EventTicket Contract

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Overview

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Features

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Contract State

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Public Variables

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Mappings

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Initialization

function initialize(
    string memory name,
    string memory symbol,
    address organizer,
    uint256 _totalSupply,
    uint256 _ticketPrice,
    uint256 _saleStart,
    uint256 _saleEnd,
    uint256 _eventDate,
    string memory baseTokenURI,
    address _platformFeeRecipient,
    uint256 _platformFeeBps
) external

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Ticket Minting

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Public Mint

function mint(uint256 quantity) external payable nonReentrant onlySaleActive whenNotPaused

• Current time is between saleStart and saleEnd
• Contract is not paused
• quantity is between 1 and 10
• Sufficient supply available
• Wallet limit not exceeded (if set)
• Sufficient payment provided (msg.value >= ticketPrice * quantity)

// Mint 3 tickets
const tx = await eventTicket.mint(3, {
  value: ethers.parseEther('0.03') // 3 tickets at 0.01 ETH each
});
await tx.wait();

event TicketMinted(address indexed to, uint256 indexed tokenId, uint256 price);

// Mint 1 ticket at 0.01 ETH but send 0.015 ETH
const tx = await eventTicket.mint(1, { value: ethers.parseEther('0.015') });
// You'll receive 0.005 ETH back automatically

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Allowlist Mint

function allowListMint(
    uint256 quantity,
    bytes32[] calldata merkleProof
) external payable nonReentrant onlySaleActive whenNotPaused

• All requirements from mint() apply
• Valid Merkle proof provided
• Address has not already claimed allowlist allocation
• quantity is between 1 and 3

const { MerkleTree } = require('merkletreejs');
const keccak256 = require('keccak256');

// Generate proof for an address
const allowlist = ['0xAddress1', '0xAddress2', '0xAddress3'];
const leaves = allowlist.map(addr => keccak256(addr));
const tree = new MerkleTree(leaves, keccak256, { sortPairs: true });
const proof = tree.getHexProof(keccak256(userAddress));

// Mint with proof
const tx = await eventTicket.allowListMint(2, proof, {
  value: ethers.parseEther('0.02')
});
await tx.wait();

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Organizer Mint

function mintFor(address to, uint256 quantity) external onlyOwner nonReentrant whenNotPaused

• Comp tickets for VIPs
• Team allocations
• Marketing giveaways
• Reserve tickets

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Check-In System

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Self Check-In

function checkIn(uint256 tokenId) external onlyEventStarted

• Current time is after eventDate
• Caller owns the ticket
• Ticket has not been used yet

1. Ticket is marked as used
2. Proof of Attendance NFT is minted to the ticket holder
3. TicketCheckedIn and ProofOfAttendanceMinted events are emitted

// Check in ticket #42
const tx = await eventTicket.checkIn(42);
const receipt = await tx.wait();

// Find POA token ID from events
const poaEvent = receipt.logs.find(log => 
  log.eventName === 'ProofOfAttendanceMinted'
);
console.log('POA Token ID:', poaEvent.args.poaTokenId);

event TicketCheckedIn(uint256 indexed tokenId, address indexed holder);
event ProofOfAttendanceMinted(address indexed attendee, uint256 indexed ticketId, uint256 poaTokenId);

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Organizer Check-In

function organizerCheckIn(uint256 tokenId) external onlyOwner onlyEventStarted

• Caller is the contract owner (organizer)
• Current time is after eventDate
• Ticket has not been used yet

• Assisted check-in at the door
• Batch check-in for groups
• Helping attendees without wallet access

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Revenue Management

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Withdraw Funds

function withdraw() external onlyOwner nonReentrant

• Caller is the contract owner
• Current time is after eventDate
• Contract has a balance > 0

1. Calculate platform fee: balance * platformFeeBps / 10000
2. Transfer platform fee to platformFeeRecipient
3. Transfer remaining balance to organizer
4. Emit WithdrawalCompleted event

// After event date has passed
const tx = await eventTicket.withdraw();
const receipt = await tx.wait();

