jsf/plugins/org.eclipse.jst.jsf.core/src/org/eclipse/jst/jsf/core/internal/CompositeTagRegistryFactory.java - jsf/webtools.jsf - Git at Google

 /*******************************************************************************
  * Copyright (c) 2001, 2008 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
  *******************************************************************************/
 package org.eclipse.jst.jsf.core.internal;

 import java.util.ArrayList;
 import java.util.Collections;
 import java.util.HashMap;
 import java.util.HashSet;
 import java.util.Iterator;
 import java.util.List;
 import java.util.Map;
 import java.util.Set;

 import org.eclipse.core.resources.IProject;
 import org.eclipse.core.runtime.content.IContentType;
 import org.eclipse.jst.jsf.common.internal.policy.CanonicallyOrderedIteratorPolicy;
 import org.eclipse.jst.jsf.common.internal.policy.IIteratorPolicy;
 import org.eclipse.jst.jsf.common.internal.policy.IdentifierOrderedIteratorPolicy;
 import org.eclipse.jst.jsf.common.internal.strategy.AbstractIdentifiableStrategy;
 import org.eclipse.jst.jsf.common.internal.strategy.IIdentifiableStrategy;
 import org.eclipse.jst.jsf.common.internal.strategy.IteratorPolicyBasedStrategyComposite;
 import org.eclipse.jst.jsf.designtime.internal.view.model.ITagRegistry;
 import org.eclipse.jst.jsf.designtime.internal.view.model.TagRegistryFactory.TagRegistryFactoryException;

 /**
  * Employs a policy-based strategy to construct a TagRegistry for a particular
  * content-type in a particular project.
  *
  * @author cbateman
  *
  */
 public final class CompositeTagRegistryFactory
 {
     private static CompositeTagRegistryFactory INSTANCE;

     private static ITagRegistryFactoryProvider   TEST_PROVIDER;
     /**
      * For JUNIT TEST ONLY!!!!!
      * @param factoryProvider
      */
     public synchronized void setTestInjectedProvider(final ITagRegistryFactoryProvider factoryProvider)
     {
         TEST_PROVIDER = factoryProvider;
         // TODO: this is risky
         _cachedExtensionsByType.clear();
     }

     /**
      * @return the single instance of the registry factory
      */
     public static synchronized CompositeTagRegistryFactory getInstance()
     {
         if (INSTANCE == null)
         {
             INSTANCE = new CompositeTagRegistryFactory();
         }
         return INSTANCE;
     }

     private final Map<TagRegistryIdentifier, Set<ITagRegistryFactoryInfo>> _cachedExtensionsByType =
         new HashMap<TagRegistryIdentifier, Set<ITagRegistryFactoryInfo>>(4);

     private CompositeTagRegistryFactory()
     {
         // singleton: no external instantiation
     }


     /**
      * @param id
      * @return a tag registry for the id or null if there isn't one.
      */
     public final ITagRegistry getRegistry(final TagRegistryIdentifier id)
     {
         final Set<ITagRegistryFactoryInfo> handlers = getAllTagRegistryFactories();

         final Set<ITagRegistryFactoryInfo> matchingHandlers = findMatchingExtensions(
                 id, handlers);

         if (matchingHandlers.size() > 0)
         {
             // optimize: if there is only one handler, no need for strategy
             if (matchingHandlers.size() == 1)
             {
                 try
                 {
                     return matchingHandlers.iterator().next().getTagRegistryFactory()
                             .createTagRegistry(id.getProject());
                 }
                 catch (TagRegistryFactoryException e)
                 {
                     JSFCorePlugin.log(e, "While trying to acquire a registry"); //$NON-NLS-1$
                 }
             }
             else
             {
                 // for now, we will order by the canonical name of the extension
                 // id in ascending order. Later, we may make this preference
                 // based.
                 final TagRegistrySelectionStrategy selectionStrategy = new TagRegistrySelectionStrategy(
                         new CanonicallyOrderedIteratorPolicy<String>());

