ExampleofHouseLeasingContract

House-leasing contract

House-leasing contract, takes assets as the transaction subject between lessor and lessee. There are 7 terms in the contract, including two aspects:     1) the lessor can register the house after depositing the rental deposit, and     2) the lessee can keep the right to use the house during the leasing period after depositing the rent. After confirming the leased house, the contract requires that the lessee shall pay the rent, and the lessor must transfer the right to the lessee within one week. Meanwhile, the contract stipulates the pre-condition for the lessor to charge the rent paid by the lessee, and the postcondition for both parties to get their deposits back after the house inspection.

---

// HouseLease.scs
contract Houselease{

party Renter{

registerHouse()

collectRent()

collectBail()

transferHouse()

checkHouse()

}

party Tenant{

confirmLease(endLeasingDuration:Date,

payDuration:Date)

payRent()

returnHouse()

collectBail()

}

house : House

infos : contractInfo

term term1 : Renter can registerHouse

while deposit $infos::renterBail.

term term2 : Tenant can confirmLease

when after Renter did registerHouse

while deposit $infos::tenantBail

where infos::startLeasingTime = now and

infos::endLeasingTime = endLeasingDuration + now

and infos::payDate = payDuration + now

and infos::payDuration = payDuration.

term term3 : Renter must transferHouse

when within 7 day after Tenant did confirmLease

while deposit $ house::useRight.

term term4 : Tenant must payRent

when before Tenant did confirmLease

while deposit $infos::rental

withdraw $house::useRight

where infos::payDate = infos::payDate + infos::payDuration

and infos::totalRental = infos::totalRental + infos::rental.

term term5 : Renter can collectRent

while withdraw $infos::totalRental

where infos::totalRental = 0.

term term6 : Tenant must returnHouse

when within 7 day after Renter did checkHouse

while deposit $house::useRight

transfer $house::useRight to Renter.

term term7_1 : Renter can collectBail

when within 15 day after Renter did checkHouse

while withdraw $infos::renterBail.

term term7_2 : Tenant can collectBail

when within 15 day after Renter did checkHouse

while withdraw $infos::tenantBail.

