javascript - 如何根据条件过滤数组

Question

我正在处理基于 Angular 色的权限，我有以下数组，

let Roles = {
  [
    { model: 'user', property: 'find', permission: 'allow' },
    { model: 'user', property: 'create', permission: 'allow' },
    { model: 'user', property: 'update', permission: 'deny' },
    { model: 'user', property: 'delete', permission: 'deny' }
  ],
  [
    { model: 'registration', property: 'find', permission: 'allow' },
    { model: 'registration', property: 'create', permission: 'deny' },
    { model: 'registration', property: 'update', permission: 'deny' },
    { model: 'registration', property: 'delete', permission: 'deny' }
  ]
  [
    { model: 'schedule', property: 'find', permission: 'allow' },
    { model: 'schedule', property: 'create', permission: 'allow' },
    { model: 'schedule', property: 'update', permission: 'allow' }
    { model: 'schedule', property: 'delete', permission: 'deny' }
  ]
}

我正在尝试获得以下输出

  let userPermissions = [{
  'menu_name': 'user',
  'canFetchData': true,
  'canCreateData': true,
  'canUpdateData': false,
  'canDeleteData': false,
}]

let registrationPermissions = [{
  'menu_name': 'registration',
  'canFetchData': true,
  'canCreateData': false,
  'canUpdateData': false,
  'canDeleteData': false,
}]

let schedulePermissions = [{
  'menu_name': 'schedule',
  'canFetchData': true,
  'canCreateData': true,
  'canUpdateData': true,
  'canDeleteData': false,
}]

生成结果的条件是，对于给定的模型和属性，如果许可允许，则它应该为真，否则为假。

我已经尝试编写 if condition 并在 if condition matches 时分配值 true 。但是对于第二个数组，值是最重要的

从 Roles 数组，我将每个数组传递给以下函数并返回结果

  private canFetchData;
  private canCreateData;
  private canUpdateData;
  private canDeleteData;

filterAndApplyPermission(data) {
for (let i = 0; i < data.length; i++) {
  if (data[i].property === 'find' && data[i].permission === 'ALLOW') {
    this.canFetchData = true;
  } else if (data[i].property === 'create' && data[i].permission === 'ALLOW') {
    this.canCreateData = true;
  } else if (data[i].property === 'update' && data[i].permission === 'ALLOW') {
    this.canUpdateData = true;
  } else if (data[i].property === 'delete' && data[i].permission === 'ALLOW') {
    this.canDeleteData = true;
  }
}

const grouped_permission = {
  'menu': data[0].model,
  'canFetchData': this.canFetchData,
  'canCreateData': this.canCreateData,
  'canUpdateData': this.canUpdateData,
  'canDeleteData': this.canDeleteData,
};
   return grouped_permission;
 }

Answer 1

您可以使用过滤器来查找特定用户的权限数组:

roleInfo
.filter(roles=>roles[0].model==="schedule")[0]

使用 reduce 创建对象并 switch对于每个属性。

rolesForUser
.reduce(
  (info,item)=>{
    switch(item.property) {
      case 'find':
        info.canFetchData = (item.permission==='allow')?true:false
        break;
      //other cases
    }
    return info;
  },
  {menu_name : user}//initial info object with menu_name set to user
);

const roleInfo = [
  [
    { model: 'user', property: 'find', permission: 'allow' },
    { model: 'user', property: 'create', permission: 'allow' },
    { model: 'user', property: 'update', permission: 'deny' },
    { model: 'user', property: 'delete', permission: 'deny' }
  ],
  [
    { model: 'registration', property: 'find', permission: 'allow' },
    { model: 'registration', property: 'create', permission: 'deny' },
    { model: 'registration', property: 'update', permission: 'deny' },
    { model: 'registration', property: 'delete', permission: 'deny' }
  ],
  [
    { model: 'schedule', property: 'find', permission: 'allow' },
    { model: 'schedule', property: 'create', permission: 'allow' },
    { model: 'schedule', property: 'update', permission: 'allow' },
    { model: 'schedule', property: 'delete', permission: 'deny' }
  ]
];

const getRoleForUser = (user,roleInfo) =>
  roleInfo
  .filter(roles=>roles[0].model===user)[0]
  .reduce(
    (info,item)=>{
      switch (item.property) {
        case 'find':
          info.canFetchData = (item.permission==='allow')?true:false
          break;
        case 'create':
          info.canCreateData = (item.permission==='allow')?true:false
          break;
        case 'update':
          info.canUpdateData = (item.permission==='allow')?true:false
          break;
        case 'delete':
          info.canDeleteData = (item.permission==='allow')?true:false
          break;
        default:
          throw new Error(`${item.property} is an unknown permission`);
      }
      return info;
    },
    {menu_name : user}
  );

console.log(getRoleForUser("registration",roleInfo));