Truffle

Use Truffle

Setting up the development environment

Prerequisites

• VS Code installed

• Node.js(+npm) installed

• Git

• Make your own MetaMask or similar to create a wallet

{% hint style="info" %} Check your environment and install using that link. {% endhint %}

Steps

1. Fund your WorldLand

When deploying contracts, you need some coins. This a way how to get world land testnet coins! Plz follow these statements:

2. Install Truffle

NOW, We start to install "Truffle" using the Node.js package manager on VS Code Terminal:

// VS Code Terminal: cmd
npm install -g truffle

{% hint style="info" %}

Better save your own time!

When installing all packages, Run the command prompt(CMD) with administrator privileges. {% endhint %}

3. Install dotenv package

// VS Code Terminal: cmd
npm install dotenv

4. Install @truffle/hdwallet-provider

// VS Code Terminal: cmd
npm install @truffle/hdwallet-provider

5. Install OpenZepplin

// VS Code Terminal: cmd
npm install --save-dev @openzeppelin/contracts

5. Open your project directory on VS Code

Create "newNFT" folder and move it to "newNFT" folder.

// VS Code Terminal: cmd
mkdir newNFT
cd newNFT

{% hint style="success" %} Check directory. It may be similar to below: {% endhint %}

// Directory structure
│
├─ addition-game-starter
│
├─ build
│
├─ contracts
│
├─ migrations
│
├─ node_modules
│
└─ test
package-lock.json
package.json
truffle-config.js

6. Create the .env file

Create a ".env" file and write your MetaMask secret recovery phrase and others.

{% hint style="danger" %} You must keep your "MNEMONIC" key. Never show your information. {% endhint %}

//.env 
MNEMONIC = *Your-MetaMask-Secret-Recovery-Phrase*

7. Edit truffle-config.js file

truffle-config.js file needs to configure some information about specific things.

Find module.export part.

// write require('dotenv').config()
require('dotenv').config()
const HDWalletProvider = require('@truffle/hdwallet-provider')
const { MNEMONIC, PROJECT_ID } = process.env;
// Modify specific network information
module.exports = {
    networks: {
        worldland: {
            provider: () => new HDwalletProvider(MNEMONIC,'https://rpc.lvscan.io/')
            network_id: 12345,
            gas: 5500000,
        }
    },
    mocha: {
      // timeout: 100000
      },
    compilers: {
        solc: {
          version: "0.8.13" // Fetch exact version from solc-bin (default: truffle's version)
          // docker: true,        // Use "0.5.1" you've installed locally with docker (default: false)
          // settings: {          // See the solidity docs for advice about optimization and evmVersion
          //  optimizer: {
          //    enabled: false,
          //    runs: 200
          //  },
          //  evmVersion: "byzantium"
          // }
        }
    },
};

8. Create a smart content

You can edit this code to your style. This code is just an example. I'll give you two types.

The below codes are the first type. The first type is the general type. You can choose it generally.

// First type
// Contract based on [https://docs.openzeppelin.com/contracts/4.x/erc721](https://docs.openzeppelin.com/contracts/4.x/erc721)
// SPDX-License-Identifier: MIT
pragma solidity ^0.8.13;

import "@openzeppelin/contracts/token/ERC721/ERC721.sol";
import "@openzeppelin/contracts/token/ERC721/extensions/ERC721URIStorage.sol";
import "@openzeppelin/contracts/utils/Counters.sol";
import "@openzeppelin/contracts/access/Ownable.sol";

contract newNFT is ERC721URIStorage, Ownable {
    using Counters for Counters.Counter;
    Counters.Counter private _tokenIds;

    constructor() ERC721("newNFT", "NFT") {}

    function mintNFT(address recipient, string memory tokenURI)
        public
        returns (uint256)
    {
        _tokenIds.increment();

        uint256 newItemId = _tokenIds.current();
        _safeMint(recipient, newItemId);
        _setTokenURI(newItemId, tokenURI);

        return newItemId;
    }
}

The below codes are the Second type.

