json - 如何在jq walk中引用父对象？

Question

我想根据步行添加一些 json。我拥有的 json 的一个简单示例如下:

{
  "valueSource": "memory",
  "dataType": "Boolean",
  "alarms": [
    {
      "setpointA": 1.0,
      "name": "Alarm",
      "priority": "Diagnostic",
      "ackMode": "Auto",
    }
  ],
  "name": "Test Alarm",
  "value": false,
  "tagType": "AtomicTag"
}

我想向“alarms”键数组中的每个对象添加以下键:

{
   "bindType": "Tag",
   "value": "[.]<parent.name>.Name"
}

哪里<parent.name>在此示例中是“测试警报”，它是警报数组项的父项的“名称”键。

到目前为止，我已经得到了这个 jq 过滤器，它添加了对象，但是 value键值错误(它获取的是警报数组项的名称而不是其父项的名称):

walk( if type == "object" and .setpointA then .label = {"bindType":"Tag", "value": "[.]\(.name).Name"} else . end)

基本上我想要这个:

{
  "valueSource": "memory",
  "dataType": "Boolean",
  "alarms": [
    {
      "setpointA": 1.0,
      "name": "Alarm",
      "priority": "Diagnostic",
      "ackMode": "Auto",
      "label": {
        "bindType": "Tag",
        "value": "[.]Test Alarm.Name"
      }
    }
  ],
  "name": "Test Alarm",
  "value": false,
  "tagType": "AtomicTag"
}

下面是我的 jqplay。它在 JSON 部分中有最终结果，其中结果应该与此匹配，但目前不匹配。 https://jqplay.org/s/-qHFIWolrD

后续问题:我该如何添加这个displayPath key 也可以吗？

Answer 1

您不能引用父级，您必须事先将引用保存在变量中，并在有权访问该变量的情况下下降。

.tags[] |= (
  .name as $name
  | # rest of your code using $name
    walk(
      if type == "object" and .setpointA
      then .label = {"bindType":"Tag", "value": "[.]\($name).Name"}
      else . end
    )
)

Demo

当您碰巧知道这些对象位于 .alarms 数组中时，您也可以迭代这些项目，选择 仅那些匹配条件的项目，然后为他们的 .label 分配您想要的任何内容(包括 $name)

.tags[] |= (
  .name as $name
  | (.alarms[] | select(has("setpointA"))).label = {
      bindType: "Tag", value: "[.]\($name).Name"
    }
)

Demo

---

编辑回复OP的后续问题

I actually don't care about the setpointA key, I just want to add the label key (as well as another displayPath key) to each item in all alarms arrays.

.tags[] |= (.name as $name | .alarms[] += (
  {bindType: "Tag", value: "[.]\($name)."} | {
          label: (.value += "Name"),
    displayPath: (.value += "Documentation")
  }
))

Demo