如何 return Cloud Workflows 实例中的特定项目？

Question

我无法从 JSON 响应实例中获取数据。我正在使用 Cloud Workflows 获取有关我的虚拟机当前状态的信息。我正在使用 return 这么长 JSON 的 .get 函数，它是高度结构化的，例如launchResult 被 return 编辑为：

{
   "name":"some name",
   "status":"some status",
   "items":[
      {
         "key":"key1",
         "property1":"xxxx",
         "property2":"ccvdvdvd"
      },
      {
         "key":"key2",
         "property1":"xxxrerex",
         "property2":"ccvdveedvd"
      }
   ],
   "kind":"some kind"
}

我可以 return 例如“某些状态”，通过 ${launchResult.status}，甚至 key1，如 {launchResult.items[0].key}.

问题是：我怎样才能像launchResult.items["key" == "key1"].property1那样做某事？我的意思是我想根据键 return 来自项目的 property1。

Answer 1

要根据地图列表中另一个属性的值从地图列表中的一个项目中获取属性，我建议如下：

遍历列表的元素，直到找到具有您要查找的属性的元素。

这是我为展示 how to use iterations along with conditionals in Cloud Workflows 实现此目的而制作的示例代码：

main:
  params: []
  steps:
  - define:
      assign:
        # Incremental variable set to zero
        - i: 0
        # Value to look up in list
        - cond: "key2"
        # A variable that contains a sample data as the JSON
        # showed in the question
        - test: 
            name: some name
            status: some status
            items:
            - key: "key1"
              property1: xxxx
              property2: ccvdvdvd
            - key: "key2"
              property1: xxxrerex
              property2: ccvdveedvd
            - key: "key3"
              property1: xxex
              property2: ccvdvffdvd
            kind: some kind
  - lookupInItems:
      switch:
        # Here we're looking for the element over the list test.items until the condition is met 
        # or the list ends
        - condition: ${i < len(test.items) and test.items[i].key!=cond}
        # If the condition is not met, keep iterating using iterate step
          next: iterate
      # If the element is found or the list ends, jumps to the read step
      next: read
  - iterate:
      assign: 
      # Increment the increment variable i
        - i: ${i+1}
      next: lookupInItems
  # If the iteration ends, check for the value
  - read:
      switch:
        # Check if the value was found
        # if this check is not made, an out of index error will occur when trying to show
        # the property of a value does not exists
        - condition: ${i < len(test.items)}
          next: found
      next: notfound
  # Print a message on the sys.log either the value was found or not
  - notfound:
      call: sys.log
      args:
        text: ${"Value " + cond + " not found in list"}
        severity: "WARNING"
      next: end
  - found:
      call: sys.log
      args:
        text: ${test.items[i].property1}
        severity: "INFO"
      next: end

另请参阅：

http://glaforge.appspot.com/article/day-6-with-cloud-workflows-arrays-and-dictionaries

如何 return Cloud Workflows 实例中的特定项目？

How to return specific item from Cloud Workflows instance?

json

yaml

conditional-statements

google-workflows