Copyright (c) 2004, 2009 IBM Corporation and others.
This program and the accompanying materials
are made available under the terms of the Eclipse Public License 2.0
which accompanies this distribution, and is available at
https://www.eclipse.org/legal/epl-2.0/
SPDX-License-Identifier: EPL-2.0
Contributors:
    IBM Corporation - initial API and implementation
/*******************************************************************************
 * Copyright (c) 2004, 2009 IBM Corporation and others.
 *
 * This program and the accompanying materials
 * are made available under the terms of the Eclipse Public License 2.0
 * which accompanies this distribution, and is available at
 * https://www.eclipse.org/legal/epl-2.0/
 *
 * SPDX-License-Identifier: EPL-2.0
 *
 * Contributors:
 *     IBM Corporation - initial API and implementation
 *******************************************************************************/
package org.eclipse.core.internal.registry;

import org.eclipse.core.runtime.*;

Since:
3.1/**
 * @since 3.1
 */
public class ConfigurationElementHandle extends Handle implements IConfigurationElement {
	static final ConfigurationElementHandle[] EMPTY_ARRAY = new ConfigurationElementHandle[0];

	public ConfigurationElementHandle(IObjectManager objectManager, int id) {
		super(objectManager, id);
	}

	protected ConfigurationElement getConfigurationElement() {
		return (ConfigurationElement) objectManager.getObject(getId(), RegistryObjectManager.CONFIGURATION_ELEMENT);
	}

	protected boolean shouldPersist() {
		return getConfigurationElement().shouldPersist();
	}

	@Override
	public String getAttribute(String propertyName) {
		return getConfigurationElement().getAttribute(propertyName);
	}

	@Override
	public String getAttribute(String attrName, String locale) {
		return getConfigurationElement().getAttribute(attrName, locale);
	}

	@Override
	public String[] getAttributeNames() {
		return getConfigurationElement().getAttributeNames();
	}

	@Override
	public IConfigurationElement[] getChildren() {
		ConfigurationElement actualCe = getConfigurationElement();
		if (actualCe.noExtraData()) {
			return (IConfigurationElement[]) objectManager.getHandles(actualCe.getRawChildren(), RegistryObjectManager.CONFIGURATION_ELEMENT);
		}
		return (IConfigurationElement[]) objectManager.getHandles(actualCe.getRawChildren(), RegistryObjectManager.THIRDLEVEL_CONFIGURATION_ELEMENT);
	}

	@Override
	public Object createExecutableExtension(String propertyName) throws CoreException {
		try {
			return getConfigurationElement().createExecutableExtension(propertyName);
		} catch (InvalidRegistryObjectException e) {
			Status status = new Status(IStatus.ERROR, RegistryMessages.OWNER_NAME, IRegistryConstants.PLUGIN_ERROR, "Invalid registry object", e); //$NON-NLS-1$
			if (objectManager instanceof RegistryObjectManager)
				((RegistryObjectManager) objectManager).getRegistry().log(status);
			throw new CoreException(status);
		}
	}

	@Override
	public String getAttributeAsIs(String name) {
		return getConfigurationElement().getAttributeAsIs(name);
	}

	@Override
	public IConfigurationElement[] getChildren(String name) {
		ConfigurationElement actualCE = getConfigurationElement();
		ConfigurationElement[] children = (ConfigurationElement[]) objectManager.getObjects(actualCE.getRawChildren(), actualCE.noExtraData() ? RegistryObjectManager.CONFIGURATION_ELEMENT : RegistryObjectManager.THIRDLEVEL_CONFIGURATION_ELEMENT);
		if (children.length == 0)
			return ConfigurationElementHandle.EMPTY_ARRAY;

		IConfigurationElement[] result = new IConfigurationElement[1];
		int idx = 0;
		for (ConfigurationElement child : children) {
			if (child.getName().equals(name)) {
				if (idx != 0) {
					IConfigurationElement[] copy = new IConfigurationElement[result.length + 1];
					System.arraycopy(result, 0, copy, 0, result.length);
					result = copy;
				}
				result[idx++] = (IConfigurationElement) objectManager.getHandle(child.getObjectId(), actualCE.noExtraData() ? RegistryObjectManager.CONFIGURATION_ELEMENT : RegistryObjectManager.THIRDLEVEL_CONFIGURATION_ELEMENT);
			}
		}
		if (idx == 0)
			return ConfigurationElementHandle.EMPTY_ARRAY;
		return result;
	}

	@Override
	public IExtension getDeclaringExtension() {
		Object result = this;
		while (!((result = ((ConfigurationElementHandle) result).getParent()) instanceof ExtensionHandle)) { /*do nothing*/
		}
		return (IExtension) result;
	}

	@Override
	public String getName() {
		return getConfigurationElement().getName();
	}

	@Override
	public Object getParent() {
		ConfigurationElement actualCe = getConfigurationElement();
		return objectManager.getHandle(actualCe.parentId, actualCe.parentType);
	}

	@Override
	public String getValue() {
		return getConfigurationElement().getValue();
	}

	@Override
	public String getValue(String locale) {
		return getConfigurationElement().getValue(locale);
	}

	@Override
	public String getValueAsIs() {
		return getConfigurationElement().getValueAsIs();
	}

	@Override
	RegistryObject getObject() {
		return getConfigurationElement();
	}

	// Method left for backward compatibility only
	@Override
	public String getNamespace() {
		return getContributor().getName();
	}

	@Override
	public String getNamespaceIdentifier() {
		// namespace name is determined by the contributing extension
		return getDeclaringExtension().getNamespaceIdentifier();
	}

	@Override
	public IContributor getContributor() {
		return getConfigurationElement().getContributor();
	}

	@Override
	public boolean isValid() {
		try {
			getConfigurationElement();
		} catch (InvalidRegistryObjectException e) {
			return false;
		}
		return true;
	}

	@Override
	public int getHandleId() {
		return getId();
	}

	
WARNING: this method must return string containing getHandleId() identifier, because some clients might have misused previously returned Object.toString() value which was in fact just Handle.hashCode() value which in turn was alwas the value of getHandleId(). 

Please read bug 515587 for details.
/**
	 * <b>WARNING</b>: this method <b>must</b> return string containing {@link #getHandleId()} identifier, because some clients might have
	 * misused previously returned {@link Object#toString()} value which was in fact just {@link #hashCode()} value which
	 * in turn was alwas the value of {@link #getHandleId()}.
	 * <p>
	 * Please read <a href="https://bugs.eclipse.org/bugs/show_bug.cgi?id=515587#c0">bug 515587</a> for details.
	 */
	@Override
	public String toString() {
		StringBuilder sb = new StringBuilder();
		sb.append("ConfigurationElementHandle ["); //$NON-NLS-1$
		sb.append("name: "); //$NON-NLS-1$
		sb.append(getName());
		String id = getAttribute("id"); //$NON-NLS-1$
		if (id != null && id.length() > 0) {
			sb.append(", id: ").append(id); //$NON-NLS-1$
		}
		String value = getValue();
		if (value != null) {
			sb.append(", value: ").append(value); //$NON-NLS-1$
		}
		sb.append(", handle id: ").append(getHandleId()); //$NON-NLS-1$
		sb.append(", namespace: "); //$NON-NLS-1$
		sb.append(getNamespaceIdentifier());
		sb.append("]"); //$NON-NLS-1$
		return sb.toString();
	}

}