json yaml conditional-statements google-workflows

How to return specific item from Cloud Workflows instance?

I have the problem to get the data out of the JSON response instance. I am using Cloud Workflows to get the information about the current state of my VMs. I am using the the .get functions that returns this long JSON that is high structured, e.g. launchResult is returned as:

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

I can return for example "some status", by ${launchResult.status}, even key1, as {launchResult.items[0].key}.

The question is: How can I do sth like launchResult.items["key" == "key1"].property1? I mean I want to return the property1 from the item based on the key.

Solution

To get the property from an item in an list of maps based on the value of another property of that map, I would suggest the following:

To iterate over the elements of the list until you get the one with the property you're looking for.

This is a sample code I made to show how to use iterations along with conditionals in Cloud Workflows to achieve this:

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