ExampleofLoanContract

Loan contract

Loan contract, refers to a contract where a lender delivers a certain amount of funds to a borrower, and the latter returns the same amount of funds within a certain period of time and pays interests to the lender. There are 6 terms in the contract that consists of two aspects:     1) the borrower shall submit a loan application stating the amount he/she wants to borrow, and     2) the lender may deposit funds into the contract account until the target of loan is reached. Before borrowing, the contract requires that the borrower must confirm the loan information and check the historical loan records, and then calculate the corresponding interests. Meanwhile, the contract asserts that the borrower pays off the loan amount before the loan date comes.

 1 // Lend Spesc.scs
 2 contract Lend{
 3 	party User{
 4 		loan : Loan
 5 		SubmitLoanApplication(l : Loan)
 6 		confirm()
 7 		getHisLoan()
 8 		payback()
 9 	}
10 	
11 	party Funder{
12 		moneyFunded : Money
13 		moneyWillGet : Money
14 		Contribute(uid : User)
15 		refund(uid : User)
16 	}
17 
18 	term term1 : User can SubmitLoanApplication.
19 
20 	term term2 : Funder can Contribute 
21 		when before uid::loan::timelimit
22 		while deposit $ value <= uid::loan::fundingGoal.
23 	
24 	term term3 : Funder can refund 
25 		when after uid::loan::timelimit and uid::loan::amount < uid::loan::fundingGoal
26 		while withdraw $ his::moneyFunded.
27 		
28 	term term4 : User must confirm 
29 		when within 3 day after his::loan::timelimit and his::loan::amount = his::loan::fundingGoal.
30 	
31 	term term5 : User can getHisLoan 
32 		when after User did confirm 
33 		while withdraw $ his::loan::amount.
34 	
35 	term term6 : User must payback 
36 		when after User did confirm and before his::loan::tenorM
37 		while 
38 			deposit $ his::loan::balance + his::loan::installment
39 			transfer $ his::loan::funders::moneyWillGet to his::loan::funders.
40 	
41 	type Loan     
42     {
43         operationName : Name//use of money
44         beneficiary : User//Borrower
45         timelimit : Date//time limit of collecting money
46         fundingGoal : integer//the amount borrower want to borrow
47         amount : integer//the money collected now
48         balance : integer//the Capital have to pay back
49         numFunders : integer
50         interestRateM : integer// monthly  
51         gracePeriod : integer//the period you don't have to pay the interest
52         tenorM :  integer//monthly//you have to pay back tenorM month later
53         installment : integer//monthly//the interest have to pay back
54         funders : set Funder
55     }
56 }

 1 /* FunderT.sol */
 2 pragma solidity >=0.4.0 <0.6.0;
 3 
 4 contract FunderT{
 5 	
 6 	uint moneyFunded;
 7 	uint moneyWillGet;
 8 	
 9 	address _FunderAddress;
10 	uint _max;
11 	
12 	function funderT() public{
13 		_max = now*1000;
14 	}
15 	function regist(address a) public {
16 		_FunderAddress = a;
17 	}
18 	
19 	function getAddress() public returns (address a){
20 		return _FunderAddress;
21 	}
22 	
23 	 function getmoneyFunded() public returns(uint _result){
24 		return moneyFunded;
25 	}
26 	
27 	function setmoneyFunded ( uint a) public{
28 		moneyFunded = a;
29 	}
30 	
31 /*	function getmoneyWillGet() public returns(uint _result){
32 		return moneyWillGet;
33 	}
34 	
35 	function setmoneyWillGet(uint a) public {
36 		moneyWillGet = a;
37 	}*/
38 	
39 
40     
41     function setmoneyWillGet(uint256 newValue) public {
42         moneyWillGet = newValue;
43     }
44 
45    
46     function getmoneyWillGet() public view returns (uint256) {
47         return moneyWillGet;
48     }
49 }

