diff --git a/spring-graphql-docs/src/docs/asciidoc/index.adoc b/spring-graphql-docs/src/docs/asciidoc/index.adoc
index 1523a079..e3308692 100644
--- a/spring-graphql-docs/src/docs/asciidoc/index.adoc
+++ b/spring-graphql-docs/src/docs/asciidoc/index.adoc
@@ -770,6 +770,53 @@ given a list of source/parent books objects.
====
+[[controllers-schema-mapping-argument-projections]]
+==== Argument Projections
+
+When accessing individual arguments from a GraphQL request, interface projections can
+be useful to access arguments through a well-defined interface.
+
+Spring Data's `@ProjectedPayload` can be used to annotate projection interfaces that
+can be declared as handler method arguments. Payload projection can work on top-level
+arguments (`DataFetchingEnvironment.getArguments()`). Alternatively, projections can
+be applied on individual arguments by using `@Argument` with a projected payload interface.
+
+Argument projections are provided by https://docs.spring.io/spring-data/commons/docs/current/reference/html/#projections.interfaces[Spring Data's Interface projections]
+when Spring Data is on the class path.
+
+[source,java,indent=0,subs="verbatim,quotes"]
+----
+ @Controller
+ public class BookController {
+
+ @QueryMapping
+ public Book bookById(BookIdProjection bookId) {
+ // ...
+ }
+
+ @MutationMapping
+ public Book addBook(@Argument BookInputProjection bookInput) {
+ // ...
+ }
+ }
+
+ @ProjectedPayload
+ interface BookIdProjection {
+
+ Long getId();
+ }
+
+ @ProjectedPayload
+ interface BookInputProjection {
+
+ String getName();
+
+ @Value("#{target.author + ' ' + target.name})
+ String getAuthorAndName();
+ }
+----
+
+
[[controllers-schema-mapping-data-loader]]
==== `DataLoader`
diff --git a/spring-graphql/src/main/java/org/springframework/graphql/data/method/annotation/support/AnnotatedControllerConfigurer.java b/spring-graphql/src/main/java/org/springframework/graphql/data/method/annotation/support/AnnotatedControllerConfigurer.java
index f056895f..53eb11c6 100644
--- a/spring-graphql/src/main/java/org/springframework/graphql/data/method/annotation/support/AnnotatedControllerConfigurer.java
+++ b/spring-graphql/src/main/java/org/springframework/graphql/data/method/annotation/support/AnnotatedControllerConfigurer.java
@@ -84,6 +84,9 @@ public class AnnotatedControllerConfigurer
*/
private static final String SCOPED_TARGET_NAME_PREFIX = "scopedTarget.";
+ private final static boolean springDataPresent = ClassUtils.isPresent(
+ "org.springframework.data.projection.SpelAwareProxyProjectionFactory",
+ AnnotatedControllerConfigurer.class.getClassLoader());
private final static boolean springSecurityPresent = ClassUtils.isPresent(
"org.springframework.security.core.context.SecurityContext",
AnnotatedControllerConfigurer.class.getClassLoader());
@@ -117,6 +120,9 @@ public class AnnotatedControllerConfigurer
@Override
public void afterPropertiesSet() {
this.argumentResolvers = new HandlerMethodArgumentResolverComposite();
+ if (springDataPresent) {
+ this.argumentResolvers.addResolver(new ProjectedPayloadMethodArgumentResolver(this.conversionService));
+ }
this.argumentResolvers.addResolver(new ArgumentMapMethodArgumentResolver());
this.argumentResolvers.addResolver(new ArgumentMethodArgumentResolver(this.conversionService));
this.argumentResolvers.addResolver(new DataFetchingEnvironmentMethodArgumentResolver());
diff --git a/spring-graphql/src/main/java/org/springframework/graphql/data/method/annotation/support/ProjectedPayloadMethodArgumentResolver.java b/spring-graphql/src/main/java/org/springframework/graphql/data/method/annotation/support/ProjectedPayloadMethodArgumentResolver.java
new file mode 100644
index 00000000..0e5d8def
--- /dev/null
+++ b/spring-graphql/src/main/java/org/springframework/graphql/data/method/annotation/support/ProjectedPayloadMethodArgumentResolver.java
@@ -0,0 +1,110 @@
+/*
+ * Copyright 2002-2021 the original author or authors.
