pragma solidity ^0.4.15;
import "./TwoPartyArbitrable.sol";
/** @title Rental
* This is a a contract for rental agreement.
* This can be used to rent objects or properties.
* Party A is the renter. Party B is the owner.
* Party A put a deposit. If everything goes well, it will be given back.
* Otherwize parties can claim an amount of damages. If they disagree, the arbitrator will have to solve this dispute.
contract Rental is TwoPartyArbitrable {
string constant RULING_OPTIONS = "Rule for party A (renter);Rule for Party B (owner)";
uint8 constant AMOUNT_OF_CHOICES = 2; // The number of ruling options available.
uint public amount; // Amount sent by party A.
uint public damagesClaimedByPartyA; // The amount party A agrees to pay to compensate damages.
uint public damagesClaimedByPartyB; // The amount party B claims to compensate damages.
/** @dev Constructor. Choose the arbitrator. Should be called by party A (the payer).
* @param _arbitrator The arbitrator of the contract.
* @param _timeout Time after which a party automatically loose a dispute.
* @param _partyB The owner.
* @param _arbitratorExtraData Extra data for the arbitrator.
* @param _metaEvidence Link to meta-evidence JSON.
Arbitrator _arbitrator,
uint _timeout,
address _partyB,
bytes _arbitratorExtraData,
string _metaEvidence
TwoPartyArbitrable(_arbitrator,_timeout,_partyB,AMOUNT_OF_CHOICES,_arbitratorExtraData, _metaEvidence)
amount += msg.value;
/** @dev Claim an amount of damages.
* Must be called before the dispute is created.
* If the amount agreed is the same for both, pay it.
* @param _damages The amount asked or agreed to be paid.
function claimDamages(uint _damages) public onlyParty {
// Make sure that parties can't change when a dispute already started.
require(status < Status.DisputeCreated, "The dispute has already been created.");
// Needed to avoid claiming 0 first and triggering an agreement. Use forfeitDeposit and unlockDeposit for the cases where 0 is claimed.
require(_damages != 0, "There must be damages.");
require(_damages <= amount, "Cannot claim more than balance."); // Make sure not to claim more than the contract has.
if (msg.sender == partyA)
damagesClaimedByPartyA = _damages;
damagesClaimedByPartyB = _damages;
if (damagesClaimedByPartyA==damagesClaimedByPartyB) { // If there is an agreement.
partyA.send((amount - damagesClaimedByPartyB) + partyAFee);
partyB.send(damagesClaimedByPartyB + partyBFee);
damagesClaimedByPartyA = 0;
damagesClaimedByPartyB = 0;
partyAFee = 0;
partyBFee = 0;
amount = 0;
status = Status.Resolved;
/** @dev Forfeit the deposit to party B.
* To be called if the good has been completely broken or that the property damages exceed the deposit.
function forfeitDeposit() public onlyPartyA {
amount = 0;
/** @dev Unlock party A deposit. To be called if the good or property has been returned without damages.
function unlockDeposit() public onlyPartyB {
amount = 0;
/** @dev Execute a ruling of a dispute. It reimburse the fee to the winning party.
* This need to be extended by contract inheriting from it.
* @param _disputeID ID of the dispute in the Arbitrator contract.
* @param _ruling Ruling given by the arbitrator. 1 : Rule for party A (renter). 2 : Rule for Party B (owner).
function executeRuling(uint _disputeID, uint _ruling) internal {
if (_ruling == PARTY_A_WINS) {
partyA.send(amount - damagesClaimedByPartyA);
else if (_ruling == PARTY_B_WINS) {
partyA.send(amount - damagesClaimedByPartyB);
amount = 0;
damagesClaimedByPartyA = 0;
damagesClaimedByPartyB = 0;