Introduction
In this tutorial, I will teach you how to build an NFT Game On the Celo Blockchain.
Monster War is an NFT game where players can mint and upgrade their monsters by paying 0.5 Celo per upgrade. Each upgrade will add one power value point to their monster. Players’ NFT monsters can also Swallow other players’ NFT monsters, but this can only be done if the attacker has minted his NFT and the power value of his monster is more than the power value of the monster they are attacking.
It’s a battle between players where each player can collect and upgrade NFTs. Players can mint their own NFTs, boost the power value of their NFTs, and swallow other players’ NFTs depending on the power value of their NFTs. Players are also able to remove their NFTs from the game.
Here is a demo app link of what you’ll be creating.
And a Screenshot
Prerequisites
To fully follow up with these tutorials, you should have a basic understanding of the following technologies.
Solidity, smart-contract, and blockchain concepts.
Hardhat.
React.
Basic web Development.
Requirements
- Solidity.
- OpenZeppelin.
- Hardhat.
- React.
- Bootstrap.
- NodeJS 12.0.1 upwards installed.
- MetaMask.
Installation
Click on this link repo from your github.
- Clone the repo to your computer.
- open the project from from vscode.
- Run
npm install
command to install all the dependencies required to run the app locally.
SmartContract
Let’s dive into the smart contract to understand how it works.
NFT Minter
The Finished Smart Contract will look like this.
// SPDX-License-Identifier: MIT
pragma solidity ^0.8.2;
import "@openzeppelin/contracts/token/ERC721/ERC721.sol";
import "@openzeppelin/contracts/token/ERC721/extensions/ERC721Enumerable.sol";
import "@openzeppelin/contracts/token/ERC721/extensions/ERC721URIStorage.sol";
import "@openzeppelin/contracts/access/Ownable.sol";
import "@openzeppelin/contracts/utils/Counters.sol";
contract MyNFT is ERC721, ERC721Enumerable, ERC721URIStorage, Ownable {
using Counters for Counters.Counter;
Counters.Counter private _tokenIdCounter;
uint internal allNFTs = 0;
constructor() ERC721("MONSTERNFT", "MNFT") {}
// struct each nft
struct NFT {
uint tokenId;
address payable owner;
uint powerValue;
string name;
}
mapping(address => bool) public minters;
mapping (uint => NFT) internal nfts;// mapping for nfts
mapping (address => uint) public playerpowervalue;// mapping for players
// modifier to check if an address has minted an nft
modifier hasmint(address _address) {
require(minters[_address], "Invalid address");
_;
}
// modifier to check if the power value of the attacker is greater than the power value of the owner
modifier canSwallow(address _address, uint _index) {
address ownerAddress = nfts[_index].owner;
require(playerpowervalue[_address] > playerpowervalue[ownerAddress], "You have less value point");
_;
}
// for minting nfts
function mint( string memory name) public payable {
uint256 tokenId = _tokenIdCounter.current();
_tokenIdCounter.increment();
_safeMint(msg.sender, tokenId);
addNFT(tokenId, name);// listing the nft
}
// adding the nft to the war room
function addNFT(uint256 _tokenId, string memory _name) private{
uint _powerValue = 0;
nfts[allNFTs] = NFT(
_tokenId,
payable(msg.sender),
_powerValue,
_name
);
allNFTs++;
minters[msg.sender] = true;
}
// swallowing an nft and tranfering the nft from the owner to the attacker if the modifier is satisfied
function swallowNFT(uint _index) external hasmint(msg.sender) canSwallow(msg.sender, _index){
require(msg.sender != nfts[_index].owner, "can't swallow your own nft");
_transfer(nfts[_index].owner, msg.sender, nfts[_index].tokenId);
playerpowervalue[nfts[_index].owner] -= nfts[_index].powerValue;
playerpowervalue[msg.sender] += nfts[_index].powerValue;
nfts[_index].owner = payable(msg.sender);
}
// increasing the powervalue of an NFT by its owner and paying 0.5 celo for the transaction
function upgradeNFT(uint _index) external payable{
require(msg.sender == nfts[_index].owner, "you cant upgrade this nft");
payable(owner()).transfer(msg.value);
nfts[_index].powerValue++;
playerpowervalue[msg.sender]++;
}
// returns true if the powervalue of the attacker is greater than the owner
function canSwallowNFT(address _address, uint _index) public view returns(bool){
if(playerpowervalue[_address] > playerpowervalue[nfts[_index].owner]){
return true;
}else{
return false;
}
}
// returns true if the address has minted an nft.