// Second type
// Contract based on (https://docs.openzeppelin.com/contracts/4.x/erc721)
// SPDX-License-Identifier: MIT
pragma solidity ^0.8.13;

import "@openzeppelin/contracts-upgradeable/token/ERC721/ERC721Upgradeable.sol";
import "@openzeppelin/contracts-upgradeable/token/ERC721/extensions/ERC721URIStorageUpgradeable.sol";
import "@openzeppelin/contracts-upgradeable/access/OwnableUpgradeable.sol";
import "@openzeppelin/contracts-upgradeable/proxy/utils/Initializable.sol";
import "@openzeppelin/contracts-upgradeable/utils/CountersUpgradeable.sol";

/*Smart contracts are immutable by default unless deployed behind an upgradeable proxy
(https://docs.openzeppelin.com/upgrades)*/

contract MyToken is Initializable, ERC721Upgradeable, ERC721URIStorageUpgradeable, OwnableUpgradeable {
    using CountersUpgradeable for CountersUpgradeable.Counter;
    CountersUpgradeable.Counter private _tokenIdCounter;
    /// @custom:oz-upgrades-unsafe-allow constructor
    constructor() {
        _disableInitializers();
    }
    function initialize() initializer public {
        __ERC721_init("MyToken", "MTK");
        __ERC721URIStorage_init();
        __Ownable_init();
    }
    function safeMint(address to, string memory uri) public onlyOwner {
        uint256 tokenId = _tokenIdCounter.current();
        _tokenIdCounter.increment();
        _safeMint(to, tokenId);
        _setTokenURI(tokenId, uri);
    }
    // The following functions are overrides required by Solidity.
    function _burn(uint256 tokenId)
        internal
        override(ERC721Upgradeable, ERC721URIStorageUpgradeable)
    {
        super._burn(tokenId);
    }
    function tokenURI(uint256 tokenId)
        public
        view
        override(ERC721Upgradeable, ERC721URIStorageUpgradeable)
        returns (string memory)
    {
        return super.tokenURI(tokenId);
    }
}

9. Write 1_initial_newNFT.js

• Make 1_initial_newNFT.js under migrations folder

• Write specific codes on 1_initial_newNFT.js

var newNFT = artifacts.require("newNFT.sol")

module.exports = function(deployer) {
  deployer.deploy(newNFT);
};

10. Compile the smart contract

// compile contract
truffle compile

When successfully compile, you can see like below:

Compiling your contracts...
===========================
> Compiling .\contracts\newNFT.sol
> Compiling .\contracts\newNFT.sol
> Artifacts written to C:\Users\SuminKim\Desktop\newNFT\nft\build\contracts
> Compiled successfully using:
   - solc: 0.8.13+commit.abaa5c0e.Emscripten.clang

11. Deploy your contract on WorldLand network

// Deploy contract
truffle migrate --network worldland

When successfully compile, you can see like below:

Compiling your contracts...
===========================
> Compiling .\contracts\newNFT.sol
> Compiling .\contracts\newNFT.sol
> Artifacts written to C:\Users\SuminKim\Desktop\newNFT\nft\build\contracts
> Compiled successfully using:
   - solc: 0.8.13+commit.abaa5c0e.Emscripten.clang


Starting migrations...
======================
> Network name:    'worldland'
> Network id:      12345
> Block gas limit: 30000000 (0x1c9c380)


1_initial_newNFT.js
===================

   Replacing 'newNFT'
   ------------------
   > transaction hash:    0x9dc71d5c4742af53b62eaf5099918ab349aa0b03b0827530a3f7c4903c3c0bd8
   > Blocks: 0            Seconds: 228
   > contract address:    0x07cc033F14e16Ced9d21ee49279C37b7cEB4832a
   > block number:        10615
   > block timestamp:     1674041065
   > account:             0x68Eb38DC93190362785Df115891a3FF04a90C5af
   > balance:             9.979944564943844782
   > gas used:            2674034 (0x28cd72)
   > gas price:           2.500000007 gwei
   > value sent:          0 ETH
   > total cost:          0.006685085018718238 ETH

   > Saving artifacts
   -------------------------------------
   > Total cost:     0.006685085018718238 ETH

Summary
=======
> Total deployments:   1
> Final cost:          0.006685085018718238 ETH

12. Finally, check contract on explore

Copy block number(10615) and check it on explore(LV Scanner)!

{% hint style="success" %} You can confirm Timestamp, Hash, and others about your contract. {% endhint %}