如何根据条件筛选数组

Question

我正在处理基于角色的权限问题，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' }
  ]
}

and I am trying to get the following output

  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，如果权限被允许，则结果应为 true，否则为 false。

我曾通过编写 if 条件语句并在条件匹配时将其值赋为 true 来尝试实现。但是对于第二个数组，值会被覆盖。

从 Roles 数组中，我正在将每个数组传递到以下函数中并返回结果。

  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;
 }

- Shaik Nizamuddin

---

你真的想要只有一个对象的三个数组吗？还是仅需要这个对象？ - bugs

可能 this.canFetchData = true; 中的 this 指的是同一个对象...不过我们需要更多的代码。 - Asons

请提供完整的上下文，你的代码中 this 的值是什么？ - Weedoze

请花几分钟时间阅读 [mcve]。提供足够的代码让他人运行和重现问题，将会快速解决问题。 - charlietfl

此外，“Roles”的语法似乎有误。 - bugs

Answer 1

您可以使用过滤器从特定用户中找到权限数组：

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

使用 reduce 创建您的对象，并对每个属性使用 switch。

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));

- HMR

Answer 2

正如您在问题中提到的那样，

基于角色的权限，我有以下数组

您可以像这样定义您的权限对象

const permissionObj = {
    find: 'canFetchData',
    create: 'canCreateData',
    update: 'canUpdateData',
    delete: 'canDeleteData'
}

你可以使用reduce()函数迭代数组，并在reduce()函数内部使用permissionObj。

演示

const dataObj =[[{
            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'
        }]
    ],
    permissionObj = {
        find: 'canFetchData',
        create: 'canCreateData',
        update: 'canUpdateData',
        delete: 'canDeleteData'
    };

let result = dataObj.reduce((r, arr) => {
    let model = '',
        obj = arr.reduce((p, o) => {
            model = o.model;
            p[permissionObj[o.property]] = o.permission.toUpperCase() === 'ALLOW';
            return p;
        }, {})
    r[`${model}Permissions`] = [Object.assign(obj, {
        menu_name: model
    })];
    return r;
}, {});

console.log(result)

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- Narendra Jadhav