#44 Creating template for writing MappingMethodReferences, enhancing templating mechanism to pass additional objects to <includeModel/> directive

processor/src/main/java/org/mapstruct/ap/writer/FreeMarkerModelElementWriter.java

@@ -19,15 +19,24 @@
 package org.mapstruct.ap.writer;
 
 import java.io.Writer;
+import java.util.Map;
 
+import freemarker.ext.beans.BeanModel;
+import freemarker.ext.beans.BeansWrapper;
+import freemarker.ext.beans.SimpleMapModel;
 import freemarker.template.Configuration;
 import freemarker.template.Template;
+import freemarker.template.TemplateHashModel;
+import freemarker.template.TemplateModel;
+import freemarker.template.TemplateModelException;
 import org.mapstruct.ap.model.ModelElement;
 import org.mapstruct.ap.model.ModelElement.Context;
 
 /**
- * Delegate for writing given {@link ModelElements} into a {@link Writer} using
- * FreeMarker templates.
+ * Delegate for writing given {@link ModelElement}s into a {@link Writer} using
+ * FreeMarker templates. Any parameters passed to the
+ * {@link ModelIncludeDirective} in addition to element itself can be accessed
+ * from within the template using the {@code ext} pseudo-element.
  *
  * @author Gunnar Morling
  */
@@ -39,8 +48,39 @@ public class FreeMarkerModelElementWriter {
 
     public void write(ModelElement modelElement, String templateName, Context context, Writer writer) throws Exception {
         Configuration configuration = context.get( Configuration.class );
-
         Template template = configuration.getTemplate( templateName );
-        template.process( modelElement, writer );
+        template.process(
+            new ExternalParamsTemplateModel(
+                new BeanModel( modelElement, BeansWrapper.getDefaultInstance() ),
+                new SimpleMapModel( context.get( Map.class ), BeansWrapper.getDefaultInstance() )
+            ),
+            writer
+        );
+    }
+
+    private static class ExternalParamsTemplateModel implements TemplateHashModel {
+
+        private final BeanModel object;
+        private final SimpleMapModel extParams;
+
+        public ExternalParamsTemplateModel(BeanModel object, SimpleMapModel extParams) {
+            this.object = object;
+            this.extParams = extParams;
+        }
+
+        @Override
+        public TemplateModel get(String key) throws TemplateModelException {
+            if ( key.equals( "ext" ) ) {
+                return extParams;
+            }
+            else {
+                return object.get( key );
+            }
+        }
+
+        @Override
+        public boolean isEmpty() throws TemplateModelException {
+            return object.isEmpty() && extParams.isEmpty();
+        }
     }
 }

processor/src/main/java/org/mapstruct/ap/writer/ModelIncludeDirective.java

@@ -19,10 +19,12 @@
 package org.mapstruct.ap.writer;
 
 import java.io.IOException;
+import java.util.HashMap;
 import java.util.Map;
 
 import freemarker.core.Environment;
 import freemarker.ext.beans.BeanModel;
+import freemarker.template.Configuration;
 import freemarker.template.TemplateDirectiveBody;
 import freemarker.template.TemplateDirectiveModel;
 import freemarker.template.TemplateException;
@@ -40,10 +42,10 @@ import org.mapstruct.ap.writer.ModelWriter.DefaultModelElementWriterContext;
  */
 public class ModelIncludeDirective implements TemplateDirectiveModel {
 
-    private DefaultModelElementWriterContext context;
+    private final Configuration configuration;
 
-    public ModelIncludeDirective(DefaultModelElementWriterContext context) {
-        this.context = context;
+    public ModelIncludeDirective(Configuration configuration) {
+        this.configuration = configuration;
     }
 
     @Override
@@ -51,13 +53,8 @@ public class ModelIncludeDirective implements TemplateDirectiveModel {
                         TemplateDirectiveBody body)
         throws TemplateException, IOException {
 
-        Object wrappedObject = ( (BeanModel) params.get( "object" ) ).getWrappedObject();
-
-        if ( !( wrappedObject instanceof ModelElement ) ) {
-            throw new IllegalArgumentException( "Given object isn't a ModelElement:" + wrappedObject );
-        }
-
-        ModelElement modelElement = (ModelElement) wrappedObject;
+        ModelElement modelElement = getModelElement( params );
+        DefaultModelElementWriterContext context = createContext( params );
 
