Substitutable Elements in JSON

• Instance example
• Schema

Instance example

A substitutable element can be used in place of the element defined as the head of its substitution group. This should appear in JSON similar to the way it appear in XML.

The example below shows the substitution of element nc:Date for element nc:DateRepresentation, which does not appear in the instance.

JSON example:

{
  "nc:Person" : {
    "nc:PersonBirthDate" : {
      "nc:Date"  : "1950-06-30"
    }
  }
}

Schema

Substitutions are not declared in JSON Schema.

A JSON Schema with the additionalProperties keyword set to true will allow for the addition of properties not defined in the schema. This is how substitutions can be permitted.

{
   "$schema": "http://json-schema.org/draft-04/schema#",
  "additionalProperties": true,
  "properties": {
    ...
  },
  "definitions": {
    ...
  }
}