Chainlink - How to pass extra parameters to the Fullfil function - chainlink

Question

I have this piece of code to call an API and return the price of a token, which is working fine:
function requestAPIValue(string memory queryToken) public returns (bytes32 requestId) {
Chainlink.Request memory req = buildChainlinkRequest(
jobId32,
address(this),
this.fulfillValue.selector
);
req.add("get", string.concat(url, queryToken));
req.add("path", path);
req.addInt(addIntParam, multiply);
return sendChainlinkRequest(req, oraclePayment);
}
function fulfillValue(bytes32 _requestId, uint256 _value)
public
recordChainlinkFulfillment(_requestId)
{
emit RequestValue(_requestId, _value);
value = _value;
}
But, in the fulfillValue function I need to store the price for this specific token, something like:
function fulfillValue(bytes32 _requestId, uint256 _value, address token)
public
recordChainlinkFulfillment(_requestId)
{
emit RequestValue(_requestId, _value);
valuesArray[token] = _value;
}
But seems like there is no way to pass extra parameters to the buildChainlinkRequest function:
https://docs.chain.link/docs/any-api/api-reference/#buildchainlinkrequest
I think this should be a very common use case, any idea how can I do that?
Thanks

Answer 1

Create a mapping of request IDs to token addresses, for example
mapping(bytes32 => address) tokens;
Populate it inside requestAPIValue function
function requestAPIValue(string memory queryToken, address token) public returns (bytes32 requestId) {
.
.
.
requestId = sendChainlinkRequest(req, oraclePayment);
tokens[requestId] = token;
}
Finally, grab it from the mapping inside the fulfillValue function since it has requestId as parameter
function fulfillValue(bytes32 _requestId, uint256 _value)
public
recordChainlinkFulfillment(_requestId)
{
address token = tokens[_requestId];
valuesArray[token] = _value;
}