src/main/java/org/apache/struts/annotations/taglib/apt/TagAnnotationProcessor.java - struts-annotations - Git at Google

 /*
  * $Id:  $
  *
  * Licensed to the Apache Software Foundation (ASF) under one
  * or more contributor license agreements.  See the NOTICE file
  * distributed with this work for additional information
  * regarding copyright ownership.  The ASF licenses this file
  * to you 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.apache.struts.annotations.taglib.apt;

 import java.io.BufferedWriter;
 import java.io.File;
 import java.io.FileOutputStream;
 import java.io.FileWriter;
 import java.io.OutputStreamWriter;
 import java.util.Collection;
 import java.util.HashMap;
 import java.util.List;
 import java.util.Map;
 import java.util.Map.Entry;
 import java.util.Set;
 import java.util.TreeMap;

 import javax.annotation.processing.AbstractProcessor;
 import javax.annotation.processing.RoundEnvironment;
 import javax.annotation.processing.SupportedAnnotationTypes;
 import javax.lang.model.element.AnnotationMirror;
 import javax.lang.model.element.AnnotationValue;
 import javax.lang.model.element.ExecutableElement;
 import javax.lang.model.element.Modifier;
 import javax.lang.model.element.TypeElement;
 import javax.lang.model.type.NoType;
 import javax.lang.model.util.ElementFilter;
 import javax.xml.parsers.DocumentBuilder;
 import javax.xml.parsers.DocumentBuilderFactory;
 import javax.xml.transform.OutputKeys;
 import javax.xml.transform.Result;
 import javax.xml.transform.Source;
 import javax.xml.transform.Transformer;
 import javax.xml.transform.TransformerFactory;
 import javax.xml.transform.dom.DOMSource;
 import javax.xml.transform.stream.StreamResult;

 import org.w3c.dom.Document;
 import org.w3c.dom.Element;
 import org.w3c.dom.Text;

 import freemarker.template.Configuration;
 import freemarker.template.DefaultObjectWrapper;
 import freemarker.template.Template;

 @SupportedAnnotationTypes({TagAnnotationProcessor.TAG, TagAnnotationProcessor.TAG_ATTRIBUTE, TagAnnotationProcessor.TAG_SKIP_HIERARCHY})
 public class TagAnnotationProcessor extends AbstractProcessor {
     public static final String TAG = "org.apache.struts2.views.annotations.StrutsTag";
     public static final String TAG_ATTRIBUTE = "org.apache.struts2.views.annotations.StrutsTagAttribute";
     public static final String TAG_SKIP_HIERARCHY = "org.apache.struts2.views.annotations.StrutsTagSkipInheritance";

     private Map<String, Tag> tags = new TreeMap<>();

     @Override
 	public boolean process(Set<? extends TypeElement> annotations, RoundEnvironment roundEnv) {
         // make sure all paramters were set
         checkOptions();

         // tags
         TypeElement tagAnnotationType = processingEnv.getElementUtils().getTypeElement(TAG);
         TypeElement attributeAnnotationType = processingEnv.getElementUtils().getTypeElement(TAG_ATTRIBUTE);
         TypeElement skipAnnotationType = processingEnv.getElementUtils().getTypeElement(TAG_SKIP_HIERARCHY);
 		Set<? extends javax.lang.model.element.Element> tagDeclarations = roundEnv.getElementsAnnotatedWith(tagAnnotationType);
 		Set<? extends javax.lang.model.element.Element> attributesDeclarations = roundEnv.getElementsAnnotatedWith(attributeAnnotationType);
 		Set<? extends javax.lang.model.element.Element> skipDeclarations = roundEnv.getElementsAnnotatedWith(skipAnnotationType);

         // find Tags
     	for (javax.lang.model.element.Element element : tagDeclarations) {
 			Map<String, Object> values = getValues(element, tagAnnotationType);
 			TypeElement type = (TypeElement) element;
 			Tag tag = new Tag();
             tag.setDescription((String) values.get("description"));
             tag.setName((String) values.get("name"));
             tag.setTldBodyContent((String) values.get("tldBodyContent"));
             tag.setTldTagClass((String) values.get("tldTagClass"));
             tag.setDeclaredType(type.getQualifiedName().toString());
             tag.setAllowDynamicAttributes((Boolean) values.get("allowDynamicAttributes"));
             // add to map
             tags.put(type.getQualifiedName().toString(), tag);
 		}