                 for (final Iterator<ITagRegistryFactoryInfo> it = matchingHandlers
                         .iterator(); it.hasNext();)
                 {
                     selectionStrategy.addStrategy(it.next().getTagRegistryFactory());
                 }
                 return selectionStrategy.perform(id.getProject());
             }
         }

         return null;
     }

     /**
      * @return get all tag registry factories
      */
     public Set<ITagRegistryFactoryInfo> getAllTagRegistryFactories()
     {
         List<String>  selectionOrder = new ArrayList<String>();
         selectionOrder.add("testInjection"); //$NON-NLS-1$
         selectionOrder.add("extensionPointInjection"); //$NON-NLS-1$
         selectionOrder.add("platformDefault"); //$NON-NLS-1$

         IdentifierOrderedIteratorPolicy<String> policy = new IdentifierOrderedIteratorPolicy<String>(selectionOrder);
         // ignore iterator values that don't exist in the list of possible selections.
         policy.setExcludeNonExplicitValues(true);
         final TagRegistryFactoryProviderSelectionStrategy providerSelector
             = new TagRegistryFactoryProviderSelectionStrategy(policy);
         providerSelector.addStrategy(
           new AbstractIdentifiableStrategy<IProject, ITagRegistryFactoryProvider, String>("testInjection", "FIXME: not for display", null) //$NON-NLS-1$ //$NON-NLS-2$
         {
             @Override
             public ITagRegistryFactoryProvider perform(IProject input)
                     throws Exception
             {
                 ITagRegistryFactoryProvider injectedProvider = null;
                 synchronized(CompositeTagRegistryFactory.class)
                 {
                      injectedProvider = TEST_PROVIDER;
                 }
                 if (injectedProvider != null)
                 {
                     final ITagRegistryFactoryProvider useMe = injectedProvider;
                     return new AbstractTagRegistryFactoryProvider()
                     {
                         @Override
                         public Set<ITagRegistryFactoryInfo> getTagRegistryFactories()
                         {
                             return useMe.getTagRegistryFactories();
                         }
                     };
                 }
                 return null;
             }
             });
         providerSelector.addStrategy(
                 new AbstractIdentifiableStrategy<IProject, ITagRegistryFactoryProvider, String>("platformDefault", "FIXME: not for display", null) //$NON-NLS-1$ //$NON-NLS-2$
               {
                   @Override
                   public ITagRegistryFactoryProvider perform(IProject input)
                           throws Exception
                   {
                       return new AbstractTagRegistryFactoryProvider()
                       {
                           @Override
                           public Set<ITagRegistryFactoryInfo> getTagRegistryFactories()
                           {
                               return TagLibraryRegistryLoader.getAllHandlers();
                           }
                       };
                   }
               });

         ITagRegistryFactoryProvider provider = providerSelector.perform(null);
         if (provider != null)
         {
             return provider.getTagRegistryFactories();
         }
         return Collections.emptySet();
     }

     private Set<ITagRegistryFactoryInfo> findMatchingExtensions(
             TagRegistryIdentifier id, Set<ITagRegistryFactoryInfo> handlers)
     {
         Set<ITagRegistryFactoryInfo> matching = _cachedExtensionsByType.get(id);

         if (matching == null)
         {
             matching = new HashSet<ITagRegistryFactoryInfo>(4);

             for (final ITagRegistryFactoryInfo handler : handlers)
             {
                 if (handler.getContentTypes().contains(id.getContentType())
                         && handler.getTagRegistryFactory().projectIsValid(id.getProject()))
                 {
                     matching.add(handler);
                 }
             }

             // if there is nothing matching, just store the empty set and
             // discard the extra memory
             if (matching.size() > 0)
             {
                 _cachedExtensionsByType.put(id, matching);
             }
             else
             {
                 _cachedExtensionsByType.put(id, Collections.EMPTY_SET);
             }
         }
         return matching;
     }

     /**
      * Identifies a content type/project context in which to request a tag
      * registry.
      *
      * @author cbateman
      *
      */
     public final static class TagRegistryIdentifier
     {
         private final IProject     _project;
         private final IContentType _contentType;

