查看“ExampleofPurchaseContract”的源代码

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=== <div style=" background:#EBEBEB; padding-top: 10px; height:45px; padding-left:15px "> Purchase contract </div> ===
{| class="wikitable"
||&nbsp;&nbsp;&nbsp;&nbsp;Purchase contract, transfers the ownership of goods from a seller to a buyer through logistics company. There are 10 terms in the contract, including three parts: <br>&nbsp;&nbsp;&nbsp;&nbsp;1) once the goods are confirmed, the seller will sign a contract and take twice the contracting price as the delivery price,<br>&nbsp;&nbsp;&nbsp;&nbsp;2) the goods are sent to the buyer through logistics when the buyer purchases the goods, and 3) only when the logistics successfully delivers the goods to the buyer can the seller get back the payment. According to relevant laws, the contract requires the buyer can apply for compensation if goods do not arrive within 10 days after payment, or the seller can automatically confirm the arrival if the buyer does not confirm or apply for refund within 7 days after arrival.
'''<syntaxhighlight lang="spec" line="1">
// purchase.scs
contract Purchase{
	party seller{
		//定义seller角色，有四个动作
		create()
		abort()
		confirmClaim()
		autoConfirm()
	}

	party buyer{
		confirmPurchase()//
		confirmReceived()
		overtimeClaim()
		claim()
		revokeClaim()
	}
	
	party logistics{
		//第三方角色，物流公司
		arrive()
	}

	balance : integer

	xxxDescription : goods//定义一个商品描述，good是下面定义的商品结构体
	
	term no1 : seller can create 
		while deposit $ xxxDescription::price*2.
	//卖家可以创建合约，同时要存入物品两倍价格作为保证金
	
	term no2 : buyer can confirmPurchase 
		when after seller did create 
		while deposit $ xxxDescription::price*2.
	//买家创建合约后买家可以确认购买，同时要存入物品两倍价格作为保证金和货款
	
	term no3 : seller can abort 
		when before buyer did confirmPurchase 
		while withdraw $ xxxDescription::price*2.
	//卖家在买家确认购买之前，可以撤回合约，并取走两倍的保证金
	
	term no4 : logistics must arrive 
		when within 10 day after buyer did confirmPurchase.
	//买家付款后10天内必须到货
	
	term no5 : buyer must confirmReceived 
		when within 7 day after logistics did arrive
		while
			withdraw $ xxxDescription::price
			transfer $ balance to seller.
	//买家在到货后7天内必须确认到货，同时双方取走保证金，卖家取走货款
	
	term no6 : buyer can claim 
		when within 7 day after logistics did arrive.
	//买家可以在到货7天内申请赔款
		
	term no7 : buyer can overtimeClaim 
		when after start + 10 day or after logistics did arrive.
	//如果货物在付款后10天内没到，买家可以申请赔款
	
	term no8 : seller can confirmClaim 
		when after buyer did claim or after buyer did overtimeClaim
		while transfer $ balance to buyer.
	//卖家可以同意退款，并把所有保证金及货款转给买家
	
	term no9 : buyer can revokeClaim 
		when after buyer did claim or after buyer did overtimeClaim
		while
			withdraw $ xxxDescription::price
			transfer $ balance to seller.
	//买家可以撤回退款申请
		
	term no10 : seller can autoConfirm 
		when before buyer did claim and 7 day after logistics did arrive
		while
			withdraw $ xxxDescription::price
			transfer $ balance to seller.
	//如果到货七天内买家没有确认或申请退款，卖家可以自动确认到货。
	
	type goods {
		name : Name//物品名称
		quantity : integer//物品数量
		price : Money//价格
		package : String//运送包装
	}
}
</syntaxhighlight>'''
'''<syntaxhighlight lang="spec" line="1">
/* buyerT.sol */
pragma solidity ^0.4.22;

contract buyerT{
	
	
	//attributes of actionconfirmPurchase
	bool _isconfirmPurchaseDone;
	uint _confirmPurchaseTime;
	
	//attributes of actionconfirmReceived
	bool _isconfirmReceivedDone;
	uint _confirmReceivedTime;
	
	//attributes of actionovertimeClaim
	bool _isovertimeClaimDone;
	uint _overtimeClaimTime;
	
	//attributes of actionclaim
	bool _isclaimDone;
	uint _claimTime;
	