  1 /* Lend.sol */
  2 pragma solidity >=0.4.0 <0.6.0;
  3 pragma experimental ABIEncoderV2;
  4 		
  5 import "./UserT.sol";
  6 import "./FunderT.sol";
  7 
  8 contract Lend {
  9 	
 10 	UserT User;
 11 	FunderT Funder;
 12 	uint start;
 13 	
 14 	
 15 	mapping (string => Loan) loan;
 16 	
 17 	struct Loan{
 18 		bytes32 operationName;
 19 		address beneficiary;
 20 		uint timelimit;
 21 		uint fundingGoal;
 22 		uint amount;
 23 		uint balance;
 24 		uint numFunders;
 25 		uint interestRateM;
 26 		uint gracePeriod;
 27 		uint tenorM;
 28 		uint installment;
 29 		address funders;
 30 	}
 31 	
 32 	
 33 	
 34 	constructor() public{
 35 		start = now;
 36 		User = new UserT();
 37 		Funder = new FunderT();
 38 	}
 39 	
 40 /*		constructor() public{
 41 	    start = now;
 42 		User = new UserT();
 43 		Funder = new FunderT();
 44 	}*/
 45 
 46 	modifier onlyUser{
 47 		require(User.getAddress()==msg.sender);
 48 		_;
 49 	}
 50 	
 51 	modifier onlyFunder{
 52 		require(Funder.getAddress()==msg.sender);
 53 		_;
 54 	}
 55 	
 56 	modifier term2Modifier(UserT uid){
 57 	//	require(now < uid.loan.timelimit);
 58 	//	require(msg.value <= uid.loan.fundingGoal);
 59 		_;
 60 	}
 61 	
 62 	modifier term3Modifier(UserT uid){
 63 //		require(now > (uid.loan.timelimit && uid.loan.amount < uid.loan.fundingGoal));
 64 		_;
 65 	}
 66 	
 67 	modifier term4Modifier{
 68 //		require((now > (User.getloan.timelimit(msg.sender) && User.getloan.amount(msg.sender) == User.getloan.fundingGoal(msg.sender))) &&(now < (User.getloan.timelimit(msg.sender) && User.getloan.amount(msg.sender) == User.getloan.fundingGoal(msg.sender))+259200));
 69 		_;
 70 	}
 71 	
 72 	modifier term5Modifier{
 73 		require(now > User.confirmTime());
 74 		_;
 75 	}
 76 	
 77 	modifier term6Modifier{
 78 //		require(now > (User.confirmTime() && now < User.getloan.tenorM(msg.sender)));
 79 //		require(User.getloan.balance(msg.sender) + User.getloan.installment(msg.sender));
 80 		_;
 81 	}
 82 	
 83 	function SubmitLoanApplication( Loan memory l) onlyUser() public {
 84 		//USER CODE HERE
 85 		//CHECK
 86 	
 87 	}
 88 	
 89 	function Contribute(UserT uid) onlyFunder() term2Modifier(uid) public payable {
 90 		//USER CODE HERE
 91 		//CHECK
 92 	
 93 	}
 94 	
 95 	function refund(UserT uid) onlyFunder() term3Modifier(uid) public payable {
 96 		//USER CODE HERE
 97 		msg.sender.transfer(Funder.getmoneyFunded());
 98 		//CHECK
 99 	
100 	}
101 	
102 	function confirm() onlyUser() term4Modifier() public {
103 		//USER CODE HERE
104 		//CHECK
105 	
106 	}
107 	
108 	function getHisLoan() onlyUser() term5Modifier() public payable {
109 		//USER CODE HERE
110 		msg.sender.transfer(User.getloan().amount);
111 		//CHECK
112 	
113 	}
114 	
115 	function payback() onlyUser() term6Modifier() public payable {
116 		//USER CODE HERE
117 		//User.getloan().funders.transfer(msg.sender);
118 		msg.sender.transfer(User.getloan().amount);
119 		//CHECK
120 	
121 	}
122 	
123 }

 1 /* UserT.sol */
 2 pragma solidity >=0.4.0 <0.6.0;
 3 pragma experimental ABIEncoderV2;
 4 
 5 
 6 import "./Lend.sol";
 7 
 8 contract UserT{
 9 	
10 	struct Loan{
11 		bytes32 operationName;
12 		address beneficiary;
13 		uint timelimit;
14 		uint fundingGoal;
15 		uint amount;
16 		uint balance;
17 		uint numFunders;
18 		uint interestRateM;
19 		uint gracePeriod;
20 		uint tenorM;
21 		uint installment;
22 		address funders;
23 	}
24 	
25 	
26 	
27 	
28 	Loan loan;
29 	//attributes of actionconfirm
30 	bool _isconfirmDone;
31 	uint _confirmTime;
32 	
33 	address _UserAddress;
34 	uint _max;
35 	
36 	constructor ()public{
37 		_max = now*1000;
38 	}
39 
40 	function regist(address a) public {
41 		_UserAddress = a;
42 	}
43 	
44 	function getAddress() public returns (address a){
45 		return _UserAddress;
46 	}
47 	
48 	function getloan() public returns(Loan memory _result) {
49 		return loan;
50 	}
51 	
52 	function setloan(Loan memory a) public{
53 		loan = a;
54 	}
55 	
56 	function confirmDone() public{
57 		_confirmTime = now;
58 		_isconfirmDone = true;
59 	}
60 	
61 	function confirmTime() public returns (uint result){
62 	    if(_isconfirmDone){
63 	        return _confirmTime;
64 	    }
65 	    return _max;
66 	}
67 	
68 }