    001    // Copyright 2007, 2008, 2010, 2011 The Apache Software Foundation
    002    //
    003    // Licensed under the Apache License, Version 2.0 (the "License");
    004    // you may not use this file except in compliance with the License.
    005    // You may obtain a copy of the License at
    006    //
    007    // http://www.apache.org/licenses/LICENSE-2.0
    008    //
    009    // Unless required by applicable law or agreed to in writing, software
    010    // distributed under the License is distributed on an "AS IS" BASIS,
    011    // WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
    012    // See the License for the specific language governing permissions and
    013    // limitations under the License.
    014
    015    package org.apache.tapestry5.internal.services;
    016
    017    import org.apache.tapestry5.Asset;
    018    import org.apache.tapestry5.ComponentResources;
    019    import org.apache.tapestry5.annotations.Path;
    020    import org.apache.tapestry5.ioc.ObjectLocator;
    021    import org.apache.tapestry5.ioc.Resource;
    022    import org.apache.tapestry5.ioc.services.SymbolSource;
    023    import org.apache.tapestry5.model.MutableComponentModel;
    024    import org.apache.tapestry5.plastic.ComputedValue;
    025    import org.apache.tapestry5.plastic.InstanceContext;
    026    import org.apache.tapestry5.plastic.PlasticField;
    027    import org.apache.tapestry5.services.AssetSource;
    028    import org.apache.tapestry5.services.transform.InjectionProvider2;
    029
    030    import java.util.Locale;
    031
    032    /**
    033     * Performs injection of assets, based on the presence of the {@link Path} annotation. This is more
    034     * useful than the
    035     * general {@link AssetObjectProvider}, because relative assets are supported.
    036     */
    037    public class AssetInjectionProvider implements InjectionProvider2
    038    {
    039        private final SymbolSource symbolSource;
    040
    041        private final AssetSource assetSource;
    042
    043        public AssetInjectionProvider(SymbolSource symbolSource, AssetSource assetSource)
    044        {
    045            this.symbolSource = symbolSource;
    046            this.assetSource = assetSource;
    047        }
    048
    049        public boolean provideInjection(PlasticField field, ObjectLocator locator, MutableComponentModel componentModel)
    050        {
    051            Path path = field.getAnnotation(Path.class);
    052
    053            if (path == null)
    054            {
    055                return false;
    056            }
    057
    058            final String expanded = symbolSource.expandSymbols(path.value());
    059
    060            final Resource baseResource = componentModel.getBaseResource();
    061
    062            ComputedValue<Asset> computedAsset = new ComputedValue<Asset>()
    063            {
    064                public Asset get(InstanceContext context)
    065                {
    066                    ComponentResources resources = context.get(ComponentResources.class);
    067
    068                    Locale locale = resources.getLocale();
    069
    070                    return assetSource.getAsset(baseResource, expanded, locale);
    071                }
    072            };
    073
    074            field.injectComputed(computedAsset);
    075
    076            return true;
    077        }
    078
    079    }