         try {
             modelElement.write( context, env.getOut() );
@@ -75,4 +72,48 @@ public class ModelIncludeDirective implements TemplateDirectiveModel {
             throw new RuntimeException( e );
         }
     }
+
+    @SuppressWarnings("rawtypes")
+    private ModelElement getModelElement(Map params) {
+        if ( !params.containsKey( "object" ) ) {
+            throw new IllegalArgumentException(
+                "Object to be included must be passed to this directive via the 'object' parameter"
+            );
+        }
+
+        BeanModel objectModel = (BeanModel) params.get( "object" );
+
+        if ( objectModel == null ) {
+            throw new IllegalArgumentException(
+                "Object passed to this directive via the 'object' parameter must not be null"
+            );
+        }
+
+        if ( !( objectModel.getWrappedObject() instanceof ModelElement ) ) {
+            throw new IllegalArgumentException( "Given object isn't a ModelElement:" + objectModel.getWrappedObject() );
+        }
+
+        return (ModelElement) objectModel.getWrappedObject();
+    }
+
+    /**
+     * Creates a writer context providing access to the FreeMarker
+     * {@link Configuration} and a map with any additional parameters passed to
+     * the directive.
+     *
+     * @param params The parameter map passed to this directive.
+     *
+     * @return A writer context.
+     */
+    @SuppressWarnings({ "rawtypes", "unchecked" })
+    private DefaultModelElementWriterContext createContext(Map params) {
+        Map<String, Object> ext = new HashMap<String, Object>( params );
+        ext.remove( "object" );
+
+        Map<Class<?>, Object> values = new HashMap<Class<?>, Object>();
+        values.put( Configuration.class, configuration );
+        values.put( Map.class, ext );
+
+        return new DefaultModelElementWriterContext( values );
+    }
 }

processor/src/main/java/org/mapstruct/ap/writer/ModelWriter.java

@@ -56,7 +56,7 @@ public class ModelWriter {
         CONFIGURATION.setObjectWrapper( new DefaultObjectWrapper() );
         CONFIGURATION.setSharedVariable(
             "includeModel",
-            new ModelIncludeDirective( new DefaultModelElementWriterContext( CONFIGURATION ) )
+            new ModelIncludeDirective( CONFIGURATION )
         );
     }
 
@@ -64,7 +64,9 @@ public class ModelWriter {
         try {
             BufferedWriter writer = new BufferedWriter( sourceFile.openWriter() );
 
-            model.write( new DefaultModelElementWriterContext( CONFIGURATION ), writer );
+            Map<Class<?>, Object> values = new HashMap<Class<?>, Object>();
+            values.put( Configuration.class, CONFIGURATION );
+            model.write( new DefaultModelElementWriterContext( values ), writer );
 
             writer.flush();
             writer.close();
@@ -85,10 +87,10 @@ public class ModelWriter {
      */
     static class DefaultModelElementWriterContext implements Context {
 
-        private Map<Class<?>, Object> values = new HashMap<Class<?>, Object>();
+        private Map<Class<?>, Object> values;
 
-        private DefaultModelElementWriterContext(Configuration configuration) {
-            values.put( Configuration.class, configuration );
+        DefaultModelElementWriterContext(Map<Class<?>, Object> values) {
+            this.values = new HashMap<Class<?>, Object>( values );
         }
 
         @Override

processor/src/main/resources/org.mapstruct.ap.model.IterableMappingMethod.ftl

@@ -42,7 +42,7 @@
                     </#list>
                 </#if>
             <#else>
-            ${targetType.name?uncap_first}.add( ${elementMappingMethod.name}( ${sourceType.typeParameters[0].name?uncap_first} ) );
+            ${targetType.name?uncap_first}.add( <@includeModel object=elementMappingMethod input="${sourceType.typeParameters[0].name?uncap_first}"/> );
             </#if>
         }
 

processor/src/main/resources/org.mapstruct.ap.model.MappingMethodReference.ftl

@@ -0,0 +1,21 @@
+<#--
+
+     Copyright 2012-2013 Gunnar Morling (http://www.gunnarmorling.de/)
+     and/or other contributors as indicated by the @authors tag. See the
+     copyright.txt file in the distribution for a full listing of all
+     contributors.
+
+     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.
+
+-->
+<#if declaringMapper??>${declaringMapper.name?uncap_first}.</#if>${name}( ${ext.input} )

processor/src/main/resources/org.mapstruct.ap.model.PropertyMapping.ftl

@@ -20,7 +20,7 @@
 -->
         <#-- a) invoke mapping method -->
         <#if mappingMethod??>
-        ${targetBeanName}.${targetAccessorName}( <#if mappingMethod.declaringMapper??>${mappingMethod.declaringMapper.name?uncap_first}.</#if>${mappingMethod.name}( ${sourceBeanName}.${sourceAccessorName}() ) );
+        ${targetBeanName}.${targetAccessorName}( <@includeModel object=mappingMethod input="${sourceBeanName}.${sourceAccessorName}()"/> );
         <#-- b) simple conversion -->
         <#elseif conversion??>
             <#if sourceType.primitive == false>