Jolt conditional match field in array and display output

Question

I can't figure out how to do condition matches based on fields in the array in Jolt.

eg I have one such the below input I want to print the value of the restaurant which matches the locale

{
  "locale": "en_US",
  "restaurants": [
    {
      "restLocale": "en_US",
      "value": "english"
    },
    {
      "restLocale": "pr_PT",
      "value": "portugese"
    }
  ]
}

here is the output I want

Output:

{
  "value": "english"
}

I tried

matching with the first value but didn't work

Answer 1

You might set object keys to the "restLocale" attibutes' values, and match object keys with the value of the "locale" attribute such as

[
  { // set object keys to the restLocale attibutes' values 
    "operation": "shift",
    "spec": {
      "*": "&",
      "restaurants": {
        "*": {
          "*": "@1,restLocale.&"
        }
      }
    }
  },
  { // match object keys with the value of the locale attribute
    "operation": "shift",
    "spec": {
      "locale": {
        "*": {
          "@2,&": ""
        }
      }
    }
  },
  { // pick the value attribute only
    "operation": "shift",
    "spec": {
      "v*": "&"
    }
  }
]

the demo on the site http://jolt-demo.appspot.com/ is :