Bug 353140 - [Help] Handle situation where documentation is not

installed

1 files changed, 226 insertions, 0 deletions

diff --git a/org.eclipse.help.base/src/org/eclipse/help/internal/base/MissingContentManager.java b/org.eclipse.help.base/src/org/eclipse/help/internal/base/MissingContentManager.java
new file mode 100644
index 000000000..af5f66d7b
--- /dev/null
+++ b/org.eclipse.help.base/src/org/eclipse/help/internal/base/MissingContentManager.java
@@ -0,0 +1,226 @@
+/*******************************************************************************

+ * Copyright (c) 2011 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

+ *******************************************************************************/

+

+package org.eclipse.help.internal.base;

+

+import java.util.ArrayList;

+import java.util.Collections;

+import java.util.HashSet;

+import java.util.Iterator;

+import java.util.List;

+import java.util.Set;

+import java.util.StringTokenizer;

+

+import org.eclipse.core.runtime.IConfigurationElement;

+import org.eclipse.core.runtime.IExtensionRegistry;

+import org.eclipse.core.runtime.Platform;

+import org.eclipse.core.runtime.preferences.IEclipsePreferences;

+import org.eclipse.core.runtime.preferences.IScopeContext;

+import org.eclipse.core.runtime.preferences.InstanceScope;

+import org.eclipse.help.internal.HelpPlugin;

+import org.osgi.service.prefs.BackingStoreException;

+

+/**

+ * Handle sunresolved toc place holders as well as situations

+ * where remote help is unavailable

+ */

+

+public class MissingContentManager {

+	

+	private static final String HELP_PROTOCOL = "help:"; //$NON-NLS-1$

+	private static final String EXTENSION_POINT_ID_TOC = HelpPlugin.PLUGIN_ID + ".toc"; //$NON-NLS-1$

+	private static final String ELEMENT_NAME_PLACEHOLDER = "placeholder"; //$NON-NLS-1$

+	private static final String ATTRIBUTE_NAME_PLUGIN = "plugin"; //$NON-NLS-1$

+	private static final String ATTRIBUTE_NAME_PLACEHOLDER_PAGE = "placeholderPage"; //$NON-NLS-1$

+	public static final String  IGNORE_MISSING_PLACEHOLDER_PREFERENCE = "ignorePlaceholders"; //$NON-NLS-1$

+	

+	// Hrefs which are processed by org.eclipse.help.internal.webapp.StatusProducer

+	public static final String REMOTE_STATUS_HREF = "NetworkHelpStatus.html"; //$NON-NLS-1$

+	public static final String REMOTE_STATUS_HELP_VIEW_HREF = "NetworkHelpStatusHV.html"; //$NON-NLS-1$

+	public static final String MISSING_TOPIC_HREF = "MissingTopicStatus.html"; //$NON-NLS-1$

+	public static final String MISSING_TOPIC_PATH = "missingTopic/"; //$NON-NLS-1$

+	public static final String MISSING_BOOKS_HREF = "MissingBooks.html"; //$NON-NLS-1$

+	public static final String MISSING_BOOKS_HELP_VIEW_HREF = "MissingBooksHV.html"; //$NON-NLS-1$

+	

+	/*

+	 * A place holder defines a page to be shown when a documentation page

+	 * which matches the specified path not installed

+	 */

+	public static class Placeholder implements Comparable {

+		public String path;

+		public String bundle;

+		public String placeholderPage;

+		

+		public Placeholder(String path, String bundle, String placeholderPage) {

+			this.path = path;

+			this.bundle = bundle;

+			this.placeholderPage = placeholderPage;

+		}

+

+		public int compareTo(Object arg0) {

+			// Sort in reverse order so more qualified strings appear before

+			// less qualified substrings

+			if (arg0 instanceof Placeholder) {

+				return((Placeholder)arg0).path.compareTo(path);

+			}

+			return 0;

+		}

+	}

+	

+	private static MissingContentManager instance;

+	private List placeholders;

+    private Set bundlesToIgnore; // A set of bundles the user does not want to see reference to

+	

+	public static MissingContentManager getInstance() {

+		if ( instance == null ) {

+			instance = new MissingContentManager();

+		}

+		return instance;

+	}

+	

+	/*

+	 * Read the extension registry 

+	 */

+	private MissingContentManager() {

+        IExtensionRegistry registry = Platform.getExtensionRegistry();

+        placeholders = new ArrayList();

+        bundlesToIgnore = new HashSet();

+        if ( BaseHelpSystem.getMode() == BaseHelpSystem.MODE_INFOCENTER ) {

+        	return; // Placeholders are not shown for infocenters

+        }

+        // Read the placeholders from the extension registry

+		IConfigurationElement[] elements = registry

+				.getConfigurationElementsFor(EXTENSION_POINT_ID_TOC);

+		for (int i = 0; i < elements.length; ++i) {

+			IConfigurationElement elem = elements[i];

+			String pluginId = elem.getContributor().getName();

+			if (elem.getName().equals(ELEMENT_NAME_PLACEHOLDER)) {

+				try {

+					String plugin = elem.getAttribute(ATTRIBUTE_NAME_PLUGIN);

+					String path = HELP_PROTOCOL  + plugin + '/';

+					String placeholder = elem

+							.getAttribute(ATTRIBUTE_NAME_PLACEHOLDER_PAGE);

+					placeholders.add(new Placeholder(path, plugin, placeholder));

+				} catch (Exception e) {

+					// log and skip

+					String msg = "Exception reading " + ELEMENT_NAME_PLACEHOLDER + " extension in bundle" + pluginId; //$NON-NLS-1$ //$NON-NLS-2$