         //find attributes to be skipped
         for (javax.lang.model.element.Element declaration : skipDeclarations) {
             //types will be ignored when hierarchy is scanned
             if (declaration instanceof ExecutableElement) {
             	ExecutableElement methodDeclaration = (ExecutableElement) declaration;
                 String typeName = ((TypeElement) methodDeclaration.getEnclosingElement()).getQualifiedName().toString();
                 String methodName = methodDeclaration.getSimpleName().toString();
                 String name = String.valueOf(Character.toLowerCase(methodName
                     .charAt(3)))
                     + methodName.substring(4);
                 Tag tag = tags.get(typeName);
                 if(tag != null) {
                     //if it is on an abstract class, there is not tag for it at this point
                     tags.get(typeName).addSkipAttribute(name);
                 }
             }
         }

         // find Tags Attributes
         for (javax.lang.model.element.Element declaration : attributesDeclarations) {
             // type
         	ExecutableElement methodDeclaration = (ExecutableElement) declaration;
         	String typeName = ((TypeElement) methodDeclaration.getEnclosingElement()).getQualifiedName().toString();
             Map<String, Object> values = getValues(methodDeclaration,
                     attributeAnnotationType);
             // create Attribute and apply values found
             TagAttribute attribute = new TagAttribute();
             String name = (String) values.get("name");
             if (name == null || name.length() == 0) {
                 // get name from method
                 String methodName = methodDeclaration.getSimpleName().toString();
                 name = String.valueOf(Character.toLowerCase(methodName
                         .charAt(3)))
                         + methodName.substring(4);
             }
             values.put("name", name);
             populateTagAttributes(attribute, values);
             // add to map
             Tag parentTag = tags.get(typeName);
             if (parentTag != null){
                 tags.get(typeName).addTagAttribute(attribute);
             }else {
                 // an abstract or base class
                 parentTag = new Tag();
                 parentTag.setDeclaredType(typeName);
                 parentTag.setInclude(false);
                 parentTag.addTagAttribute(attribute);
                 tags.put(typeName, parentTag);
             }
         }

         // we can't process the hierarchy on the first pass because
         // apt does not guarantee that the base classes will be processed
         // before their subclasses
         for (Map.Entry<String, Tag> entry : tags.entrySet()) {
             processHierarchy(entry.getValue());
         }

         // save
         saveAsXml();
         saveTemplates();
         return true;
     }

     private static void populateTagAttributes(TagAttribute attribute, Map<String, Object> values) {
         attribute.setRequired((Boolean) values.get("required"));
         attribute.setRtexprvalue((Boolean) values.get("rtexprvalue"));
         attribute.setDefaultValue((String) values.get("defaultValue"));
         attribute.setType((String) values.get("type"));
         attribute.setDescription((String) values.get("description"));
         attribute.setName((String) values.get("name"));
     }

     private void processHierarchy(Tag tag) {
     	TypeElement type = processingEnv.getElementUtils().getTypeElement(tag.getDeclaredType());
     	List<String> skipAttributes = tag.getSkipAttributes();
     	while (type !=null && !(type instanceof NoType) && getAnnotation(type, TAG_SKIP_HIERARCHY) == null) {
     		Tag parentTag = tags.get(type.getQualifiedName().toString());
             // copy parent annotations to this tag
             if(parentTag != null) {
                 for(TagAttribute attribute : parentTag.getAttributes()) {
                     if(!skipAttributes.contains(attribute.getName())){
                         tag.addTagAttribute(attribute);
                     }
                 }
             } else {
                 // Maybe the parent class is already compiled
                 addTagAttributesFromParent(tag, type);
             }
             type = (TypeElement) processingEnv.getTypeUtils().asElement(type.getSuperclass());
     	}
     }

     private void addTagAttributesFromParent(Tag tag, TypeElement type) {
     	for (ExecutableElement method : ElementFilter.methodsIn(processingEnv.getElementUtils().getAllMembers(type))) {
     		AnnotationMirror annotation = getAnnotation(method, TAG_ATTRIBUTE);
 			if (method.getModifiers().contains(Modifier.PUBLIC) && annotation != null) {
 				String name = String.valueOf(Character.toLowerCase(method.getSimpleName()
 	                    .charAt(3)))
 	                    + method.getSimpleName().subSequence(4, method.getSimpleName().length());
     			if (!tag.getSkipAttributes().contains(name)) {
     				Map<String, Object> values = new HashMap<>();
     				for (Entry<? extends ExecutableElement, ? extends AnnotationValue> entry : processingEnv.getElementUtils().getElementValuesWithDefaults(annotation).entrySet()) {
     					values.put(entry.getKey().getSimpleName().toString(), entry.getValue().getValue());
     				}
     				TagAttribute attribute = new TagAttribute();
                     populateTagAttributes(attribute, values);
                     attribute.setName(name);
                     tag.addTagAttribute(attribute);
     			}
     		}
     	}
     }

     private AnnotationMirror getAnnotation(javax.lang.model.element.Element element, String annotationName) {
     	TypeElement annotation = processingEnv.getElementUtils().getTypeElement(annotationName);
     	if (element != null && element.getAnnotationMirrors() != null) {
     	for (AnnotationMirror mirror : element.getAnnotationMirrors()) {
     		if (mirror.getAnnotationType().asElement().equals(annotation)) {
     			return mirror;
     		}
     	}
     	}
         return null;
     }

     private void checkOptions() {
         if (getOption("tlibVersion") == null)
             throw new IllegalArgumentException("'tlibVersion' is missing");
         if (getOption("jspVersion") == null)
             throw new IllegalArgumentException("'jspVersion' is missing");
         if (getOption("shortName") == null)
             throw new IllegalArgumentException("'shortName' is missing");
         if (getOption("description") == null)
             throw new IllegalArgumentException("'description' is missing");
         if (getOption("displayName") == null)
             throw new IllegalArgumentException("'displayName' is missing");
         if (getOption("uri") == null)
             throw new IllegalArgumentException("'uri' is missing");
         if (getOption("outTemplatesDir") == null)
             throw new IllegalArgumentException("'outTemplatesDir' is missing");
         if (getOption("outFile") == null)
             throw new IllegalArgumentException("'outFile' is missing");
     }

     private void saveTemplates() {
         // freemarker configuration
         Configuration config = new Configuration();
         config.setClassForTemplateLoading(getClass(), "");
         config.setObjectWrapper(new DefaultObjectWrapper());

         try {
             // load template
             Template template = config.getTemplate("tag.ftl");
             String rootDir = (new File(getOption("outTemplatesDir")))
                     .getAbsolutePath();
             for (Tag tag : tags.values()) {
                 if (tag.isInclude()) {
                     // model
                     HashMap<String, Tag> root = new HashMap<>();
                     root.put("tag", tag);

                     try (BufferedWriter writer = new BufferedWriter(new FileWriter(
                             new File(rootDir, tag.getName() + ".html")))){
                     	template.process(root, writer);
                     }
                 }
             }
         } catch (Exception e) {
             // oops we cannot throw checked exceptions
             throw new RuntimeException(e);
         }
     }

     private void saveAsXml() {
         DocumentBuilderFactory factory = DocumentBuilderFactory.newInstance();
         DocumentBuilder builder;

         try {
             // create xml document
             builder = factory.newDocumentBuilder();
             Document document = builder.newDocument();
             document.setXmlVersion("1.0");

             // taglib
             Element tagLib = document.createElement("taglib");
             tagLib.setAttribute("xmlns", "http://java.sun.com/xml/ns/j2ee");
             tagLib.setAttribute("xmlns:xsi", "http://www.w3.org/2001/XMLSchema-instance");
             tagLib.setAttribute("xsi:schemaLocation", "http://java.sun.com/xml/ns/j2ee http://java.sun.com/xml/ns/j2ee/web-jsptaglibrary_2_0.xsd");
             tagLib.setAttribute("version", getOption("jspVersion"));
             document.appendChild(tagLib);
             // tag lib attributes
             appendTextNode(document, tagLib, "description",
                     getOption("description"), true);
             appendTextNode(document, tagLib, "display-name",
                     getOption("displayName"), false);
             appendTextNode(document, tagLib, "tlib-version",
                     getOption("tlibVersion"), false);
             appendTextNode(document, tagLib, "short-name",
                     getOption("shortName"), false);
             appendTextNode(document, tagLib, "uri", getOption("uri"), false);

