Examples

Example 1: If the template is set as

{
    "literal": "a literal",
    "field": "@@$.id",
    "var": "%my_var%",
    "array_of_objects": [ "@@$.phones" ],
    "array_of_primitives": [ "@@$.numbers" ],
    "object": { "*":"@@$.address" }
}

and the given JSON expression passed to the input of the node:

{
   "id": 123,
   "name": "fred",
   "address": {
      "street": "101 Main St",
      "city": "London"
   },
   "numbers": [ 1, 2, 3 ],
   "phones": [
     {
     "type": "mobile",
     "number": "111-222-3333"
     },
     {
     "type": "home",
     "number": "444-444-5555"
     }
   ]
}

the node will generate this as the output:

    "literal": "a literal",
    "field": 123,
    "var": "Value of my_var",
    "array_of_objects": [
        {
            "type": "mobile",
            "number": "111-222-3333"
        },
        {
            "type": "home",
            "number": "444-444-5555"
        }
    ],
    "array_of_primitives": [
        1,
        2,
        3
    ],
    "object": {
        "street": "101 Main St",
        "city": "London"
    }
}

To create this output, the node traversed the template to build the output. It produced these fields:

• literal – The value was set to a literal value.
• field – The value of the field is obtained from the path expression $.id , which has the value 123 in the input document.
• var – The value is specified as the name of a flow variable named city, the value of which is set in the output.
• array_of_objects – The value of the field is obtained from the path expression $.phones. Because the template specified this path within an array, the path expression is expected to return an array.
• array_of_primitives – An array of primitive values is returned by specifying the path expression $.numbers within array syntax.
• object – An object is replaced by the fetched value by specifying the special key value "*" in the object. If this is found, the object in the template is replaced by the object returned by the $.address path.

The JSON sent to the node is:

{
    "services": [
        {
            "_id": "5f9ae9765bffe304360d10d6",
            "name": "Upload"
        },
        {
            "_id": "5f9ae9765bffe304565656b3",
            "name": "Download"
        }
    ]
}

The template contains a query expression (as indicated by the '?')

{
    "id": "@@$.services[?(@.name == \"Upload\")]._id"
}

This query finds the object in the "services" array which has its "name" field set to "Upload". It then returns the "_id" field from that object to produce this output:

{"id":"5f9ae9765bffe304360d10d6"}