IdeaValidator.sol

pragma solidity ^0.4.24;

contract IdeaRegistry {
  function registerIdea(uint hash) public;
}

contract IdeaValidator {
  address owner;
  address registryAddress;
  mapping (address => bool) validators;
  mapping (uint => Idea) pendingIdeas;

  struct Idea {
    address owner;
    bool isValid;
  }

  modifier ownerOnly() {
    require(msg.sender == owner);
    _;
  }

  modifier validatorOnly(address user) {
    require(validators[user] == true);
    _;
  }

  constructor() public {
    owner = msg.sender;
  }

  function addRegistryAddress(address _registryAddress) public ownerOnly {
    registryAddress = _registryAddress;
  }

  function submitIdea(uint hash) public {
    // Ensure idea hasn't been submitted already
    require(pendingIdeas[hash].owner == address(0));

    // Check that idea isn't already registered in the official IdeaRegistry
    require(registryAddress != address(0));
    contract registry = IdeaRegistry(registryAddress);
    require(registry.getIdea(hash).owner == address(0));
    pendingIdeas[hash] = Idea(msg.sender, false);
  }

  function acceptIdea(uint hash, bool isValid) public validatorOnly(msg.sender) {
    pendingIdeas[hash].isValid = isValid;
    // go to the other contract and add this idea to it

    if (isValid == true) {
      require(registryAddress != address(0))
      contract registry = IdeaRegistry(registryAddress);
      registry.registerIdea(hash);
    }
  }

  function addValidator(address newValidator) public ownerOnly {
    validators[newValidator] = true;
  }
}