function hasMinted(address _address) public view returns(bool){
if(minters[_address] == true){
return true;
}else{
return false;
}
}
// returning all nfts
function getAllNFTS(uint _index) public view returns(NFT memory){
return nfts[_index];
}
// remove the nft from war room
function remove(uint _index) external {
require(msg.sender == nfts[_index].owner, "can't remove this nft");
nfts[_index] = nfts[allNFTs - 1];
delete nfts[allNFTs - 1];
allNFTs--;
_transfer(address(this), msg.sender, nfts[_index].tokenId);
}
// getting the length of save the planet nfts in the list
function getNFTlength() public view returns (uint256) {
return allNFTs;
}
// The following functions are overrides required by Solidity.
function _beforeTokenTransfer(address from, address to, uint256 tokenId)
internal
override(ERC721, ERC721Enumerable)
{
super._beforeTokenTransfer(from, to, tokenId);
}
// destroy an NFT
function _burn(uint256 tokenId) internal override(ERC721, ERC721URIStorage) {
super._burn(tokenId);
}
// return IPFS url of NFT metadata
function tokenURI(uint256 tokenId)
public
view
override(ERC721, ERC721URIStorage)
returns (string memory)
{
return super.tokenURI(tokenId);
}
function supportsInterface(bytes4 interfaceId)
public
view
override(ERC721, ERC721Enumerable)
returns (bool)
{
return super.supportsInterface(interfaceId);
}
}
Breakdown
The first step is to declare the license and solidity version and import all the necessary OpenZeppelin contracts.
// SPDX-License-Identifier: MIT
pragma solidity ^0.8.2;
import "@openzeppelin/contracts/token/ERC721/ERC721.sol";
import "@openzeppelin/contracts/token/ERC721/extensions/ERC721Enumerable.sol";
import "@openzeppelin/contracts/token/ERC721/extensions/ERC721URIStorage.sol";
import "@openzeppelin/contracts/access/Ownable.sol";
import "@openzeppelin/contracts/utils/Counters.sol";
These contracts provide functionality for creating ERC721 tokens, as well as additional functionality for enumeration, URI storage, Burnable, Ownable, and Counters. OpenZeppelin is an open-source secure framework for building smart contracts. To learn more about open zeppelin smart contracts, click here.
We’ll be using the ERC721 Token standard.
Next, we’ll inherit all the imported open zeppelin contracts and create our constructors and variables.
contract MyNFT is ERC721, ERC721Enumerable, ERC721URIStorage, Ownable {
Here we declared the contract MyNFT
, and it inherits from several OpenZeppelin contracts like the ERC721
, ERC721Enumerable
, ERC721URIStorage
, and Ownable
. Inheriting from these contracts provides a range of functionality for our contract.
using Counters for Counters.Counter;
Counters.Counter private _tokenIdCounter;
uint internal allNFTs = 0;
constructor() ERC721("MONSTERNFT", "MNFT") {}
Next, set up our counter to enables the use of the Counters contract from the OpenZeppelin library.
Then we declare a private variable called _tokenIdCounter
of the Counters.Counter type. This variable is used to keep track of the number of NFTs that have been minted and an internal uint variable called allNFTs
This variable is used to keep track of the number of NFTs that are currently in the war room.
