Polishing docs and removing unused code

Author: rstoyanchev

spring-graphql-docs/src/docs/asciidoc/index.adoc

@@ -696,8 +696,9 @@ You can explicitly specify the argument name, for example `@Argument("bookInput"
 it not specified, it defaults to the method parameter name, but this requires the
 `-parameters` compiler flag with Java 8+ or debugging information from the compiler.
 
-The "required" character of an `@Argument` or its default value is controlled at the schema
-level.
+The `@Argument` annotation does not have a "required" flag, nor the option to specify a
+default value. Both of these can be specified at the GraphQL schema level and are enforced
+by the GraphQL Engine.
 
 You can use `@Argument` on a `Map<String, Object>` argument, to obtain all argument
 values. The name attribute on `@Argument` must not be set.

spring-graphql/src/main/java/org/springframework/graphql/data/method/annotation/Argument.java

@@ -31,9 +31,9 @@
  * and a parameter name is not specified, then the map parameter is populated
  * via {@link graphql.schema.DataFetchingEnvironment#getArguments()}.
  *
- * <p>This annotation  does not specify whether the input argument is required
- * and if it should use a default value: this should be done at the schema
- * in order to be enforced by the GraphQL engine itself.
+ * <p>Note that this annotation has neither a "required" flag nor the option to
+ * specify a default value, both of which can be specified at the GraphQL schema
+ * level and are enforced by the GraphQL Java engine.
  *
  * @author Rossen Stoyanchev
  * @since 1.0.0

spring-graphql/src/main/java/org/springframework/graphql/data/method/annotation/BatchMapping.java

@@ -24,7 +24,7 @@
 import org.springframework.core.annotation.AliasFor;
 
 /**
- * Annotation for handler methods that batch load field values, given a list
+ * Annotation for a handler method that batch loads field values, given a list
  * of source/parent values. For example:
  *
  * <pre class="code">
@@ -34,9 +34,10 @@
  * }
  * </pre>
  *
- * <p>The annotated method is registered as a batch loading function and along
+ * <p>The annotated method is registered as a batch loading function via
+ * {@link org.springframework.graphql.execution.BatchLoaderRegistry}, and along
  * with it, a {@link graphql.schema.DataFetcher} for the field is registered
- * transparently that looks up the field through the registered
+ * transparently that looks up the field value through the registered
  * {@code DataLoader}.
  *
  * <p>Effectively, a shortcut for:
@@ -46,7 +47,7 @@
  * public class BookController {
  *
  *     public BookController(BatchLoaderRegistry registry) {
- *         registry.forTypePair(Long.class, Author.class).registerBatchLoader((ids, env) -> ...);
+ *         registry.forTypePair(Long.class, Author.class).registerBatchLoader((ids, environment) -> ...);
  *     }
  *
  *     &#064;SchemaMapping
@@ -60,7 +61,7 @@
  * @author Rossen Stoyanchev
  * @since 1.0.0
  */
-@Target({ElementType.TYPE, ElementType.METHOD})
+@Target(ElementType.METHOD)
 @Retention(RetentionPolicy.RUNTIME)
 @Documented
 public @interface BatchMapping {
@@ -79,12 +80,12 @@
 	String value() default "";
 
 	/**
-	 * Customizes the name of the parent/container type for the GraphQL field.
-	 * <p>By default, if not specified, it is derived from the class name of the
-	 * List of source/parent values injected into the handler method.
-	 * <p>This value for this attribute can be initialized from a class-level
+	 * Customizes the name of the source/parent type for the GraphQL field.
+	 * <p>By default, if not specified, it is based on the simple class name of
+	 * the List of source/parent values injected into the handler method.
+	 * <p>The value for this attribute can also be inherited from a class-level
 	 * {@link SchemaMapping @SchemaMapping}. When used on both levels, the one
-	 * on the method level overrides the one at the class level.
+	 * here overrides the one at the class level.
 	 */
 	String typeName() default "";
 

spring-graphql/src/main/java/org/springframework/graphql/data/method/annotation/QueryMapping.java

@@ -32,7 +32,7 @@
  * @author Rossen Stoyanchev
  * @since 1.0.0
  */
-@Target(value = {ElementType.TYPE, ElementType.METHOD})
+@Target(ElementType.METHOD)
 @Retention(RetentionPolicy.RUNTIME)
 @Documented
 @SchemaMapping(typeName = "Query")

spring-graphql/src/main/java/org/springframework/graphql/data/method/annotation/SchemaMapping.java

@@ -52,7 +52,7 @@
 	String value() default "";
 
 	/**
-	 * Customizes the name of the parent/container type for the GraphQL field.
+	 * Customizes the name of the source/parent type for the GraphQL field.
 	 * <p>By default, if not specified, it is derived from the class name of a
 	 * {@link DataFetchingEnvironment#getSource() source} argument injected into
 	 * the handler method.

spring-graphql/src/main/java/org/springframework/graphql/data/method/annotation/ValueConstants.java

@@ -26,7 +26,6 @@
 import org.springframework.core.convert.TypeDescriptor;
 import org.springframework.graphql.data.method.HandlerMethodArgumentResolver;
 import org.springframework.graphql.data.method.annotation.Argument;
-import org.springframework.graphql.data.method.annotation.ValueConstants;
 import org.springframework.util.Assert;
 import org.springframework.util.StringUtils;
 import org.springframework.validation.DataBinder;

spring-graphql/src/main/java/org/springframework/graphql/data/method/annotation/support/ArgumentMethodArgumentResolver.java

@@ -30,9 +30,10 @@
 import org.springframework.util.Assert;
 
 /**
- * An extension of {@link HandlerMethod} for annotated handler methods adapted
- * to a batch loader function with a list of values and {@link BatchLoaderEnvironment}
- * as their input.
+ * An extension of {@link HandlerMethod} for annotated handler methods adapted to
+ * {@link org.dataloader.BatchLoaderWithContext} or
+ * {@link org.dataloader.MappedBatchLoaderWithContext} with the list of keys and
+ * {@link BatchLoaderEnvironment} as their input.
  *
  * @author Rossen Stoyanchev
  * @since 1.0.0
@@ -47,7 +48,7 @@ public BatchLoaderHandlerMethod(HandlerMethod handlerMethod) {
 
 	/**
 	 * Invoke the underlying batch loading method, resolving its arguments from
-	 * the given keys for batch loading and the {@link BatchLoaderEnvironment}.
+	 * the given keys  and the {@link BatchLoaderEnvironment}.
 	 *
 	 * @param keys the batch loading keys
 	 * @param environment the environment available to batch loaders

spring-graphql/src/main/java/org/springframework/graphql/data/method/annotation/support/BatchLoaderHandlerMethod.java

@@ -33,7 +33,7 @@ public boolean supportsParameter(MethodParameter parameter) {
     }
 
     @Override
-    public Object resolveArgument(MethodParameter parameter, DataFetchingEnvironment environment) throws Exception {
+    public Object resolveArgument(MethodParameter parameter, DataFetchingEnvironment environment) {
         return null;
     }
 

spring-graphql/src/main/java/org/springframework/graphql/data/method/annotation/support/ContinuationHandlerMethodArgumentResolver.java

@@ -28,10 +28,10 @@
 import org.springframework.util.Assert;
 
 /**
- * Resolver that retrieves arguments of type {@link DataLoader} from the
- * {@link DataFetchingEnvironment}.
+ * Resolver for a {@link DataLoader} obtained via
+ * {@link DataFetchingEnvironment#getDataLoader(String)}.
  *
- * <p>The {@code DataLoader} is looked up by deriving the key using one of the following:
+ * <p>The {@code DataLoader} key is based on one of the following:
  * <ol>
  * <li>The full name of the value type from the DataLoader generic types.</li>
  * <li>The method parameter name.</li>

spring-graphql/src/main/java/org/springframework/graphql/data/method/annotation/support/DataLoaderMethodArgumentResolver.java

@@ -25,7 +25,7 @@
 import org.springframework.util.Assert;
 
 /**
- * Resolver for parent/container of a field, obtained via
+ * Resolver for the source/parent of a field, obtained via
  * {@link DataFetchingEnvironment#getSource()}.
  *
  * <p>This resolver supports any non-simple value type, also excluding arrays