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javascript - 节点 Ramda + 根据值查找对象

问题描述

可以根据值获取对象吗？

在下面的示例 json 中，键名具有type，因此需要根据 type 值获取结果。

例如，如果 type='user' 则仅获取用户对象而不是员工对象的结果。

在这里，我正在努力拥有两个密钥（用户和员工），您能否建议如何处理

var list =[
  {"doc":{"type":"user","Title":"test1","Relations":{"users":[{"name": "user1"},{"name": "user2"},{"name": "user3"}],"employee":[{"emp": "user2"}]}}},
  {"doc":{"type":"employee","Title":"test2","Relations":{"users":[{"name": "user1"}],"employee":[{"name": "emp1"},{"name": "emp2"},{"name": "emp3"}]}}}
];

const getDetails = R.chain(R.pipe(
  R.path(['doc', 'Relations']),
  R.pick(['users', 'employee']),
  R.values
))

const result = getDetails(list)

console.log(result)
<script src="//cdnjs.cloudflare.com/ajax/libs/ramda/0.25.0/ramda.min.js"></script>

电流输出：

[[{"name": "user1"}, {"name": "user2"}, {"name": "user3"}], [{"emp": "user2"}], [{"name": "user1"}], [{"name": "emp1"}, {"name": "emp2"}, {"name": "emp3"}]]

期望输出：

[[{"name": "user1"}, {"name": "user2"}, {"name": "user3"}], [{"name": "emp1"}, {"name": "emp2"}, {"name": "emp3"}]]

标签： javascriptnode.jsobjectnpmramda.js

解决方案

您可以使用R.cond基于一组谓词的分支逻辑，例如是否type是user或employee在您的示例中。

使用这种方法，您将需要切换R.chain到R.map以匹配您的预期列表，除非您想要对数组进行额外的展平。

const list = [
  {"doc":{"type":"user","Title":"test1","Relations":{"users":[{"name": "user1"},{"name": "user2"},{"name": "user3"}],"employee":[{"emp": "user2"}]}}},
  {"doc":{"type":"employee","Title":"test2","Relations":{"users":[{"name": "user1"}],"employee":[{"name": "emp1"},{"name": "emp2"},{"name": "emp3"}]}}}
]

const getDetails = R.map(R.pipe(
  R.prop('doc'),
  R.cond([
    [R.propEq('type', 'user'), R.path(['Relations', 'users'])],
    [R.propEq('type', 'employee'), R.path(['Relations', 'employee'])]
  ])
))

const expected = [[{"name": "user1"}, {"name": "user2"}, {"name": "user3"}], [{"name": "emp1"}, {"name": "emp2"}, {"name": "emp3"}]]

console.log(R.equals(expected, getDetails(list)))
<script src="//cdnjs.cloudflare.com/ajax/libs/ramda/0.25.0/ramda.min.js"></script>

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