Calling functions of contract on other chains

[nikola-bozin]

Hello, im just curious to know is situation explained bellow possible:

Let contract X be on Rinkeby network.
contract X has function: myFunction()

Let contract Y be on Goerli network.

Can contract Y communicate with contract X by calling his function "myFunction" by only knowing his address and abi?

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Why im asking this question...

If you go to website: https://docs.chain.link/docs/ethereum-addresses/ where you can find contract addresses for some data feeds, as we used it in FundMe.sol and PriceConverter.sol contracts, you wont find contract on Goerli network. So if i want to deploy my FundMe contract on Goerli, i cannot pass him argument in constructor on what address to find AggregatorV3Interface contract since there is no Goerli DataFeed on chainlink.

So what i tought i could to, is to create a contract on Rinkeby Network (contract X) [why on rinkeby? because there is contract that returns ETH->USD on rinkeby network from chainlink] that will have function that returns a conversionRate of ETH->USD ( myFunction() ) and since i know the ABI and contract ADDRESS that is deployed on Rinkeby network,
i create Contract object that will return me required data(price in USD for passed value of ETH) for FundMe (contract Y) that is on Goerli network.

Is there some work-around for this?

[technophile-04]

actually No, smart contracts are only interoperable with other smart contracts in the same network because the network is isolated.

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Sadly chainlink doesn't have any data feed contract on goerli netwrok. Only Kovan and Rinkeby testnets are available.
although now i would suggest either use Kovan for both contracts or rinkeby.

You can give a read to this article : https://blog.chain.link/cross-chain-smart-contracts/

[PatrickAlphaC]

To add to this, Chainlink is working on a project called CCIP to help do cross-chain stuff exactly as described:

https://chain.link/cross-chain

[nikola-bozin]

Thank you for your answers! Gonna check it out!