We also declare our constructor named “MONSTERNFT” and the symbol “MNFT”. This sets up the basic functionality for the contract to manage non-fungible tokens.
struct NFT {
uint tokenId;
address payable owner;
uint powerValue;
string name;
}
Next, we declare a struct called NFT
. The struct has four fields: tokenId
(a uint that represents the unique ID of the NFT), owner
(an address that represents the owner of the NFT), powerValue
(a uint that represents the power value of the NFT), and name
(a string that represents the name of the NFT).
mapping(address => bool) public minters;
mapping (uint => NFT) internal nfts;
mapping (address => uint) public playerpowervalue;
We also declare three mappings. First, minters
(a mapping addresses to booleans that represents whether an address is a minter or not), nfts
(a mapping uint to NFT to accomodate the list of nfts minted) and playerpowervalue
(a mapping address to uint to keep track of the power value of each player).
modifier hasmint(address _address) {
require(minters[_address], "Invalid address");
_;
}
modifier canSwallow(address _address, uint _index) {
address ownerAddress = nfts[_index].owner;
require(playerpowervalue[_address] > playerpowervalue[ownerAddress], "You have less value point");
_;
}
Next we added two modifiers.
hasmint
This modifier checks whether the address calling the function has already minted an NFT by verifying that the address is a valid minter. If the address is not a valid minter, the function execution is aborted. otherwise, it is allowed to proceed.
canSwallow
This modifier checks whether the power value of the attacker is greater than the power value of the owner of the NFT before allowing the swallowNFT()
function to execute. If the power value of the attacker is less than or equal to the owner’s power value, the function execution is aborted.
let’s look at the functions
function mint( string memory name) public payable {
uint256 tokenId = _tokenIdCounter.current();
_tokenIdCounter.increment();
_safeMint(msg.sender, tokenId);
addNFT(tokenId, name);// listing the nft
}
Let’s declare a function called mint()
The Mint function allows a player to mint their own NFTs. The function takes a string as a parameter used to specify the name of the NFT. The function first generates a unique tokenId
for the NFT and increments the tokenId counter
. It then calls the _safeMint
function, inherited from the ERC721
contract and is used to mint the NFT. Finally, it calls the addNFT
function which adds the NFT to the game.
function addNFT(uint256 _tokenId, string memory _name) private{
uint _powerValue = 0;
nfts[allNFTs] = NFT(
_tokenId,
payable(msg.sender),
_powerValue,
_name
);
allNFTs++;
minters[msg.sender] = true;
}
The AddNFT()
function adds the NFT to the game. The function takes a tokenId
and a name as parameters. It then creates a new NFT struct with the given parameters and adds it to the internal NFTs mapping. It also adds the player to the minters mapping and increments the allNFTs
variable.
function swallowNFT(uint _index) external hasmint(msg.sender) canSwallow(msg.sender, _index){
require(msg.sender != nfts[_index].owner, "can't swallow your own nft");
_transfer(nfts[_index].owner, msg.sender, nfts[_index].tokenId);
playerpowervalue[nfts[_index].owner] -= nfts[_index].powerValue;
playerpowervalue[msg.sender] += nfts[_index].powerValue;
nfts[_index].owner = payable(msg.sender);
}
The SwallowNFT()
function allows a player to swallow another player’s NFT. This function takes an index as a parameter which is used to specify the NFT to be swallowed. The function is protected by two modifiers. hasmint
and canSwallow
. The hasmint
modifier checks if the address has minted an NFT and the canSwallow
modifier checks if the power value of the attacker is greater than the power value of the owner. If both the modifiers pass, the function transfers the NFT from the owner to the attacker, decreases the power value of the owner and increases the power value of the attacker.
function upgradeNFT(uint _index) external payable{
require(msg.sender == nfts[_index].owner, "you cant upgrade this nft");
payable(owner()).transfer(msg.value);
nfts[_index].powerValue++;
playerpowervalue[msg.sender]++;
}
The UpgradeNFT()
function allows a player to upgrade the power value of their NFT. This function takes an index
as a parameter which is used to specify the NFT to be upgraded. The function requires that the sender of the transaction is the owner of the NFT. If this requirement is met, the function transfers 0.5 Celo from the owner of the nft to the contract owner and increases the power value of the NFT and the player.