         /**
          * @param project
          * @param contentType
          */
         public TagRegistryIdentifier(final IProject project,
                 final IContentType contentType)
         {
             _project = project;
             _contentType = contentType;
         }

         /**
          * @return project
          */
         public IProject getProject()
         {
             return _project;
         }

         /**
          * @return content type
          */
         public IContentType getContentType()
         {
             return _contentType;
         }

         public boolean equals(final Object o) {
         	if (o instanceof TagRegistryIdentifier) {
 	        	final TagRegistryIdentifier other = (TagRegistryIdentifier)o;
 	        	final int otherProjectHash = other.getProject() != null ? other.getProject().hashCode() : 0;
 	        	final int thisProjectHash = getProject() != null ? getProject().hashCode() : 0;
 	        	if (otherProjectHash == thisProjectHash &&
 	        			other.getContentType().equals(this.getContentType()))
 	        		return true;
         	}
         	return false;
         }

         public int hashCode() {
         	return (getProject() != null ? getProject().hashCode() : 0) + 7*_contentType.hashCode();
         }

     }

     private static class TagRegistrySelectionStrategy
             extends
             IteratorPolicyBasedStrategyComposite<IProject, ITagRegistry, ITagRegistry, String, IIdentifiableStrategy<IProject, ITagRegistry, String>>
     {
         private static final ITagRegistry NO_RESULT = null;

         protected TagRegistrySelectionStrategy(IIteratorPolicy<String> policy)
         {
             super(policy);
         }

         @Override
         public ITagRegistry getNoResult()
         {
             return NO_RESULT;
         }
     }

     private static class TagRegistryFactoryProviderSelectionStrategy
             extends
             IteratorPolicyBasedStrategyComposite<IProject, ITagRegistryFactoryProvider, ITagRegistryFactoryProvider, String, IIdentifiableStrategy<IProject, ITagRegistryFactoryProvider, String>>
     {
         protected TagRegistryFactoryProviderSelectionStrategy(
                 IIteratorPolicy<String> policy)
         {
             super(policy);
         }

         private static final ITagRegistryFactoryProvider NO_RESULT = null;

         @Override
         public ITagRegistryFactoryProvider getNoResult()
         {
             return NO_RESULT;
         }
     }
 }
	/*******************************************************************************
	* Copyright (c) 2001, 2008 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
	*******************************************************************************/
	package org.eclipse.jst.jsf.core.internal;

	import java.util.ArrayList;
	import java.util.Collections;
	import java.util.HashMap;
	import java.util.HashSet;
	import java.util.Iterator;
	import java.util.List;
	import java.util.Map;
	import java.util.Set;

	import org.eclipse.core.resources.IProject;
	import org.eclipse.core.runtime.content.IContentType;
	import org.eclipse.jst.jsf.common.internal.policy.CanonicallyOrderedIteratorPolicy;
	import org.eclipse.jst.jsf.common.internal.policy.IIteratorPolicy;
	import org.eclipse.jst.jsf.common.internal.policy.IdentifierOrderedIteratorPolicy;
	import org.eclipse.jst.jsf.common.internal.strategy.AbstractIdentifiableStrategy;
	import org.eclipse.jst.jsf.common.internal.strategy.IIdentifiableStrategy;
	import org.eclipse.jst.jsf.common.internal.strategy.IteratorPolicyBasedStrategyComposite;
	import org.eclipse.jst.jsf.designtime.internal.view.model.ITagRegistry;
	import org.eclipse.jst.jsf.designtime.internal.view.model.TagRegistryFactory.TagRegistryFactoryException;

	/**
	* Employs a policy-based strategy to construct a TagRegistry for a particular
	* content-type in a particular project.
	*
	* @author cbateman
	*
	*/
	public final class CompositeTagRegistryFactory
	{
	private static CompositeTagRegistryFactory INSTANCE;

	private static ITagRegistryFactoryProvider TEST_PROVIDER;
	/**
	* For JUNIT TEST ONLY!!!!!
	* @param factoryProvider
	*/
	public synchronized void setTestInjectedProvider(final ITagRegistryFactoryProvider factoryProvider)
	{
	TEST_PROVIDER = factoryProvider;
	// TODO: this is risky
	_cachedExtensionsByType.clear();
	}