type contractInfo {

renterBail : Money

tenantBail : Money

rental : Money

totalRental : Money

penalty : Money

startLeasingTime : Date

endLeasingTime : Date

payDate : Date

payDuration : Date

}

type House {

ownershipNumber : integer

location : String

area : integer

usage : String

price : Money

useRight : String

usufruct : String

dispositionRight : String

possessionRight : String

}

}

  1 /* Houselease.sol */
  2 pragma solidity ^0.4.0;
  3 		
  4 import "./RenterT.sol";
  5 import "./TenantT.sol";
  6 
  7 contract Houselease {
  8 	
  9 	RenterT Renter;
 10 	TenantT Tenant;
 11 	
 12 	House house;
 13 	contractInfo infos;
 14 	
 15 	uint start;
 16 	struct contractInfo{
 17 		uint renterBail;
 18 		uint tenantBail;
 19 		uint rental;
 20 		uint totalRental;
 21 		uint penalty;
 22 		uint startLeasingTime;
 23 		uint endLeasingTime;
 24 		uint payDate;
 25 		uint payDuration;
 26 	}
 27 	struct House{
 28 		uint ownershipNumber;
 29 		bytes32 location;
 30 		uint area;
 31 		bytes32 usage;
 32 		uint price;
 33 		uint useRight;
 34 		uint usufruct;
 35 		uint dispositionRight;
 36 		uint possessionRight;
 37 	}
 38 	
 39 	function Houselease(){
 40 		start = now;
 41 		Renter = new RenterT();
 42 		Tenant = new TenantT();
 43 	}
 44 
 45 	modifier onlyRenter{
 46 		require(Renter.contains(msg.sender));
 47 		_;
 48 	}
 49 	
 50 	modifier onlyTenant{
 51 		require(Tenant.contains(msg.sender));
 52 		_;
 53 	}
 54 	
 55 	modifier term2Modifier{
 56 		require(now > Renter.registerHouseTime());
 57 		require(infos.tenantBail > 0);
 58 		_;
 59 	}
 60 	
 61 	modifier term3Modifier{
 62 		require((now > Tenant.confirmLeaseTime()) &&(now < Tenant.confirmLeaseTime()+604800));
 63 		require(house.useRight > 0);
 64 		_;
 65 	}
 66 	
 67 	modifier term4Modifier{
 68 		require(now < Tenant.confirmLeaseTime());
 69 		require(infos.rental > 0);
 70 		_;
 71 	}
 72 	
 73 	modifier term6Modifier{
 74 		require((now > Renter.checkHouseTime()) &&(now < Renter.checkHouseTime()+604800));
 75 		require(house.useRight > 0);
 76 		_;
 77 	}
 78 	
 79 	modifier term7_1Modifier{
 80 		require((now > Renter.checkHouseTime()) &&(now < Renter.checkHouseTime()+1296000));
 81 		_;
 82 	}
 83 	
 84 	modifier term7_2Modifier{
 85 		require((now > Renter.checkHouseTime()) &&(now < Renter.checkHouseTime()+1296000));
 86 		_;
 87 	}
 88 	
 89 	function registerHouse() onlyRenter() public payable {
 90 		//USER CODE HERE
 91 		//CHECK
 92 	
 93 	}
 94 	
 95 	function confirmLease(uint endLeasingDuration, uint payDuration) onlyTenant() term2Modifier() public payable {
 96 		//USER CODE HERE
 97 		infos.startLeasingTime = now;
 98 		infos.endLeasingTime = endLeasingDuration + now;
 99 		infos.payDate = payDuration + now;
100 		infos.payDuration = payDuration;
101 		//CHECK
102 		assert(infos.startLeasingTime == now && (infos.endLeasingTime == endLeasingDuration + now && (infos.payDate == payDuration + now && infos.payDuration == payDuration)));
103 	}
104 	
105 	function transferHouse() onlyRenter() term3Modifier() public payable {
106 		//USER CODE HERE
107 		//CHECK
108 	
109 	}
110 	
111 	function payRent() onlyTenant() term4Modifier() public payable {
112 		//USER CODE HERE
113 		infos.payDate = infos.payDate + infos.payDuration;
114 		infos.totalRental = infos.totalRental + infos.rental;
115 		msg.sender.transfer(house.useRight);
116 		//CHECK
117 		assert(infos.payDate == infos.payDate + infos.payDuration && infos.totalRental == infos.totalRental + infos.rental);
118 	}
119 	
120 	function collectRent() onlyRenter() term7_1Modifier() public payable {
121 		//USER CODE HERE
122 		infos.totalRental = 0;
123 		msg.sender.transfer(infos.totalRental);
124 		//CHECK
125 		assert(infos.totalRental == 0);
126 	}
127 	
128 	function returnHouse() onlyTenant() term6Modifier() public payable {
129 		//USER CODE HERE
130 		address(Renter).transfer(house.useRight);
131 		//CHECK
132 	
133 	}
134 	
135 }

  1 /* RenterT.sol */
  2 pragma solidity ^0.4.22;
  3 
  4 contract RenterT{
  5 	
  6 	
  7 	//attributes of actionregisterHouse
  8 	bool _isregisterHouseDone;
  9 	uint _registerHouseTime;
 10 	
 11 	//attributes of actioncollectRent
 12 	bool _iscollectRentDone;
 13 	uint _collectRentTime;
 14 	
 15 	//attributes of actioncollectBail
 16 	bool _iscollectBailDone;
 17 	uint _collectBailTime;
 18 	
 19 	//attributes of actiontransferHouse
 20 	bool _istransferHouseDone;
 21 	uint _transferHouseTime;
 22 	
 23 	//attributes of actioncheckHouse
 24 	bool _ischeckHouseDone;
 25 	uint _checkHouseTime;
 26 	
 27 	uint _max;
 28 	bool _isRenterDone;
 29 	uint _i;
 30 	
 31 	address[] _RenterAddress;
 32 	function RenterT(){
 33 		_max = now*1000;
 34 	}
 35 	
 36 	function regist(address a) public {
 37 		_RenterAddress[_i] = a;
 38 		_i++;
 39 	}
 40 	
 41 	function getAddress(uint _i) public returns (address a){
 42 		return _RenterAddress[_i];
 43 	}
 44 	
 45 	function registerHouseDone(address a){
 46 		_registerHouseTime = now;
 47 		_isRenterDone = true;
 48 	}
 49 	
 50 	function registerHouseTime() returns (uint result){
 51 	    if(_isregisterHouseDone){
 52 	        return _registerHouseTime;
 53 	    }
 54 	    return _max;
 55 	}
 56 	
 57 	function collectRentDone(address a){
 58 		_collectRentTime = now;
 59 		_isRenterDone = true;
 60 	}
 61 	
 62 	function collectRentTime() returns (uint result){
 63 	    if(_iscollectRentDone){
 64 	        return _collectRentTime;
 65 	    }
 66 	    return _max;
 67 	}
 68 	
 69 	function collectBailDone(address a){
 70 		_collectBailTime = now;
 71 		_isRenterDone = true;
 72 	}
 73 	
 74 	function collectBailTime() returns (uint result){
 75 	    if(_iscollectBailDone){
 76 	        return _collectBailTime;
 77 	    }
 78 	    return _max;
 79 	}
 80 	
 81 	function transferHouseDone(address a){
 82 		_transferHouseTime = now;
 83 		_isRenterDone = true;
 84 	}
 85 	
 86 	function transferHouseTime() returns (uint result){
 87 	    if(_istransferHouseDone){
 88 	        return _transferHouseTime;
 89 	    }
 90 	    return _max;
 91 	}
 92 	
 93 	function checkHouseDone(address a){
 94 		_checkHouseTime = now;
 95 		_isRenterDone = true;
 96 	}
 97 	
 98 	function checkHouseTime() returns (uint result){
 99 	    if(_ischeckHouseDone){
100 	        return _checkHouseTime;
101 	    }
102 	    return _max;
103 	}
104 	
105 	function contains(address a) returns (bool result) {
106 	    for (uint _j = 0; _j < _RenterAddress.length; _j++ ) {  //for loop example
107             if (a == _RenterAddress[_j]){
108                 return true;
109             }         
110       }
111       return false;
112 	}
113 	
114 }