	//attributes of actionrevokeClaim
	bool _isrevokeClaimDone;
	uint _revokeClaimTime;
	
	uint _max;
	bool _isbuyerDone;
	uint _i = 0;
	
	address[] _buyerAddress;
	function buyerT(){
		_max = now*1000;
	}
	
	function regist(address a) public {
		_buyerAddress[_i] = a;
		_i++;
	}
	
	function getAddress() public returns (address a){
		return _buyerAddress[_i];
	}
	
	function confirmPurchaseDone(address a){
		_confirmPurchaseTime = now;
		_isbuyerDone = true;
	}
	
	function confirmPurchaseTime() returns (uint result){
	    if(_isconfirmPurchaseDone){
	        return _confirmPurchaseTime;
	    }
	    return _max;
	}
	
	function confirmReceivedDone(address a){
		_confirmReceivedTime = now;
		_isbuyerDone = true;
	}
	
	function confirmReceivedTime() returns (uint result){
	    if(_isconfirmReceivedDone){
	        return _confirmReceivedTime;
	    }
	    return _max;
	}
	
	function overtimeClaimDone(address a){
		_overtimeClaimTime = now;
		_isbuyerDone = true;
	}
	
	function overtimeClaimTime() returns (uint result){
	    if(_isovertimeClaimDone){
	        return _overtimeClaimTime;
	    }
	    return _max;
	}
	
	function claimDone(address a){
		_claimTime = now;
		_isbuyerDone = true;
	}
	
	function claimTime() returns (uint result){
	    if(_isclaimDone){
	        return _claimTime;
	    }
	    return _max;
	}
	
	function revokeClaimDone(address a){
		_revokeClaimTime = now;
		_isbuyerDone = true;
	}
	
	function revokeClaimTime() returns (uint result){
	    if(_isrevokeClaimDone){
	        return _revokeClaimTime;
	    }
	    return _max;
	}
	
	function contains(address a) returns (bool result) {
	    for (uint _j = 0; _j < _buyerAddress.length; _j++ ) {  //for loop example
            if (a == _buyerAddress[_j]){
                return true;
            }         
      }
      return false;
	}
	
}
</syntaxhighlight>'''
'''<syntaxhighlight lang="spec" line="1">
/* logisticsT.sol */
pragma solidity ^0.4.22;

contract logisticsT{
	
	
	//attributes of actionarrive
	bool _isarriveDone;
	uint _arriveTime;
	
	uint _max;
	bool _islogisticsDone;
	uint _i = 0;
	
	address[] _logisticsAddress;
	function logisticsT(){
		_max = now*1000;
	}
	
	function regist(address a) public {
		_logisticsAddress[_i] = a;
	}
	
	function getAddress() public returns (address a){
		return _logisticsAddress[_i];
	}
	
	function arriveDone(address a){
		_arriveTime = now;
		_islogisticsDone = true;
	}
	
	function arriveTime() returns (uint result){
	    if(_isarriveDone){
	        return _arriveTime;
	    }
	    return _max;
	}
	
	function contains(address a) returns (bool result) {
	    for (uint _j = 0; _j < _logisticsAddress.length; _j++ ) {  //for loop example
            if (a == _logisticsAddress[_j]){
                return true;
            }
      }
      return false;
	}
	
}
</syntaxhighlight>'''
'''<syntaxhighlight lang="spec" line="1">
/* Purchase.sol */
pragma solidity ^0.4.0;
		
import "./sellerT.sol";
import "./buyerT.sol";
import "./logisticsT.sol";

contract Purchase {
	
	sellerT seller;
	buyerT buyer;
	logisticsT logistics;
	
	uint balance;
	goods xxxDescription;
	
	uint start;
	struct goods{
		bytes32 name;
		uint quantity;
		uint price;
		bytes32 package;
	}
	
	function Purchase(){
		start = now;
		seller = new sellerT();
		buyer = new buyerT();
		logistics = new logisticsT();
	}

	modifier onlyseller{
		require(seller.contains(msg.sender));
		_;
	}
	
	modifier onlybuyer{
		require(buyer.contains(msg.sender));
		_;
	}
	
	modifier onlylogistics{
		require(logistics.contains(msg.sender));
		_;
	}
	
	modifier no2Modifier{
		require(now > seller.createTime());
		require(xxxDescription.price * 2 > 0);
		_;
	}
	
	modifier no3Modifier{
		require(now < buyer.confirmPurchaseTime());
		_;
	}
	
	modifier no4Modifier{
		require((now > buyer.confirmPurchaseTime()) &&(now < buyer.confirmPurchaseTime()+864000));
		_;
	}
	
	modifier no5Modifier{
		require((now > logistics.arriveTime()) &&(now < logistics.arriveTime()+604800));
		_;
	}
	
