/*
* This file is part of JGAP.
*
* JGAP offers a dual license model containing the LGPL as well as the MPL.
*
* For licensing information please see the file license.txt included with JGAP
* or have a look at the top of class org.jgap.Chromosome which representatively
* includes the JGAP license policy applicable for any file delivered with JGAP.
*/
package org.jgap.data;
import java.util.*;
/*
* Abstract base class for generating a document holding its elements in a
* tree. Inherit from this class and create your own DocumentBuilder.
* For example, have a look at XMLDocumentBuilder.
*
* @author Klaus Meffert
* @since 2.0
*/
public abstract class DocumentBuilderBase {
/**@todo add new class DocumentCreatorBase that reads in data written by
* DocumentBuilderBase */
/** String containing the CVS revision. Read out via reflection!*/
private final static String CVS_REVISION = "$Revision: 1.8 $";
/**
* Builds a document from the given input (input data + existing document).
* @param a_dataholder the input structure holding the data to
* be represented as a generic document
* @param a_document the document to put the elements in
* @throws Exception
* @return the document built up by adding elements
*
* @author Klaus Meffert
* @since 2.0
*/
public Object buildDocument(final IDataCreators a_dataholder,
final Object a_document)
throws Exception {
// Traverse over input structure.
// ------------------------------
IDataElementList tree = a_dataholder.getTree();
int len = tree.getLength();
IDataElement elem;
for (int i = 0; i < len; i++) {
elem = tree.item(i);
doTraverse(elem, a_document, null);
}
return a_document;
}
/**
* Recursive traversing over data tree containing elements to be transformed
* into tags.
* @param a_elem IDataElement
* @param a_document Document
* @param a_Element Element
* @throws Exception
*
* @author Klaus Meffert
* @since 2.0
*/
private void doTraverse(final IDataElement a_elem, final Object a_document,
final Object a_Element)
throws Exception {
String tagName = a_elem.getTagName();
Object element = createElementGeneric(a_document, a_Element, tagName);
Map attributes = a_elem.getAttributes();
Set keys = attributes.keySet();
Iterator it = keys.iterator();
String key, value;
while (it.hasNext()) {
key = (String) it.next();
value = (String) attributes.get(key);
setAttribute(element, key, value);
}
IDataElementList list = a_elem.getChildNodes();
if (list != null) {
for (int j = 0; j < list.getLength(); j++) {
IDataElement elem2 = list.item(j);
doTraverse(elem2, a_document, element);
}
}
}
/**
* Generically creates an element (Template Method).
* @param a_document could be used as factory to create the element with
* @param a_element null or existing element as template
* @param a_tagName name of tag to create for the element
* @return created element
*
* @author Klaus Meffert
* @since 2.0
*/
private Object createElementGeneric(final Object a_document,
final Object a_element,
final String a_tagName) {
Object element;
if (a_element == null) {
element = createElement(a_document, null, a_tagName);
documentAppendChild(a_document, element);
}
else {
Object xmlElement2 = createElement(a_document, a_element, a_tagName);
elementAppendChild(a_element, xmlElement2);
element = xmlElement2;
}
return element;
}
/**
* Append a child to a given document.
* @param a_document to append element on (e.g. org.w3c.dom.Document)
* @param a_element to append to document (e.g. org.w3c.com.Element)
* @return a_document with appended element (e.g. org.w3c.dom.Document)
*
* @author Klaus Meffert
* @since 2.0
*/
protected abstract Object documentAppendChild(Object a_document,
Object a_element);
/**
* Append a child to a given element.
* @param a_rootElement to append childElement on (e.g. org.w3c.com.Element)
* @param a_childElement to append to rootElement (e.g. org.w3c.com.Element)
* @return rootElement with appended childElement (e.g. org.w3c.com.Element)
*
* @author Klaus Meffert
* @since 2.0
*/
protected abstract Object elementAppendChild(Object a_rootElement,
Object a_childElement);
/**
* Creates an element with help for a given document.
* @param a_document could be used as factory to create the element with
* @param a_element null or existing element as template
* @param a_tagName name of tag to create for the element
* @return created element
*
* @author Klaus Meffert
* @since 2.0
*/
protected abstract Object createElement(Object a_document, Object a_element,
String a_tagName);
/**
* Sets an attribute for a given Element.
* @param a_element the Element to set an attribute for
* (e.g. org.w3c.com.Element)
* @param a_key the key of the attribute
* @param a_value the value of the attribute
*
* @author Klaus Meffert
* @since 2.0
*/
protected abstract void setAttribute(Object a_element, String a_key,
String a_value);
}