我在使用 Ramda sortWith 按多列(升序或降序)对深度嵌套的对象数组进行排序时遇到问题。显然,排序是区分大小写的,并且导致以小写字母开头的值被放置到排序数组的最末尾。
首先,我导入必要的 ramda 函数:
import { sortWith, path, useWith, split, ascend, descend } from 'ramda'
然后我有这个数组:
const theList = [
{
name: 'A',
purchase: {
period: {
start: '2020-01-08T21:00:00Z',
end: '3070-10-27T21:00:00Z',
},
},
},
{
name: 'b',
purchase: {
period: {
start: '2019-09-30T19:00:00Z',
end: '3070-10-27T21:00:00Z',
},
},
},
{
name: 'C',
purchase: {
period: {
start: '2020-01-26T21:00:00Z',
end: '3070-10-27T21:00:00Z',
},
},
},
]
为了排序,我有这个带有规则的数组:
const sort = [
{ oder: 'asc', name: 'name' },
{ oder: 'desc', name: 'purchase.period.start' },
]
最后,我尝试使用给定的规则集对该数组进行排序:
const sortFunctions = sort.map(({ order, name }) => (
(order === 'asc')
? ascend(useWith(path, [split('.')])(name))
: descend(useWith(path, [split('.')])(name))
))
return sortWith(sortFunctions)(theList)
但是结果如下:
[
{
"name": "b",
"purchase": {
"period": {
"start": "2019-09-30T19:00:00Z",
"end": "3070-10-27T21:00:00Z"
}
}
},
{
"name": "C",
"purchase": {
"period": {
"start": "2020-01-26T21:00:00Z",
"end": "3070-10-27T21:00:00Z"
}
}
},
{
"name": "A",
"purchase": {
"period": {
"start": "2020-01-08T21:00:00Z",
"end": "3070-10-27T21:00:00Z"
}
}
}
]
所以这里的问题是 b
没有像预期的那样位于中间,因为它考虑了区分大小写。不仅如此,该列表的顺序似乎也与预期顺序相反。
我在这里做错了什么以及如何让它忽略区分大小写?
最佳答案
通过稍微修改代码版本(使用管道而不是 useWith
,我更愿意尽可能避免),我们可以在像这样的比较器:
const makeSorter = compose (
sortWith,
map (({order, name}) => (order == 'desc' ? descend : ascend) (
compose (toLower, path (split ('.', name)))
))
)
const sorts = [
{ order: 'asc', name: 'name' },
{ order: 'desc', name: 'purchase.period.start' },
]
// Switched the order to make the sorting clear
const theList = [{name: "C", purchase: {period: {start: "2020-01-26T21: 00: 00Z", end: "3070-10-27T21: 00: 00Z"}}}, {name: "A", purchase: {period: {start: "2020-01-08T21: 00: 00Z", end: "3070-10-27T21: 00: 00Z"}}}, {name: "b", purchase: {period: {start: "2019-09-30T19: 00: 00Z", end: "3070-10-27T21: 00: 00Z"}}}]
console .log (
makeSorter (sorts) (theList)
)
<script src="https://cdnjs.cloudflare.com/ajax/libs/ramda/0.27.0/ramda.js"></script>
<script> const {compose, sortWith, map, ascend, descend, toLower, path, split} = R </script>
我还将测试从 asc
更改为 desc
因为我使用过类似的东西,其中 asc
是默认值,并且该字段是选修的。 (desc
在需要时是强制性的。)
这只是避免了我们传递给 ascend
或 descend
的函数中的一些重复:
(order == 'desc' ? descend : ascend)
我还没有测试这实际上适用于多种排序,因为这些值在“名称”上都不一致,但看起来应该有效。
关于javascript - 使用 ramda sortWith 进行不区分大小写的排序,我们在Stack Overflow上找到一个类似的问题: https://stackoverflow.com/questions/60492229/