json_selector

json_selector extracts an element from a JSON document, much like json_path, but using a recursive match rather than a full static path. This is especially useful when the JSON path may change slightly between requests. Use this transform to find a JSON path dynamically and a subsequent transform to change a token in an adjacent field.

The input token must be a JSON document.

Configuration

The config supports the following fields:

Key	Description
match (required)	A full or partial JSON path, optionally containing a value to match. If the path contains an equal sign with a value the path will only match if the value matches the JSON document. If no value is given the path will match if it exists.
recursive	If true, allows the match path to be partial instead of requiring a full path from the document root.
levelsUp	The number of levels to move up from the matched JSON path.

info

Only one JSON path may be matched. Make a feature request if you need more.

Example - Key Existence

Configuration

"type": "json_selector",
"config": {
    "match": "nick_name",
    "recursive": "true",
    "levelsUp": "1"
}

• match means look for the existence of a value at path nick_name
• recursive means look anywhere in the document
• levelsUp means extract the token from 1 level above the match

Input Token

{
    "people": {
        "2ba4Cd4": {
            "first_name": "john",
            "last_name": "smith",
            "nick_name": "johnny"
        }
        "a59dFc1": {
            "id": 7592,
            "first_name": "steve",
            "last_name": "mould"
        }
    }
}

Transformed Token

{
    "id": 7592,
    "first_name": "steve",
    "last_name": "mould"
}

Example - Key Value Match

Configuration

"type": "json_selector",
"config": {
    "match": "address.zip=30303",
    "recursive": "true",
    "levelsUp": "2"
}

• match means look for the path address.zip where the value is 30303
• recursive means look anywhere in the document
• levelsUp means extract the token from 2 levels above the match

Input Token

{
    "people": {
        "2ba4Cd4": {
            "first_name": "john",
            "last_name": "smith",
            "address": {
                "street": "123 Placid St.",
                "state": "CA",
                "zip": 90210
            }
        }
        "a59dFc1": {
            "id": 7592,
            "first_name": "steve",
            "last_name": "mould",
            "address": {
                "street": "701 Loop Circle",
                "state": "GA",
                "zip": 30303
            }
        }
    }
}

Transformed Token

{
    "id": 7592,
    "first_name": "steve",
    "last_name": "mould",
    "address": {
        "street": "701 Loop Circle",
        "state": "GA",
        "zip": 30303
    }
}