             // create tags
             for (Map.Entry<String, Tag> entry : tags.entrySet()) {
                 Tag tag = entry.getValue();
                 if (tag.isInclude())
                     createElement(document, tagLib, tag);
             }

             // save to file
             TransformerFactory tf = TransformerFactory.newInstance();
             tf.setAttribute("indent-number", 2);
             Transformer transformer = tf.newTransformer();
             // if tiger would just format it :(
             // formatting bug in tiger
             // (http://bugs.sun.com/bugdatabase/view_bug.do?bug_id=6296446)

             transformer.setOutputProperty(OutputKeys.INDENT, "yes");
             transformer.setOutputProperty(OutputKeys.ENCODING, "UTF-8");

             //create output directory if it does not exists
             File outputFile = new File(getOption("outFile"));
             File parentDir = outputFile.getParentFile();
             if (!parentDir.exists())
                 parentDir.mkdirs();

             Source source = new DOMSource(document);
             Result result = new StreamResult(new OutputStreamWriter(
                     new FileOutputStream(outputFile)));
             transformer.transform(source, result);
         } catch (Exception e) {
             // oops we cannot throw checked exceptions
             throw new RuntimeException(e);
         }
     }

     private String getOption(String name) {
         // there is a bug in the 1.5 apt implementation:
         // http://bugs.sun.com/bugdatabase/view_bug.do?bug_id=6258929
         // this is a hack-around
         if (processingEnv.getOptions().containsKey(name)){
             return processingEnv.getOptions().get(name);
         }
         for (Map.Entry<String, String> entry : processingEnv.getOptions()
                 .entrySet()) {
             String key = entry.getKey();
             String[] splitted = key.split("=");
             if (splitted[0].equals("-A" + name))
                 return splitted[1];
         }
         return null;
     }

     private static void createElement(Document doc, Element tagLibElement, Tag tag) {
         Element tagElement = doc.createElement("tag");
         tagLibElement.appendChild(tagElement);
         appendTextNode(doc, tagElement, "description", tag.getDescription(),
                 true);
         appendTextNode(doc, tagElement, "name", tag.getName(), false);
         appendTextNode(doc, tagElement, "tag-class", tag.getTldTagClass(),
                 false);
         appendTextNode(doc, tagElement, "body-content",
                 tag.getTldBodyContent(), false);

         // save attributes
         for (TagAttribute attribute : tag.getAttributes()) {
             createElement(doc, tagElement, attribute);
         }

         appendTextNode(doc, tagElement, "dynamic-attributes", String.valueOf(tag.isAllowDynamicAttributes()), false);
     }

     private static void createElement(Document doc, Element tagElement, TagAttribute attribute) {
         Element attributeElement = doc.createElement("attribute");
         tagElement.appendChild(attributeElement);
         appendTextNode(doc, attributeElement, "description", attribute
                 .getDescription(), true);
         appendTextNode(doc, attributeElement, "name", attribute.getName(),
                 false);
         appendTextNode(doc, attributeElement, "required", String
                 .valueOf(attribute.isRequired()), false);
         appendTextNode(doc, attributeElement, "rtexprvalue", String
                 .valueOf(attribute.isRtexprvalue()), false);
     }

     private static void appendTextNode(Document doc, Element element, String name,
             String text, boolean cdata) {
         Text textNode = cdata ? doc.createCDATASection(text) : doc
                 .createTextNode(text);
         Element newElement = doc.createElement(name);
         newElement.appendChild(textNode);
         element.appendChild(newElement);
     }

     /**
      * Get values of annotation
      *
      * @param declaration The annotation declaration
      * @param type
      *            The type of the annotation
      * @return name->value map of annotation values
      */
     private Map<String, Object> getValues(javax.lang.model.element.Element element, TypeElement type) {
         Map<String, Object> values = new TreeMap<>();
         Collection<? extends AnnotationMirror> annotations = element
                 .getAnnotationMirrors();
         // iterate over the mirrors.

