DATAREST-885 - PatchOperation now evaluates SpEL expression.

Original pull request: spring-projects#223.

Author: Mathias Düsterhöft

spring-data-rest-webmvc/src/main/java/org/springframework/data/rest/webmvc/json/patch/PatchOperation.java

@@ -26,6 +26,7 @@
  * Abstract base class representing and providing support methods for patch operations.
  * 
  * @author Craig Walls
+ * @author Mathias Düsterhöft
  */
 public abstract class PatchOperation {
 
@@ -164,7 +165,7 @@ protected Object getValueFromTarget(Object target) {
 	 *         otherwise.
 	 */
 	protected <T> Object evaluateValueFromTarget(Object targetObject, Class<T> entityType) {
-		return value instanceof LateObjectEvaluator ? ((LateObjectEvaluator) value).evaluate(entityType) : value;
+		return value instanceof LateObjectEvaluator ? ((LateObjectEvaluator) value).evaluate(spelExpression.getValueType(targetObject)) : value;
 	}
 
 	/**

spring-data-rest-webmvc/src/test/java/org/springframework/data/rest/webmvc/json/patch/ReplaceOperationTest.java

@@ -15,13 +15,17 @@
  */
 package org.springframework.data.rest.webmvc.json.patch;
 
-import static org.junit.Assert.*;
+import static org.junit.Assert.assertEquals;
+import static org.junit.Assert.assertNotNull;
+import static org.junit.Assert.assertTrue;
 
 import java.util.ArrayList;
 import java.util.List;
 
 import org.junit.Test;
 
+import com.fasterxml.jackson.databind.ObjectMapper;
+
 public class ReplaceOperationTest {
 
 	@Test
@@ -38,6 +42,20 @@ public void replaceBooleanPropertyValue() throws Exception {
 		assertTrue(todos.get(1).isComplete());
 	}
 
+	@Test
+	public void replaceObjectPropertyValue() throws Exception {
+		// initial Todo list
+		Todo todo = new Todo(1L, "A", false);
+
+		ReplaceOperation replace = new ReplaceOperation("/type", new JsonLateObjectEvaluator(new ObjectMapper().readTree("{\"value\":\"new\"}")));
+		replace.perform(todo, Todo.class);
+
+		assertNotNull(todo.getType());
+		assertNotNull(todo.getType().getValue());
+		assertTrue(todo.getType().getValue().equals("new"));
+
+	}
+
 	@Test
 	public void replaceTextPropertyValue() throws Exception {
 		// initial Todo list

spring-data-rest-webmvc/src/test/java/org/springframework/data/rest/webmvc/json/patch/Todo.java

@@ -16,20 +16,26 @@
 
 package org.springframework.data.rest.webmvc.json.patch;
 
-import lombok.AllArgsConstructor;
 import lombok.Data;
 import lombok.NoArgsConstructor;
 
 /**
  * @author Roy Clarkson
  * @author Craig Walls
+ * @author Mathias Düsterhöft
  */
 @Data
 @NoArgsConstructor
-@AllArgsConstructor
 class Todo {
 
 	private Long id;
 	private String description;
 	private boolean complete;
+	private TodoType type = new TodoType();
+
+	public Todo(Long id, String description, boolean complete) {
+		this.id = id;
+		this.description = description;
+		this.complete = complete;
+	}
 }

spring-data-rest-webmvc/src/test/java/org/springframework/data/rest/webmvc/json/patch/TodoType.java

@@ -0,0 +1,18 @@
+package org.springframework.data.rest.webmvc.json.patch;
+
+import javax.persistence.Embeddable;
+
+import lombok.AllArgsConstructor;
+import lombok.Data;
+import lombok.NoArgsConstructor;
+
+/**
+ * @author Mathias Düsterhöft
+ */
+@Embeddable
+@Data
+@AllArgsConstructor
+@NoArgsConstructor
+public class TodoType {
+    private String value = "none";
+}