Miscellaneous Transforms

Miscellaneous transforms provide utilities for iteration, JSONPath queries, type checking, and more.

forEach

Iterates over an array and applies transforms to each item. The current item is available as item, and the index as _idx.

[
  { "updatedItems": "input.items | forEach([{ name: 'upper(item.name)' }, { priceWithTax: 'item.price * 1.1' }])" }
]

Parameters:

• val — The input array
• transforms — Array of transforms to apply to each item
• context (optional) — An object made available to expressions
• filterOn (optional) — A field name to filter results; only items where this field is truthy are included

With filter:

[
  {
    "adults": "input.people | forEach([{ name: 'upper(item.name)', isAdult: 'item.age >= 18' }], {}, 'isAdult')"
  }
]

jsonpath

Queries an object or array using JSONPath expressions.

input.data | jsonpath('$.store.book[*].title')

You can also query multiple fields at once:

input.data | jsonpath([{ titles: '$.store.book[*].title' }, { prices: '$.store.book[*].price' }])

type

Returns the type of a value as a string.

"hello" | type      // "String"
42 | type           // "Number"
true | type         // "Boolean"
[1,2,3] | type      // "Array"
{...} | type        // "Object"

parseJson

Parses a JSON string into an object or array.

'{"name":"Alice"}' | parseJson    // { name: "Alice" }

UUID

Generates a random UUID (v4).

null | UUID    // "550e8400-e29b-41d4-a716-446655440000"

evaluateExpression

Interpolates values into a template string expression. Variables are referenced from the context.

"'Hello, ' + input.name" | evaluateExpression

Where evaluateExpression evaluates the string as a MozJexl expression and returns the result. This is useful when you have expression strings stored in data.