How to create and deploy erc-1155 NFT

summary

ERC1155 Created NFT The gold standard for ; Each major market lists new tokens as ERC1155 standard . In this paper , We will understand ERC1155 Token standard and how to create ERC1155 Tokens, .

What are we going to do ：

1. establish 3 individual NFT aggregate
2. Create and deploy ERC-1155 contract
3. Update contract to be compatible OpenSea
4. Deploy our NFT aggregate

What do you need? ：

• Used to create NFT Image assets
• MetaMask And some of the Ropsten test ETH.
• understand ERC20 and ERC721 (NFT) generation Currency standard .

What is? ERC1155？

ERC1155 It is a multi token standard , Allow homogenization to be created in a contract 、 Non homogenous and semi homogenous tokens . stay ERC1155 Before , If a use case needs ERC20（ Homogenization ） and ERC721（ Heterogeneity ） Tokens, , A separate contract is needed to achieve this .ERC1155 It also allows you to start multiple in one smart contract NFT aggregate , Instead of creating different contracts for each set ; This improves the efficiency of smart contract construction and minimizes the number of transactions , It's very important , Because it consumes less blockchain space . Use ERC1155, You can also transfer tokens in batches , Instead of transferring tokens to a single address in the previous standard .

ERC1155 A common example of application is the decentralized game based on blockchain , Because the game needs coins and Collectibles , therefore ERC1155 It has become the standard there .ERC1155 It has become NFT Standards in the field .

Previous ERC721 With tokens ID One to one mapping with address .ERC1155 There is a fairly complex mapping , Among them, tokens id The address in the combination is mapped to the balance of the token .

Create metadata URI

We will create 3 individual NFT aggregate （ stone 、 Paper and scissors ）, There is one in each set NFT. Upload our files to decentralized storage IPFS, We can adopt CLI Upload files or use this very easy-to-use tool NFT Storage.

We will use the second option ,NFT Storage . Sign in NFT Store and upload stones 、 Paper and scissors image files . After successful upload , You should see the following ：

Click on “Actions”, Copy each picture IPFS URL; We need it as metadata for each collection .

We're going to create three JSON Metadata files to store information about us NFT Information for collection .

• 1.json: Rock collection
• 2.json: Paper collection
• 3.json: Scissors collection

our 1.json The file looks like this ：

{
     //1.

    "name": "Rocks",

    "description": "This is a collection of Rock NFTs.",

    "image": "https://ipfs.io/ipfs/bafkreifvhjdf6ve4jfv6qytqtux5nd4nwnelioeiqx5x2ez5yrgrzk7ypi",

}

• name： NFT The name of .

• description： NFT Description of .

• image： Link to the image we obtained before （IPFS URL）.

• If a set has multiple images （ This is usually the case ）, An additional parameter will be added id To distinguish the tags in the set .

Create remaining JSON file 2.json and 3.json, Used for collecting cloth and scissors respectively .

In order to effectively integrate all JSON File upload to IPFS, We will archive them in content addressed format .https://car.ipfs.io/ Help with IPFS Compatible content addressed archives (.car) Format archive file .

Go to IPFS CAR , And upload the above three JSON file . After the upload , download .car File and upload it to NFT Storage. All of us JSON Files are now stored as archives in IPFS On . Copy uploaded .car Of documents IPFS URL, You should be able to do this through URL Enter the file name at the end to access JSON file , for example ：

https://ipfs.io/ipfs/bafybeihjjkwdrxxjnuwevlqtqmh3iegcadc32sio4wmo7bv2gbf34qs34a/1.json

Create and deploy ERC1155 contract

We will use OpenZeppelin Contract library to create our ERC1155 contract , And use Ethereum REMIX IDE stay Ropsten Test online deployment . Make sure you have some Ropsten test ETH, You can also Ropsten Faucet Obtain test currency .

stay REMIX Create a new file in token.sol And paste the following code into it .

// SPDX-License-Identifier: MIT
pragma solidity ^0.8.0;

import "@openzeppelin/contracts/token/ERC1155/ERC1155.sol";

contract rockPaperScissors is ERC1155 {
    uint256 public constant Rock = 1;
    uint256 public constant Paper = 2;
    uint256 public constant Scissors = 3;

    constructor() ERC1155("https://ipfs.io/ipfs/bafybeihjjkwdrxxjnuwevlqtqmh3iegcadc32sio4wmo7bv2gbf34qs34a/{id}.json") {
        _mint(msg.sender, Rock, 1, "");
        _mint(msg.sender, Paper, 1, "");
        _mint(msg.sender, Scissors, 1, "");
    }
}

The explanation of the above code ：

The first 1 That's ok ： Appoint SPDX The license type , stay Solidity ^0.6.8 Added after . Whenever the source code of a smart contract is open to the public , These licenses can help solve / Avoid copyright issues . If you don't want to specify any license type , You can use special values UNLICENSED Or skip the entire comment （ Will not lead to mistakes , Just a warning ）.

The first 2 That's ok ： Statement Solidity edition .

The first 4 That's ok ： Import OpenZeppelin ERC1155 contract .

The first 6-9 That's ok ： Create a rockPaperScissors And create three variables Rock、Paper and Scissors; Then assign each appropriate ID.

The first 11-15 That's ok ： Use car The link to the file initializes the constructor as a parameter , Use parameters to cast different NFT aggregate ：

The address to which the token will be minted , there msg.sender It refers to the deployer of the contract .token id, We have done for token id Assigned a name , So the name is used here . The number of each token . The last one is the data field left blank .

Compile contract , Go to the third tab of the left menu , choice Injected Web3 As an environment and deploy by selecting the correct contract name ：

from MetaMask Approve the transaction . Upon completion of the transaction , Your contract will be deployed .

Now you can enter the address and token ID To perform functions such as obtaining token balances . We can also enter tokens id To retrieve tokens URI.

OpenSea Returned URI Format . So we need to cover URI Function to return the file name as a string ：

// SPDX-License-Identifier: MIT
pragma solidity ^0.8.0;

import "@openzeppelin/contracts/token/ERC1155/ERC1155.sol";
import "@openzeppelin/contracts/utils/Strings.sol";

contract rockPaperScissors is ERC1155 {
    uint256 public constant Rock = 1;
    uint256 public constant Paper = 2;
    uint256 public constant Scissors = 3;

    constructor() ERC1155("https://ipfs.io/ipfs/bafybeihjjkwdrxxjnuwevlqtqmh3iegcadc32sio4wmo7bv2gbf34qs34a/{id}.json") {
        _mint(msg.sender, Rock, 1, "");
        _mint(msg.sender, Paper, 1, "");
        _mint(msg.sender, Scissors, 1, "");
    }

    function uri(uint256 _tokenid) override public pure returns (string memory) {
        return string(
            abi.encodePacked(
                "https://ipfs.io/ipfs/bafybeihjjkwdrxxjnuwevlqtqmh3iegcadc32sio4wmo7bv2gbf34qs34a/",
                Strings.toString(_tokenid),".json"
            )
        );
    }
}

Add ：

The first 5 That's ok ： Import OpenZeppelin contract , take Integer Convert to String.

The first 18-25 That's ok ： By creating custom URI Function and convert tokens from integers to strings to cover URI function , Then return to the complete URI.

Recompile the contract and deploy . When you query now URI The contract of , It will return OpenSea Supported format .

Conclusion

Congratulations on deploying ERC1155 Tokens, . If you do it here now , You will understand ERC1155 Multi token standard and how to create and deploy ERC1155 NFT.