Bagaimana cara membuat Token ERC20 dan meluncurkan ICO untuk di publikasikan
Kesempatan ini Saya akan menulis tentang Smart Kontrak Ethereum. Jika Anda tertarik untuk mempelajari lebih lanjut tentang Smart Contrak dan membangun aplikasi Terdesentralisasi, Monggo di simak. Dasar-dasar Berikut adalah beberapa istilah dasar yang akan kami gunakan dalam artikel ini. Jika Anda akrab dengan konsep-konsep berikut ini, jangan ragu untuk melompat ke bagian berikutnya. Ethereum berdasarkan ERC20 Token: Dalam token Ethereum mewakili barang yang dapat diperdagangkan seperti koin, poin loyalitas, dll. Anda dapat membuat mata uang kripto Anda sendiri berdasarkan Ethereum. Selain itu, manfaat mengikuti standar ERC20 adalah bahwa token Anda akan kompatibel dengan klien atau dompet lain yang menggunakan standar yang sama. Kontrak Pintar: Kontrak Cerdas adalah blok kode yang mengeksekusi diri yang ditempatkan pada blockchain Ethereum. Mereka mengandung fungsi data & kode. Kontrak membuat keputusan, berinteraksi dengan kontrak lain, menyimpan data dan mentransfer Eter (unit mata uang kripto dalam blockchain Ethereum) di antara pengguna. Soliditas: Bahasa untuk menulis kontrak pintar. MetaMask / Mist / MEW Wallet: Fasilitas digital yang menyimpan Ether Anda dan token berbasis Ethereum lainnya. Jika anda sudah paham terminologi dasar yang digunakan dalam artikel ini, mari kita mulai.
STEP 1. CODE (Pengcodingan)
Kesempatan ini Saya akan menulis tentang Smart Kontrak Ethereum. Jika Anda tertarik untuk mempelajari lebih lanjut tentang Smart Contrak dan membangun aplikasi Terdesentralisasi, Monggo di simak. Dasar-dasar Berikut adalah beberapa istilah dasar yang akan kami gunakan dalam artikel ini. Jika Anda akrab dengan konsep-konsep berikut ini, jangan ragu untuk melompat ke bagian berikutnya. Ethereum berdasarkan ERC20 Token: Dalam token Ethereum mewakili barang yang dapat diperdagangkan seperti koin, poin loyalitas, dll. Anda dapat membuat mata uang kripto Anda sendiri berdasarkan Ethereum. Selain itu, manfaat mengikuti standar ERC20 adalah bahwa token Anda akan kompatibel dengan klien atau dompet lain yang menggunakan standar yang sama. Kontrak Pintar: Kontrak Cerdas adalah blok kode yang mengeksekusi diri yang ditempatkan pada blockchain Ethereum. Mereka mengandung fungsi data & kode. Kontrak membuat keputusan, berinteraksi dengan kontrak lain, menyimpan data dan mentransfer Eter (unit mata uang kripto dalam blockchain Ethereum) di antara pengguna. Soliditas: Bahasa untuk menulis kontrak pintar. MetaMask / Mist / MEW Wallet: Fasilitas digital yang menyimpan Ether Anda dan token berbasis Ethereum lainnya. Jika anda sudah paham terminologi dasar yang digunakan dalam artikel ini, mari kita mulai.
STEP 1. CODE (Pengcodingan)
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 transfer(address _to, uint256 _value) returns (bool success) {
//Default assumes totalSupply can't be over max (2^256 - 1).
//If your token leaves out totalSupply and can issue more tokens as time goes on, you need to check if it doesn't wrap.
//Replace the if with this one instead.
//if (balances[msg.sender] >= _value && balances[_to] + _value > balances[_to]) {
if (balances[msg.sender] >= _value && _value > 0) {
balances[msg.sender] -= _value;
balances[_to] += _value;
Transfer(msg.sender, _to, _value);
return true;
} else { return false; }
}
function transferFrom(address _from, address _to, uint256 _value) returns (bool success) {
//same as above. Replace this line with the following if you want to protect against wrapping uints.
//if (balances[_from] >= _value && allowed[_from][msg.sender] >= _value && balances[_to] + _value > balances[_to]) {
if (balances[_from] >= _value && allowed[_from][msg.sender] >= _value && _value > 0) {
balances[_to] += _value;
balances[_from] -= _value;
allowed[_from][msg.sender] -= _value;
Transfer(_from, _to, _value);
return true;
} else { return false; }
}
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;
}
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 transfer(address _to, uint256 _value) returns (bool success) {
//Default assumes totalSupply can't be over max (2^256 - 1).
//If your token leaves out totalSupply and can issue more tokens as time goes on, you need to check if it doesn't wrap.
//Replace the if with this one instead.
//if (balances[msg.sender] >= _value && balances[_to] + _value > balances[_to]) {
if (balances[msg.sender] >= _value && _value > 0) {
balances[msg.sender] -= _value;
balances[_to] += _value;
Transfer(msg.sender, _to, _value);
return true;
} else { return false; }
}
function transferFrom(address _from, address _to, uint256 _value) returns (bool success) {
//same as above. Replace this line with the following if you want to protect against wrapping uints.
//if (balances[_from] >= _value && allowed[_from][msg.sender] >= _value && balances[_to] + _value > balances[_to]) {
if (balances[_from] >= _value && allowed[_from][msg.sender] >= _value && _value > 0) {
balances[_to] += _value;
balances[_from] -= _value;
allowed[_from][msg.sender] -= _value;
Transfer(_from, _to, _value);
return true;
} else { return false; }
}
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;
}
STEP 2
Unduh MetaMask untuk membuat Wallet. Atau Anda bisa menggunakan My Ether Wallet. Demi kesederhanaan mari kita gunakan MetaMask dalam proyek ini. Setelah Anda mengunduh ekstensi, lanjutkan dan buat akun barui. Kemudian pilih "Ropsten TestNet" Yg berada sudut kiri atas. Sebelum kami menyebarkan kontrak ke blockchain Utama Ethereum, kami akan mengujinya terhadap TestNet dan memastikan semuanya berjalan sesuai harapan. seperti ini:
