Merge 647107e into 65ffe26

src/main/scala/sangria/schema/Schema.scala

@@ -11,6 +11,7 @@ import sangria.{ast, introspection}
 import sangria.validation._
 import sangria.introspection._
 import sangria.renderer.{SchemaFilter, SchemaRenderer}
+import sangria.schema.transformations.TransformSchema
 import sangria.streaming.SubscriptionStreamLike
 
 import scala.annotation.implicitNotFound
@@ -906,6 +907,10 @@ case class Schema[Ctx, Val](
     case ast.ListType(ofType, _) ⇒ getOutputType(ofType) map (ListType(_))
   }
 
+  def filterFields(filter: List[Field[Ctx, Any]] => List[Field[Ctx, Any]]): Schema[Ctx, Val] = {
+    TransformSchema.filterFields[Ctx, Val](this, filter)
+  }
+
   lazy val directImplementations: Map[String, Vector[ObjectLikeType[_, _]]] = {
     typeList
       .collect{case objectLike: ObjectLikeType[_, _] ⇒ objectLike}

src/main/scala/sangria/schema/transformations/FieldFilteredAstSchemaBuilder.scala

@@ -0,0 +1,32 @@
+package sangria.schema.transformations
+
+import sangria.ast
+import sangria.ast.InterfaceTypeExtensionDefinition
+import sangria.schema.{AstSchemaMaterializer, DefaultAstSchemaBuilder, Field, InterfaceType, MatOrigin, ObjectType}
+
+
+class FieldFilteredAstSchemaBuilder[Ctx](filter: List[Field[Ctx, Any]] => List[Field[Ctx, Any]]) extends DefaultAstSchemaBuilder[Ctx] {
+
+  override def extendObjectType(
+                        origin: MatOrigin,
+                        existing: ObjectType[Ctx, _],
+                        extensions: List[ast.ObjectTypeExtensionDefinition],
+                        fields: () ⇒ List[Field[Ctx, Any]],
+                        interfaces: List[InterfaceType[Ctx, Any]],
+                        mat: AstSchemaMaterializer[Ctx]): ObjectType[Ctx, Any] = {
+    super.extendObjectType(origin, existing, extensions, applyFilter(fields), interfaces, mat)
+  }
+
+  override def extendInterfaceType(origin: MatOrigin,
+                                   existing: InterfaceType[Ctx, _],
+                                   extensions: List[InterfaceTypeExtensionDefinition],
+                                   fields: () => List[Field[Ctx, Any]],
+                                   mat: AstSchemaMaterializer[Ctx]): InterfaceType[Ctx, Any] = {
+    super.extendInterfaceType(origin, existing, extensions, applyFilter(fields), mat)
+  }
+
+  def applyFilter(fieldsFn: () => List[Field[Ctx, Any]]): () => List[Field[Ctx, Any]] = {
+    () => filter(fieldsFn())
+  }
+}
+

src/main/scala/sangria/schema/transformations/TransformSchema.scala

@@ -0,0 +1,21 @@
+package sangria.schema.transformations
+
+import sangria.ast.{Document, ObjectTypeExtensionDefinition}
+import sangria.schema.{AstSchemaMaterializer, Field, Schema}
+
+object TransformSchema {
+
+  def filterFields[Ctx, Val](schema: Schema[Ctx, Val], filter: List[Field[Ctx, Any]] => List[Field[Ctx, Any]]): Schema[Ctx, Val] = {
+    AstSchemaMaterializer.extendSchema(
+      schema,
+      emptyExtensionDocument(schema.query.name),
+      new FieldFilteredAstSchemaBuilder[Ctx](filter)
+    )
+  }
+
+  private def emptyExtensionDocument(queryName: String): Document = {
+    Document(Vector(
+      ObjectTypeExtensionDefinition(queryName, Vector.empty, Vector.empty)
+    ))
+  }
+}