jsf/plugins/org.eclipse.jst.jsf.core/src/org/eclipse/jst/jsf/core/internal/JSFCorePlugin.java

/*******************************************************************************
 * Copyright (c) 2005 Oracle Corporation.
 * 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:
 *    Gerry Kessler - initial API and implementation
 *    Ian Trimble - JSFLibraryRegistry work
 *******************************************************************************/
package org.eclipse.jst.jsf.core.internal;

import java.util.Collections;
import java.util.HashMap;
import java.util.Map;

import org.eclipse.core.runtime.IConfigurationElement;
import org.eclipse.core.runtime.IExtension;
import org.eclipse.core.runtime.IExtensionPoint;
import org.eclipse.core.runtime.ILog;
import org.eclipse.core.runtime.IStatus;
import org.eclipse.core.runtime.Platform;
import org.eclipse.core.runtime.Status;
import org.eclipse.core.runtime.preferences.InstanceScope;
import org.eclipse.jface.preference.IPreferenceStore;
import org.eclipse.jst.jsf.context.IDelegatingFactory;
import org.eclipse.jst.jsf.context.resolver.structureddocument.IStructuredDocumentContextResolverFactory;
import org.eclipse.jst.jsf.designtime.context.AbstractDTExternalContextFactory;
import org.eclipse.jst.jsf.designtime.el.AbstractDTMethodResolver;
import org.eclipse.jst.jsf.designtime.el.AbstractDTPropertyResolver;
import org.eclipse.jst.jsf.designtime.el.AbstractDTVariableResolver;
import org.eclipse.jst.jsf.designtime.internal.resolver.ViewBasedTaglibResolverFactory;
import org.eclipse.ui.preferences.ScopedPreferenceStore;
import org.eclipse.wst.common.frameworks.internal.WTPPlugin;
import org.osgi.framework.Bundle;
import org.osgi.framework.BundleContext;

/**
 * JSF Core plugin.
 * 
 * @author Gerry Kessler - Oracle, Ian Trimble - Oracle
 */
public class JSFCorePlugin extends WTPPlugin
{
    /**
     * The plugin id
     */
    public static final String             PLUGIN_ID = "org.eclipse.jst.jsf.core"; // org.eclipse.jst.jsf.core.internal.JSFCorePlugin";
    // //$NON-NLS-1$

    // The shared instance.
    private static JSFCorePlugin           plugin;

    private IPreferenceStore               preferenceStore;

    private ViewBasedTaglibResolverFactory _tagLibResolverFactory;

    /**
     * The constructor.
     */
    public JSFCorePlugin()
    {
        plugin = this;
    }

    /**
     * This method is called upon plug-in activation
     * 
     * @param context
     * @throws Exception
     */
    @Override
    public void start(final BundleContext context) throws Exception
    {
        super.start(context);
//        IStructuredDocumentContextResolverFactory factory = 
//            IStructuredDocumentContextResolverFactory.INSTANCE;

//        if (factory instanceof IDelegatingFactory)
//        {
//            _tagLibResolverFactory = new ViewBasedTaglibResolverFactory();
//            ((IDelegatingFactory) factory)
//                    .addFactoryDelegate(_tagLibResolverFactory);
//        }
//        else
//        {
//            log("Error adding tag resolver delegate", new Throwable());
//        }
    }

    /**
     * This method is called when the plug-in is stopped
     * 
     * @param context
     * @throws Exception
     */
    @Override
    public void stop(final BundleContext context) throws Exception
    {
        super.stop(context);

        IStructuredDocumentContextResolverFactory factory = IStructuredDocumentContextResolverFactory.INSTANCE;

        if (factory instanceof IDelegatingFactory
                && _tagLibResolverFactory != null)
        {
            ((IDelegatingFactory) factory)
                    .removeFactoryDelegate(_tagLibResolverFactory);
        }
        plugin = null;
    }

