将唯一键推送到稳固的数组中。

Question

我想要构建一个简单的智能契约，它能够创建资产并将具有不同角色的用户添加到其中。每个用户应该只能在每个资产分配的时间内拥有一个角色。

稳固的代码：

contract AccessManagement {

struct Authorization {
    string role;
    bool active;
}

struct Asset {
    address owner;
    address[] authorizationList;
    mapping(address => Authorization) authorizationStructs;
    bool initialized;    
}

mapping(string => Asset) assetStructs;
string[] assetList;

function newAsset(string assetKey) public returns(bool success) {
    // Check for duplicates
    assetStructs[assetKey].owner = msg.sender;
    assetStructs[assetKey].initialized = true;
    assetList.push(assetKey);
    return true;
} 

function addAuthorization(string assetKey, address authorizationKey, string authorizationRole) public returns(bool success) {
    // ??? - Require Role "Admin"
    // ??? - Push only if "authorizationKey" is unique. Otherwise change the values.
    assetStructs[assetKey].authorizationList.push(authorizationKey);
    assetStructs[assetKey].authorizationStructs[authorizationKey].role = authorizationRole;
    assetStructs[assetKey].authorizationStructs[authorizationKey].active = true;
    return true;
}
function getAssetAuthorization(string assetKey, address authorizationKey) public constant returns(string authorizationRole) {
    return(assetStructs[assetKey].authorizationStructs[authorizationKey].role);
}
}

我对此提出的问题：

• 如果"authorizationKey“是唯一的，我如何确保它被推入authorizationList[]？如果它不是唯一的，则只应更改值。
• 如何检查"assetStructsassetKey.authorizationStructsmsg.sender.role“是否等于管理？

Answer 1

我没看到你在任何地方都在使用授权名单。你可以把它移走。为了确保始终只有一个授权密钥，您可以使用现有的映射。现有条目将被覆盖。当您想知道键是否存在时，请检查active是否为true，因为对于所有不存在的键，默认情况下都是false。您需要在某个时候迭代所有的地址吗？

要检查角色是否等于Admin，我将为角色创建一个枚举并与之进行比较。就像这样：

// Enum
enum Roles { User, Admin };

// Struct
struct Authorization {
    Roles role;
    bool active;
}

// Checking
if (assetStructs[assetKey].authorizationStructs[authorizationKey].role == Roles.Admin) {
    // something here
}