Build an NFT Decentralization Trading Platform from Scratch

In this article, we will explore how to implement a smart contract-based NFT Decentralization trading platform. Unlike ERC-20 tokens, which trade through an automated market maker mechanism, NFT transactions typically use an order book model. We will achieve the decentralized trading functionality of NFTs by writing smart contracts and a simple front-end page.

Characteristics of NFT Trading

NFT( Non-fungible tokens ) follow the ERC-721 protocol, where each token is unique. Due to the non-fungibility of NFTs, they cannot be priced using price curves like fungible tokens. Currently, the mainstream way of trading NFTs is through an order book model, similar to displaying goods on supermarket shelves.

There are mainly two modes of order book trading:

1. Pricing Order: The seller sets the price, and the buyer can purchase if they find it acceptable.
2. Purchase Order: The buyer issues a purchase order, and the seller can sell if they find the price suitable.

This article will focus on the implementation of the pricing order model.

Core Functions of the NFT Platform

A basic NFT trading platform should have the following functions:

1. List Products: Allow sellers to set prices for listing NFTs.
2. Purchase goods: Allow buyers to purchase NFTs at the set price.
3. Transaction fee collection: Collect trading fees based on the transaction price proportionally.

Smart Contract Implementation

Our smart contract needs to implement the following key methods:

1. Launch NFT

The seller calls this method to list the NFT for sale:

solidity function listNFT(address nftAddress, uint256 tokenId, uint256 price) public { // Verify NFT ownership // Add listing record
// Trigger listing event }

2. Purchase NFT

The buyer calls this method to purchase the listed NFT:

solidity function purchaseNFT(address nftAddress, uint256 tokenId) public payable { // Get NFT listing information // Calculate and deduct handling fees // Transfer NFT to buyer // Transfer to seller // Trigger purchase event
}

3. Cancel listing

The seller can cancel the listed NFT:

solidity function cancelListing(address nftAddress, uint256 tokenId) public { // Validate caller permissions // Mark the listing status as invalid // Trigger cancel event }

4. Withdrawal fee

The platform owner can withdraw the accumulated fees:

solidity function withdrawFees() public onlyOwner { // Transfer the handling fee in the contract to the specified address }

Front-end Development

The front-end page mainly includes the following parts:

1. Connect Wallet: Use Ant Design Web3 to implement wallet connection functionality

2. Mint page: used for minting test NFTs

3. Portfolio page: Displays the NFTs held by the user, supports listing and delisting operations.

4. Buy page: Displays all NFTs for sale and supports purchase operations.

We use Next.js to develop the frontend and deploy it to the Vercel platform.

By following the above steps, we have achieved a basic functional NFT decentralized trading platform. This simple demo demonstrates the core logic of NFT trading and lays the foundation for further development of a more complex NFT trading system.

It is important to note that this article is for learning reference only. Actual NFT trading platforms in production environments need to consider more factors such as security and scalability.