从其他智能合约调用chainlink？

Question

I need to get a value from an array which I read through a chainlink oracle. So far so good, but I need that value in another contract to make use of it, how could I make this happen?

Also, how can I make a combined payment, when someone buys one Service, the money would also be used to pay the gas for the Chainlink fee?

thanks!

Answer 1

To read a value from a Chainlink data feed, you need to pass a feed's address to the AggregatorV3Interface.sol interface.

AggregatorV3Interface dataFeed = AggregatorV3Interface(0x9326....);

You then can call the interface's latestRoundData() function, which returns a tuple of values that contain the information you requested. For an example price feed:

(
  uint80 roundID, 
  int price,
  uint startedAt,
  uint timeStamp,
  uint80 answeredInRound
) = priceFeed.latestRoundData();

See https://docs.chain.link/docs/get-the-latest-price/ for more details.

When you say combined payment, what do you mean? If the Chainlink data feed call (as above) is called during a transaction, that transaction's gas will be used to pay for the computation. So if a user buys a service and sends gas with that call, and then in that call the data feed is called, the original sender's gas will be used to call the data feed method.