求网站建设详细过程,建网站需要什么步骤,触屏网站meta标签,温州网站制作推广前提
Roles: 实现对用户地址的角色权限管控,添加、删除角色。
Producer: 生产商角色管控。
...
FoodInfoItem: 食品信息管控。生产商、中间商、超市添加食品信息。
Trace:食品溯源合约,主要负责对以上几个合约的统筹协作。
Roles
// SPDX-License-Identifier: MIT
pragm…前提
Roles: 实现对用户地址的角色权限管控,添加、删除角色。
Producer: 生产商角色管控。
...
FoodInfoItem: 食品信息管控。生产商、中间商、超市添加食品信息。
Trace:食品溯源合约,主要负责对以上几个合约的统筹协作。
Roles
// SPDX-License-Identifier: MIT
pragma solidity 0.4 0.9;//角色库管理所有角色地址
// 1. 实现增加角色地址
// 2. 移除角色地址
// 3. 判断角色地址是否被授权
library Roles{struct Role{mapping (address bool) bearer;}// 在 Solidity 中映射mapping不能在函数内部声明为局部变量// 也不能在当前版本0.8.0中作为库library的成员变量。// 假如role 显示声明storage,那么算是合约中的状态变量,而且不能是memoryfunction add(Role storage role,address account) public { require(!has(role,account),Roles:account already has role);role.bearer[account] true;}function remove(Role storage role,address account) public {require(!has(role,account),Roles:account has no role );role.bearer[account] false;}function has(Role storage role,address account) public view returns(bool){require(account ! address(0),Roles: account cannot be zero address);return role.bearer[account];}}
Producer
PS:这下面这三个都是代表角色代码几乎一样的看会这个其他都会。
// SPDX-License-Identifier: MIT
pragma solidity 0.4 0.9;
import ./Roles.sol;
/**
*title Producer
*dev
*/
contract Producer {using Roles for Roles.Role;event ProducerAdded(address indexed account);event ProducerRemoved(address indexed account);Roles.Role private _producers; // 使用这个相当于使用库constructor(address producer){ // 初始化给账户添加权限_addProducer(producer);}// 关于下面这几个函数为什么要拆分提高代码可读性。modifier onlyProducer(){require(isProducer(msg.sender),Producer:caller has no Producer role);_;}// 用户是否拥有权限function isProducer(address account) public view returns (bool) {return _producers.has(account);}function addProducer(address account) public onlyProducer {_addProducer(account); // 不是很理解为什么设置只有生产者角色才能为地址添加生产者角色权限}function removeRroducer(address account) public {_removeProducer(account);}function _addProducer(address account) internal {_producers.add(account); // 我们看向Roles的add()其实还有一个参数,但是我们 using for 了那个参数就相当于 _producers本身emit ProducerAdded(account);}function _removeProducer(address account) internal {_producers.remove(account);emit ProducerRemoved(account);}}
Retailer
// SPDX-License-Identifier: MIT
pragma solidity 0.4 0.9;
import ./Roles.sol;// 超市
contract Retailer {using Roles for Roles.Role;event RetailerAdded(address indexed account);event RetailerRemoved(address indexed account);Roles.Role private _retailers; // 使用这个相当于使用库constructor(address retailer){ // 初始化给账户添加权限_addRetailer(retailer);}// 关于下面这几个函数为什么要拆分提高代码可读性。modifier onlyRetailer(){require(isRetailer(msg.sender),Retailer:caller has no Retailer role);_;}// 用户是否拥有权限function isRetailer(address account) public view returns (bool) {return _retailers.has(account);}function addRetailer(address account) public onlyRetailer {_addRetailer(account); }function removeRroducer(address account) public {_removeRetailer(account);}function _addRetailer(address account) internal {_retailers.add(account); // 我们看向Roles的add()其实还有一个参数,但是我们 using for 了那个参数就相当于 _Retailers本身emit RetailerAdded(account);}function _removeRetailer(address account) internal {_retailers.remove(account);emit RetailerRemoved(account);}}
Distributor
// SPDX-License-Identifier: MIT
pragma solidity 0.4 0.9;
import ./Roles.sol;
// 中间商
contract Distributor {using Roles for Roles.Role;event DistributorAdded(address indexed account);event DistributorRemoved(address indexed account);Roles.Role private _distributors; // 使用这个相当于使用库constructor(address distributor){ // 初始化给账户添加权限_addDistributor(distributor);}// 关于下面这几个函数为什么要拆分提高代码可读性。modifier onlyDistributor(){require(isDistributor(msg.sender),Distributor:caller has no Distributor role);_;}// 用户是否拥有权限function isDistributor(address account) public view returns (bool) {return _distributors.has(account);}function addDistributor(address account) public onlyDistributor {_addDistributor(account); }function removeRroducer(address account) public {_removeDistributor(account);}function _addDistributor(address account) internal {_distributors.add(account); // 我们看向Roles的add()其实还有一个参数,但是我们 using for 了那个参数就相当于 _Distributors本身emit DistributorAdded(account);}function _removeDistributor(address account) internal {_distributors.remove(account);emit DistributorRemoved(account);}}
FoodInfoItem
// SPDX-License-Identifier: MIT
pragma solidity 0.4 0.9;
pragma experimental ABIEncoderV2;//食品信息管理合约
// 1. 保存食品基本信息:时间戳(流转过程中),用户名(流转过程中),用户地址信息(流转过程中),食品质量(流转过程中),食物名称,当前用户名称,质量,状态.