function canSwallowNFT(address _address, uint _index) public view returns(bool){
if(playerpowervalue[_address] > playerpowervalue[nfts[_index].owner]){
return true;
}else{
return false;
}
}
The CanSwallowNFT()
function returns true if the power value of the attacker is greater than the power value of the owner of the NFT. The function takes an address
and an index
as parameters. The address is used to specify the attacker, and the index is used to specify the NFT to be swallowed. The function returns true if the power value of the attacker is greater than the power value of the owner of the nft.
function hasMinted(address _address) public view returns(bool){
if(minters[_address] == true){
return true;
}else{
return false;
}
}
The HasMinted()
function returns true if the address has minted an NFT. The function takes an address
as a parameter which is used to specify the address to check. The function returns true if the address has minted an NFT. This will be usefull in our front-end.
function getAllNFTS(uint _index) public view returns(NFT memory){
return nfts[_index];
}
The GetAllNFTS()
function returns all NFTs. The function takes an index
as a parameter which is used to specify the NFT to be returned. The function returns an NFT struct with the given index
.
function remove(uint _index) external {
require(msg.sender == nfts[_index].owner, "can't remove this nft");
nfts[_index] = nfts[allNFTs - 1];
delete nfts[allNFTs - 1];
allNFTs--;
_transfer(address(this), msg.sender, nfts[_index].tokenId);
}
The Remove()
function removes an NFT from the game. The function takes an index
as a parameter to specify the NFT to be removed. The function requires that the sender of the transaction is the owner of the NFT. If this requirement is met, the function transfers the NFT from the contract to the owner and deletes the NFT from the internal nfts mapping.
function getNFTlength() public view returns (uint256) {
return allNFTs;
}
The GetNFTlength()
function returns the length of the NFTs in the list. The function returns the value of the allNFTs
variable which is the length of all monster NFTs in the list.
The rest of the functions are overrides that are required by solidity.
That’s it For the smart contract. Next, we’ll be looking at the front end.
Front end
Stack
We’ll use the following stack for this section.
- Hardhat
- React
Setup
Clone the full project from this repository to follow up with this section.
Here is an example of the env file
MNEMONIC=""
REACT_APP_STORAGE_API_KEY=""
Deployment
We’ll use hardhat to deploy our smart-contracts to the celo blockchain.
Configure your hardhat.config
file to look like this to enable hardhat to deploy the smart contracts to the celo blockchain.
require("@nomiclabs/hardhat-waffle");
require("dotenv").config({ path: ".env" });
// This is a sample Hardhat task. To learn how to create your own go to
// https://hardhat.org/guides/create-task.html
task("accounts", "Prints the list of accounts", async (taskArgs, hre) => {
const accounts = await hre.ethers.getSigners();
for (const account of accounts) {
console.log(account.address);
}
});
const getEnv = (variable, optional = false) => {
if (!process.env[variable]) {
if (optional) {
console.warn(
`[@env]: Environmental variable for ${variable} is not supplied.`
);
} else {
throw new Error(
`You must create an environment variable for ${variable}`
);
}
}
return process.env[variable]?.replace(/\\n/gm, "\n");
};
// Your mnemomic key
const MNEMONIC = getEnv("MNEMONIC");
// You need to export an object to set up your config
// Go to https://hardhat.org/config/ to learn more
/**
* @type import('hardhat/config').HardhatUserConfig
*/
module.exports = {
solidity: "0.8.9",
networks: {
alfajores: {
url: "https://alfajores-forno.celo-testnet.org",
accounts: {
mnemonic: process.env.MNEMONIC,
path: "m/44'/52752'/0'/0",
},
chainId: 44787,
},
},
};
Next let’s create a script to deploy the smart contract.
const hre = require("hardhat");
async function main() {
const MyNFT = await hre.ethers.getContractFactory("MyNFT");
const myNFT = await MyNFT.deploy();
await myNFT.deployed();
console.log("MyNFT deployed to:", myNFT.address);
storeContractData(myNFT);
}
function storeContractData(contract) {
const fs = require("fs");
const contractsDir = __dirname + "/../src/contracts";
if (!fs.existsSync(contractsDir)) {
fs.mkdirSync(contractsDir);
}
fs.writeFileSync(
contractsDir + "/MyNFT-address.json",
JSON.stringify({ MyNFT: contract.address }, undefined, 2)
);
const MyNFTArtifact = artifacts.readArtifactSync("MyNFT");
fs.writeFileSync(
contractsDir + "/MyNFT.json",
JSON.stringify(MyNFTArtifact, null, 2)
);
}
main()
.then(() => process.exit(0))
.catch((error) => {
console.error(error);
process.exit(1);
});
The script above will deploy the smart contract and create a contract folder for the ABI and contract address of the smart contract.
