具有提升权限的 Solidity 调用合约

Question

I have two contracts, one for handling staking and one for minting a NFT. The flow I want is for the user to stake in frontend react app which will invoke the staking contract. The user will then be eligible to mint a NFT when staked.

Now the issue I am facing is that because the minting role is called from stakingExample contract, which requires the user to invoke this, but as it has a critical function (mint) of the other contract, it should be protected with permissions such that only StakingExample can call NFTExample contract.

Is there a way to allow the user to run NFTExample with elevated permissions temporary in smart contract?

Example of staking contract:

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

import "@openzeppelin/contracts/access/AccessControl.sol";
import "@openzeppelin/contracts/token/ERC20/IERC20.sol";
import "@openzeppelin/contracts/token/ERC20/utils/SafeERC20.sol";

contract StakingExample is AccessControl {

    bytes32 public constant CONTRACT_ROLE = keccak256("CONTRACT_ROLE");
    NFTExample public _NFTExample;

    ...

    function someStakingFunction() {
        // code that stakes and 
        // set some variable that tracks if user have minted
    }

    function claimNFT(uint256 _pid, string memory _tokenURI) public onlyRole(CONTRACT_ROLE) {
        // checks if user have unclaimed NFT
        if (haveUnclaimed) {
            _NFTExample.mintItem(msg.sender, _tokenURI)
        }
    }
}

Example of NFT contract:

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

import "@openzeppelin/contracts/access/AccessControl.sol";
import "@openzeppelin/contracts/token/ERC721/extensions/ERC721URIStorage.sol";
import "@openzeppelin/contracts/token/ERC721/extensions/ERC721Enumerable.sol";
import "@openzeppelin/contracts/utils/Counters.sol";

contract CMRGachaSeedNFT is ERC721URIStorage, AccessControl, ERC721Enumerable {
    bytes32 public constant CONTRACT_ROLE = keccak256("CONTRACT_ROLE");

    using Counters for Counters.Counter;
    Counters.Counter private _tokenIds;

    ...
    
    // Only Contract Role can call mint item, which mint item and transfers it to user's address
    function mintItem(address _address, string memory _tokenURI)
        public
        onlyRole(CONTRACT_ROLE)
        returns (uint256)
    {
        // Do some checks

        // Mint
        _tokenIds.increment();

        uint256 newItemId = _tokenIds.current();
        _mint(_address, newItemId);
        _setTokenURI(newItemId, _tokenURI);

        return newItemId;
    }
}

Answer 1

You need to add one function in staking contract which shows amount of the staking:

function showStakeAmount() external view returns(uint256){
    //I don't know your codes about this but you need a mapping to store
    //the stake amount of each user and here you return it but something like this:
    return StakingAmountOfUsers(msg.sender);
}

Then you need an interface of the staking contract and its address, also make an modifier in NFT contract (Following changes must be added):

interface StakingInterface{
    function showStakeAmount() external view returns(uint256);
}

contract CMRGachaSeedNFT is ERC721URIStorage, AccessControl, ERC721Enumerable {
    uint256 AmountThatShouldBeStaked;

    StakingInterface StakingContract;

    constructor(address STAKING_CONTRACT_ADDRESS){
        StakingContract = StakingInterface(STAKING_CONTRACT_ADDRESS);
    }
    
    modifier isStaked(){
        require(StakingContract.showStakeAmount() > AmountThatShouldBeStaked, "You did not stake enough amount of X token");
        _;
    }

    function mintItem(address _address, string memory _tokenURI)
        public
        onlyRole(CONTRACT_ROLE)
        returns (uint256)
        isStaked()
    {
        //Continue coding...
    }
}