Package graphql.schema

Class SchemaTransformer

java.lang.Object
graphql.schema.SchemaTransformer
@PublicApi public class SchemaTransformer extends Object
Transforms a GraphQLSchema object by calling bac on a provided visitor.

To change a GraphQLSchemaElement node in the schema you need to return GraphQLTypeVisitor.changeNode(TraverserContext, GraphQLSchemaElement) which instructs the schema transformer to change that element upon leaving that visitor method. 

 
  public TraversalControl visitGraphQLObjectType(GraphQLObjectType objectType, TraverserContext<GraphQLSchemaElement> context) {
      GraphQLObjectType newObjectType = mkSomeNewNode(objectType);
      return changeNode(context, newObjectType);
  }

To delete an element use GraphQLTypeVisitor.deleteNode(TraverserContext) 

 
  public TraversalControl visitGraphQLObjectType(GraphQLObjectType objectType, TraverserContext<GraphQLSchemaElement> context) {
      return deleteNode(context, objectType);
  }

To insert elements use either GraphQLTypeVisitor.insertAfter(TraverserContext, GraphQLSchemaElement) or GraphQLTypeVisitor.insertBefore(TraverserContext, GraphQLSchemaElement) which will insert the new node before or after the current node being visited 

 
  public TraversalControl visitGraphQLObjectType(GraphQLObjectType objectType, TraverserContext<GraphQLSchemaElement> context) {
      GraphQLObjectType newObjectType = mkSomeNewNode();
      return insertAfter(context, newObjectType);
  }

  • Constructor Details

    • SchemaTransformer

      public SchemaTransformer()

  • Method Details

    • transformSchema

      public static GraphQLSchema transformSchema(GraphQLSchema schema, GraphQLTypeVisitor visitor)
      Transforms a GraphQLSchema and returns a new GraphQLSchema object.
      Parameters:
      schema - the schema to transform
      visitor - the visitor call back
      Returns:
      a new GraphQLSchema instance.

    • transformSchema

      public static GraphQLSchema transformSchema(GraphQLSchema schema, GraphQLTypeVisitor visitor, Consumer<GraphQLSchema.Builder> postTransformation)
      Transforms a GraphQLSchema and returns a new GraphQLSchema object.
      Parameters:
      schema - the schema to transform
      visitor - the visitor call back
      postTransformation - a callback that can be as a final step to the schema
      Returns:
      a new GraphQLSchema instance.

    • transformSchemaWithDeletes

      public static GraphQLSchema transformSchemaWithDeletes(GraphQLSchema schema, GraphQLTypeVisitor visitor)
      Transforms a GraphQLSchema with support for delete operations.

      When a visitor uses GraphQLTypeVisitor.deleteNode(TraverserContext) to delete schema elements, the traversal does not continue to the children of deleted nodes. This can cause issues when types are only reachable through fields that get deleted, as those types won't be visited and transformed.

      This method ensures all types in the schema are visited by temporarily adding them as extra root types during transformation. This guarantees that even types only reachable through deleted fields will be properly visited and transformed.

      Use this method instead of transformSchema(GraphQLSchema, GraphQLTypeVisitor) when your visitor deletes fields or types that may reference other types via circular dependencies.

      Parameters:
      schema - the schema to transform
      visitor - the visitor call back
      Returns:
      a new GraphQLSchema instance.
      See Also:

    • transformSchemaWithDeletes

      public static GraphQLSchema transformSchemaWithDeletes(GraphQLSchema schema, GraphQLTypeVisitor visitor, Consumer<GraphQLSchema.Builder> postTransformation)
      Transforms a GraphQLSchema with support for delete operations.

      When a visitor uses GraphQLTypeVisitor.deleteNode(TraverserContext) to delete schema elements, the traversal does not continue to the children of deleted nodes. This can cause issues when types are only reachable through fields that get deleted, as those types won't be visited and transformed.

      This method ensures all types in the schema are visited by temporarily adding them as extra root types during transformation. This guarantees that even types only reachable through deleted fields will be properly visited and transformed.

      Use this method instead of transformSchema(GraphQLSchema, GraphQLTypeVisitor, Consumer) when your visitor deletes fields or types that may reference other types via circular dependencies.

      Parameters:
      schema - the schema to transform
      visitor - the visitor call back
      postTransformation - a callback that can be used as a final step to the schema (can be null)
      Returns:
      a new GraphQLSchema instance.
      See Also:

    • transformSchema

      public static <T extends GraphQLSchemaElement> T transformSchema(T schemaElement, GraphQLTypeVisitor visitor)
      Transforms a GraphQLSchemaElement and returns a new element.
      Type Parameters:
      T - for two
      Parameters:
      schemaElement - the schema element to transform
      visitor - the visitor call back
      Returns:
      a new GraphQLSchemaElement instance.

    • transform

      public GraphQLSchema transform(GraphQLSchema schema, GraphQLTypeVisitor visitor)

    • transform

      public GraphQLSchema transform(GraphQLSchema schema, GraphQLTypeVisitor visitor, Consumer<GraphQLSchema.Builder> postTransformation)

    • transform

      public <T extends GraphQLSchemaElement> T transform(T schemaElement, GraphQLTypeVisitor visitor)