Deploy the smart contracts to the celo block-chain by running this command
npx hardhat run scripts/deploy.js --network alfajores
You should see something like this in the terminal
MyNFT deployed to: 0x49F39D9531B826826EDc7066161F20570105AFb1
Now Let’s look at the index.js
file in the root of the project.
import React from "react";
import ReactDOM from "react-dom";
import {
ContractKitProvider,
Alfajores,
NetworkNames,
} from "@celo-tools/use-contractkit";
import App from "./App";
import reportWebVitals from "./reportWebVitals";
import "bootstrap-icons/font/bootstrap-icons.css";
import "bootstrap/dist/css/bootstrap.min.css";
import "@celo-tools/use-contractkit/lib/styles.css";
import "react-toastify/dist/ReactToastify.min.css";
ReactDOM.render(
<React.StrictMode>
<ContractKitProvider
networks={[Alfajores]}
network={{
name: NetworkNames.Alfajores,
rpcUrl: "https://alfajores-forno.celo-testnet.org",
graphQl: "https://alfajores-blockscout.celo-testnet.org/graphiql",
explorer: "https://alfajores-blockscout.celo-testnet.org",
chainId: 44787,
}}
dapp={{
name: "NFT MONSTER GAME",
description: "A simple dapp for nft gaming",
}}
>
<App />
</ContractKitProvider>
</React.StrictMode>,
document.getElementById("root")
);
// If you want to start measuring performance in your app, pass a function
// to log results (for example: reportWebVitals(console.log))
// or send to an analytics endpoint. Learn more: https://bit.ly/CRA-vitals
reportWebVitals();
In the Index.js
we made some necessary imports like the ContractKitProvider
, Alfajore
s, and NetworkNames
from the use-contract kit.
Next, we wrapped our ContractKitProvider
around the app Component to enable our app to connect to the celo test network.
Click here to learn more about ContractKit
Hooks
In our hooks folder, we have three files, useBalance
, useContract
and useMinterContract
.
For the useBalance.js file,
import { useState, useEffect, useCallback } from "react";
import { useContractKit } from "@celo-tools/use-contractkit";
export const useBalance = () => {
const { address, kit } = useContractKit();
const [balance, setBalance] = useState(0);
const getBalance = useCallback(async () => {
// fetch a connected wallet token balance
const value = await kit.getTotalBalance(address);
setBalance(value);
}, [address, kit]);
useEffect(() => {
if (address) getBalance();
}, [address, getBalance]);
return {
balance,
getBalance,
};
};
The useBalance.js
file uses the useBalance
custom hook which is used to get the balance of an account that is connected to the dapp.
For the useContract.js
file
import { useState, useEffect, useCallback } from "react";
import { useContractKit } from "@celo-tools/use-contractkit";
export const useContract = (abi, contractAddress) => {
const { getConnectedKit, address } = useContractKit();
const [contract, setContract] = useState(null);
const getContract = useCallback(async () => {
const kit = await getConnectedKit();
// get a contract interface to interact with
setContract(new kit.web3.eth.Contract(abi, contractAddress));
}, [getConnectedKit, abi, contractAddress]);
useEffect(() => {
if (address) getContract();
}, [address, getContract]);
return contract;
};
The useContract.js
file uses the useContract
custom hook which is used to get an instance of a smart contract.
import { useContract } from "./useContract";
import MyNFTAbi from "../contracts/MyNFT.json";
import MyNFTContractAddress from "../contracts/MyNFT-address.json";
export const useMinterContract = () =>
useContract(MyNFTAbi.abi, MyNFTContractAddress.MyNFT);
The useMinterContract
import the ABI and contract address from the JSON files that we generated when we run the deploy scripts which is then used to create and export an instance of their smart contracts.
