Call read only ink contract functions from subxt

Question

How do i do something like

cargo contract call --contract --message get --suri //Alice

in subxt or from a rust backend the docs in subxt focus mostly on signing and submitting txs and events hence wasnt able to really find out how to call read only ink functions

Answer 1

Calling a read or write function should be the same in an ink! contract. Both are a contract message.

EDIT:

So when calling a contract the bare_call function returns the ContractExecReturn type. This is defined by the generic ContractResult type where we are interested in the result field, which is set to ExecReturnValue. Then we need to decode the data field's bytes into the return value returned by the message. You can look at these integration tests for how you can do it (it is calling the following contract message)

Note that we had to decode the bytes [1..] for some reason to get the correct value. I can't explain you how yet unfortunately (see open question)