Call ink contract using rust

Question

I'm a developer who wants to call the ink contract's function from the outside. I already know that ink contract supports cross-contract. But what I want to do is call the function using subxt or node_runtime crate or etc. I don't want to use polkadot js, but want to implement all features in rust and test it. (rust version of web3.js and polkadot.js)

I tried to implement this by using this function: https://github.com/paritytech/subxt/blob/master/testing/integration-tests/src/frame/contracts.rs#L136 but I don't know how to use this function in testnet(rococo or Shibuya) or my local node.

And I also tried to use node_runtime and many other things, but I couldn't make it.

Thank you for any support.

Answer 1

With Rust, it's a bit more complicated than with JS/TS.

Here's an example of how to call a contract using subxt:

// assuming you have `api` and the contract address
let mut call_data = Vec::<u8>::new();
        //append the selector
call_data.append(&mut (&blake2_256("method_name".as_bytes())[0..4]).to_vec());
        //append the arguments
call_data.append(&mut scale::Encode::encode(&(
            AccountId32::from_string(&arg1).ok()?,
            arg2,
            arg3,
        )));
api.tx().contracts().call(
            AccountId32::from_string(contract).ok()?.into(), // contract address
            0, // transferred_value
            20_000_000_000, // gas limit
            None, // storage deposit limit
            call_data, // the call data
        ))
        .sign_and_submit(&signer) // your signer object