how to interact with the contract with more complex arguments(sort of a string of struct)

Question

I want develop a contract that can be interacted from outside with a considerably complex argument(like a string of struct), but the Ethereum seems that the contracts can only be communicated with functions using simple arguments like type uint, string, bytes, how can I manage it? I mean if I want to develop a function with arguments of a string of struct of unspecified length, how can I manage it?

Answer 1

Currently Solidity does not allow you to pass complex types as function arguments into or out of a smart contract. So currently you neither do

function setMyStruct (myStruct ms) { ... }

nor can you do

function getMyStruct constant returns (myStruct ms) { ... }

On work-around is to pass the elements of the struct one by one into the setter and return them one by one from the getter as in

contract testStruct {
    struct myStr {
        int a;
        string b;
    }
    myStr storedStr;

    function setMyStr(int a, string b) {
        storedStr.a = a;
        storedStr.b = b;
    }

    function getMyStr() constant returns (int a, string b) {
        a = storedStr.a;
        b = storedStr.b;
    }
}

Check also the following links to follow up on that:

• https://github.com/ethereum/solidity/issues/40
• https://www.pivotaltracker.com/n/projects/1189488/stories/91594340
• Is it impossible to use an array of strings as the argument to solidity function?