Inside the utils folder open the minter.js
file, it should look like this.
import { ethers } from "ethers";
// mint an NFT
export const createNft = async (minterContract, performActions, name) => {
await performActions(async (kit) => {
if (!name) return;
const { defaultAccount } = kit;
try {
// mint the NFT and save the IPFS url to the blockchain
let transaction = await minterContract.methods
.mint(name)
.send({ from: defaultAccount });
return transaction;
} catch (error) {
console.log("Error uploading file: ", error);
}
});
};
// fetch all NFTs on the smart contract
export const getNfts = async (minterContract) => {
try {
const nfts = [];
const nftsLength = await minterContract.methods.getNFTlength().call();
// contract starts minting from index 1
for (let i = 0; i < Number(nftsLength); i++) {
const nft = new Promise(async (resolve) => {
const _nft = await minterContract.methods.getAllNFTS(i).call();
const owner = await fetchNftOwner(minterContract, i);
resolve({
index: i,
powerValue: _nft.powerValue,
name: _nft.name,
owner: owner,
});
});
nfts.push(nft);
}
return Promise.all(nfts);
} catch (e) {
console.log({ e });
}
};
// get the owner address of an NFT
export const fetchNftOwner = async (minterContract, index) => {
try {
return await minterContract.methods.ownerOf(index).call();
} catch (e) {
console.log({ e });
}
};
export const minted = async (minterContract, _address) => {
try {
return await minterContract.methods.hasMinted(_address).call();
} catch (e) {
console.log({ e });
}
};
export const checkPowervalue = async (minterContract, _address, _index) => {
try {
return await minterContract.methods.canSwallowNFT(_address, _index).call();
} catch (e) {
console.log({ e });
}
};
// get the address that deployed the NFT contract
export const fetchNftContractOwner = async (minterContract) => {
try {
let owner = await minterContract.methods.owner().call();
return owner;
} catch (e) {
console.log({ e });
}
};
export const swallow = async (minterContract, performActions, index) => {
try {
await performActions(async (kit) => {
try {
console.log(minterContract, index);
const { defaultAccount } = kit;
await minterContract.methods
.swallowNFT(index)
.send({ from: defaultAccount });
} catch (error) {
console.log({ error });
}
});
} catch (error) {
console.log(error);
}
};
export const upgrade = async (minterContract, performActions, index) => {
try {
await performActions(async (kit) => {
try {
const price = ethers.utils.parseUnits(String(0.5), "ether");
const { defaultAccount } = kit;
await minterContract.methods
.upgradeNFT(index)
.send({ from: defaultAccount, value: price });
} catch (error) {
console.log({ error });
}
});
} catch (error) {
console.log(error);
}
};
export const remove = async (minterContract, performActions, index) => {
try {
await performActions(async (kit) => {
try {
const { defaultAccount } = kit;
await minterContract.methods
.remove(index)
.send({ from: defaultAccount });
} catch (error) {
console.log({ error });
}
});
} catch (error) {
console.log(error);
}
};
Now lets break down the components
import { ethers } from "ethers";
// mint an NFT
export const createNft = async (minterContract, performActions, name) => {
await performActions(async (kit) => {
if (!name) return;
const { defaultAccount } = kit;
try {
let transaction = await minterContract.methods
.mint(name)
.send({ from: defaultAccount });
return transaction;
} catch (error) {
console.log("Error uploading file: ", error);
}
});
};
First, we made the necessary import and then we declared the createNft()
function. This function is used to mint an NFT. It takes the minterContract
and performActions
as arguments, along with the name of the NFT. It then uses the defaultAccount
from the kit to mint the NFT.