    /**
     * Returns the shared instance.
     * 
     * @return the shared instance
     */
    public static JSFCorePlugin getDefault()
    {
        return plugin;
    }

    /**
     * @param e
     * @param msg
     */
    public static void log(final Exception e, final String msg)
    {
        final ILog log = getDefault().getLog();

        log.log(new Status(IStatus.ERROR, PLUGIN_ID, IStatus.OK, msg, e));
    }

    /**
     * Logs using the default ILog implementation provided by getLog().
     * 
     * @param severity
     *            Severity (IStatus constant) of log entry
     * @param message
     *            Human-readable message describing log entry
     * @param ex
     *            Throwable instance (can be null)
     */
    public static void log(final int severity, final String message,
            final Throwable ex)
    {
        getDefault().getLog().log(
                new Status(severity, PLUGIN_ID, IStatus.OK, message, ex));
    }

    /**
     * Logs using the default ILog implementation provided by getLog().
     * 
     * @param severity
     *            Severity (IStatus constant) of log entry
     * @param message
     *            Human-readable message describing log entry
     */
    public static void log(final int severity, final String message)
    {
        log(severity, message, null);
    }

    /**
     * Logs a message for this plugin
     * 
     * @param message
     * @param t
     */
    public static void log(final String message, final Throwable t)
    {
        final ILog log = plugin.getLog();
        log.log(new Status(IStatus.ERROR, plugin.getBundle().getSymbolicName(),
                0, message, t));
    }

    @Override
    public String getPluginID()
    {
        return PLUGIN_ID;
    }

    /**
     * @return all registered symbol source providers
     */
    public synchronized static Map<String, AbstractDTVariableResolver> getVariableResolvers()
    {
        if (_registeredVariableResolvers == null)
        {
            registerVariableResolverProviders();
            if (_registeredVariableResolvers == null)
            {
                throw new AssertionError("registerProviders failed"); //$NON-NLS-1$
            }
        }
        return Collections.unmodifiableMap(_registeredVariableResolvers);
    }

    private static Map<String, AbstractDTVariableResolver> _registeredVariableResolvers;
    private final static String                            VARIABLE_RESOLVER_EXT_POINT_NAME = "variableresolver"; //$NON-NLS-1$

    private static void registerVariableResolverProviders()
    {
        _registeredVariableResolvers = new HashMap();
        loadRegisteredExtensions(VARIABLE_RESOLVER_EXT_POINT_NAME,
                _registeredVariableResolvers, VARIABLE_RESOLVER_EXT_POINT_NAME);
    }

    /**
     * @return a map of all registered property resolvers by id
     */
    public synchronized static Map<String, AbstractDTPropertyResolver> getPropertyResolvers()
    {
        if (_registeredPropertyResolvers == null)
        {
            registerPropertyResolverProviders();
            if (_registeredPropertyResolvers == null)
            {
                throw new AssertionError("registerProviders failed"); //$NON-NLS-1$
            }
        }
        return Collections.unmodifiableMap(_registeredPropertyResolvers);
    }

    private static Map<String, AbstractDTPropertyResolver> _registeredPropertyResolvers;
    private final static String                            PROPERTY_RESOLVER_EXT_POINT_NAME = "propertyresolver"; //$NON-NLS-1$

    private static void registerPropertyResolverProviders()
    {
        _registeredPropertyResolvers = new HashMap();
        loadRegisteredExtensions(PROPERTY_RESOLVER_EXT_POINT_NAME,
                _registeredPropertyResolvers, PROPERTY_RESOLVER_EXT_POINT_NAME);
    }