         for (AnnotationMirror mirror : annotations) {
             // if the mirror in this iteration is for our note declaration...
             if (mirror.getAnnotationType().asElement().equals(type)) {
                 for (Entry<? extends ExecutableElement, ? extends AnnotationValue> elementEntry : processingEnv.getElementUtils().getElementValuesWithDefaults(mirror).entrySet()) {
                     values.put(elementEntry.getKey().getSimpleName().toString(), elementEntry.getValue().getValue());
                 }
             }
         }

         return values;
     }

 }
	/*
	* $Id: $
	*
	* Licensed to the Apache Software Foundation (ASF) under one
	* or more contributor license agreements. See the NOTICE file
	* distributed with this work for additional information
	* regarding copyright ownership. The ASF licenses this file
	* to you 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.apache.struts.annotations.taglib.apt;

	import java.io.BufferedWriter;
	import java.io.File;
	import java.io.FileOutputStream;
	import java.io.FileWriter;
	import java.io.OutputStreamWriter;
	import java.util.Collection;
	import java.util.HashMap;
	import java.util.List;
	import java.util.Map;
	import java.util.Map.Entry;
	import java.util.Set;
	import java.util.TreeMap;

	import javax.annotation.processing.AbstractProcessor;
	import javax.annotation.processing.RoundEnvironment;
	import javax.annotation.processing.SupportedAnnotationTypes;
	import javax.lang.model.element.AnnotationMirror;
	import javax.lang.model.element.AnnotationValue;
	import javax.lang.model.element.ExecutableElement;
	import javax.lang.model.element.Modifier;
	import javax.lang.model.element.TypeElement;
	import javax.lang.model.type.NoType;
	import javax.lang.model.util.ElementFilter;
	import javax.xml.parsers.DocumentBuilder;
	import javax.xml.parsers.DocumentBuilderFactory;
	import javax.xml.transform.OutputKeys;
	import javax.xml.transform.Result;
	import javax.xml.transform.Source;
	import javax.xml.transform.Transformer;
	import javax.xml.transform.TransformerFactory;
	import javax.xml.transform.dom.DOMSource;
	import javax.xml.transform.stream.StreamResult;

	import org.w3c.dom.Document;
	import org.w3c.dom.Element;
	import org.w3c.dom.Text;

	import freemarker.template.Configuration;
	import freemarker.template.DefaultObjectWrapper;
	import freemarker.template.Template;

	@SupportedAnnotationTypes({TagAnnotationProcessor.TAG, TagAnnotationProcessor.TAG_ATTRIBUTE, TagAnnotationProcessor.TAG_SKIP_HIERARCHY})
	public class TagAnnotationProcessor extends AbstractProcessor {
	public static final String TAG = "org.apache.struts2.views.annotations.StrutsTag";
	public static final String TAG_ATTRIBUTE = "org.apache.struts2.views.annotations.StrutsTagAttribute";
	public static final String TAG_SKIP_HIERARCHY = "org.apache.struts2.views.annotations.StrutsTagSkipInheritance";

	private Map<String, Tag> tags = new TreeMap<>();

	@Override
	public boolean process(Set<? extends TypeElement> annotations, RoundEnvironment roundEnv) {
	// make sure all paramters were set
	checkOptions();

	// tags
	TypeElement tagAnnotationType = processingEnv.getElementUtils().getTypeElement(TAG);
	TypeElement attributeAnnotationType = processingEnv.getElementUtils().getTypeElement(TAG_ATTRIBUTE);
	TypeElement skipAnnotationType = processingEnv.getElementUtils().getTypeElement(TAG_SKIP_HIERARCHY);
	Set<? extends javax.lang.model.element.Element> tagDeclarations = roundEnv.getElementsAnnotatedWith(tagAnnotationType);
	Set<? extends javax.lang.model.element.Element> attributesDeclarations = roundEnv.getElementsAnnotatedWith(attributeAnnotationType);
	Set<? extends javax.lang.model.element.Element> skipDeclarations = roundEnv.getElementsAnnotatedWith(skipAnnotationType);

	// find Tags
	for (javax.lang.model.element.Element element : tagDeclarations) {
	Map<String, Object> values = getValues(element, tagAnnotationType);
	TypeElement type = (TypeElement) element;
	Tag tag = new Tag();
	tag.setDescription((String) values.get("description"));
	tag.setName((String) values.get("name"));
	tag.setTldBodyContent((String) values.get("tldBodyContent"));
	tag.setTldTagClass((String) values.get("tldTagClass"));
	tag.setDeclaredType(type.getQualifiedName().toString());
	tag.setAllowDynamicAttributes((Boolean) values.get("allowDynamicAttributes"));
	// add to map
	tags.put(type.getQualifiedName().toString(), tag);
	}

