Java tutorial
// Copyright 2006 Chibacon /* * * Artistic License * * Preamble * * The intent of this document is to state the conditions under which a Package may be copied, such that * the Copyright Holder maintains some semblance of artistic control over the development of the * package, while giving the users of the package the right to use and distribute the Package in a * more-or-less customary fashion, plus the right to make reasonable modifications. * * Definitions: * * "Package" refers to the collection of files distributed by the Copyright Holder, and derivatives * of that collection of files created through textual modification. * * "Standard Version" refers to such a Package if it has not been modified, or has been modified * in accordance with the wishes of the Copyright Holder. * * "Copyright Holder" is whoever is named in the copyright or copyrights for the package. * * "You" is you, if you're thinking about copying or distributing this Package. * * "Reasonable copying fee" is whatever you can justify on the basis of media cost, duplication * charges, time of people involved, and so on. 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THIS PACKAGE IS PROVIDED "AS IS" AND WITHOUT ANY EXPRESS OR IMPLIED * WARRANTIES, INCLUDING, WITHOUT LIMITATION, THE IMPLIED WARRANTIES OF * MERCHANTIBILITY AND FITNESS FOR A PARTICULAR PURPOSE. * */ package org.chiba.xml.xforms; import org.apache.commons.logging.Log; import org.apache.commons.logging.LogFactory; import org.apache.xerces.dom.ElementImpl; import org.apache.xerces.dom.NodeImpl; import org.chiba.xml.events.ChibaEventNames; import org.chiba.xml.ns.NamespaceConstants; import org.chiba.xml.ns.NamespaceResolver; import org.chiba.xml.xforms.core.Model; import org.chiba.xml.xforms.exception.XFormsException; import org.chiba.xml.xforms.ui.BindingElement; import org.w3c.dom.Element; import org.w3c.dom.Node; import org.w3c.dom.events.Event; import org.w3c.dom.events.EventTarget; import java.util.HashMap; /** * Superclass for all XForms elements. This includes either all elements from * the XForms namespace and all bound elements which may be from foreign * namespaces but wear XForms binding attributes. Custom elements also extend * this class. * * @author Joern Turner * @author Ulrich Nicolas Lissé * @version $Id: XFormsElement.java,v 1.1 2009/02/17 09:00:54 civilis Exp $ */ public abstract class XFormsElement implements XFormsConstants { /** * the Container object holding the whole DOM Document of this form */ protected Container container = null; /** * the annotated DOM Element */ protected Element element = null; /** * the DOM EventTarget */ protected EventTarget target = null; /** * the Model object of this XFormsElement */ protected Model model = null; /** * the id of this Element */ protected String id; /** * the original id of this Element (when repeated) */ protected String originalId; /** * the xforms prefix used in this Document */ protected String xformsPrefix = null; /** * Logger */ protected static Log LOGGER = LogFactory.getLog(XFormsElement.class); /** * Creates a new XFormsElement object. * * @param element the DOM Element annotated by this object */ public XFormsElement(Element element) { this.element = element; this.target = (EventTarget) element; this.container = getContainerObject(); this.xformsPrefix = NamespaceResolver.getPrefix(this.element, NamespaceConstants.XFORMS_NS); // todo: perform id mgmt and registration explicitely in a component builder if (this.element.hasAttributeNS(null, "id")) { this.id = this.element.getAttributeNS(null, "id"); } else { this.id = this.container.generateId(); this.element.setAttributeNS(null, "id", this.id); } registerId(); } /** * Creates a new XFormsElement object. * * @param element the DOM Element annotated by this object * @param model the Model object of this XFormsElement */ public XFormsElement(Element element, Model model) { this(element); this.model = model; } // lifecycle methods /** * Performs element init. * * @throws XFormsException if any error occurred during init. */ public abstract void init() throws XFormsException; /** * Performs element disposal. * * @throws XFormsException if any error occurred during disposal. */ public abstract void dispose() throws XFormsException; /** * returns the Container object of this Element. * * @return Container object of this Element */ public Container getContainerObject() { return (Container) ((ElementImpl) this.element.getOwnerDocument().getDocumentElement()).getUserData(); } /** * Returns the DOM element of this element. * * @return the DOM element of this element. */ public Element getElement() { return this.element; } // member access methods /** * Returns the global id of this element. * * @return the global id of this element. */ public String getId() { return this.id; } /** * Returns the context model of this element. * * @return the context