Replaced BinderSupport with a refactored AbstractBinder that delegates to a FieldBinder whose creation is the responsibility of each subclass.

git-svn-id: https://src.springframework.org/svn/spring-framework/trunk@1639 50f2f4bb-b051-0410-bef5-90022cba6387

org.springframework.context/src/main/java/org/springframework/model/binder/support/AbstractBinder.java

@@ -19,17 +19,26 @@ import java.util.ArrayList;
 import java.util.List;
 import java.util.Map;
 
+import org.springframework.context.MessageSource;
+import org.springframework.model.binder.Binder;
+import org.springframework.model.binder.BindingResult;
 import org.springframework.model.binder.BindingResults;
 import org.springframework.model.binder.MissingFieldException;
+import org.springframework.util.Assert;
 
 /**
- * A template that encapsulates the general bulk-binding algorithm.
+ * Base Binder implementation that defines common structural elements.
+ * Subclasses should be parameterized & implement {@link #bind(Map, Object)}.
  * @author Keith Donald
  * @since 3.0
  * @see #setRequiredFields(String[])
- * @see #bind(Map, FieldBinder)
+ * @see #setMessageSource(MessageSource)
+ * @see #createFieldBinder()
+ * @see #bind(Map, Object)
  */
-public class BindTemplate  {
+public abstract class AbstractBinder<M> implements Binder<M> {
+
+	private MessageSource messageSource;
 
 	private String[] requiredFields;
 
@@ -42,10 +51,28 @@ public class BindTemplate  {
 		this.requiredFields = fieldNames;
 	}
 
-	// implementing Binder
+	/**
+	 * Configure the MessageSource that resolves localized {@link BindingResult} alert messages.
+	 * @param messageSource the message source
+	 */
+	public void setMessageSource(MessageSource messageSource) {
+		Assert.notNull(messageSource, "The MessageSource is required");
+		this.messageSource = messageSource;
+	}
+
+	/**
+	 * The configured MessageSource that resolves binding result alert messages.
+	 */
+	protected MessageSource getMessageSource() {
+		return messageSource;
+	}
+
+	// Binder implementation
 
-	public BindingResults bind(Map<String, ? extends Object> fieldValues, FieldBinder fieldBinder) {
+	public final BindingResults bind(Map<String, ? extends Object> fieldValues, M model) {
+		fieldValues = filter(fieldValues, model);
 		checkRequired(fieldValues);
+		FieldBinder fieldBinder = this.createFieldBinder(model);
 		ArrayListBindingResults results = new ArrayListBindingResults(fieldValues.size());
 		for (Map.Entry<String, ? extends Object> fieldValue : fieldValues.entrySet()) {
 			results.add(fieldBinder.bind(fieldValue.getKey(), fieldValue.getValue()));
@@ -53,6 +80,26 @@ public class BindTemplate  {
 		return results;
 	}
 
+	// subclass hooks
+
+	/**
+	 * Subclasses must implement this method to create the {@link FieldBinder}
+	 * instance for the given model. 
+	 */
+	protected abstract FieldBinder createFieldBinder(M model);
+
+	/**
+	 * Filter the fields to bind.
+	 * Allows for pre-processing the fieldValues Map before any binding occurs.
+	 * For example, you might insert empty or default values for fields that are not present.
+	 * As another example, you might collapse multiple fields into a single field.
+	 * Default implementation simply returns the fieldValues Map unchanged. 
+	 * @param fieldValues the original fieldValues Map provided by the caller
+	 * @return the filtered fieldValues Map that will be used to bind
+	 */
+	protected Map<String, ? extends Object> filter(Map<String, ? extends Object> fieldValues, M model) {
+		return fieldValues;
+	}
 
 	// internal helpers
 
@@ -77,4 +124,4 @@ public class BindTemplate  {
 		}
 	}
 
-}
+}

org.springframework.context/src/main/java/org/springframework/model/binder/support/BinderSupport.java

@@ -1,83 +0,0 @@
-/*
- * Copyright 2004-2009 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.model.binder.support;
-
-import org.springframework.context.MessageSource;
-import org.springframework.model.binder.BindingResult;
-import org.springframework.model.binder.MissingFieldException;
-import org.springframework.util.Assert;
-
-/**
- * Binder implementation support class that defines common structural elements.
- * @author Keith Donald
- * @since 3.0
- * @see #setRequiredFields(String[])
- * @see #setMessageSource(MessageSource)
- * @see #createBindTemplate()
- */
-public abstract class BinderSupport {
-
-	private BindTemplate bindTemplate;
-
-	private MessageSource messageSource;
-
-	public BinderSupport() {
-		bindTemplate = createBindTemplate();
-	}
-
-	/**
-	 * Configure the fields for which values must be present in each bind attempt.
-	 * @param fieldNames the required field names
-	 * @see MissingFieldException
-	 */
-	public void setRequiredFields(String[] fieldNames) {
-		bindTemplate.setRequiredFields(fieldNames);
-	}
-	
-	/**
-	 * Configure the MessageSource that resolves localized {@link BindingResult} alert messages.
-	 * @param messageSource the message source
-	 */
-	public void setMessageSource(MessageSource messageSource) {
-		Assert.notNull(messageSource, "The MessageSource is required");
-		this.messageSource = messageSource;
-	}
-
-	// subclass hooks
-	
-	/**
-	 * Create the template defining the bulk-binding algorithm.
-	 * Subclasses may override to customize the algorithm.
-	 */
-	protected BindTemplate createBindTemplate() {
-		return new BindTemplate();
-	}
-
-	/**
-	 * The template defining the bulk-binding algorithm.
-	 */
-	protected BindTemplate getBindTemplate() {
-		return bindTemplate;
-	}
-	
-	/**
-	 * The configured MessageSource that resolves binding result alert messages.
-	 */
-	protected MessageSource getMessageSource() {
-		return messageSource;
-	}
-	
-}

org.springframework.context/src/main/java/org/springframework/model/binder/support/FieldBinder.java