	//find attributes to be skipped
	for (javax.lang.model.element.Element declaration : skipDeclarations) {
	//types will be ignored when hierarchy is scanned
	if (declaration instanceof ExecutableElement) {
	ExecutableElement methodDeclaration = (ExecutableElement) declaration;
	String typeName = ((TypeElement) methodDeclaration.getEnclosingElement()).getQualifiedName().toString();
	String methodName = methodDeclaration.getSimpleName().toString();
	String name = String.valueOf(Character.toLowerCase(methodName
	.charAt(3)))
	+ methodName.substring(4);
	Tag tag = tags.get(typeName);
	if(tag != null) {
	//if it is on an abstract class, there is not tag for it at this point
	tags.get(typeName).addSkipAttribute(name);
	}
	}
	}

	// find Tags Attributes
	for (javax.lang.model.element.Element declaration : attributesDeclarations) {
	// type
	ExecutableElement methodDeclaration = (ExecutableElement) declaration;
	String typeName = ((TypeElement) methodDeclaration.getEnclosingElement()).getQualifiedName().toString();
	Map<String, Object> values = getValues(methodDeclaration,
	attributeAnnotationType);
	// create Attribute and apply values found
	TagAttribute attribute = new TagAttribute();
	String name = (String) values.get("name");
	if (name == null \|\| name.length() == 0) {
	// get name from method
	String methodName = methodDeclaration.getSimpleName().toString();
	name = String.valueOf(Character.toLowerCase(methodName
	.charAt(3)))
	+ methodName.substring(4);
	}
	values.put("name", name);
	populateTagAttributes(attribute, values);
	// add to map
	Tag parentTag = tags.get(typeName);
	if (parentTag != null){
	tags.get(typeName).addTagAttribute(attribute);
	}else {
	// an abstract or base class
	parentTag = new Tag();
	parentTag.setDeclaredType(typeName);
	parentTag.setInclude(false);
	parentTag.addTagAttribute(attribute);
	tags.put(typeName, parentTag);
	}
	}

	// we can't process the hierarchy on the first pass because
	// apt does not guarantee that the base classes will be processed
	// before their subclasses
	for (Map.Entry<String, Tag> entry : tags.entrySet()) {
	processHierarchy(entry.getValue());
	}

	// save
	saveAsXml();
	saveTemplates();
	return true;
	}

	private static void populateTagAttributes(TagAttribute attribute, Map<String, Object> values) {
	attribute.setRequired((Boolean) values.get("required"));
	attribute.setRtexprvalue((Boolean) values.get("rtexprvalue"));
	attribute.setDefaultValue((String) values.get("defaultValue"));
	attribute.setType((String) values.get("type"));
	attribute.setDescription((String) values.get("description"));
	attribute.setName((String) values.get("name"));
	}

	private void processHierarchy(Tag tag) {
	TypeElement type = processingEnv.getElementUtils().getTypeElement(tag.getDeclaredType());
	List<String> skipAttributes = tag.getSkipAttributes();
	while (type !=null && !(type instanceof NoType) && getAnnotation(type, TAG_SKIP_HIERARCHY) == null) {
	Tag parentTag = tags.get(type.getQualifiedName().toString());
	// copy parent annotations to this tag
	if(parentTag != null) {
	for(TagAttribute attribute : parentTag.getAttributes()) {
	if(!skipAttributes.contains(attribute.getName())){
	tag.addTagAttribute(attribute);
	}
	}
	} else {
	// Maybe the parent class is already compiled
	addTagAttributesFromParent(tag, type);
	}
	type = (TypeElement) processingEnv.getTypeUtils().asElement(type.getSuperclass());
	}
	}

