I need to apply a JOLT transform to some JSON.

Example input JSON is...

{
  "allergen" : [ "Peanuts", "Egg", "Milk" ],
  "diagnosed_by_doc" : "Yes",
  "diagnosis_age" : "3-5 years old",
  "doc_type" : [ "Allergist", "Dermatologist", "Other Healthcare Provider" ],
  "tests" : [ "Skin prick test", "Blood tests", "Oral food challenge" ],
  "outgrown" : "No"
}

The expected output would be:

{
  "allergen" : "Peanuts",
  "diagnosed_by_doc" : "Yes",
  "diagnosis_age" : "3-5 years old",
  "diagnosed_by_allergist": true,
  "diagnosed_by_dermatologist": true,
  "diagnosed_by_other_healthcare_provider": true,
  "skin_prick_test": true,
  "blood_test": true,
  "oral_food_challenge": true,
  "outgrown" : "No"
},
{
  "allergen" : "Egg",
  "diagnosed_by_doc" : "Yes",
  "diagnosis_age" : "3-5 years old",
  "diagnosed_by_allergist": true,
  "diagnosed_by_dermatologist": true,
  "diagnosed_by_other_healthcare_provider": true,
  "skin_prick_test": true,
  "blood_test": true,
  "oral_food_challenge": true,
  "outgrown" : "No"
},
{
  "allergen" : "Milk",
  "diagnosed_by_doc" : "Yes",
  "diagnosis_age" : "3-5 years old",
  "diagnosed_by_allergist": true,
  "diagnosed_by_dermatologist": true,
  "diagnosed_by_other_healthcare_provider": true,
  "skin_prick_test": true,
  "blood_test": true,
  "oral_food_challenge": true,
  "outgrown" : "No"
},

How can I apply two transforms to this JSON?

1. Each item in the allergen list becomes its own JSON object.
2. Each item in the doc_type and tests list get "converted to boolean". That is to say, if the doc_type list contains Allergist then the resulting JSON object would contain diagnosed_by_allergist: true. If the phrase "Allergist" is not present then it's not necessary for the resulting object to contain diagnosed_by_allergist: false. (This is more of a conditional operation than a data conversion).

In the original JSON, all the subsequent data applies to each allergen. So, for example, diagnosis_age applies the same to the resulting Peanuts, Egg, and Milk JSON objects.

What JOLT transform spec can I use to "flatten" the allergen list into individual objects and conditionally present fields?

CodePudding user response：

You can walk through the allergen list by using "@" wildcard individually to represent each attributes while using conditional logic through use of object representation by curly braces for the lists doc_type and tests within the first shift transformation spec, and the second spec is used to remove object key names such as

[
  {
    "operation": "shift",
    "spec": {
      "allergen": {
        "*": {
          "@": "&1.&2",
          "@(2,diagnosed_by_doc)": "&.diagnosed_by_doc",
          "@(2,diagnosis_age)": "&.diagnosis_age",
          "@(2,doc_type)": {
            "*": {
              "Allergist": {
                "#true": "&3.diagnosed_by_allergist"
              },
              "Dermatologist": {
                "#true": "&3.diagnosed_by_dermatologist"
              },
              "Other Healthcare Provider": {
                "#true": "&3.diagnosed_by_other_healthcare_provider"
              }
            }
          },
          "@(2,tests)": {
            "*": {
              "Skin prick test": {
                "#true": "&3.diagnosed_by_skin_prick_test"
              },
              "Blood tests": {
                "#true": "&3.diagnosed_by_blood_test"
              },
              "Oral food challenge": {
                "#true": "&3.diagnosed_by_oral_food_challenge"
              }
            }
          },
          "@(2,outgrown)": "&.outgrown"
        }
      }
    }
  },
  {
    "operation": "shift",
    "spec": {
      "*": ""
    }
  }
]