如果使用 Dataweave 存在元素，则将键添加到数组

Question

我有一个 JSON 对象，它包含 subject1、subject2、subject3 等字段，并以字符串数组作为值。

如果分配给字段 subject1、subject2、subject3 的字符串数组中存在任何搜索元素，那么我需要将 Json 对象中的键或该字段添加到现有数组 (myArray)，

    %dw 2.0
    var myArray = [];
    var subjects = {
    "subject1" = ["sectionA", "sectionB", "sectionC"],
    "subject2" = ["sectionB", "sectionD", "sectionE"],
    "subject3" = ["sectionC", "sectionF", "sectionG"],
    }
    
    fun getSubjects(section) = mapping mapObject ((value, key, index) ->
       if(value contains key) myArray << key
       else myArray 
    )

    ---

    {
      "subjects" : getSubjects(var.section) // var.section = sectionA
    }

但我收到此错误“无法将数组强制转换为对象”。有更好的方法吗？

Answer 1

我认为这就是你想要做的；因为数据在 dataweave 中是不可变的，所以如果您想在更改数组内容等内容时迭代集合，则必须使用 reduce 之类的东西。

%dw 2.0

var subjects = {
    "subject1": ["sectionA", "sectionB", "sectionC"],
    "subject2": ["sectionB", "sectionD", "sectionE"],
    "subject3": ["sectionC", "sectionF", "sectionG"]
}

var section = "sectionA"

fun getSubjects(section) = subjects pluck $$ reduce ((subject, myArray=[]) ->
    if (subjects[subject] contains section) myArray << subject
    else myArray
)

---
{
    subjects: getSubjects(section)
}

产量：

{
  subjects: [
    "subject1"
  ]
}

Answer 2

还有一种方法可以做到这一点，如下所示，我们发送变量和需要匹配的字符串

%dw 2.0
var myArray = []
var subjects = {
"subject1" : ["sectionA", "sectionB", "sectionC"],
"subject2" : ["sectionA", "sectionD", "sectionE"],
"subject3" : ["sectionC", "sectionF", "sectionG"],
 }
 
fun adding(inputarray,matchingkey)= flatten(inputarray mapObject ((value, key) -> 
 (("myArray"): (myArray ++ [key])) if ((value) contains matchingkey) 
 ) pluck $)
 
---
 
adding(subjects,"sectionC")

输出为：

[
  "subject1", 
  "subject3"
]

如果使用 Dataweave 存在元素，则将键添加到数组

Add Key to an Array if Element Exist using Dataweave

dataweave

mulesoft