Tutorial Membuat Token ERC20 Sendiri Menggunakan Smart Contract

Tutorial Membuat Token ERC20 Sendiri Menggunakan Smart Contract - Token Erc20 merupakan mata uang digital atau biasa kita sebut Cryptocurrency. Berbeda dengan Bitcoin dan Etehereum, Token Erc20 ini masih belum memakai server blockchain sendiri. Token Erc20 ini masih menumpang pada server blockchain Ethereum menggunakan fitur smart contract. Token Erc20 ini juga bisa kita sebut juga sebagai anak dari Ethereum.

ICO merupakan penggalangan dana untuk membangun aplikasi yang berkaitan dengan Blockchain dan implementasinya seperti bitcoin, smart contract, dan smart ledger. Kita tidak bisa menganggap remeh Token Erc20 ini sudah banyak sekali ICO yang memakai Token Erc20 yang sukses dan dibanjiri investor.

Ternyata kita dapat membuat Token Erc20 ini sendiri dengan menggunakan fitur smart contract, berikut Cara Membuat Token ERC20 Sendiri.

Step 1:

Buka Text Editor favoritmu kemudian salin kode dibawah ini

pragma solidity ^0.4.4;

contract Token {

/// @return total amount of tokens
    function totalSupply() constant returns (uint256 supply) {}

/// @param _owner The address from which the balance will be retrieved
    /// @return The balance
    function balanceOf(address _owner) constant returns (uint256 balance) {}

/// @notice send `_value` token to `_to` from `msg.sender`
    /// @param _to The address of the recipient
    /// @param _value The amount of token to be transferred
    /// @return Whether the transfer was successful or not
    function transfer(address _to, uint256 _value) returns (bool success) {}

/// @notice send `_value` token to `_to` from `_from` on the condition it is approved by `_from`
    /// @param _from The address of the sender
    /// @param _to The address of the recipient
    /// @param _value The amount of token to be transferred
    /// @return Whether the transfer was successful or not
    function transferFrom(address _from, address _to, uint256 _value) returns (bool success) {}

/// @notice `msg.sender` approves `_addr` to spend `_value` tokens
    /// @param _spender The address of the account able to transfer the tokens
    /// @param _value The amount of wei to be approved for transfer
    /// @return Whether the approval was successful or not
    function approve(address _spender, uint256 _value) returns (bool success) {}

/// @param _owner The address of the account owning tokens
    /// @param _spender The address of the account able to transfer the tokens
    /// @return Amount of remaining tokens allowed to spent
    function allowance(address _owner, address _spender) constant returns (uint256 remaining) {}

event Transfer(address indexed _from, address indexed _to, uint256 _value);
    event Approval(address indexed _owner, address indexed _spender, uint256 _value);

}

contract StandardToken is Token {

function balanceOf(address _owner) constant returns (uint256 balance) {
        return balances[_owner];
    }

function approve(address _spender, uint256 _value) returns (bool success) {
        allowed[msg.sender][_spender] = _value;
        Approval(msg.sender, _spender, _value);
        return true;
    }

function allowance(address _owner, address _spender) constant returns (uint256 remaining) {
      return allowed[_owner][_spender];
    }

mapping (address => uint256) balances;
    mapping (address => mapping (address => uint256)) allowed;
    uint256 public totalSupply;
}

contract HashnodeTestCoin is StandardToken { // CHANGE THIS. Update the contract name.

/* Public variables of the token */

/*
    NOTE:
    The following variables are OPTIONAL vanities. One does not have to include them.
    They allow one to customise the token contract & in no way influences the core functionality.
    Some wallets/interfaces might not even bother to look at this information.
    */
    string public name;                   // Token Name
    uint8 public decimals;                // How many decimals to show. To be standard complicant keep it 18
    string public symbol;                 // An identifier: eg SBX, XPR etc..
    string public version = 'H1.0'; 
    uint256 public unitsOneEthCanBuy;     // How many units of your coin can be bought by 1 ETH?
    uint256 public totalEthInWei;         // WEI is the smallest unit of ETH (the equivalent of cent in USD or satoshi in BTC). We'll store the total ETH raised via our ICO here.  
    address public fundsWallet;           // Where should the raised ETH go?

// This is a constructor function 
    // which means the following function name has to match the contract name declared above
    function HashnodeTestCoin() {
        balances[msg.sender] = 1000000000000000000000;               // Give the creator all initial tokens. This is set to 1000 for example. If you want your initial tokens to be X and your decimal is 5, set this value to X * 100000. (CHANGE THIS)
        totalSupply = 1000000000000000000000;                        // Update total supply (1000 for example) (CHANGE THIS)
        name = "HashnodeTestCoin";                                   // Set the name for display purposes (CHANGE THIS)
        decimals = 18;                                               // Amount of decimals for display purposes (CHANGE THIS)
        symbol = "HTCN";                                             // Set the symbol for display purposes (CHANGE THIS)
        unitsOneEthCanBuy = 10;                                      // Set the price of your token for the ICO (CHANGE THIS)
        fundsWallet = msg.sender;                                    // The owner of the contract gets ETH
    }

function() payable{
        totalEthInWei = totalEthInWei + msg.value;
        uint256 amount = msg.value * unitsOneEthCanBuy;
        require(balances[fundsWallet] >= amount);

balances[fundsWallet] = balances[fundsWallet] - amount;
        balances[msg.sender] = balances[msg.sender] + amount;

Transfer(fundsWallet, msg.sender, amount); // Broadcast a message to the blockchain

//Transfer ether to fundsWallet
        fundsWallet.transfer(msg.value);                               
    }

/* Approves and then calls the receiving contract */
    function approveAndCall(address _spender, uint256 _value, bytes _extraData) returns (bool success) {
        allowed[msg.sender][_spender] = _value;
        Approval(msg.sender, _spender, _value);

//call the receiveApproval function on the contract you want to be notified. This crafts the function signature manually so one doesn't have to include a contract in here just for this.
        //receiveApproval(address _from, uint256 _value, address _tokenContract, bytes _extraData)
        //it is assumed that when does this that the call *should* succeed, otherwise one would use vanilla approve instead.
        if(!_spender.call(bytes4(bytes32(sha3("receiveApproval(address,uint256,address,bytes)"))), msg.sender, _value, this, _extraData)) { throw; }
        return true;
    }
}

source Token-Factory.

Edit pada bagian
totalSupply = supply token (1000000000000000000000 = 1000)
name = Nama token erc20mu
decimals = 18
symbol = simbol token
unitsOneEthCanBuy = harga token

Step 2:
Kemudian install metamask pada browser mu kemudian buat akun dan masuk pada mode Ropsten TesNet pada bagian pojok atas kanan.

Step 3:
Masuk ke Remix IDE kemudian paste code diatas yang sudah kalian edit. seletah itu Compile code tersebut abaikan pesan error yang ada. Kemudian pilih tab Run dan klik Create pada bagian nama token. Notfikasi MetaMask akan muncul kemudian kita klik Submit.

Kemudian kita hanya perlu menambahkan Token di Metamask dengan menggunakan Contract Address token tadi.