graphql.introspection

Class IntrospectionWithDirectivesSupport

java.lang.Object

graphql.introspection.IntrospectionWithDirectivesSupport

@PublicApi
public class IntrospectionWithDirectivesSupport
extends java.lang.Object

The graphql specification does not allow you to retrieve the directives and their argument values that are present on types, enums, fields and input fields, so this class allows you to change the schema and enhance the Introspection types to contain this information. This allows you to get a directive say like `@example(argName : "someValue")` that is on a field or type at introspection time and act on it. This class takes a predicate that allows you to filter the directives you want to expose to the world. An `appliedDirectives` field is added and this contains extra fields that hold the directives and their applied values. For example the `__Field` type becomes as follows:

      type __Field {
          name: String!
          // other fields ...
          appliedDirectives: [_AppliedDirective!]!   // NEW FIELD
      }

     type _AppliedDirective {                        // NEW INTROSPECTION TYPE
          name: String!
          args: [_DirectiveArgument!]!
      }

      type _DirectiveArgument {                      // NEW INTROSPECTION TYPE
          name: String!
          value: String!
      }
  

Nested Class Summary

Nested Classes

Modifier and Type	Class and Description
static interface	IntrospectionWithDirectivesSupport.DirectivePredicate A callback which allows you to decide what directives may be included in introspection extensions
static interface	IntrospectionWithDirectivesSupport.DirectivePredicateEnvironment The parameter environment on a call to IntrospectionWithDirectivesSupport.DirectivePredicate

Constructor Summary

Constructors

Constructor and Description
IntrospectionWithDirectivesSupport() This version lists all directives on a schema element
IntrospectionWithDirectivesSupport(IntrospectionWithDirectivesSupport.DirectivePredicate directivePredicate) This version allows you to filter what directives are listed via the provided predicate
IntrospectionWithDirectivesSupport(IntrospectionWithDirectivesSupport.DirectivePredicate directivePredicate, java.lang.String typePrefix) This version allows you to filter what directives are listed via the provided predicate Some graphql systems (graphql-js in 2021) cannot cope with extra types starting with `__` so we use a `_` as a prefx by default.

Method Summary

Modifier and Type	Method and Description
GraphQLSchema	apply(GraphQLSchema schema) This will transform the schema to have the new extension shapes

Methods inherited from class java.lang.Object

clone, equals, finalize, getClass, hashCode, notify, notifyAll, toString, wait, wait, wait

Constructor Detail

IntrospectionWithDirectivesSupport

public IntrospectionWithDirectivesSupport()

This version lists all directives on a schema element

IntrospectionWithDirectivesSupport

public IntrospectionWithDirectivesSupport(IntrospectionWithDirectivesSupport.DirectivePredicate directivePredicate)

This version allows you to filter what directives are listed via the provided predicate

Parameters:

directivePredicate - the filtering predicate to decide what directives are shown

IntrospectionWithDirectivesSupport

public IntrospectionWithDirectivesSupport(IntrospectionWithDirectivesSupport.DirectivePredicate directivePredicate,
                                          java.lang.String typePrefix)

This version allows you to filter what directives are listed via the provided predicate Some graphql systems (graphql-js in 2021) cannot cope with extra types starting with `__` so we use a `_` as a prefx by default. You can supply your own prefix via this constructor. See: https://github.com/graphql-java/graphql-java/pull/2221 for more details

Parameters:

directivePredicate - the filtering predicate to decide what directives are shown

typePrefix - the prefix to put on the new `AppliedDirectives` type

Method Detail

apply

public GraphQLSchema apply(GraphQLSchema schema)

This will transform the schema to have the new extension shapes

Parameters:

schema - the original schema

Returns:

the transformed schema with new extension types and fields in it for Introspection