/*******************************************************************************
* Copyright (c) 2011, 2015 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;
/**
* Handles unresolved 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<Placeholder> {
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;
}
@Override
public int compareTo(Placeholder o) {
return o.path.compareTo(path);
}
}
private static MissingContentManager instance;
private List<Placeholder> placeholders;
private Set<String> 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<Placeholder> iter = placeholders.iterator(); iter.hasNext(); ) {
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<Placeholder> unresolved;
unresolved = new ArrayList<>();
for (Iterator<Placeholder> iter = placeholders.iterator(); iter.hasNext(); ) {
Placeholder ph = iter.next();
String bundle = ph.bundle;
if (bundle != null && !bundlesToIgnore.contains(bundle) ) {
if (Platform.getBundle(bundle) == null ) {
unresolved.add(ph);
}
}
}
return 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); //$NON-NLS-1$
}
}
}