export const getNfts = async (minterContract) => {
try {
const nfts = [];
const nftsLength = await minterContract.methods.getNFTlength().call();
// contract starts minting from index 1
for (let i = 0; i < Number(nftsLength); i++) {
const nft = new Promise(async (resolve) => {
const _nft = await minterContract.methods.getAllNFTS(i).call();
const owner = await fetchNftOwner(minterContract, i);
resolve({
index: i,
powerValue: _nft.powerValue,
name: _nft.name,
owner: owner,
});
});
nfts.push(nft);
}
return Promise.all(nfts);
} catch (e) {
console.log({ e });
}
};
The getNfts()
function is used to fetch all NFTs stored on the smart contract. It takes the minterContract
as an argument and returns an array of NFTs.
export const fetchNftOwner = async (minterContract, index) => {
try {
return await minterContract.methods.ownerOf(index).call();
} catch (e) {
console.log({ e });
}
};
The fetchNftOwner()
function is used to get the owner address of an NFT. It takes the minterContract
and the index of the NFT as arguments and returns the owner address.
export const minted = async (minterContract, _address) => {
try {
return await minterContract.methods.hasMinted(_address).call();
} catch (e) {
console.log({ e });
}
};
The minted()
function checks if a particular address has minted an NFT. It takes the minterContract
and the address
as arguments and returns a boolean.
export const checkPowervalue = async (minterContract, _address, _index) => {
try {
return await minterContract.methods.canSwallowNFT(_address, _index).call();
} catch (e) {
console.log({ e });
}
};
The checkPowervalue()
function is used to check the power value of an NFT. It takes the minterContract
, address
, and index
of the NFT as arguments and returns a boolean.
export const fetchNftContractOwner = async (minterContract) => {
try {
let owner = await minterContract.methods.owner().call();
return owner;
} catch (e) {
console.log({ e });
}
};
The fetchNftContractOwner()
function is used to get the address that deployed the NFT contract. It takes the minterContract
as an argument and returns the address.
export const swallow = async (minterContract, performActions, index) => {
try {
await performActions(async (kit) => {
try {
console.log(minterContract, index);
const { defaultAccount } = kit;
await minterContract.methods
.swallowNFT(index)
.send({ from: defaultAccount });
} catch (error) {
console.log({ error });
}
});
} catch (error) {
console.log(error);
}
};
The swallow()
function is used to swallow an NFT. It takes the minterContract
and performActions
as arguments, along with the index of the NFT. It then uses the defaultAccount
from the kit to call the swallowNFT
method and swallow the NFT.
export const upgrade = async (minterContract, performActions, index) => {
try {
await performActions(async (kit) => {
try {
const price = ethers.utils.parseUnits(String(0.5), "ether");
const { defaultAccount } = kit;
await minterContract.methods
.upgradeNFT(index)
.send({ from: defaultAccount, value: price });
} catch (error) {
console.log({ error });
}
});
} catch (error) {
console.log(error);
}
};
The upgrade()
function is used to upgrade an NFT. It takes the minterContract
and performActions
as arguments, along with the index of the NFT. It then uses the defaultAccount
from the kit to call the upgradeNFT
method and upgrade the NFT.
export const remove = async (minterContract, performActions, index) => {
try {
await performActions(async (kit) => {
try {
const { defaultAccount } = kit;
await minterContract.methods
.remove(index)
.send({ from: defaultAccount });
} catch (error) {
console.log({ error });
}
});
} catch (error) {
console.log(error);
}
};
The remove()
function is used to remove an NFT. It takes the minterContract
and performActions
as arguments, along with the index of the NFT. It then uses the defaultAccount
from the kit to call the remove method and remove the NFT.
There you have it. We have successfully interacted with our smart contract.
Next Steps
I hope you learned a lot from this tutorial. Here are some relevant links that would aid your learning further.
- https://docs.celo.org/
- https://solidity-by-example.org/
- https://www.openzeppelin.com/contracts
- https://docs.soliditylang.org/en/v0.8.17/
About the author
I’m Jonathan Iheme, A full stack block-chain Developer from Nigeria.
References
- https://web3.storage/docs/
- https://docs.celo.org/developer/contractkit/
- https://docs.celo.org/
- https://dacade.org/communities/celo/courses/celo-201/learning-modules/30a4b854-6722-488f-937f-c26591b89f2e
Thank You!!