CODEWITHSUNDEEP
chainlink
amansta
amansta

Reputation: 11

GET API Chainlink not returning value

I posted my code below. I tried amending the basic chainlink example to use another API. I used the dummy API, made sure to change the path so that I would get a uint and sent LINK to the smart contract, but it does not end up returning the employee age (I don't think this needs the multiply action as there are no decimals). Any help would be appreciated!

// This example code is designed to quickly deploy an example contract using Remix.

pragma solidity ^0.6.0;

import "https://raw.githubusercontent.com/smartcontractkit/chainlink/master/evm-contracts/src/v0.6/ChainlinkClient.sol";

contract APIConsumer is ChainlinkClient {
  
    uint256 public volume;
    
    address private oracle;
    bytes32 private jobId;
    uint256 private fee;
    
    /**
     * Network: Kovan
     * Chainlink - 0x2f90A6D021db21e1B2A077c5a37B3C7E75D15b7e
     * Chainlink - 29fa9aa13bf1468788b7cc4a500a45b8
     * Fee: 0.1 LINK
     */
    constructor() public {
        setPublicChainlinkToken();
        oracle = 0x2f90A6D021db21e1B2A077c5a37B3C7E75D15b7e;
        jobId = "29fa9aa13bf1468788b7cc4a500a45b8";
        fee = 0.1 * 10 ** 18; // 0.1 LINK
    }
    
    /**
     * Create a Chainlink request to retrieve API response, find the target
     * data, then multiply by 1000000000000000000 (to remove decimal places from data).
     ************************************************************************************
     *                                    STOP!                                         * 
     *         THIS FUNCTION WILL FAIL IF THIS CONTRACT DOES NOT OWN LINK               *
     *         ----------------------------------------------------------               *
     *         Learn how to obtain testnet LINK and fund this contract:                 *
     *         ------- https://docs.chain.link/docs/acquire-link --------               *
     *         ---- https://docs.chain.link/docs/fund-your-contract -----               *
     *                                                                                  *
     ************************************************************************************/
    function requestVolumeData() public returns (bytes32 requestId) 
    {
        Chainlink.Request memory request = buildChainlinkRequest(jobId, address(this), this.fulfill.selector);
        
        // Set the URL to perform the GET request on
        request.add("get", "http://dummy.restapiexample.com/api/v1/employees");
        
        // Set the path to find the desired data in the API response, where the response format is:
        // {"RAW":
        //      {"ETH":
        //          {"USD":
        //              {
        //                  ...,
        //                  "VOLUME24HOUR": xxx.xxx,
        //                  ...
        //              }
        //          }
        //      }
        //  }
        request.add("path", "data.0.employee_age");
        
        // Multiply the result by 1000000000000000000 to remove decimals
      //  int timesAmount = 10**18;
    //    request.addInt("times", timesAmount);
        
        // Sends the request
        return sendChainlinkRequestTo(oracle, request, fee);
    }
    
    /**
     * Receive the response in the form of uint256
     */ 
    function fulfill(bytes32 _requestId, uint256 _volume) public recordChainlinkFulfillment(_requestId)
    {
        volume = _volume;
    }
    
    /**
     * Withdraw LINK from this contract
     * 
     * NOTE: DO NOT USE THIS IN PRODUCTION AS IT CAN BE CALLED BY ANY ADDRESS.
     * THIS IS PURELY FOR EXAMPLE PURPOSES ONLY.
     */
    function withdrawLink() external {
        LinkTokenInterface linkToken = LinkTokenInterface(chainlinkTokenAddress());
        require(linkToken.transfer(msg.sender, linkToken.balanceOf(address(this))), "Unable to transfer");
    }
}

Upvotes: 1

Views: 437

Answers (3)

Sid Ali
Sid Ali

Reputation: 1857

According to the documentation The req.addInt('times', timesAmount) is mandatory, If the API that you call returns a number without any decimals then provide 1as timesAmount :

The req.addInt('times', timesAmount) request parameter provides the oracle node with the multiplier timesAmount by which the fetched volume is multiplied. Use this to remove any decimals from the volume. Note: The times parameter is mandatory. If the API that you call returns a number without any decimals then provide 1as timesAmount. The APIConsumer in the example above is flexible enough to call any public API as long as the URL in get, path, and timesAmounnt are correct.

Upvotes: 0

Harry Papacharissiou
Harry Papacharissiou

Reputation: 856

I took the standard APIConsumer from the CL docs, changed the URL of the GET request to yours, set the path to data.0.employee_age, then commented out the line that adds the 'times' to the request, and it worked successfully, I got back 61

Upvotes: 1

amansta
amansta

Reputation: 11

Sorry for the spam, I ended up multiplying the value and it started returning. Why is this the case?

request.add("path", "data.0.employee_age");

// Multiply the result by 1000000000000000000 to remove decimals
int timesAmount = 10**5;
request.addInt("times", timesAmount);

Upvotes: 0

Related Questions