| /******************************************************************************* |
| * Copyright (c) 2001, 2004 IBM Corporation and others. |
| * 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 |
| * |
| * Contributors: |
| * IBM Corporation - initial API and implementation |
| * Jens Lukowski/Innoopract - initial renaming/restructuring |
| * |
| *******************************************************************************/ |
| package org.eclipse.wst.sse.ui.internal.util; |
| |
| |
| |
| import org.eclipse.core.runtime.IConfigurationElement; |
| import org.eclipse.core.runtime.IExtension; |
| import org.eclipse.core.runtime.IExtensionPoint; |
| import org.eclipse.core.runtime.IExtensionRegistry; |
| import org.eclipse.core.runtime.IPluginRegistry; |
| import org.eclipse.wst.sse.ui.internal.Logger; |
| |
| |
| /** |
| * Template implementation of a registry reader that creates objects |
| * representing registry contents. Typically, an extension contains one |
| * element, but this reader handles multiple elements per extension. |
| * |
| * To start reading the extensions from the registry for an extension point, |
| * call the method <code>readRegistry</code>. |
| * |
| * To read children of an IConfigurationElement, call the method |
| * <code>readElementChildren</code> from your implementation of the method |
| * <code>readElement</code>, as it will not be done by default. |
| */ |
| public abstract class RegistryReader { |
| |
| |
| protected static final String TAG_DESCRIPTION = "description"; //$NON-NLS-1$ |
| |
| /** |
| * The constructor. |
| */ |
| protected RegistryReader() { |
| } |
| |
| /** |
| * This method extracts description as a subelement of the given element. |
| * |
| * @return description string if defined, or empty string if not. |
| */ |
| protected String getDescription(IConfigurationElement config) { |
| IConfigurationElement[] children = config.getChildren(TAG_DESCRIPTION); |
| if (children.length >= 1) { |
| return children[0].getValue(); |
| } |
| return ""; //$NON-NLS-1$ |
| } |
| |
| /** |
| * Logs the error in the workbench log using the provided text and the |
| * information in the configuration element. |
| */ |
| protected void logError(IConfigurationElement element, String text) { |
| IExtension extension = element.getDeclaringExtension(); |
| StringBuffer buf = new StringBuffer(); |
| buf.append("Plugin " + extension.getNamespace() + ", extension " + extension.getExtensionPointUniqueIdentifier()); //$NON-NLS-2$//$NON-NLS-1$ |
| buf.append("\n" + text); //$NON-NLS-1$ |
| Logger.log(Logger.ERROR, buf.toString()); |
| } |
| |
| /** |
| * Logs a very common registry error when a required attribute is missing. |
| */ |
| protected void logMissingAttribute(IConfigurationElement element, String attributeName) { |
| logError(element, "Required attribute '" + attributeName + "' not defined"); //$NON-NLS-2$//$NON-NLS-1$ |
| } |
| |
| /** |
| * Logs a registry error when the configuration element is unknown. |
| */ |
| protected void logUnknownElement(IConfigurationElement element) { |
| logError(element, "Unknown extension tag found: " + element.getName()); //$NON-NLS-1$ |
| } |
| |
| /** |
| * Apply a reproducable order to the list of extensions provided, such |
| * that the order will not change as extensions are added or removed. |
| */ |
| protected IExtension[] orderExtensions(IExtension[] extensions) { |
| // By default, the order is based on plugin id sorted |
| // in ascending order. The order for a plugin providing |
| // more than one extension for an extension point is |
| // dependent in the order listed in the XML file. |
| Sorter sorter = new Sorter() { |
| public boolean compare(Object extension1, Object extension2) { |
| String s1 = ((IExtension) extension1).getNamespace().toUpperCase(); |
| String s2 = ((IExtension) extension2).getNamespace().toUpperCase(); |
| //Return true if elementTwo is 'greater than' elementOne |
| return s2.compareTo(s1) > 0; |
| } |
| }; |
| |
| Object[] sorted = sorter.sort(extensions); |
| IExtension[] sortedExtension = new IExtension[sorted.length]; |
| System.arraycopy(sorted, 0, sortedExtension, 0, sorted.length); |
| return sortedExtension; |
| } |
| |
| /** |
| * Implement this method to read element's attributes. If children should |
| * also be read, then implementor is responsible for calling |
| * <code>readElementChildren</code>. Implementor is also responsible |
| * for logging missing attributes. |
| * |
| * @return true if element was recognized, false if not. |
| */ |
| protected abstract boolean readElement(IConfigurationElement element); |
| |
| /** |
| * Read the element's children. This is called by the subclass' |
| * readElement method when it wants to read the children of the element. |
| */ |
| protected void readElementChildren(IConfigurationElement element) { |
| readElements(element.getChildren()); |
| } |
| |
| /** |
| * Read each element one at a time by calling the subclass implementation |
| * of <code>readElement</code>. |
| * |
| * Logs an error if the element was not recognized. |
| */ |
| protected void readElements(IConfigurationElement[] elements) { |
| for (int i = 0; i < elements.length; i++) { |
| if (!readElement(elements[i])) |
| logUnknownElement(elements[i]); |
| } |
| } |
| |
| /** |
| * Read one extension by looping through its configuration elements. |
| */ |
| protected void readExtension(IExtension extension) { |
| readElements(extension.getConfigurationElements()); |
| } |
| |
| /** |
| * @deprecated use readRegistry(IExtensionRegistry registry, String pluginId, String extensionPoint) |
| */ |
| protected void readRegistry(IPluginRegistry registry, String pluginId, String extensionPoint) { |
| IExtensionPoint point = registry.getExtensionPoint(pluginId, extensionPoint); |
| if (point != null) { |
| IExtension[] extensions = point.getExtensions(); |
| extensions = orderExtensions(extensions); |
| for (int i = 0; i < extensions.length; i++) |
| readExtension(extensions[i]); |
| } |
| } |
| |
| /** |
| * Start the registry reading process using the supplied plugin ID and |
| * extension point. |
| */ |
| protected void readRegistry(IExtensionRegistry registry, String pluginId, String extensionPoint) { |
| IExtensionPoint point = registry.getExtensionPoint(pluginId, extensionPoint); |
| if (point != null) { |
| IExtension[] extensions = point.getExtensions(); |
| extensions = orderExtensions(extensions); |
| for (int i = 0; i < extensions.length; i++) |
| readExtension(extensions[i]); |
| } |
| } |
| } |