+ *
+ * Licensed under the Apache License, Version 2.0 (the "License");
+ * you may not use this file except in compliance with the License.
+ * You may obtain a copy of the License at
+ *
+ * http://www.apache.org/licenses/LICENSE-2.0
+ *
+ * Unless required by applicable law or agreed to in writing, software
+ * distributed under the License is distributed on an "AS IS" BASIS,
+ * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
+ * See the License for the specific language governing permissions and
+ * limitations under the License.
+ */
+package org.springframework.graphql.data.method.annotation.support;
+
+
+import graphql.schema.DataFetchingEnvironment;
+
+import org.springframework.beans.BeansException;
+import org.springframework.beans.factory.BeanClassLoaderAware;
+import org.springframework.beans.factory.BeanFactory;
+import org.springframework.beans.factory.BeanFactoryAware;
+import org.springframework.core.MethodParameter;
+import org.springframework.core.annotation.AnnotatedElementUtils;
+import org.springframework.core.convert.ConversionService;
+import org.springframework.data.projection.SpelAwareProxyProjectionFactory;
+import org.springframework.data.web.ProjectedPayload;
+import org.springframework.graphql.data.method.HandlerMethodArgumentResolver;
+import org.springframework.graphql.data.method.annotation.Argument;
+import org.springframework.lang.Nullable;
+
+/**
+ * Resolver to obtain a {@link ProjectedPayload @ProjectedPayload}
+ * for {@link DataFetchingEnvironment#getArguments()}.
+ *
+ * Projected payloads consist of the projection interface and accessor methods.
+ * Projections can be closed or open projections. Closed projections use interface
+ * getter methods to access underlying properties directly. Open projection methods
+ * make use of the {@code @Value} annotation to evaluate SpEL expressions against the
+ * underlying {@code target} object.
+ *
+ *
For example:
+ *
+ * @ProjectedPayload
+ * interface BookProjection {
+ * String getName();
+ * }
+ *
+ * @ProjectedPayload
+ * interface BookProjection {
+ * @Value("#{target.author + ' ' + target.name}")
+ * String getAuthorAndName();
+ * }
+ *
+ *
+ * @author Mark Paluch
+ * @since 1.0.0
+ */
+public class ProjectedPayloadMethodArgumentResolver implements HandlerMethodArgumentResolver,
+ BeanFactoryAware, BeanClassLoaderAware {
+
+ private final SpelAwareProxyProjectionFactory projectionFactory = new SpelAwareProxyProjectionFactory();
+
+ private final ArgumentMethodArgumentResolver argumentResolver;
+
+ public ProjectedPayloadMethodArgumentResolver(@Nullable ConversionService conversionService) {
+ this.argumentResolver = new ArgumentMethodArgumentResolver(conversionService){
+ @Override
+ protected Object convert(Object rawValue, Class targetType) {
+ return project(targetType, rawValue);
+ }
+ };
+ }
+
+ @Override
+ public boolean supportsParameter(MethodParameter parameter) {
+ Class type = parameter.getParameterType();
+
+ if (!type.isInterface()) {
+ return false;
+ }
+
+ return AnnotatedElementUtils.findMergedAnnotation(type, ProjectedPayload.class) != null;
+ }
+
+ @Override
+ public Object resolveArgument(MethodParameter parameter, DataFetchingEnvironment environment) throws Exception {
+ if(parameter.getParameterAnnotation(Argument.class) != null){
+ return argumentResolver.resolveArgument(parameter, environment);
+ }
+
+ return project(parameter.getParameterType(), environment.getArguments());
+ }
+
+ protected Object project(Class projectionType, Object source){
+ return this.projectionFactory.createProjection(projectionType, source);
+ }
+
+ @Override
+ public void setBeanFactory(BeanFactory beanFactory) throws BeansException {
+ this.projectionFactory.setBeanFactory(beanFactory);
+ }
+
+ @Override
+ public void setBeanClassLoader(ClassLoader classLoader) {
+ this.projectionFactory.setBeanClassLoader(classLoader);
+ }
+}
diff --git a/spring-graphql/src/test/java/org/springframework/graphql/data/method/annotation/support/SchemaMappingInvocationTests.java b/spring-graphql/src/test/java/org/springframework/graphql/data/method/annotation/support/SchemaMappingInvocationTests.java
index 74331899..fd3fb66f 100644
--- a/spring-graphql/src/test/java/org/springframework/graphql/data/method/annotation/support/SchemaMappingInvocationTests.java
+++ b/spring-graphql/src/test/java/org/springframework/graphql/data/method/annotation/support/SchemaMappingInvocationTests.java
@@ -29,6 +29,7 @@ import reactor.core.publisher.Mono;
import reactor.test.StepVerifier;
import org.springframework.context.annotation.AnnotationConfigApplicationContext;
+import org.springframework.data.web.ProjectedPayload;
import org.springframework.graphql.Author;
import org.springframework.graphql.Book;
import org.springframework.graphql.BookCriteria;
@@ -52,6 +53,7 @@ import static org.assertj.core.api.Assertions.assertThat;
* Test GraphQL requests handled through {@code @SchemaMapping} methods.