	modifier no6Modifier{
		require((now > logistics.arriveTime()) &&(now < logistics.arriveTime()+604800));
		_;
	}
	
	modifier no7Modifier{
		require(now > start + 864000 || now > logistics.arriveTime());
		_;
	}
	
	modifier no8Modifier{
		require(now > buyer.claimTime() || now > buyer.overtimeClaimTime());
		_;
	}
	
	modifier no9Modifier{
		require(now > buyer.claimTime() || now > buyer.overtimeClaimTime());
		_;
	}
	
	modifier no10Modifier{
		require(now < buyer.claimTime() && now > logistics.arriveTime()+604800);
		_;
	}
	
	function create() onlyseller() public payable {
		//USER CODE HERE
		//CHECK
	
	}
	
	function confirmPurchase() onlybuyer() no2Modifier() public payable {
		//USER CODE HERE
		//CHECK
	
	}
	
	function abort() onlyseller() no3Modifier() public payable {
		//USER CODE HERE
		msg.sender.transfer(xxxDescription.price * 2);
		//CHECK
	
	}
	
	function arrive() onlylogistics() no4Modifier() public {
		//USER CODE HERE
		//CHECK
	
	}
	
	function confirmReceived() onlybuyer() no5Modifier() public payable {
		//USER CODE HERE
		msg.sender.transfer(xxxDescription.price);
		address(seller).transfer(balance);
		//CHECK
	
	}
	
	function claim() onlybuyer() no6Modifier() public {
		//USER CODE HERE
		//CHECK
	
	}
	
	function overtimeClaim() onlybuyer() no7Modifier() public {
		//USER CODE HERE
		//CHECK
	
	}
	
	function confirmClaim() onlyseller() no8Modifier() public payable {
		//USER CODE HERE
		address(buyer).transfer(balance);
		//CHECK
	
	}
	
	function revokeClaim() onlybuyer() no9Modifier() public payable {
		//USER CODE HERE
		msg.sender.transfer(xxxDescription.price);
		address(seller).transfer(balance);
		//CHECK
	
	}
	
	function autoConfirm() onlyseller() no10Modifier() public payable {
		//USER CODE HERE
		msg.sender.transfer(xxxDescription.price);
		address(seller).transfer(balance);
		//CHECK
	
	}
	
}
</syntaxhighlight>'''
'''<syntaxhighlight lang="spec" line="1">
/* sellerT.sol */
pragma solidity ^0.4.22;

contract sellerT{
	
	
	//attributes of actioncreate
	bool _iscreateDone;
	uint _createTime;
	
	//attributes of actionabort
	bool _isabortDone;
	uint _abortTime;
	
	//attributes of actionconfirmClaim
	bool _isconfirmClaimDone;
	uint _confirmClaimTime;
	
	//attributes of actionautoConfirm
	bool _isautoConfirmDone;
	uint _autoConfirmTime;
	
	uint _max;
	bool _issellerDone;
	uint _i = 0;
	
	address[] _sellerAddress;
	function sellerT(){
		_max = now*1000;
	}
	
	function regist(address a) public {
		_sellerAddress[_i] = a;
		_i++;
	}
	
	function getAddress() public returns (address a){
		return _sellerAddress[_i];
	}
	
	function createDone(address a){
		_createTime = now;
		_issellerDone = true;
	}
	
	function createTime() returns (uint result){
	    if(_iscreateDone){
	        return _createTime;
	    }
	    return _max;
	}
	
	function abortDone(address a){
		_abortTime = now;
		_issellerDone = true;
	}
	
	function abortTime() returns (uint result){
	    if(_isabortDone){
	        return _abortTime;
	    }
	    return _max;
	}
	
	function confirmClaimDone(address a){
		_confirmClaimTime = now;
		_issellerDone = true;
	}
	
	function confirmClaimTime() returns (uint result){
	    if(_isconfirmClaimDone){
	        return _confirmClaimTime;
	    }
	    return _max;
	}
	
	function autoConfirmDone(address a){
		_autoConfirmTime = now;
		_issellerDone = true;
	}
	
	function autoConfirmTime() returns (uint result){
	    if(_isautoConfirmDone){
	        return _autoConfirmTime;
	    }
	    return _max;
	}
	
	function contains(address a) returns (bool result) {
	    for (uint _j = 0; _j < _sellerAddress.length; _j++ ) {  //for loop example
            if (a == _sellerAddress[_j]){
                return true;
            }         
      }
      return false;
	}
	
}

</syntaxhighlight>'''