Return string (64 chars) to another contract in solidity

Question

I have two contracts :

contract Child {

      mapping(string => string) private strings;


      function GetString(string key) public constant returns(string value) {
        return strings[key];
      }

}


contract Parent {

     Child c;


     function GetString(string key) public constant returns(string value) {
         return c.GetString(key);
     }

 }

I got a compilation error :

Return argument type is not implicitly convertible to expected type

I think this is a restriction of solidity that a contract cannot read a variable-sized data that is returned by another contract

Since my string can have more than 32 chars (i cannot use the bytes32 type), how can i achieve that ?

Thanks for your help !

MC

Answer 1

For now, it's not possible to pass strings between contracts.

I would consider chopping the string up into two bytes32 chunks. It would be more gas-efficient.

Web3 clients are better suited to pack/unpack/convert. In my opinion, it's usually best to transfer the burden of data type conversion to clients.

Hope it helps.