/**
* Copyright 2010 JBoss Inc
*
* Licensed under the Apache License, Version 2.0 (the "License");
* you may not use this file except in compliance with the License.
* You may obtain a copy of the License at
*
* http://www.apache.org/licenses/LICENSE-2.0
*
* Unless required by applicable law or agreed to in writing, software
* distributed under the License is distributed on an "AS IS" BASIS,
* WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
* See the License for the specific language governing permissions and
* limitations under the License.
*/
package org.eclipse.webdav.dom;
import java.util.Enumeration;
import java.util.NoSuchElementException;
import org.eclipse.webdav.Policy;
import org.w3c.dom.Document;
import org.w3c.dom.Element;
/**
* An element editor for sets of hrefs, for example, the WebDAV
* predecessor-set element.
* <p>
* <b>Note:</b> This class/interface is part of an interim API that is still under
* development and expected to change significantly before reaching stability.
* It is being made available at this early stage to solicit feedback from pioneering
* adopters on the understanding that any code that uses this API will almost
* certainly be broken (repeatedly) as the API evolves.
* </p>
*/
public class HrefSet extends ElementEditor {
/**
* Creates a new editor on the given href set element with the given
* name. The element is assumed to be well formed.
*
* @param root an href element
* @param name the name of the element that this editor is expected
* to manipulate.
* @throws MalformedElementException if there is reason to
* believe that the element is not well formed
*/
public HrefSet(Element root, QualifiedName name) throws MalformedElementException {
super(root, name.getLocalName());
ensure(DAV_NS.equals(name.getQualifier()), Policy.bind("ensure.mustHaveDAVQualifier")); //$NON-NLS-1$
}
/**
* Adds the given href to the end of the set of hrefs. If the href
* already exists it is not added.
*
* @param href the href to add to the end of the set of hrefs
*/
public void addHref(String href) {
String encodedHref = encodeHref(href);
if (isDuplicate(encodedHref))
return;
appendChild(root, "href", encodedHref); //$NON-NLS-1$
}
/**
* Creates a new href set element with the given name and sets it as
* the root of the given document. Returns an editor on the new href set
* element. The document must not be <code>null</code>, and must not
* already have a root element.
*
* @param document the document that will become the root of a new
* href set element
* @return an element editor on a href set element
*/
public static HrefSet create(Document document, QualifiedName name) {
Assert.isNotNull(document);
Assert.isTrue(document.getOwnerDocument() == null);
Assert.isNotNull(name);
Assert.isTrue(DAV_NS.equals(name.getQualifier()));
Element element = create(document, name.getLocalName());
try {
return new HrefSet(element, name);
} catch (MalformedElementException e) {
Assert.isTrue(false, Policy.bind("assert.internalError")); //$NON-NLS-1$
return null; // Never reached.
}
}
/**
* Returns an <code>Enumeration</code> over the set of hrefs.
*
* @return an <code>Enumeration</code> of href <code>String</code>s
*/
public Enumeration getHrefs() {
final Element firstHref = getFirstChild(root, "href"); //$NON-NLS-1$
Enumeration e = new Enumeration() {
Element currentHref = firstHref;
public boolean hasMoreElements() {
return currentHref != null;
}
public Object nextElement() {
if (!hasMoreElements())
throw new NoSuchElementException();
String href = getFirstText(currentHref);
currentHref = getNextSibling(currentHref, "href"); //$NON-NLS-1$
return decodeHref(href);
}
};
return e;
}
/**
* Inserts the given newHref after the given refHref in the set of
* hrefs. If newHref already exists it is not inserted.
*
* @param refHref the existing href
* @param newHref the new href to be inserted after the existing href
*/
public void insertHrefAfter(String refHref, String newHref) {
String refHrefEncoded = encodeHref(refHref);
String newHrefEncoded = encodeHref(newHref);
if (isDuplicate(newHrefEncoded))
return;
Element child = getFirstChild(root, "href"); //$NON-NLS-1$
while (child != null) {
if (refHrefEncoded.equals(getFirstText(child))) {
Element nextSibling = getNextSibling(child, "href"); //$NON-NLS-1$
if (nextSibling == null)
appendChild(root, "href", newHrefEncoded); //$NON-NLS-1$
else
insertBefore(nextSibling, "href", newHrefEncoded); //$NON-NLS-1$
return;
}
child = getNextSibling(child, "href"); //$NON-NLS-1$
}
Assert.isTrue(false, Policy.bind("assert.noHrefRef")); //$NON-NLS-1$
}
/**
* Inserts the given newHref before the given refHref in the set of
* hrefs. If newHref already exists it is not inserted.
*
* @param refHref the existing href
* @param newHref the new href to be inserted before the existing href
*/
public void insertHrefBefore(String newHref, String refHref) {
String refHrefEncoded = encodeHref(refHref);
String newHrefEncoded = encodeHref(newHref);
if (isDuplicate(newHrefEncoded))
return;
Element child = getFirstChild(root, "href"); //$NON-NLS-1$
while (child != null) {
if (refHrefEncoded.equals(getFirstText(child))) {
insertBefore(child, "href", newHrefEncoded); //$NON-NLS-1$
return;
}
child = getNextSibling(child, "href"); //$NON-NLS-1$
}
Assert.isTrue(false, Policy.bind("assert.noHrefRef")); //$NON-NLS-1$
}
protected boolean isDuplicate(String encodedHref) {
Element child = getFirstChild(root, "href"); //$NON-NLS-1$
while (child != null) {
if (encodedHref.equals(getFirstText(child)))
return true;
child = getNextSibling(child, "href"); //$NON-NLS-1$
}
return false;
}
/**
* Remove the given href from the set of hrefs.
*
* @param href the href to remove from the set of hrefs
*/
public void removeHref(String href) {
String encodedHref = encodeHref(href);
Element child = getFirstChild(root, "href"); //$NON-NLS-1$
while (child != null) {
if (encodedHref.equals(getFirstText(child))) {
root.removeChild(child);
return;
}
child = getNextSibling(child, "href"); //$NON-NLS-1$
}
}
}