 1 /* TenantT.sol */
 2 pragma solidity ^0.4.22;
 3 
 4 contract TenantT{
 5 	
 6 	
 7 	//attributes of actionconfirmLease
 8 	bool _isconfirmLeaseDone;
 9 	uint _confirmLeaseTime;
10 	
11 	//attributes of actionpayRent
12 	bool _ispayRentDone;
13 	uint _payRentTime;
14 	
15 	//attributes of actionreturnHouse
16 	bool _isreturnHouseDone;
17 	uint _returnHouseTime;
18 	
19 	//attributes of actioncollectBail
20 	bool _iscollectBailDone;
21 	uint _collectBailTime;
22 	
23 	uint _max;
24 	bool _isTenantDone;
25 	uint _i;
26 	
27 	address[] _TenantAddress;
28 	function TenantT(){
29 		_max = now*1000;
30 	}
31 	
32 	function regist(address a) public {
33 		_TenantAddress[_i] = a;
34 		_i++;
35 	}
36 	
37 	function getAddress(uint _i) public returns (address a){
38 		return _TenantAddress[_i];
39 	}
40 	
41 	function confirmLeaseDone(address a){
42 		_confirmLeaseTime = now;
43 		_isTenantDone = true;
44 	}
45 	
46 	function confirmLeaseTime() returns (uint result){
47 	    if(_isconfirmLeaseDone){
48 	        return _confirmLeaseTime;
49 	    }
50 	    return _max;
51 	}
52 	
53 	function payRentDone(address a){
54 		_payRentTime = now;
55 		_isTenantDone = true;
56 	}
57 	
58 	function payRentTime() returns (uint result){
59 	    if(_ispayRentDone){
60 	        return _payRentTime;
61 	    }
62 	    return _max;
63 	}
64 	
65 	function returnHouseDone(address a){
66 		_returnHouseTime = now;
67 		_isTenantDone = true;
68 	}
69 	
70 	function returnHouseTime() returns (uint result){
71 	    if(_isreturnHouseDone){
72 	        return _returnHouseTime;
73 	    }
74 	    return _max;
75 	}
76 	
77 	function collectBailDone(address a){
78 		_collectBailTime = now;
79 		_isTenantDone = true;
80 	}
81 	
82 	function collectBailTime() returns (uint result){
83 	    if(_iscollectBailDone){
84 	        return _collectBailTime;
85 	    }
86 	    return _max;
87 	}
88 	
89 	function contains(address a) returns (bool result) {
90 	    for (uint _j = 0; _j < _TenantAddress.length; _j++ ) {  //for loop example
91             if (a == _TenantAddress[_j]){
92                 return true;
93             }         
94       }
95       return false;
96 	}
97 	
98 }