XmlSerializer.java

/*  Copyright (c) 2006-2007, Vladimir Nikic
    All rights reserved.
	
    Redistribution and use of this software in source and binary forms, 
    with or without modification, are permitted provided that the following 
    conditions are met:
	
    * Redistributions of source code must retain the above
      copyright notice, this list of conditions and the
      following disclaimer.
	
    * Redistributions in binary form must reproduce the above
      copyright notice, this list of conditions and the
      following disclaimer in the documentation and/or other
      materials provided with the distribution.
	
    * The name of HtmlCleaner may not be used to endorse or promote 
      products derived from this software without specific prior
      written permission.

    THIS SOFTWARE IS PROVIDED BY THE COPYRIGHT HOLDERS AND CONTRIBUTORS "AS IS" 
    AND ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE 
    IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE 
    ARE DISCLAIMED. IN NO EVENT SHALL THE COPYRIGHT OWNER OR CONTRIBUTORS BE 
    LIABLE FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR 
    CONSEQUENTIAL DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF 
    SUBSTITUTE GOODS OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS 
    INTERRUPTION) HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN 
    CONTRACT, STRICT LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) 
    ARISING IN ANY WAY OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE 
    POSSIBILITY OF SUCH DAMAGE.
	
    You can contact Vladimir Nikic by sending e-mail to
    nikic_vladimir@yahoo.com. Please include the word "HtmlCleaner" in the
    subject line.
*/

package org.htmlcleaner;

import java.io.*;
import java.util.*;

/**
 * <p>Abstract XML serializer - contains common logic for descendants.</p>
 */
public abstract class XmlSerializer extends Serializer {

	protected XmlSerializer(CleanerProperties props) {
		super(props);
    }

    /**
     * @deprecated Use writeToStream() instead.
     */
    @Deprecated
    public void writeXmlToStream(TagNode tagNode, OutputStream out, String charset) throws IOException {
         super.writeToStream(tagNode, out, charset);
    }

    /**
     * @deprecated Use writeToStream() instead.
     */
    @Deprecated
    public void writeXmlToStream(TagNode tagNode, OutputStream out) throws IOException {
         super.writeToStream(tagNode, out);
    }

    /**
     * @deprecated Use writeToFile() instead.
     */
    @Deprecated
    public void writeXmlToFile(TagNode tagNode, String fileName, String charset) throws IOException {
        super.writeToFile(tagNode, fileName, charset);
    }

    /**
     * @deprecated Use writeToFile() instead.
     */
    @Deprecated
    public void writeXmlToFile(TagNode tagNode, String fileName) throws IOException {
        super.writeToFile(tagNode, fileName);
    }

    /**
     * @deprecated Use getAsString() instead.
     */
    @Deprecated
    public String getXmlAsString(TagNode tagNode, String charset) throws IOException {
        return super.getAsString(tagNode, charset);
    }

    /**
     * @deprecated Use getAsString() instead.
     */
    @Deprecated
    public String getXmlAsString(TagNode tagNode) throws IOException {
        return super.getAsString(tagNode);
    }

    /**
     * @deprecated Use write() instead.
     */
    @Deprecated
    public void writeXml(TagNode tagNode, Writer writer, String charset) throws IOException {
        super.write(tagNode, writer, charset);
    }

    protected String escapeXml(String xmlContent) {
        return Utils.escapeXml(xmlContent, props, false);
    }

    protected boolean dontEscape(TagNode tagNode) {
        return props.isUseCdataForScriptAndStyle() && isScriptOrStyle(tagNode);
    }

    protected boolean isMinimizedTagSyntax(TagNode tagNode) {
        final TagInfo tagInfo = props.getTagInfoProvider().getTagInfo(tagNode.getName());
        return tagNode.getChildren().size() == 0 &&
               ( props.isUseEmptyElementTags() || (tagInfo != null && tagInfo.isEmptyTag()) );
    }

    protected void serializeOpenTag(TagNode tagNode, Writer writer, boolean newLine) throws IOException {
        String tagName = tagNode.getName();

        if (Utils.isEmptyString(tagName)) {
            return;
        }
        
        boolean nsAware = props.isNamespacesAware();

        Set<String> definedNSPrefixes = null;
        Set<String> additionalNSDeclNeeded = null;

        String tagPrefix = Utils.getXmlNSPrefix(tagName);
        if (tagPrefix != null) {
            if (nsAware) {
                definedNSPrefixes = new HashSet<String>();
                tagNode.collectNamespacePrefixesOnPath(definedNSPrefixes);
                if ( !definedNSPrefixes.contains(tagPrefix) ) {
                    additionalNSDeclNeeded = new TreeSet<String>();
                    additionalNSDeclNeeded.add(tagPrefix);
                }
            } else {
                tagName = Utils.getXmlName(tagName);
            }
        }

        writer.write("<" + tagName);

        // write attributes
        for (Map.Entry<String, String> entry: tagNode.getAttributes().entrySet()) {
            String attName = entry.getKey();
            String attPrefix = Utils.getXmlNSPrefix(attName);
            if (attPrefix != null) {
                if (nsAware) {
                    // collect used namespace prefixes in attributes in order to explicitly define
                    // ns declaration if needed; otherwise it would be ill-formed xml
                    if (definedNSPrefixes == null) {
                        definedNSPrefixes = new HashSet<String>();
                        tagNode.collectNamespacePrefixesOnPath(definedNSPrefixes);
                    }
                    if ( !definedNSPrefixes.contains(attPrefix) ) {
                        if (additionalNSDeclNeeded == null) {
                            additionalNSDeclNeeded = new TreeSet<String>();
                        }
                        additionalNSDeclNeeded.add(attPrefix);
                    }
                } else {
                    attName = Utils.getXmlName(attName);
                }
            }
            writer.write(" " + attName + "=\"" + escapeXml(entry.getValue()) + "\"");
        }

        // write namespace declarations 
        if (nsAware) {
            Map<String, String> nsDeclarations = tagNode.getNamespaceDeclarations();
            if (nsDeclarations != null) {
                for (Map.Entry<String, String> entry: nsDeclarations.entrySet()) {
                    String prefix = entry.getKey();
                    String att = "xmlns";
                    if (prefix.length() > 0) {
                         att += ":" + prefix;
                    }
                    writer.write(" " + att + "=\"" + escapeXml(entry.getValue()) + "\"");
                }
            }
        }

        // write additional namespace declarations needed for this tag in order xml to be well-formed
        if (additionalNSDeclNeeded != null) {
            for (String prefix: additionalNSDeclNeeded) {
                writer.write(" xmlns:" + prefix + "=\"" + prefix + "\"");
            }
        }

        if ( isMinimizedTagSyntax(tagNode) ) {
            writer.write(" />");
            if (newLine) {
                writer.write("\n");
            }
        } else if (dontEscape(tagNode)) {
            writer.write("><![CDATA[");
        } else {
            writer.write(">");
        }
    }

    protected void serializeEndTag(TagNode tagNode, Writer writer, boolean newLine) throws IOException {
        String tagName = tagNode.getName();

        if (Utils.isEmptyString(tagName)) {
            return;
        }

        if (dontEscape(tagNode)) {
            writer.write("]]>");
        }

        if (Utils.getXmlNSPrefix(tagName) != null && !props.isNamespacesAware()) {
            tagName = Utils.getXmlName(tagName);
        }
        writer.write( "</" + tagName + ">" );

        if (newLine) {
            writer.write("\n");
        }
    }

}