TagTransformation.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
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      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
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    * The name of HtmlCleaner may not be used to endorse or promote
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      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
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    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.util.Map;
import java.util.LinkedHashMap;

/**
 * Describes how specified tag is transformed to another one, or is ignored during parsing
 */
public class TagTransformation {

    private String sourceTag;
    private String destTag;
    private boolean preserveSourceAttributes;
    private Map attributeTransformations;

    /**
     * Creates new tag transformation from source tag to target tag specifying whether
     * source tag attributes are preserved.
     * @param sourceTag Name of the tag to be transformed.
     * @param destTag Name of tag to which source tag is to be transformed.
     * @param preserveSourceAttributes Tells whether source tag attributes are preserved in transformation.
     */
    public TagTransformation(String sourceTag, String destTag, boolean preserveSourceAttributes) {
        this.sourceTag = sourceTag.toLowerCase();
        if (destTag == null) {
            this.destTag = null;
        } else {
            this.destTag = Utils.isValidXmlIdentifier(destTag) ? destTag.toLowerCase() : sourceTag;
        }
        this.preserveSourceAttributes = preserveSourceAttributes;
    }

    /**
     * Creates new tag transformation from source tag to target tag preserving
     * all source tag attributes.
     * @param sourceTag Name of the tag to be transformed.
     * @param destTag Name of tag to which source tag is to be transformed.
     */
    public TagTransformation(String sourceTag, String destTag) {
        this(sourceTag, destTag, true);
    }

    /**
     * Creates new tag transformation in which specified tag will be skipped (ignored)
     * during parsing process.
     * @param sourceTag
     */
    public TagTransformation(String sourceTag) {
        this(sourceTag, null);
    }

    /**
     * Adds new attribute transformation to this tag transformation. It tells how destination
     * attribute will look like. Small templating mechanism is used to describe attribute value:
     * all names between ${ and } inside the template are evaluated against source tag attributes.
     * That way one can make attribute values consist of mix of source tag attributes.
     *
     * @param targetAttName Name of the destination attribute 
     * @param transformationDesc Template describing attribute value.
     */
    public void addAttributeTransformation(String targetAttName, String transformationDesc) {
        if (attributeTransformations == null) {
            attributeTransformations = new LinkedHashMap();
        }
        attributeTransformations.put(targetAttName.toLowerCase(), transformationDesc);
    }

    /**
     * Adds new attribute transformation in which destination attrbute will not exists
     * (simply removes it from list of attributes).
     * @param targetAttName
     */
    public void addAttributeTransformation(String targetAttName) {
        addAttributeTransformation(targetAttName, null);
    }

    boolean hasAttributeTransformations() {
        return attributeTransformations != null;
    }

    String getSourceTag() {
        return sourceTag;
    }

    String getDestTag() {
        return destTag;
    }

    boolean isPreserveSourceAttributes() {
        return preserveSourceAttributes;
    }

    Map getAttributeTransformations() {
        return attributeTransformations;
    }
    
}