// Get withdrawal amount from event
const withdrawalEvent = receipt.logs.find(log => 
  log.eventName === 'WithdrawalCompleted'
);
console.log('Withdrawn:', ethers.formatEther(withdrawalEvent.args.amount));

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Administrative Functions

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Set Allowlist

function setAllowListRoot(bytes32 newRoot) external onlyOwner

const { MerkleTree } = require('merkletreejs');
const keccak256 = require('keccak256');

// Create allowlist
const allowlist = [
  '0x1234567890123456789012345678901234567890',
  '0x2345678901234567890123456789012345678901',
  '0x3456789012345678901234567890123456789012'
];

const leaves = allowlist.map(addr => keccak256(addr));
const tree = new MerkleTree(leaves, keccak256, { sortPairs: true });
const root = tree.getRoot();

// Set root on contract
const tx = await eventTicket.setAllowListRoot(root);
await tx.wait();

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Set Max Tickets Per Wallet

function setMaxTicketsPerWallet(uint256 newMax) external onlyOwner

// Allow maximum 10 tickets per wallet
await eventTicket.setMaxTicketsPerWallet(10);

// Remove limit entirely
await eventTicket.setMaxTicketsPerWallet(0);

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Pause/Unpause

function pause() external onlyOwner
function unpause() external onlyOwner

• Security incidents
• Technical issues
• Emergency situations

// Pause minting
await eventTicket.pause();

// Resume after fixing issue
await eventTicket.unpause();

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View Functions

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Check Ticket Validity

function isTicketValid(uint256 tokenId) external view returns (bool)

const isValid = await eventTicket.isTicketValid(42);
if (isValid) {
  console.log('Ticket #42 is valid and unused');
}

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Get Available Tickets

function availableTickets() external view returns (uint256 remaining)

const available = await eventTicket.availableTickets();
console.log(`${available} tickets remaining`);

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Token URI

function tokenURI(uint256 tokenId) public view override returns (string memory)

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Events

event TicketMinted(address indexed to, uint256 indexed tokenId, uint256 price);

event TicketCheckedIn(uint256 indexed tokenId, address indexed holder);

event ProofOfAttendanceMinted(address indexed attendee, uint256 indexed ticketId, uint256 poaTokenId);

event AllowListUpdated(bytes32 newRoot);

event WithdrawalCompleted(address indexed organizer, uint256 amount);

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Errors

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Complete Example

const { ethers } = require('ethers');

// 1. Create event via factory
const factory = new ethers.Contract(factoryAddress, factoryABI, signer);
const tx1 = await factory.createEvent(
  'DevCon 2024',
  'DEVCON24',
  1000,
  ethers.parseEther('0.01'),
  Math.floor(Date.now() / 1000),
  Math.floor(Date.now() / 1000) + 604800,
  Math.floor(Date.now() / 1000) + 1209600,
  'https://api.example.com/metadata/'
);
const receipt1 = await tx1.wait();
const eventAddress = receipt1.logs[0].args.contractAddress;

// 2. Connect to event contract
const eventTicket = new ethers.Contract(eventAddress, eventTicketABI, signer);

// 3. Buy tickets
const tx2 = await eventTicket.mint(2, {
  value: ethers.parseEther('0.02')
});
await tx2.wait();

// 4. Check available tickets
const available = await eventTicket.availableTickets();
console.log(`${available} tickets remaining`);

// 5. After event, check in
const tx3 = await eventTicket.checkIn(1);
await tx3.wait();

// 6. Organizer withdraws funds
const organizerSigner = new ethers.Wallet(organizerKey, provider);
const eventTicketAsOrganizer = eventTicket.connect(organizerSigner);
const tx4 = await eventTicketAsOrganizer.withdraw();
await tx4.wait();

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Security Considerations

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Gas Optimization Tips

• Mint multiple tickets in one transaction (up to 10)
• Use mintFor for batch comp tickets (up to 50)
• Allowlist minting uses less gas than regular minting
• Check-in gas cost is constant regardless of ticket price

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