/*

  * Copyright 2004-2008 the Seasar Foundation and the Others.

  *

  * 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.seasar.uruma.component.factory;

 import java.io.File;

 import java.io.InputStream;

 import javax.xml.XMLConstants;

 import javax.xml.parsers.SAXParser;

 import javax.xml.parsers.SAXParserFactory;

 import javax.xml.transform.stream.StreamSource;

 import javax.xml.validation.Schema;

 import javax.xml.validation.SchemaFactory;

 import org.seasar.framework.container.factory.ClassPathResourceResolver;

 import org.seasar.framework.exception.ResourceNotFoundRuntimeException;

 import org.seasar.framework.exception.SAXRuntimeException;

 import org.seasar.framework.util.InputStreamUtil;

 import org.seasar.framework.util.SAXParserFactoryUtil;

 import org.seasar.framework.xml.SaxHandler;

 import org.seasar.framework.xml.SaxHandlerParser;

 import org.seasar.framework.xml.TagHandlerContext;

 import org.seasar.uruma.component.Template;

 import org.seasar.uruma.core.UrumaConstants;

 import org.xml.sax.SAXException;

 /**

  * 画面定義 XML ファイルを読み込み、コンポーネントツリーを生成するためのクラスです。<br />

  * 

  * @author y-komori

  */

 public class ComponentTreeBuilder {

     protected ClassPathResourceResolver resolver = new ClassPathResourceResolver();

     /**

      * 指定されたパスの画面定義XMLを読み込み、コンポーネントツリーを生成します。<br />

      * 

      * @param path

      *            画面定義XMLのパス

      * @return {@link Template} オブジェクト

      */

     public Template build(final String path) {

         final SaxHandlerParser parser = createSaxHandlerParser(path);

         final InputStream is = getInputStream(path);

         try {

             Template template = (Template) parser.parse(is, path);

             return template;

         } finally {

             InputStreamUtil.close(is);

         }

     }

     protected InputStream getInputStream(final String path) {

         final InputStream is = resolver.getInputStream(path);

         if (is == null) {

             throw new ResourceNotFoundRuntimeException(path);

         }

         return is;

     }

     protected SaxHandlerParser createSaxHandlerParser(final String path) {

         System.setProperty("javax.xml.parsers.SAXParserFactory",

                 "com.sun.org.apache.xerces.internal.jaxp.SAXParserFactoryImpl");

         final SAXParserFactory factory = SAXParserFactoryUtil.newInstance();

         factory.setNamespaceAware(true);

         final SchemaFactory schemaFactory = SchemaFactory

                 .newInstance(XMLConstants.W3C_XML_SCHEMA_NS_URI);

         InputStream is = getInputStream(UrumaConstants.SCHEMA_PATH);

         try {

             final Schema schema = schemaFactory.newSchema(new StreamSource(is));

             factory.setSchema(schema);

         } catch (SAXException ex) {

             throw new SAXRuntimeException(ex);

         } finally {

             InputStreamUtil.close(is);

         }

         final SAXParser saxParser = SAXParserFactoryUtil.newSAXParser(factory);

         final SaxHandler handler = createSaxHandler();

         createContext(handler, path);

         return new SaxHandlerParser(handler, saxParser);

     }

     protected SaxHandler createSaxHandler() {

         SaxHandler handler = new SaxHandler(new UrumaTagHandlerRule());

         return handler;

     }

     protected void createContext(final SaxHandler handler, final String path) {

         final TagHandlerContext context = handler.getTagHandlerContext();

         context.addParameter(UrumaTagHandler.PARAM_PATH, path);

         context.addParameter(UrumaTagHandler.PARAM_BASE_PATH, (new File(path))

                 .getParent());

     }

 }