	private void addTagAttributesFromParent(Tag tag, TypeElement type) {
	for (ExecutableElement method : ElementFilter.methodsIn(processingEnv.getElementUtils().getAllMembers(type))) {
	AnnotationMirror annotation = getAnnotation(method, TAG_ATTRIBUTE);
	if (method.getModifiers().contains(Modifier.PUBLIC) && annotation != null) {
	String name = String.valueOf(Character.toLowerCase(method.getSimpleName()
	.charAt(3)))
	+ method.getSimpleName().subSequence(4, method.getSimpleName().length());
	if (!tag.getSkipAttributes().contains(name)) {
	Map<String, Object> values = new HashMap<>();
	for (Entry<? extends ExecutableElement, ? extends AnnotationValue> entry : processingEnv.getElementUtils().getElementValuesWithDefaults(annotation).entrySet()) {
	values.put(entry.getKey().getSimpleName().toString(), entry.getValue().getValue());
	}
	TagAttribute attribute = new TagAttribute();
	populateTagAttributes(attribute, values);
	attribute.setName(name);
	tag.addTagAttribute(attribute);
	}
	}
	}
	}

	private AnnotationMirror getAnnotation(javax.lang.model.element.Element element, String annotationName) {
	TypeElement annotation = processingEnv.getElementUtils().getTypeElement(annotationName);
	if (element != null && element.getAnnotationMirrors() != null) {
	for (AnnotationMirror mirror : element.getAnnotationMirrors()) {
	if (mirror.getAnnotationType().asElement().equals(annotation)) {
	return mirror;
	}
	}
	}
	return null;
	}

	private void checkOptions() {
	if (getOption("tlibVersion") == null)
	throw new IllegalArgumentException("'tlibVersion' is missing");
	if (getOption("jspVersion") == null)
	throw new IllegalArgumentException("'jspVersion' is missing");
	if (getOption("shortName") == null)
	throw new IllegalArgumentException("'shortName' is missing");
	if (getOption("description") == null)
	throw new IllegalArgumentException("'description' is missing");
	if (getOption("displayName") == null)
	throw new IllegalArgumentException("'displayName' is missing");
	if (getOption("uri") == null)
	throw new IllegalArgumentException("'uri' is missing");
	if (getOption("outTemplatesDir") == null)
	throw new IllegalArgumentException("'outTemplatesDir' is missing");
	if (getOption("outFile") == null)
	throw new IllegalArgumentException("'outFile' is missing");
	}

	private void saveTemplates() {
	// freemarker configuration
	Configuration config = new Configuration();
	config.setClassForTemplateLoading(getClass(), "");
	config.setObjectWrapper(new DefaultObjectWrapper());

	try {
	// load template
	Template template = config.getTemplate("tag.ftl");
	String rootDir = (new File(getOption("outTemplatesDir")))
	.getAbsolutePath();
	for (Tag tag : tags.values()) {
	if (tag.isInclude()) {
	// model
	HashMap<String, Tag> root = new HashMap<>();
	root.put("tag", tag);

	try (BufferedWriter writer = new BufferedWriter(new FileWriter(
	new File(rootDir, tag.getName() + ".html")))){
	template.process(root, writer);
	}
	}
	}
	} catch (Exception e) {
	// oops we cannot throw checked exceptions
	throw new RuntimeException(e);
	}
	}

	private void saveAsXml() {
	DocumentBuilderFactory factory = DocumentBuilderFactory.newInstance();
	DocumentBuilder builder;

	try {
	// create xml document
	builder = factory.newDocumentBuilder();
	Document document = builder.newDocument();
	document.setXmlVersion("1.0");

	// taglib
	Element tagLib = document.createElement("taglib");
	tagLib.setAttribute("xmlns", "http://java.sun.com/xml/ns/j2ee");
	tagLib.setAttribute("xmlns:xsi", "http://www.w3.org/2001/XMLSchema-instance");
	tagLib.setAttribute("xsi:schemaLocation", "http://java.sun.com/xml/ns/j2ee http://java.sun.com/xml/ns/j2ee/web-jsptaglibrary_2_0.xsd");
	tagLib.setAttribute("version", getOption("jspVersion"));
	document.appendChild(tagLib);
	// tag lib attributes
	appendTextNode(document, tagLib, "description",
	getOption("description"), true);
	appendTextNode(document, tagLib, "display-name",
	getOption("displayName"), false);
	appendTextNode(document, tagLib, "tlib-version",
	getOption("tlibVersion"), false);
	appendTextNode(document, tagLib, "short-name",
	getOption("shortName"), false);
	appendTextNode(document, tagLib, "uri", getOption("uri"), false);

	// create tags
	for (Map.Entry<String, Tag> entry : tags.entrySet()) {
	Tag tag = entry.getValue();
	if (tag.isInclude())
	createElement(document, tagLib, tag);
	}

