JSONExtractor

The source JSON document. The JSON document can come from any string expression, including attribute values and workspace parameters.

This parameter identifies the feature attribute into which the result of the JSON query should be put.  

This parameter is the JSON query whose value will be stored in the target attribute.

A JSON query is primarily used to refer to values in some JSON text. They can also be used to extract some metadata about the JSON text, such as the type (object, array, string, etc.) of JSON value or the number of elements in an array. The outermost JSON value, which must be an object or an array, is always referred to by the term "json".  Contained values can be referred to using JavaScript-like square bracket index operators.  

A value in an array can be referred to using its zero-based position in the array (for example, json[2] for the third element).

A value in an object can be referred to using its object key name

json["key"]

All of the values in an array or object can be collectively referred to using a wildcard index

json[*]

The query used by this transformer can have multiple expressions, which are separated by a '+' operator, as well as string literal values. This allows more complex attribute values to be easily created from the JSON text. For example:

json["name"]["first"] + " " + json["name"]["last"]

The JSONFragmenter transformer contains more information on JSON queries.

If the JSON query cannot be fully evaluated, a message will be logged, and the feature will be output without setting the target attribute.