| /******************************************************************************* |
| * Copyright (c) 2010 Oracle 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: |
| * Oracle Corporation - initial API and implementation and/or initial documentation |
| *******************************************************************************/ |
| |
| package org.eclipse.jst.jsf.common.metadata.query.internal; |
| |
| import org.eclipse.core.runtime.CoreException; |
| import org.eclipse.jst.jsf.common.JSFCommonPlugin; |
| import org.eclipse.jst.jsf.common.internal.pde.AbstractSimpleClassExtensionRegistryReader; |
| import org.eclipse.jst.jsf.common.metadata.internal.IMetaDataDomainContext; |
| import org.eclipse.jst.jsf.common.metadata.internal.IMetaDataDomainQueryFactory; |
| |
| /** |
| * Entry point for querying metadata. Delegates query creation to the domainQueryFactory registered for the domain. |
| * <p> |
| * Usage Ex.: |
| * IMetaDataDomainContext context = MetaDataQueryContextFactory.getInstance().createTaglibDomainContext(project, uri); |
| * ITaglibMetaDataQuery query = MetaDataQueryFactory.getInstance().createQuery(context); |
| */ |
| public final class MetaDataQueryFactory { |
| private static MetaDataQueryFactory INSTANCE = new MetaDataQueryFactory(); |
| private static DomainQueryFactoryReader DOMAIN_QUERY_FACTORY_READER; |
| /** |
| * @return the singleton instance of the MetaDataQueryFactory |
| */ |
| public static MetaDataQueryFactory getInstance() { |
| synchronized(INSTANCE) { |
| return INSTANCE; |
| } |
| } |
| |
| private MetaDataQueryFactory() { |
| DOMAIN_QUERY_FACTORY_READER = new DomainQueryFactoryReader(); |
| } |
| |
| /** |
| * Create a query for against a domain of metadata |
| * |
| * @param <T> |
| * @param context |
| * @return {@link IMetaDataQuery} |
| */ |
| public <T extends IMetaDataQuery> T createQuery(final IMetaDataDomainContext context) { |
| //given domain id, get the query factory |
| final IMetaDataDomainQueryFactory factory = DOMAIN_QUERY_FACTORY_READER.getFactoryFor(context.getDomainId()); |
| if (factory != null) |
| return (T)factory.createQuery(context); |
| |
| JSFCommonPlugin.log(new UnsupportedOperationException(), "Unknown query factory for domain id: "+context.getDomainId()); //$NON-NLS-1$ |
| return null; |
| } |
| |
| private static class DomainQueryFactoryReader |
| extends |
| AbstractSimpleClassExtensionRegistryReader<IMetaDataDomainQueryFactory> { |
| |
| private static final String EXT_PT_ID = "domainQueryFactory"; //$NON-NLS-1$ |
| private static final String EXT_PT_ELEMENT = "factory"; //$NON-NLS-1$ |
| private static final String EXT_PT_ATTR = "class"; //$NON-NLS-1$ |
| |
| /** |
| * Constructor |
| */ |
| protected DomainQueryFactoryReader() { |
| super(JSFCommonPlugin.PLUGIN_ID, |
| EXT_PT_ID, EXT_PT_ELEMENT, EXT_PT_ATTR, |
| new CompareOrgEclipseJstContributorsLastComparator<IMetaDataDomainQueryFactory>() |
| ); |
| } |
| |
| @Override |
| protected void handleLoadFailure(final CoreException ce) { |
| JSFCommonPlugin.log(ce, |
| "Error loading IMetaDataDomainQueryFactory from extension"); //$NON-NLS-1$ |
| |
| } |
| |
| public IMetaDataDomainQueryFactory getFactoryFor(final String domainId) { |
| for (final IMetaDataDomainQueryFactory factory : getExtensions()) { |
| if (factory.getDomainIdentifier().equals(domainId)){ |
| return factory; |
| } |
| } |
| return null; |
| } |
| } |
| } |