@@ -18,9 +18,9 @@ package org.springframework.model.binder.support;
 import org.springframework.model.binder.BindingResult;
 
 /**
- * BindTemplate callback interface for binding a single field value.
+ * Binder callback interface for binding a single field value.
  * @author Keith Donald
- * @see BindTemplate#bind(java.util.Map, BindCallback)
+ * @see AbstractBinder#createFieldBinder(Object)
  */
 public interface FieldBinder {
 

org.springframework.context/src/main/java/org/springframework/model/binder/support/GenericBinder.java

@@ -15,8 +15,6 @@
  */
 package org.springframework.model.binder.support;
 
-import java.util.Map;
-
 import org.springframework.expression.EvaluationContext;
 import org.springframework.expression.EvaluationException;
 import org.springframework.expression.Expression;
@@ -29,7 +27,6 @@ import org.springframework.model.alert.Alert;
 import org.springframework.model.alert.Severity;
 import org.springframework.model.binder.Binder;
 import org.springframework.model.binder.BindingResult;
-import org.springframework.model.binder.BindingResults;
 
 /**
  * A {@link Binder} implementation that accepts any target object and uses
@@ -38,19 +35,20 @@ import org.springframework.model.binder.BindingResults;
  * @author Mark Fisher
  * @since 3.0
  */
-public class GenericBinder extends BinderSupport implements Binder<Object> {
+public class GenericBinder extends AbstractBinder<Object> {
 
 	private final ExpressionParser parser = new SpelExpressionParser(
 			SpelExpressionParserConfiguration.CreateObjectIfAttemptToReferenceNull
 					| SpelExpressionParserConfiguration.GrowListsOnIndexBeyondSize);
 
-	public BindingResults bind(Map<String, ? extends Object> fieldValues, Object model) {
+	@Override
+	protected FieldBinder createFieldBinder(Object model) {
 		StandardEvaluationContext evaluationContext = new StandardEvaluationContext();
 		evaluationContext.setRootObject(model);
-		FieldBinder fieldBinder = new EvaluationContextFieldBinder(parser, evaluationContext);
+		return new EvaluationContextFieldBinder(parser, evaluationContext);
-		return getBindTemplate().bind(fieldValues, fieldBinder);
 	}
 
+
 	private static class EvaluationContextFieldBinder implements FieldBinder {
 
 		private final ExpressionParser parser;

org.springframework.context/src/main/java/org/springframework/model/ui/support/PresentationModelBinder.java

@@ -18,11 +18,9 @@ package org.springframework.model.ui.support;
 import java.util.Map;
 
 import org.springframework.context.MessageSource;
-import org.springframework.model.binder.Binder;
 import org.springframework.model.binder.BindingResult;
-import org.springframework.model.binder.BindingResults;
+import org.springframework.model.binder.support.AbstractBinder;
 import org.springframework.model.binder.support.AlertBindingResult;
-import org.springframework.model.binder.support.BinderSupport;
 import org.springframework.model.binder.support.FieldBinder;
 import org.springframework.model.binder.support.FieldNotEditableResult;
 import org.springframework.model.binder.support.FieldNotFoundResult;
@@ -39,28 +37,15 @@ import org.springframework.model.ui.PresentationModel;
  * @see #setRequiredFields(String[])
  * @see #bind(Map, PresentationModel)
  */
-public class PresentationModelBinder extends BinderSupport implements Binder<PresentationModel> {
+public class PresentationModelBinder extends AbstractBinder<PresentationModel> {
 
-	public BindingResults bind(Map<String, ? extends Object> fieldValues, PresentationModel model) {
-		fieldValues = filter(fieldValues, model);
-		return getBindTemplate().bind(fieldValues, new FieldModelBinder(model, getMessageSource()));
-	}
-	
 	// subclassing hooks
-	
+
-	/**
+	@Override
-	 * Filter the fields to bind.
+	protected FieldBinder createFieldBinder(PresentationModel model) {
-	 * Allows for pre-processing the fieldValues Map before any binding occurs.
+		return new FieldModelBinder(model, getMessageSource());
-	 * For example, you might insert empty or default values for fields that are not present.
-	 * As another example, you might collapse multiple fields into a single field.
-	 * Default implementation simply returns the fieldValues Map unchanged. 
-	 * @param fieldValues the original fieldValues Map provided by the caller
-	 * @return the filtered fieldValues Map that will be used to bind
-	 */
-	protected Map<String, ? extends Object> filter(Map<String, ? extends Object> fieldValues, PresentationModel model) {
-		return fieldValues;
 	}
-	
+
 	// internal helpers
 	
 	private static class FieldModelBinder implements FieldBinder {
@@ -93,4 +78,4 @@ public class PresentationModelBinder extends BinderSupport implements Binder<Pre
 		}
 	}
 
-}
+}