tapestry-core/src/main/java/org/apache/tapestry5/internal/structure/ComponentPageElementResourcesSourceImpl.java

// Copyright 2008 The Apache Software Foundation
//
// Licensed under the Apache License, Version 2.0 (the "License");
// you may not use this file except in compliance with the License.
// You may obtain a copy of the License at
//
//     http://www.apache.org/licenses/LICENSE-2.0
//
// Unless required by applicable law or agreed to in writing, software
// distributed under the License is distributed on an "AS IS" BASIS,
// WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
// See the License for the specific language governing permissions and
// limitations under the License.

package org.apache.tapestry5.internal.structure;

import org.apache.tapestry5.internal.services.ComponentClassCache;
import org.apache.tapestry5.internal.services.ComponentMessagesSource;
import org.apache.tapestry5.internal.services.LinkFactory;
import org.apache.tapestry5.internal.services.RequestPageCache;
import org.apache.tapestry5.ioc.internal.util.CollectionFactory;
import org.apache.tapestry5.ioc.internal.util.Defense;
import org.apache.tapestry5.ioc.services.TypeCoercer;
import org.apache.tapestry5.services.ComponentClassResolver;
import org.apache.tapestry5.services.ContextValueEncoder;

import java.util.Locale;
import java.util.Map;

public class ComponentPageElementResourcesSourceImpl implements ComponentPageElementResourcesSource
{
    private final Map<Locale, ComponentPageElementResources> cache = CollectionFactory.newConcurrentMap();

    private final ComponentMessagesSource componentMessagesSource;

    private final TypeCoercer typeCoercer;

    private final ComponentClassCache componentClassCache;

    private final ContextValueEncoder contextValueEncoder;

    private final LinkFactory linkFactory;

    private final RequestPageCache requestPageCache;

    private final ComponentClassResolver componentClassResolver;

    public ComponentPageElementResourcesSourceImpl(ComponentMessagesSource componentMessagesSource,
                                                   TypeCoercer typeCoercer,
                                                   ComponentClassCache componentClassCache,
                                                   ContextValueEncoder contextValueEncoder, LinkFactory linkFactory,
                                                   RequestPageCache requestPageCache,
                                                   ComponentClassResolver componentClassResolver)
    {
        this.componentMessagesSource = componentMessagesSource;
        this.typeCoercer = typeCoercer;
        this.componentClassCache = componentClassCache;
        this.contextValueEncoder = contextValueEncoder;
        this.linkFactory = linkFactory;
        this.requestPageCache = requestPageCache;
        this.componentClassResolver = componentClassResolver;
    }

    public ComponentPageElementResources get(Locale locale)
    {
        Defense.notNull(locale, "locale");

        ComponentPageElementResources result = cache.get(locale);

        if (result == null)
        {
            result = new ComponentPageElementResourcesImpl(locale, componentMessagesSource, typeCoercer,
                                                           componentClassCache,
                                                           contextValueEncoder, linkFactory, requestPageCache,
                                                           componentClassResolver);

            // Small race condition here, where we may create two instances of the CPER for the same locale,
            // but that's not worth worrying about.

            cache.put(locale, result);
        }

        return result;
    }
}