    /**
     * @return a map of all registered method resolvers by id
     */
    public synchronized static Map<String, AbstractDTMethodResolver> getMethodResolvers()
    {
        if (_registeredMethodResolvers == null)
        {
            registerMethodResolverProviders();
            if (_registeredMethodResolvers == null)
            {
                throw new AssertionError("registerProviders failed"); //$NON-NLS-1$
            }
        }
        return Collections.unmodifiableMap(_registeredMethodResolvers);
    }

    private static Map<String, AbstractDTMethodResolver> _registeredMethodResolvers;
    private final static String                          METHOD_RESOLVER_EXT_POINT_NAME = "methodresolver"; //$NON-NLS-1$

    private static void registerMethodResolverProviders()
    {
        _registeredMethodResolvers = new HashMap();
        loadRegisteredExtensions(METHOD_RESOLVER_EXT_POINT_NAME,
                _registeredMethodResolvers, METHOD_RESOLVER_EXT_POINT_NAME);

    }

    /**
     * @return a map of all registered external context providers by id
     */
    public synchronized static Map<String, AbstractDTExternalContextFactory> getExternalContextProviders()
    {
        if (_registeredExternalContextProviders == null)
        {
            registerExternalContextProviders();
            if (_registeredExternalContextProviders == null)
            {
                throw new AssertionError("registerProviders failed"); //$NON-NLS-1$
            }
        }
        return Collections.unmodifiableMap(_registeredExternalContextProviders);
    }

    private static Map<String, AbstractDTExternalContextFactory> _registeredExternalContextProviders;
    private final static String                                  EXTERNAL_CONTEXT_EXT_POINT_NAME = "externalcontext"; //$NON-NLS-1$

    private static void registerExternalContextProviders()
    {
        _registeredExternalContextProviders = new HashMap();
        loadRegisteredExtensions(EXTERNAL_CONTEXT_EXT_POINT_NAME,
                _registeredExternalContextProviders,
                EXTERNAL_CONTEXT_EXT_POINT_NAME);
    }

    private static <ResolverProvider> void loadRegisteredExtensions(
            final String extName, final Map<String, ResolverProvider> registry,
            final String elementName)
    {
        final IExtensionPoint point = Platform.getExtensionRegistry()
                .getExtensionPoint(plugin.getBundle().getSymbolicName(),
                        extName);
        final IExtension[] extensions = point.getExtensions();

        for (final IExtension extension : extensions)
        {
            final IConfigurationElement[] elements = extension
                    .getConfigurationElements();
            final String bundleId = extension.getContributor().getName();

            for (final IConfigurationElement element : elements)
            {
                if (elementName.equals(element.getName())
                        && element.getAttribute("class") != null //$NON-NLS-1$
                        && element.getAttribute("id") != null) //$NON-NLS-1$
                {
                    final String factoryClassName = element
                            .getAttribute("class"); //$NON-NLS-1$
                    final String id = element.getAttribute("id"); //$NON-NLS-1$
                    final Bundle bundle = Platform.getBundle(bundleId);

                    if (bundle != null)
                    {
                        try
                        {
                            final Class factoryClass = bundle
                                    .loadClass(factoryClassName);

                            final Object variableResolver = factoryClass
                                    .newInstance();

                            registry.put(id,
                                    (ResolverProvider) variableResolver);
                        }
                        catch (final Exception e)
                        {
                            final ILog logger_ = getDefault().getLog();
                            logger_
                                    .log(new Status(
                                            IStatus.ERROR,
                                            plugin.getBundle()
                                                    .getSymbolicName(),
                                            0,
                                            "Error loading resolver provider extension point", e)); //$NON-NLS-1$
                        }
                    }
                }
            }
        }
    }

    /**
     * @return the preference store for this bundle TODO: this is copied from
     *         AbstractUIPlugin; need to upgrade to new IPreferencesService
     */
    public IPreferenceStore getPreferenceStore()
    {
        // Create the preference store lazily.
        if (this.preferenceStore == null)
        {
            this.preferenceStore = new ScopedPreferenceStore(
                    new InstanceScope(), getBundle().getSymbolicName());

        }
        return this.preferenceStore;
    }
}