// 2. 对食品基本信息进行初始化
// 3. 实现两个方法:中间商添加食品信息;超市添加食品信息
// 4. 实现显示食品信息的方法contract FoodInfoItem {uint[] _timestamp; //保存食品流转过程中各个阶段的时间戳string[] _traceName; //保存食品流转过程各个阶段的用户名address[] _traceAddress; //保存食品流转过程各个阶段的用户地址信息和用户一一对应uint8[] _traceQuality; //保存食品流转过程中各个阶段的质量string _name; //食品名称string _currentTraceName; //当前用户名称uint8 _quality; //质量0优质 1合格 2不合格uint8 _status; //状态0:生产 1:分销 2:出售address _owner;// 初始化食品,创建者是生产商constructor(string memory name,string memory traceName,uint8 quality,address producer) public {_name name;_currentTraceName traceName;_quality quality;_owner producer;_status 0;// 不多说看上面状态变量都能明白_timestamp.push(block.timestamp); _traceName.push(traceName);_traceAddress.push(producer);_traceQuality.push(quality);}// 中间商添加食品信息function addTraceInfoByDistributor(string memory traceName,uint8 quality,address distributor) public returns(bool){require(_status 0, FoddIndo: caller must be distributor);_currentTraceName traceName;_quality quality;_status 1;_timestamp.push(block.timestamp); _traceName.push(traceName);_traceAddress.push(distributor);_traceQuality.push(quality);return true;}// 超市添加食品信息function addTraceInfoByRetailer(string memory traceName,uint8 quality,address retailer)public returns(bool){require(_status 1, FoddIndo: caller must be retailer);_currentTraceName traceName;_quality quality;_status 2;_timestamp.push(block.timestamp); _traceName.push(traceName);_traceAddress.push(retailer);_traceQuality.push(quality);return true;}// 拿到食品流转的全部信息function getTraceInfo() public view returns(uint[] memory,string[] memory,address[] memory,uint8[] memory){return (_timestamp,_traceName,_traceAddress,_traceQuality);}// 拿到生产商一开始添加食品信息function getFood() public view returns(uint,string memory,address,uint8,string memory){return (_timestamp[0],_traceName[0],_traceAddress[0],_traceQuality[0],_name);}}
Trace
// SPDX-License-Identifier: MIT
pragma solidity 0.4.22 0.9.0;
pragma experimental ABIEncoderV2; // 开启实验性功能包括对map,数组的编码和解码等
import ./FoodInfoItem.sol;
import ./Distributor.sol;
import ./Producer.sol;
import ./Retailer.sol;//食品溯源合约负责具体食品溯源信息的生成
// 1.实现生产食品的方法(新建食品信息)
// 2.实现食品分销过程中增加溯源信息的接口
// 3.实现食品出售过程中增加溯源信息的接口
// 4.实现获取食品溯源信息接口contract Trace is Distributor,Producer,Retailer {mapping(uint256 address) foods; //食品溯源id到 - 具体食品溯源合约的映射表uint[] foodList; // 食品溯源id数组//构造函数初始化,一起把父类角色初始化constructor(address producer,address distributor,address retailer) Producer(producer) Distributor(distributor) Retailer(retailer) {}// 生产商调用调用添加食品信息function newFood(string memory name,uint256 traceNumber, // 溯源idstring memory traceName,uint8 quality) public onlyProducer returns (address) {require(foods[traceNumber] address(0), Trace:traceNumber already exist); // 检测溯源id对应食品合约是否已经存在,已存在id不能用。FoodInfoItem food new FoodInfoItem( // 初始化食品合约name,traceName,quality,msg.sender);foods[traceNumber] address(food); // 往映射表添加地址foodList.push(traceNumber); // 往食品溯源数组添加溯源idreturn address(food);}// 中间商调用,添加食品信息function addTraceInfoByDistributor(uint256 traceNumber,string memory traceName,uint8 quality) public onlyDistributor returns (bool) {require(foods[traceNumber] ! address(0), Trace:traceNumber does not exist); // id 对应食品合约没存在,代表没食品returnFoodInfoItem(foods[traceNumber]).addTraceInfoByDistributor(traceName,quality,msg.sender); // 调用对应的食品合约方法}// 超市调用,添加食品信息function addTraceInfoByRetailer(uint256 traceNumber,string memory traceName,uint8 quality) public onlyRetailer returns (bool) {require(foods[traceNumber] ! address(0), Trace:traceNumber does not exist);returnFoodInfoItem(foods[traceNumber]).addTraceInfoByRetailer(traceName,quality,msg.sender);}// 拿到所有食品信息function getTraceInfo(uint256 traceNumber) public view returns (uint[] memory,string[] memory,address[] memory,uint8[] memory) {require(foods[traceNumber] ! address(0), Trace:traceNumber does not exist);return FoodInfoItem(foods[traceNumber]).getTraceInfo();}//拿到单条食品信息function getFood(uint256 traceNumber) public view returns (uint,string memory,address,uint8,string memory) {require(foods[traceNumber] ! address(0), Trace:traceNumber does not exist);return FoodInfoItem(foods[traceNumber]).getFood();}// 拿到全部食品的溯源id数组function getAllFood() public view returns (uint[] memory) {return foodList;}}