	/**
	* @return the single instance of the registry factory
	*/
	public static synchronized CompositeTagRegistryFactory getInstance()
	{
	if (INSTANCE == null)
	{
	INSTANCE = new CompositeTagRegistryFactory();
	}
	return INSTANCE;
	}

	private final Map<TagRegistryIdentifier, Set<ITagRegistryFactoryInfo>> _cachedExtensionsByType =
	new HashMap<TagRegistryIdentifier, Set<ITagRegistryFactoryInfo>>(4);

	private CompositeTagRegistryFactory()
	{
	// singleton: no external instantiation
	}


	/**
	* @param id
	* @return a tag registry for the id or null if there isn't one.
	*/
	public final ITagRegistry getRegistry(final TagRegistryIdentifier id)
	{
	final Set<ITagRegistryFactoryInfo> handlers = getAllTagRegistryFactories();

	final Set<ITagRegistryFactoryInfo> matchingHandlers = findMatchingExtensions(
	id, handlers);

	if (matchingHandlers.size() > 0)
	{
	// optimize: if there is only one handler, no need for strategy
	if (matchingHandlers.size() == 1)
	{
	try
	{
	return matchingHandlers.iterator().next().getTagRegistryFactory()
	.createTagRegistry(id.getProject());
	}
	catch (TagRegistryFactoryException e)
	{
	JSFCorePlugin.log(e, "While trying to acquire a registry"); //$NON-NLS-1$
	}
	}
	else
	{
	// for now, we will order by the canonical name of the extension
	// id in ascending order. Later, we may make this preference
	// based.
	final TagRegistrySelectionStrategy selectionStrategy = new TagRegistrySelectionStrategy(
	new CanonicallyOrderedIteratorPolicy<String>());

	for (final Iterator<ITagRegistryFactoryInfo> it = matchingHandlers
	.iterator(); it.hasNext();)
	{
	selectionStrategy.addStrategy(it.next().getTagRegistryFactory());
	}
	return selectionStrategy.perform(id.getProject());
	}
	}

	return null;
	}

	/**
	* @return get all tag registry factories
	*/
	public Set<ITagRegistryFactoryInfo> getAllTagRegistryFactories()
	{
	List<String> selectionOrder = new ArrayList<String>();
	selectionOrder.add("testInjection"); //$NON-NLS-1$
	selectionOrder.add("extensionPointInjection"); //$NON-NLS-1$
	selectionOrder.add("platformDefault"); //$NON-NLS-1$

	IdentifierOrderedIteratorPolicy<String> policy = new IdentifierOrderedIteratorPolicy<String>(selectionOrder);
	// ignore iterator values that don't exist in the list of possible selections.
	policy.setExcludeNonExplicitValues(true);
	final TagRegistryFactoryProviderSelectionStrategy providerSelector
	= new TagRegistryFactoryProviderSelectionStrategy(policy);
	providerSelector.addStrategy(
	new AbstractIdentifiableStrategy<IProject, ITagRegistryFactoryProvider, String>("testInjection", "FIXME: not for display", null) //$NON-NLS-1$ //$NON-NLS-2$
	{
	@Override
	public ITagRegistryFactoryProvider perform(IProject input)
	throws Exception
	{
	ITagRegistryFactoryProvider injectedProvider = null;
	synchronized(CompositeTagRegistryFactory.class)
	{
	injectedProvider = TEST_PROVIDER;
	}
	if (injectedProvider != null)
	{
	final ITagRegistryFactoryProvider useMe = injectedProvider;
	return new AbstractTagRegistryFactoryProvider()
	{
	@Override
	public Set<ITagRegistryFactoryInfo> getTagRegistryFactories()
	{
	return useMe.getTagRegistryFactories();
	}
	};
	}
	return null;
	}
	});
	providerSelector.addStrategy(
	new AbstractIdentifiableStrategy<IProject, ITagRegistryFactoryProvider, String>("platformDefault", "FIXME: not for display", null) //$NON-NLS-1$ //$NON-NLS-2$
	{
	@Override
	public ITagRegistryFactoryProvider perform(IProject input)
	throws Exception
	{
	return new AbstractTagRegistryFactoryProvider()
	{
	@Override
	public Set<ITagRegistryFactoryInfo> getTagRegistryFactories()
	{
	return TagLibraryRegistryLoader.getAllHandlers();
	}
	};
	}
	});