	// save to file
	TransformerFactory tf = TransformerFactory.newInstance();
	tf.setAttribute("indent-number", 2);
	Transformer transformer = tf.newTransformer();
	// if tiger would just format it :(
	// formatting bug in tiger
	// (http://bugs.sun.com/bugdatabase/view_bug.do?bug_id=6296446)

	transformer.setOutputProperty(OutputKeys.INDENT, "yes");
	transformer.setOutputProperty(OutputKeys.ENCODING, "UTF-8");

	//create output directory if it does not exists
	File outputFile = new File(getOption("outFile"));
	File parentDir = outputFile.getParentFile();
	if (!parentDir.exists())
	parentDir.mkdirs();

	Source source = new DOMSource(document);
	Result result = new StreamResult(new OutputStreamWriter(
	new FileOutputStream(outputFile)));
	transformer.transform(source, result);
	} catch (Exception e) {
	// oops we cannot throw checked exceptions
	throw new RuntimeException(e);
	}
	}

	private String getOption(String name) {
	// there is a bug in the 1.5 apt implementation:
	// http://bugs.sun.com/bugdatabase/view_bug.do?bug_id=6258929
	// this is a hack-around
	if (processingEnv.getOptions().containsKey(name)){
	return processingEnv.getOptions().get(name);
	}
	for (Map.Entry<String, String> entry : processingEnv.getOptions()
	.entrySet()) {
	String key = entry.getKey();
	String[] splitted = key.split("=");
	if (splitted[0].equals("-A" + name))
	return splitted[1];
	}
	return null;
	}

	private static void createElement(Document doc, Element tagLibElement, Tag tag) {
	Element tagElement = doc.createElement("tag");
	tagLibElement.appendChild(tagElement);
	appendTextNode(doc, tagElement, "description", tag.getDescription(),
	true);
	appendTextNode(doc, tagElement, "name", tag.getName(), false);
	appendTextNode(doc, tagElement, "tag-class", tag.getTldTagClass(),
	false);
	appendTextNode(doc, tagElement, "body-content",
	tag.getTldBodyContent(), false);

	// save attributes
	for (TagAttribute attribute : tag.getAttributes()) {
	createElement(doc, tagElement, attribute);
	}

	appendTextNode(doc, tagElement, "dynamic-attributes", String.valueOf(tag.isAllowDynamicAttributes()), false);
	}

	private static void createElement(Document doc, Element tagElement, TagAttribute attribute) {
	Element attributeElement = doc.createElement("attribute");
	tagElement.appendChild(attributeElement);
	appendTextNode(doc, attributeElement, "description", attribute
	.getDescription(), true);
	appendTextNode(doc, attributeElement, "name", attribute.getName(),
	false);
	appendTextNode(doc, attributeElement, "required", String
	.valueOf(attribute.isRequired()), false);
	appendTextNode(doc, attributeElement, "rtexprvalue", String
	.valueOf(attribute.isRtexprvalue()), false);
	}

	private static void appendTextNode(Document doc, Element element, String name,
	String text, boolean cdata) {
	Text textNode = cdata ? doc.createCDATASection(text) : doc
	.createTextNode(text);
	Element newElement = doc.createElement(name);
	newElement.appendChild(textNode);
	element.appendChild(newElement);
	}

	/**
	* Get values of annotation
	*
	* @param declaration The annotation declaration
	* @param type
	* The type of the annotation
	* @return name->value map of annotation values
	*/
	private Map<String, Object> getValues(javax.lang.model.element.Element element, TypeElement type) {
	Map<String, Object> values = new TreeMap<>();
	Collection<? extends AnnotationMirror> annotations = element
	.getAnnotationMirrors();
	// iterate over the mirrors.

	for (AnnotationMirror mirror : annotations) {
	// if the mirror in this iteration is for our note declaration...
	if (mirror.getAnnotationType().asElement().equals(type)) {
	for (Entry<? extends ExecutableElement, ? extends AnnotationValue> elementEntry : processingEnv.getElementUtils().getElementValuesWithDefaults(mirror).entrySet()) {
	values.put(elementEntry.getKey().getSimpleName().toString(), elementEntry.getValue().getValue());
	}
	}
	}

	return values;
	}

	}