How to send calldata of view/pure functions in remix?

Question

I’m aware that, in Remix, I could input msg.data as calldata values and send that as a transaction. It works for me when I send encoded function calls with parameters.

However, how do I encode and send calldata of functions without any parameters or view/pure functions and see the returned values in the console?

For example, in my case, I have a Proxy contract which points to an implementation contract. I'm using the UUPS proxy setup provided by OpenZeppelin. The implementation contract has a view or pure function that looks like this:

function owner() public view returns (address) { ... }

How should I encode this and pass it into the calldata input in Remix and see the returned value in its console?

PS: The contract I'm interacting with is a proxy and so it has the fallback function. The owner() function in the example is in the implementation contract which the proxy is pointed to.

Answer 1

I had the exact same question when learning proxies. There are a few ways to do it. You could use ethers.js encodeFunctionData() (more info with examples) or https://abi.hashex.org/ like this

Pass the result 8da5cb5b into Remix's calldata window. If execution was successful it worked!

To see the call result

1. Click "Debug" on the transaction

2. In debugger window fast forward transaction to the end

3. Copy the returned hex value and parse it using something like https://www.convertstring.com/EncodeDecode/HexDecode