使用API3请求链下数据¶

pragma solidity 0.8.9;

import "@api3/airnode-protocol/contracts/rrp/requesters/RrpRequesterV0.sol";

// A Requester that will return the requested data by calling the specified airnode.
// Make sure you specify the right _rrpAddress for your chain.

contract Requester is RrpRequesterV0 {
    mapping(bytes32 => bool) public incomingFulfillments;
    mapping(bytes32 => int256) public fulfilledData;

    constructor(address _rrpAddress) RrpRequesterV0(_rrpAddress) {}

    /**
     * The main makeRequest function that will trigger the Airnode request
     * airnode: Airnode address
     * endpointId: The endpoint ID for the specific endpoint
     * sponsor: The requester contract itself (in this case)
     * sponsorWallet: The wallet that will make the actual request (needs to be funded)
     * parameters: encoded API parameters
     */
    function makeRequest(
        address airnode,
        bytes32 endpointId,
        address sponsor,
        address sponsorWallet,
        bytes calldata parameters

    ) external {
        bytes32 requestId = airnodeRrp.makeFullRequest(
            airnode,
            endpointId,
            sponsor,
            sponsorWallet,
            address(this),
            this.fulfill.selector,
            parameters
        );
        incomingFulfillments[requestId] = true;
    }

    // The callback function with the requested data
    function fulfill(bytes32 requestId, bytes calldata data)
        external
        onlyAirnodeRrp
    {
        require(incomingFulfillments[requestId], "No such request made");
        delete incomingFulfillments[requestId];
        int256 decodedData = abi.decode(data, (int256));
        fulfilledData[requestId] = decodedData;
    }
}

// SPDX-License-Identifier: MIT
pragma solidity 0.8.17;

import "@openzeppelin/contracts/access/Ownable.sol";
import "@api3/contracts/v0.8/interfaces/IProxy.sol";

contract DataFeedReaderExample is Ownable {
    // This contract reads from a single proxy. Your contract can read from multiple proxies.
    address public proxy;

    // Updating the proxy address is a security-critical action. In this example, only
    // the owner is allowed to do so.
    function setProxy(address _proxy) public onlyOwner {
        proxy = _proxy;
    }

    function readDataFeed()
        external
        view
        returns (int224 value, uint256 timestamp)
    {
        (value, timestamp) = IProxy(proxy).read();
        // If you have any assumptions about `value` and `timestamp`, make sure
        // to validate them right after reading from the proxy.
    }
}

//SPDX-License-Identifier: MIT
pragma solidity 0.8.9;
import "@api3/airnode-protocol/contracts/rrp/requesters/RrpRequesterV0.sol";

contract RemixQrngExample is RrpRequesterV0 {
    event RequestedUint256(bytes32 indexed requestId);
    event ReceivedUint256(bytes32 indexed requestId, uint256 response);

    address public airnode;
    bytes32 public endpointIdUint256;
    address public sponsorWallet;
    mapping(bytes32 => bool) public waitingFulfillment;

    // These are for Remix demonstration purposes, their use is not practical.
    struct LatestRequest { 
      bytes32 requestId;
      uint256 randomNumber;
    }
    LatestRequest public latestRequest;

    constructor(address _airnodeRrp) RrpRequesterV0(_airnodeRrp) {}

    // Normally, this function should be protected, as in:
    // require(msg.sender == owner, "Sender not owner");
    function setRequestParameters(
        address _airnode,
        bytes32 _endpointIdUint256,
        address _sponsorWallet
    ) external {
        airnode = _airnode;
        endpointIdUint256 = _endpointIdUint256;
        sponsorWallet = _sponsorWallet;
    }

    function makeRequestUint256() external {
        bytes32 requestId = airnodeRrp.makeFullRequest(
            airnode,
            endpointIdUint256,
            address(this),
            sponsorWallet,
            address(this),
            this.fulfillUint256.selector,
            ""
        );
        waitingFulfillment[requestId] = true;
        latestRequest.requestId = requestId;
        latestRequest.randomNumber = 0;
        emit RequestedUint256(requestId);
    }

    function fulfillUint256(bytes32 requestId, bytes calldata data)
        external
        onlyAirnodeRrp
    {
        require(
            waitingFulfillment[requestId],
            "Request ID not known"
        );
        waitingFulfillment[requestId] = false;
        uint256 qrngUint256 = abi.decode(data, (uint256));
        // Do what you want with `qrngUint256` here...
        latestRequest.randomNumber = qrngUint256;
        emit ReceivedUint256(requestId, qrngUint256);
    }
}