dependentRequired : Object<String, Array<String>>

dependentRequired

Object<String, Array<String>>

Validation succeeds if, for each name that appears in both the instance and as a name within this keyword’s value, every item in the corresponding array is also the name of a property in the instance.

Value	This keyword must be set to an object where each value is an array of unique strings
Kind	Assertion
Applies To	Object
Base Dialect	2020-12
Changed In	None
Introduced In	2019-09
Vocabulary	Validation
Specification	https://json-schema.org/draft/2020-12/json-schema-validation.html#section-6.5.4
Metaschema	https://json-schema.org/draft/2020-12/meta/validation
Official Tests	draft2020-12/dependentRequired.json
Default	`{}`
Annotation	None
Affected By	None
Affects	None
Also See	required (Vocabulary: Validation) dependentSchemas (Vocabulary: Applicator) if (Vocabulary: Applicator) then (Vocabulary: Applicator) else (Vocabulary: Applicator)

The dependentRequired keyword restricts object instances to define certain properties if other properties are also defined.

Common Pitfall

Note that multiple potentially interrelated dependencies can be declared at once, in which case every dependency must be transitively fulfilled for the object instance to be valid. For example, if a schema marks the property B as required if the property A is present and also marks the property C as required if the property B is present, defining the property A transitively requires both the B and C properties to be present in the object instance.

Digging Deeper

The dependentSchemas keyword is a generalisation of this keyword to describe object dependencies beyond property requirement.

Remember that JSON Schema is a constraint-driven language. Therefore, non-object instances successfully validate against this keyword. If needed, make use of the type keyword to constraint the accepted type accordingly.

Examples

A schema that constrains object instances with a single property dependency Schema

{
  "$schema": "https://json-schema.org/draft/2020-12/schema",
  "dependentRequired": {
    "foo": [ "bar", "baz" ]
  }
}

Valid An object value that defines the dependency and all of the dependents is valid Instance

{ "foo": 1, "bar": 2, "baz": 3 }

Invalid An object value that defines the dependency and some of the dependents is invalid Instance

{ "foo": 1, "bar": 2 }

Invalid An object value that defines the dependency and none of the dependents is invalid Instance

{ "foo": 1 }

Valid An object value that does not define the dependency is valid Instance

{ "qux": 4 }

Valid An empty object value is valid as no dependencies apply Instance

{}

Valid A non-object value is valid Instance

"Hello World"

A schema that constrains object instances with a transitive property dependencies Schema

{
  "$schema": "https://json-schema.org/draft/2020-12/schema",
  "dependentRequired": {
    "foo": [ "bar" ],
    "bar": [ "baz" ]
  }
}

Valid An object value that satisfies the transitive dependency is valid Instance

{ "foo": 1, "bar": 2, "baz": 3 }

Invalid An object value that only satisfies the first part of the transitive dependency is invalid Instance

{ "foo": 1, "bar": 2 }

Valid An object value that only satisfies the second part of the transitive dependency is valid Instance

{ "bar": 2, "baz": 3 }