model of this element. */ public Model getModel() { return this.model; } /** * returns the parent XFormsElement object of the DOM parent Node if any or * null otherwise. * * @return the parent XFormsElement object of the DOM parent Node if any or * null otherwise. */ public XFormsElement getParentObject() { return (XFormsElement) ((ElementImpl) this.element.getParentNode()).getUserData(); } /** * Returns the DOM event target of this element. * * @return the DOM event target of this element. */ public EventTarget getTarget() { return this.target; } /** * returns the value of a given XForms attribute * @param name the localname of the attribute * @return the value of the attribute as string or null if attribute is not found */ public String getXFormsAttribute(String name) { return getXFormsAttribute(this.element, name); } /** * returns the value of a given XForms attribute. First tries to fetch it from * the XForms namespace. If not successful tries to find it in the null namespace. * * @param name the localname of the attribute * @return the value of the attribute as string or null if attribute is not found */ public static String getXFormsAttribute(Element element, String name) { if (element.hasAttributeNS(NamespaceConstants.XFORMS_NS, name)) { return element.getAttributeNS(NamespaceConstants.XFORMS_NS, name); } if (element.hasAttributeNS(null, name)) { return element.getAttributeNS(null, name); } return null; } // id handling /** * Registers this element with the container. */ public void registerId() { this.container.register(this); if (this.originalId != null) { String tmpId = this.id; this.id = this.originalId; this.container.register(this); this.id = tmpId; } } /** * Deregisters this element from the container. */ public void deregister() { this.container.deregister(this); } /** * Stores the original id and sets the generated id as new id. * * @param generatedId the generated id. */ public void setGeneratedId(String generatedId) throws XFormsException { this.originalId = this.id; this.id = generatedId; this.element.setAttributeNS(null, "id", this.id); if (this.model.isReady()) { // dispatch internal chiba event HashMap map = new HashMap(); map.put("originalId", this.originalId); this.container.dispatch(this.target, ChibaEventNames.ID_GENERATED, map); } } // standard methods /** * Check wether this object and the specified object are equal. * * @param object the object in question. * @return <code>true</code> if this object and the specified object are * equal, <code>false</code> otherwise. */ public boolean equals(Object object) { if (object == null) { return false; } if (object == this) { return true; } if (!(object instanceof XFormsElement)) { return false; } return ((XFormsElement) object).getId().equals(getId()); } /** * Returns a string representation of this object. * * @return a string representation of this object. */ public String toString() { return "[" + getElement().getNodeName() + ":" + id + "]"; } /** * Returns the logger object. * * @return the logger object. */ protected Log getLogger() { return LOGGER; } /** * returns true if the current events' default processing is cancelled by * some listener on the element itself e.g. * <pre> * <model ev:event="xforms-revalidate" ev:defaultAction="cancel"> * </pre> * would cancel all revalidation (the default action for this event) for * this model. * * @param event the event to investigate * @return true if the current events' default processing is cancelled * @deprecated */ protected boolean isCancelled(Event event) { if (event.getCancelable()) { // todo: check parents with phase='capture' for this event if (element.hasAttributeNS(NamespaceConstants.XMLEVENTS_NS, "event")) { String s = element.getAttributeNS(NamespaceConstants.XMLEVENTS_NS, "event"); if (s.equals(event.getType())) { if (element.getAttributeNS(NamespaceConstants.XMLEVENTS_NS, "defaultAction").equals("cancel")) { return true; //performDefault gets cancelled by cancelling listener on this model } } } } return false; } /** * determines the context path for given XFormsElement * * @param start the XFormsElement for which the parentContextPath will be calculated * @return the parent context path or null if no parent exists */ protected String getParentContextPath(Node start) { String result = null; NodeImpl parent = (NodeImpl) start.getParentNode(); if (parent == null) return null; Object o = parent.getUserData(); if (o instanceof XFormsElement) { XFormsElement xCurrent = (XFormsElement) parent.getUserData(); if (xCurrent == null) { getParentContextPath(parent); } if (xCurrent instanceof BindingElement) { if (((BindingElement) xCurrent).isBound()) { String locationPath = ((BindingElement) xCurrent).getLocationPath(); return locationPath; } else { result = getParentContextPath(parent.getParentNode()); } } } else { return getParentContextPath(parent); } return result; } } // end of class