+					HelpPlugin.logError(msg, e);

+				}

+			}

+		}

+		Collections.sort(placeholders);

+		// Read the preferences to find any ignored placeholders

+		String ignoredBundles = Platform.getPreferencesService().getString(HelpBasePlugin.PLUGIN_ID, IGNORE_MISSING_PLACEHOLDER_PREFERENCE, "", null); //$NON-NLS-1$

+		if (ignoredBundles.length() > 0) {

+			StringTokenizer tokenizer = new StringTokenizer(ignoredBundles, " ,"); //$NON-NLS-1$

+			while (tokenizer.hasMoreTokens()) {

+				bundlesToIgnore.add(tokenizer.nextToken());

+			}

+		}	

+	}

+	

+	/**

+     * Called when a page cannot be found

+	 * @param path the path of the page that could not be loaded

+	 * @return a place holder page if defined, otherwise an error page

+	 */

+	public String getPageNotFoundPage(String path, boolean showPlaceholderPage) {

+		for (Iterator iter = placeholders.iterator(); iter.hasNext(); ) {

+			Placeholder placeholder = (Placeholder) iter.next();

+			if (path.startsWith(placeholder.path) && Platform.getBundle(placeholder.bundle) == null) {

+				if ( showPlaceholderPage) {

+				    return placeholder.placeholderPage;

+				} else {

+				    return "/org.eclipse.help.webapp/" + MISSING_TOPIC_PATH + path.substring(HELP_PROTOCOL.length()); //$NON-NLS-1$

+				}

+			}	

+		}

+		return Platform.getPreferencesService().getString(HelpBasePlugin.PLUGIN_ID, "page_not_found", null, null); //$NON-NLS-1$

+	}	

+	

+	/**

+	 * 

+	 * @return true if there is an unresolved place holder and this is not an infocenter

+	 */

+	public boolean isUnresolvedPlaceholders() {

+		if (BaseHelpSystem.getMode()==BaseHelpSystem.MODE_INFOCENTER) {

+			return false;

+		}

+		Placeholder[] unresolvedPlaceHolders = getUnresolvedPlaceholders();

+		return unresolvedPlaceHolders.length > 0;

+	}

+	

+	/**

+	 * If any help is missing returns an appropriate page

+	 * @return null if no help is unavailable or an appropriate page if 

+	 *  the plug-in that corresponds to a place holder is not available. 

+	 *  The returned page will be in the format /plug-in/path.

+	 */

+	public String getHelpMissingPage(boolean isHelpView) {	

+		Placeholder[] unresolvedPlaceHolders = getUnresolvedPlaceholders();

+		if (unresolvedPlaceHolders.length == 0) {

+		    	return null;

+		} else {

+			    String suffix = isHelpView ? MISSING_BOOKS_HELP_VIEW_HREF : MISSING_BOOKS_HREF;

+		    	return "/org.eclipse.help.webapp" + '/'+ suffix; //$NON-NLS-1$

+		}	

+	}

+	

+	/**

+	 * Get the page to be shown when some remote help is known to be unavailable

+	 */

+	public String getRemoteHelpUnavailablePage(boolean isHelpView) {

+		if ( BaseHelpSystem.getMode()!=BaseHelpSystem.MODE_INFOCENTER ) {

+		    String suffix = isHelpView ? REMOTE_STATUS_HELP_VIEW_HREF : REMOTE_STATUS_HREF;

+			return "/org.eclipse.help.webapp/" + suffix; //$NON-NLS-1$

+		} 

+		return null;

+	}

+

+	public Placeholder[] getUnresolvedPlaceholders() {

+		List unresolved;

+		unresolved = new ArrayList();

+		for (Iterator iter = placeholders.iterator(); iter.hasNext(); ) {			

+			Placeholder ph = (Placeholder) iter.next();

+			String bundle = ph.bundle;

+			if (bundle != null && !bundlesToIgnore.contains(bundle) ) {

+			    if (Platform.getBundle(bundle) == null ) {

+			    	unresolved.add(ph);

+			    }

+			}

+		}

+		return (Placeholder[]) unresolved.toArray(new Placeholder[unresolved.size()]);

+	}

+	

+	// Modifies the preferences to ignore any bundles that are currently unresolved placeholders

+	public void ignoreAllMissingPlaceholders() {

+		Placeholder[] unresolved = getUnresolvedPlaceholders();

+		String ignoredBundles = Platform.getPreferencesService().getString(HelpBasePlugin.PLUGIN_ID, IGNORE_MISSING_PLACEHOLDER_PREFERENCE, "", null); //$NON-NLS-1$	

+		for ( int i = 0; i < unresolved.length; i++) {

+			String bundle = unresolved[i].bundle;

+			bundlesToIgnore.add(bundle);

+			if (ignoredBundles.length() > 0) {

+				ignoredBundles = ignoredBundles + ',';

+			}

+			ignoredBundles = ignoredBundles + bundle;

+

+		}

+		IScopeContext instanceScope = InstanceScope.INSTANCE; 

+		IEclipsePreferences prefs = instanceScope.getNode(HelpBasePlugin.PLUGIN_ID);

+		prefs.put(IGNORE_MISSING_PLACEHOLDER_PREFERENCE, ignoredBundles);

+		try {

+			prefs.flush();

+		} catch (BackingStoreException e) {

+			HelpBasePlugin.logError("Cannot save preferences", e); //$NON-NLS-1$

+		}

+	}

+

+}