID you saved to your notepad.const { ethers } = require("hardhat"); require("dotenv").config({ path: ".env" }); async function main() { // URL from where we can extract the metadata for a LW3Punks const metadataURL = "ipfs://YOUR-METADATA-CID/"; /* A ContractFactory in ethers.js is an abstraction used to deploy new smart contracts, so lw3PunksContract here is a factory for instances of our LW3Punks contract. */ const lw3PunksContract = await ethers.getContractFactory("LW3Punks"); // deploy the contract const deployedLW3PunksContract = await lw3PunksContract.deploy(metadataURL); await deployedLW3PunksContract.deployed(); // print the address of the deployed contract console.log("LW3Punks Contract Address:", deployedLW3PunksContract.address); } // Call the main function and catch if there is any error main() .then(() => process.exit(0)) .catch((error) => { console.error(error); process.exit(1); });
-
Now open the hardhat.config.js file, we would add the
mumbai
network here so that we can deploy our contract to mumbai. Replace all the lines in thehardhat.config.js
file with the given below linesrequire("@nomicfoundation/hardhat-toolbox"); require("dotenv").config({ path: ".env" }); const ALCHEMY_API_KEY_URL = process.env.ALCHEMY_API_KEY_URL; const MUMBAI_PRIVATE_KEY = process.env.MUMBAI_PRIVATE_KEY; module.exports = { solidity: "0.8.4", networks: { mumbai: { url: ALCHEMY_API_KEY_URL, accounts: [MUMBAI_PRIVATE_KEY], }, }, };
-
Compile the contract, open up a terminal pointing at
hardhat-tutorial
directory and execute this commandnpx hardhat compile
-
To deploy, open up a terminal pointing at
hardhat-tutorial
directory and execute this commandnpx hardhat run scripts/deploy.js --network mumbai
-
Save the LW3Punks contract address that was printed on your terminal in your notepad, you would need it futher down in the tutorial.
-
To develop the website we would be using React and Next Js. React is a javascript framework which is used to make websites and Next Js is built on top of React.
-
First, You would need to create a new
next
app. Your folder structure should look something like- IPFS-Practical - hardhat-tutorial - my-app
-
To create this
my-app
, in the terminal point to NFT-Collection folder and typenpx create-next-app@latest
and press
enter
for all the questions -
Now to run the app, execute these commands in the terminal
cd my-app npm run dev
-
Now go to
http://localhost:3000
, your app should be running ๐ค -
Now lets install Web3Modal library(https://github.com/Web3Modal/web3modal). Web3Modal is an easy-to-use library to help developers add support for multiple providers in their apps with a simple customizable configuration. By default Web3Modal Library supports injected providers like (Metamask, Dapper, Gnosis Safe, Frame, Web3 Browsers, etc), You can also easily configure the library to support Portis, Fortmatic, Squarelink, Torus, Authereum, D'CENT Wallet and Arkane. Open up a terminal pointing at
my-app
directory and execute this commandnpm install web3modal
-
In the same terminal also install
ethers.js
npm install ethers
-
In your public folder, download this folder and all the images in it the LW3Punks folder. Make sure that the name of the downloaded folder is
LW3Punks
-
Now go to styles folder and replace all the contents of
Home.modules.css
file with the following code, this would add some styling to your dapp:.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: 20px; width: 200px; cursor: pointer; margin-bottom: 2%; } @media (max-width: 1000px) { .main { width: 100%; flex-direction: column; justify-content: center; align-items: center; } }
-
Open you index.js file under the pages folder and paste the following code, explanation of the code can be found in the comments.
import { Contract, providers, utils } from "ethers"; import Head from "next/head"; import React, { useEffect, useRef, useState } from "react"; import Web3Modal from "web3modal"; import { abi, NFT_CONTRACT_ADDRESS } from "../constants"; import styles from "../styles/Home.module.css"; export default function Home() { // walletConnected keep track of whether the user's wallet is connected or not const [walletConnected, setWalletConnected] = useState(false); // loading is set to true when we are waiting for a transaction to get mined const [loading, setLoading] = useState(false); // tokenIdsMinted keeps track of the number of tokenIds that have been minted const [tokenIdsMinted, setTokenIdsMinted] = useState("0"); // Create a reference to the Web3 Modal (used for connecting to Metamask) which persists as long as the page is open const web3ModalRef = useRef(); /** * publicMint: Mint an NFT */ const publicMint = async () => { try { console.log("Public mint"); // We need a Signer here since this is a 'write' transaction. const signer = await getProviderOrSigner(true); // Create a new instance of the Contract with a Signer, which allows // update methods const nftContract = new Contract(NFT_CONTRACT_ADDRESS, abi, signer); // call the mint from the contract to mint the LW3Punks const tx = await nftContract.mint({ // value signifies the cost of one LW3Punks which is "0.01" eth. // We are parsing `0.01` string to ether using the utils library from ethers.js value: utils.parseEther("0.01"), }); setLoading(true); // wait for the transaction to get mined await tx.wait(); setLoading(false); window.alert("You successfully minted a LW3Punk!"); } catch (err) { console.error(err); } }; /* connectWallet: Connects the MetaMask wallet */ const connectWallet = async () => { try { // Get the provider from web3Modal, which in our case is MetaMask // When used for the first time, it prompts the user to connect their wallet await getProviderOrSigner(); setWalletConnected(true); } catch (err) { console.error(err); } }; /** * getTokenIdsMinted: gets the number of tokenIds that have been minted */ const getTokenIdsMinted = async () => { try { // Get the provider from web3Modal, which in our case is MetaMask // No need for the Signer here, as we are only reading state from the blockchain const provider = await getProviderOrSigner(); // We connect to the Contract using a Provider, so we will only // have read-only access to the Contract const nftContract = new Contract(NFT_CONTRACT_ADDRESS, abi, provider); // call the tokenIds from the contract const _tokenIds = await nftContract.tokenIds(); console.log("tokenIds", _tokenIds); //_tokenIds is a `Big Number`. We need to convert the Big Number to a string setTokenIdsMinted(_tokenIds.toString()); } catch (err) { console.error(err); } }; /** * Returns a Provider or Signer object representing the Ethereum RPC with or without the * signing capabilities of metamask attached * * A `Provider` is needed to interact with the blockchain - reading transactions, reading balances, reading state, etc. * * A `Signer` is a special type of Provider used in case a `write` transaction needs to be made to the blockchain, which involves the connected account * needing to make a digital signature to authorize the transaction being sent. Metamask exposes a Signer API to allow your website to * request signatures from the user using Signer functions. * * @param {*} needSigner - True if you need the signer, default false otherwise */ const getProviderOrSigner = async (needSigner = false) => { // Connect to Metamask // Since we store `web3Modal` as a reference, we need to access the `current` value to get access to the underlying object const provider = await web3ModalRef.current.connect(); const web3Provider = new providers.Web3Provider(provider); // If user is not connected to the Mumbai network, let them know and throw an error const { chainId } = await web3Provider.getNetwork(); if (chainId !== 80001) { window.alert("Change the network to Mumbai"); throw new Error("Change network to Mumbai"); } if (needSigner) { const signer = web3Provider.getSigner(); return signer; } return web3Provider; }; // useEffects are used to react to changes in state of the website // The array at the end of function call represents what state changes will trigger this effect // In this case, whenever the value of `walletConnected` changes - this effect will be called useEffect(() => { // if wallet is not connected, create a new instance of Web3Modal and connect the MetaMask wallet if (!walletConnected) { // Assign the Web3Modal class to the reference object by setting it's `current` value // The `current` value is persisted throughout as long as this page is open web3ModalRef.current = new Web3Modal({ network: "mumbai", providerOptions: {}, disableInjectedProvider: false, }); connectWallet(); getTokenIdsMinted(); // set an interval to get the number of token Ids minted every 5 seconds setInterval(async function () { await getTokenIdsMinted(); }, 5 * 1000); } }, [walletConnected]); /* renderButton: Returns a button based on the state of the dapp */ const renderButton = () => { // If wallet is not connected, return a button which allows them to connect their wallet if (!walletConnected) { return ( <button onClick={connectWallet} className={styles.button}> Connect your wallet </button> ); } // If we are currently waiting for something, return a loading button if (loading) { return <button className={styles.button}>Loading...</button>; } return ( <button className={styles.button} onClick={publicMint}> Public Mint ๐ </button> ); }; return ( <div> <Head> <title>LW3Punks</title> <meta name="description" content="LW3Punks-Dapp" /> <link rel="icon" href="/favicon.ico" /> </Head> <div className={styles.main}> <div> <h1 className={styles.title}>Welcome to LW3Punks!</h1> <div className={styles.description}> Its an NFT collection for LearnWeb3 students. </div> <div className={styles.description}> {tokenIdsMinted}/10 have been minted </div> {renderButton()} </div> <div> <img className={styles.image} src="./LW3punks/1.png" /> </div> </div> <footer className={styles.footer}>Made with ❤ by LW3Punks</footer> </div> ); }
-
Now create a new folder under the my-app folder and name it
constants
. -
In the constants folder create a file,
index.js
and paste the following code.- Replace
"address of your NFT contract"
with the address of the LW3Punks contract that you deployed and saved to your notepad. - Replace
---your abi---
with the abi of your LW3Punks Contract. To get the abi for your contract, go to yourhardhat-tutorial/artifacts/contracts/LW3Punks.sol
folder and from yourLW3Punks.json
file get the array marked under the"abi"
key.
export const abi =---your abi--- export const NFT_CONTRACT_ADDRESS = "address of your NFT contract"
- Replace
-
Now in your terminal which is pointing to
my-app
folder, executenpm run dev
Your LW3Punks NFT dapp should now work without errors ๐
Make sure before proceeding you have pushed all your code to github :)
We will now deploy your dApp, so that everyone can see your website and you can share it with all of your LearnWeb3 DAO friends.
-
Go to https://vercel.com/ and sign in with your GitHub
-
Then click on
New Project
button and then select your IPFS-Practical repo -
When configuring your new project, Vercel will allow you to customize your
Root Directory
-
Click
Edit
next toRoot Directory
and set it tomy-app
-
Select the Framework as
Next.js
-
Now you can see your deployed website by going to your dashboard, selecting your project, and copying the
domain
from there! Save thedomain
on notepad, you would need it later. -
Share your website link with everyone on discord :) and spread happiness.