/*
    * Copyright 2002,2004 The Apache Software Foundation.
    *
    * 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.apache.commons.jelly.tags.xml;
  
  import java.io.File;
  import java.io.InputStream;
  import java.io.Reader;
  import java.io.StringReader;
  import java.net.MalformedURLException;
  import java.net.URL;
  
  import org.apache.commons.jelly.JellyTagException;
  import org.apache.commons.jelly.TagSupport;
  import org.apache.commons.jelly.XMLOutput;
  import org.apache.commons.logging.Log;
  import org.apache.commons.logging.LogFactory;
  import org.dom4j.Document;
  import org.dom4j.DocumentException;
  import org.dom4j.io.SAXContentHandler;
  import org.dom4j.io.SAXReader;
  import org.xml.sax.SAXException;
  
  /***
   * An abstract base class for any tag which parsers its body as XML.
   *
   * @author <a href="mailto:jstrachan@apache.org">James Strachan</a>
   * @version $Revision: 155420 $
   */
  public abstract class ParseTagSupport extends TagSupport {
  
      /*** The Log to which logging calls will be made. */
      private static final Log log = LogFactory.getLog(ParseTagSupport.class);
  
      /*** The variable that will be generated for the document */
      private String var;
  
      /*** The markup text to be parsed */
      private String text;
  
      /*** The SAXReader used to parser the document */
      private SAXReader saxReader;
  
      public ParseTagSupport() {
      }
  
  
      // Properties
      //-------------------------------------------------------------------------
      /*** The variable name that will be used for the Document variable created
       */
      public String getVar() {
          return var;
      }
  
      /*** Sets the variable name that will be used for the Document variable created
       */
      public void setVar(String var) {
          this.var = var;
      }
  
      /***
       * Returns the text to be parsed
       * @return String
       */
      public String getText() {
          return text;
      }
  
      /***
       * Sets the text to be parsed by this parser
       * @param text The text to be parsed by this parser
       */
      public void setText(String text) {
          this.text = text;
      }
  
  
      /*** @return the SAXReader used for parsing, creating one lazily if need be  */
      public SAXReader getSAXReader() throws SAXException {
          if (saxReader == null) {
              saxReader = createSAXReader();
          }
          return saxReader;
      }
  
      /*** Sets the SAXReader used for parsing */
     public void setSAXReader(SAXReader saxReader) {
         this.saxReader = saxReader;
     }
 
 
     // Implementation methods
     //-------------------------------------------------------------------------
 
     /***
      * Factory method to create a new SAXReader
      */
     protected abstract SAXReader createSAXReader() throws SAXException;
 
 
     /***
      * Parses the body of this tag and returns the parsed document
      */
     protected Document parseBody(XMLOutput output) throws JellyTagException {
         SAXContentHandler handler = new SAXContentHandler();
         XMLOutput newOutput = new XMLOutput(handler);
 
         try {
             handler.startDocument();
             invokeBody( newOutput);
             handler.endDocument();
             return handler.getDocument();
         } catch (SAXException e) {
             throw new JellyTagException(e);
         }
     }
 
     /***
      * Parses the give piece of text as being markup
      */
     protected Document parseText(String text) throws JellyTagException {
         if ( log.isDebugEnabled() ) {
             log.debug( "About to parse: " + text );
         }
 
         try {
             return getSAXReader().read( new StringReader( text ) );
         }
         catch (DocumentException e) {
             throw new JellyTagException(e);
         }
         catch (SAXException e) {
             throw new JellyTagException(e);
         }
     }
 
     /***
      * Parses the given source
      */
     protected Document parse(Object source) throws JellyTagException {
         // #### we should allow parsing to output XML events to
         // the output if no var is specified
 
 
         try {
             if (source instanceof String) {
                 String uri = (String) source;
                 source = context.getResource(uri);
             }
 
             if (source instanceof URL) {
                 return getSAXReader().read((URL) source);
             }
             else if (source instanceof File) {
                 return getSAXReader().read((File) source);
             }
             else if (source instanceof Reader) {
                 return getSAXReader().read((Reader) source);
             }
             else if (source instanceof InputStream) {
                 return getSAXReader().read((InputStream) source);
             }
             else {
                 throw new IllegalArgumentException(
                     "Invalid source argument. Must be a String, Reader, InputStream or URL."
                         + " Was type; "
                         + source.getClass().getName()
                         + " with value: "
                         + source);
             }
         }
         catch (DocumentException e) {
             throw new JellyTagException(e);
         }
         catch (SAXException e) {
             throw new JellyTagException(e);
         }
         catch (MalformedURLException e) {
             throw new JellyTagException(e);
         }
     }
 }