XMLSettingStorage.java

/*
  XMLSettingStorage.java

  (c) 2010-2012 Edward Swartz

  All rights reserved. This program and the accompanying materials
  are made available under the terms of the Eclipse Public License v1.0
  which accompanies this distribution, and is available at
  http://www.eclipse.org/legal/epl-v10.html
 */
package ejs.base.settings;

import java.io.IOException;
import java.io.InputStream;
import java.io.OutputStream;
import org.w3c.dom.Document;
import org.w3c.dom.Element;
import org.w3c.dom.Node;
import org.w3c.dom.NodeList;

import ejs.base.settings.ISettingSection.Type;
import ejs.base.utils.StorageException;
import ejs.base.utils.StreamXMLStorage;
import ejs.base.utils.XMLUtils;


/**
 * @author ejs
 *
 */
public class XMLSettingStorage implements ISettingStorage {

	/**
	 * 
	 */
	private static final String SECTION = "section";
	private ISettingStorageObjectHandler objectHandler;
	private final String rootElement;

	/**
	 * 
	 */
	public XMLSettingStorage(String rootElement) {
		this.rootElement = rootElement;
	}
	
	/* (non-Javadoc)
	 * @see v9t9.base.core.settings.ISettingStorage#setObjectHandler(v9t9.base.core.settings.ISettingStorageObjectHandler)
	 */
	public void setObjectHandler(ISettingStorageObjectHandler handler) {
		this.objectHandler = handler;
	}
	
	/* (non-Javadoc)
	 * @see v9t9.base.core.settings.ISettingStorage#load(java.io.File)
	 */
	public ISettingSection load(InputStream inputStream) throws IOException {
		StreamXMLStorage storage = new StreamXMLStorage();
		storage.setInputStream(inputStream);
		ISettingSection root = new SettingsSection(null);
		try {
			storage.load(rootElement);

			loadSection(root, storage.getDocumentElement());
			
		} catch (StorageException e) {
			if (e.getCause() instanceof IOException)
				throw (IOException) e.getCause();
			throw (IOException) new IOException().initCause(e);
		}
		return root;
	}

	/**
	 * @param section 
	 * @param documentElement
	 */
	private void loadSection(ISettingSection section, Element sectionElement) {
		
		NodeList nodeList = sectionElement.getChildNodes();
		Node node = nodeList.item(0);
		while (node != null) {
			if (node instanceof Element) {
				Element element = (Element) node;
				node = node.getNextSibling();
				String type = element.getNodeName();
				String valueStr = XMLUtils.getTrimmedText(element);
				String name = element.getAttribute("name");
				if (name.length() == 0) {
					if (type.equals("item")) {
						// compatibility
						loadDialogSettingsSection(section, sectionElement);
						return;
					}
					continue;
				}
				
				Object value = valueStr; 
				if (type.equals(Type.Int.getXmlName())) {
					try {
						value = Integer.parseInt(valueStr);
					} catch (NumberFormatException e) {
					}
				} else if (type.equals(Type.Double.getXmlName())) {
					try {
						value = Double.parseDouble(valueStr);
					} catch (NumberFormatException e) {
					}
				} else if (type.equals(Type.Boolean.getXmlName())) {
					value = Boolean.valueOf(valueStr);
				} else if (type.equals(Type.Object.getXmlName())) {
					if (objectHandler != null)
						value = objectHandler.decodeObject(valueStr);
					else
						value = valueStr;
				} else if (type.equals(Type.String.getXmlName())) {
					// done
				} else if (type.equals(Type.StringArray.getXmlName())) {
					Element[] stringElements = XMLUtils.getChildElementsNamed(element, Type.String.getXmlName());
					String[] strings = new String[stringElements.length];
					for (int i = 0; i < strings.length; i++) {
						strings[i] = XMLUtils.getTrimmedText(stringElements[i]).trim();
					}
					value = strings;
				} else if (type.equals(Type.Section.getXmlName())) {
					ISettingSection subSection = new SettingsSection(name);
					loadSection(subSection, element);
					value = subSection;
				} else {
					continue;
				}
				
				section.put(name, value);
			} else {
				node = node.getNextSibling();
			}
		}
	}

	/**
	 * @param section
	 * @param sectionElement
	 */
	private void loadDialogSettingsSection(ISettingSection section,
			Element sectionElement) {
		for (Element itemElement : XMLUtils.getChildElementsNamed(sectionElement, "item")) {
			String value = itemElement.getAttribute("value");
			String name = itemElement.getAttribute("key");
			if (name.length() == 0)
				continue;
			
			section.put(name, value);
		}
		
		for (Element listElement : XMLUtils.getChildElementsNamed(sectionElement, "list")) {
			String name = listElement.getAttribute("key");
			if (name.length() == 0)
				continue;
			
			Element[] stringElements = XMLUtils.getChildElementsNamed(listElement, "item");
			String[] strings = new String[stringElements.length];
			for (int i = 0; i < strings.length; i++) {
				strings[i] = stringElements[i].getAttribute("value");
			}
			section.put(name, strings);
		}
		
		for (Element subSectionElement : XMLUtils.getChildElementsNamed(sectionElement, SECTION)) {
			String name = subSectionElement.getAttribute("name");
			if (name.length() == 0)
				continue;
			
			ISettingSection subSection = new SettingsSection(name);
			loadDialogSettingsSection(subSection, subSectionElement);
			
			section.put(name, subSection);
		}
	}

	/* (non-Javadoc)
	 * @see v9t9.base.core.settings.ISettingStorage#save(java.io.File)
	 */
	public void save(OutputStream outputStream, ISettingSection section) throws IOException {
		StreamXMLStorage storage = new StreamXMLStorage();
		storage.setOutputStream(outputStream);
		try {
			storage.create(rootElement);
			saveSection(storage.getDocumentElement(), section);
			storage.save();
		} catch (StorageException e) {
			if (e.getCause() instanceof IOException)
				throw (IOException) e.getCause();
			throw (IOException) new IOException().initCause(e);
		}
	}
	
	private void saveSection(Element sectionElement, ISettingSection section) {
		if (section == null)
			return;

		// normal settings first
		Document doc = sectionElement.getOwnerDocument();
		for (ISettingSection.SettingEntry entry : section) {
			Element el = doc.createElement(entry.type.getXmlName());
			
			el.setAttribute("name", entry.name);
			if (entry.type == Type.Section) {
				continue;
			} else if (entry.type == Type.StringArray) {
				for (String str : (String[]) entry.value) {
					Element strel = el.getOwnerDocument().createElement(Type.String.getXmlName());
					el.appendChild(strel);
					XMLUtils.setText(strel, str);
				}
			} else {
				XMLUtils.setText(el, entry.value.toString());
			}
			sectionElement.appendChild(el);
		}
		
		// sections at end
		for (ISettingSection.SettingEntry entry : section) {
			if (entry.type == Type.Section) {
				Element el = doc.createElement(entry.type.getXmlName());
				el.setAttribute("name", entry.name);
				saveSection(el, (ISettingSection) entry.value);
				sectionElement.appendChild(el);
			}
		}
	}

}