*
* @author Rossen Stoyanchev
+ * @author Mark Paluch
*/
public class SchemaMappingInvocationTests {
@@ -96,6 +98,40 @@ public class SchemaMappingInvocationTests {
assertThat(bookList.get(1).getName()).isEqualTo("Animal Farm");
}
+ @Test
+ void queryWithProjectedArgument() {
+ String query = "{ " +
+ " booksByProjectedArguments(author:\"Orwell\") { " +
+ " id" +
+ " name" +
+ " }" +
+ "}";
+
+ Mono resultMono = graphQlService().execute(new RequestInput(query, null, null, null, "1"));
+
+ List bookList = GraphQlResponse.from(resultMono).toList("booksByProjectedArguments", Book.class);
+ assertThat(bookList).hasSize(2);
+ assertThat(bookList.get(0).getName()).isEqualTo("Nineteen Eighty-Four");
+ assertThat(bookList.get(1).getName()).isEqualTo("Animal Farm");
+ }
+
+ @Test
+ void booksByProjectedCriteria() {
+ String query = "{ " +
+ " booksByProjectedCriteria(criteria: {author:\"Orwell\"}) { " +
+ " id" +
+ " name" +
+ " }" +
+ "}";
+
+ Mono resultMono = graphQlService().execute(new RequestInput(query, null, null, null, "1"));
+
+ List bookList = GraphQlResponse.from(resultMono).toList("booksByProjectedCriteria", Book.class);
+ assertThat(bookList).hasSize(2);
+ assertThat(bookList.get(0).getName()).isEqualTo("Nineteen Eighty-Four");
+ assertThat(bookList.get(1).getName()).isEqualTo("Animal Farm");
+ }
+
@Test
void queryWithArgumentViaDataFetchingEnvironment() {
String query = "{ " +
@@ -204,6 +240,16 @@ public class SchemaMappingInvocationTests {
return BookSource.findBooksByAuthor(criteria.getAuthor());
}
+ @QueryMapping
+ public List booksByProjectedArguments(BookProjection projection) {
+ return BookSource.findBooksByAuthor(projection.getAuthor());
+ }
+
+ @QueryMapping
+ public List booksByProjectedCriteria(@Argument BookProjection criteria) {
+ return BookSource.findBooksByAuthor(criteria.getAuthor());
+ }
+
@SchemaMapping
public CompletableFuture author(Book book, DataLoader dataLoader) {
return dataLoader.load(book.getAuthorId());
@@ -227,4 +273,11 @@ public class SchemaMappingInvocationTests {
}
}
+ @ProjectedPayload
+ interface BookProjection {
+
+ String getAuthor();
+
+ }
+
}
diff --git a/spring-graphql/src/test/resources/books/schema.graphqls b/spring-graphql/src/test/resources/books/schema.graphqls
index d2c34855..8c3c4b72 100644
--- a/spring-graphql/src/test/resources/books/schema.graphqls
+++ b/spring-graphql/src/test/resources/books/schema.graphqls
@@ -2,6 +2,8 @@ type Query {
bookById(id: ID): Book
books(id: ID, name: String, author: String): [Book]
booksByCriteria(criteria:BookCriteria): [Book]
+ booksByProjectedArguments(name: String, author: String): [Book]
+ booksByProjectedCriteria(criteria:BookCriteria): [Book]
authorById(id: ID): Author
}