	ITagRegistryFactoryProvider provider = providerSelector.perform(null);
	if (provider != null)
	{
	return provider.getTagRegistryFactories();
	}
	return Collections.emptySet();
	}

	private Set<ITagRegistryFactoryInfo> findMatchingExtensions(
	TagRegistryIdentifier id, Set<ITagRegistryFactoryInfo> handlers)
	{
	Set<ITagRegistryFactoryInfo> matching = _cachedExtensionsByType.get(id);

	if (matching == null)
	{
	matching = new HashSet<ITagRegistryFactoryInfo>(4);

	for (final ITagRegistryFactoryInfo handler : handlers)
	{
	if (handler.getContentTypes().contains(id.getContentType())
	&& handler.getTagRegistryFactory().projectIsValid(id.getProject()))
	{
	matching.add(handler);
	}
	}

	// if there is nothing matching, just store the empty set and
	// discard the extra memory
	if (matching.size() > 0)
	{
	_cachedExtensionsByType.put(id, matching);
	}
	else
	{
	_cachedExtensionsByType.put(id, Collections.EMPTY_SET);
	}
	}
	return matching;
	}

	/**
	* Identifies a content type/project context in which to request a tag
	* registry.
	*
	* @author cbateman
	*
	*/
	public final static class TagRegistryIdentifier
	{
	private final IProject _project;
	private final IContentType _contentType;

	/**
	* @param project
	* @param contentType
	*/
	public TagRegistryIdentifier(final IProject project,
	final IContentType contentType)
	{
	_project = project;
	_contentType = contentType;
	}

	/**
	* @return project
	*/
	public IProject getProject()
	{
	return _project;
	}

	/**
	* @return content type
	*/
	public IContentType getContentType()
	{
	return _contentType;
	}

	public boolean equals(final Object o) {
	if (o instanceof TagRegistryIdentifier) {
	final TagRegistryIdentifier other = (TagRegistryIdentifier)o;
	final int otherProjectHash = other.getProject() != null ? other.getProject().hashCode() : 0;
	final int thisProjectHash = getProject() != null ? getProject().hashCode() : 0;
	if (otherProjectHash == thisProjectHash &&
	other.getContentType().equals(this.getContentType()))
	return true;
	}
	return false;
	}

	public int hashCode() {
	return (getProject() != null ? getProject().hashCode() : 0) + 7*_contentType.hashCode();
	}

	}

	private static class TagRegistrySelectionStrategy
	extends
	IteratorPolicyBasedStrategyComposite<IProject, ITagRegistry, ITagRegistry, String, IIdentifiableStrategy<IProject, ITagRegistry, String>>
	{
	private static final ITagRegistry NO_RESULT = null;

	protected TagRegistrySelectionStrategy(IIteratorPolicy<String> policy)
	{
	super(policy);
	}

	@Override
	public ITagRegistry getNoResult()
	{
	return NO_RESULT;
	}
	}

	private static class TagRegistryFactoryProviderSelectionStrategy
	extends
	IteratorPolicyBasedStrategyComposite<IProject, ITagRegistryFactoryProvider, ITagRegistryFactoryProvider, String, IIdentifiableStrategy<IProject, ITagRegistryFactoryProvider, String>>
	{
	protected TagRegistryFactoryProviderSelectionStrategy(
	IIteratorPolicy<String> policy)
	{
	super(policy);
	}

	private static final ITagRegistryFactoryProvider NO_RESULT = null;

	@Override
	public ITagRegistryFactoryProvider getNoResult()
	{
	return NO_RESULT;
	}
	}
	}