001// Copyright 2011-2013 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
015package org.apache.tapestry5.services.javascript;
016
017import org.apache.tapestry5.Asset;
018import org.apache.tapestry5.func.F;
019import org.apache.tapestry5.func.Flow;
020import org.apache.tapestry5.func.Mapper;
021import org.apache.tapestry5.func.Predicate;
022import org.apache.tapestry5.ioc.ServiceBinder;
023import org.apache.tapestry5.ioc.ServiceBindingOptions;
024import org.apache.tapestry5.ioc.annotations.UsesOrderedConfiguration;
025import org.apache.tapestry5.ioc.internal.util.InternalUtils;
026import org.apache.tapestry5.services.AssetSource;
027
028import java.util.List;
029
030/**
031 * An extensible implementation of {@link JavaScriptStack} that can be used as the implementation of a service.
032 * The contributions to the service are used to supply the libraries, stylesheets, and initialization for a
033 * JavaScriptStack, allowing the stack to be more dynamically configured. In practice, one will use
034 * {@link ServiceBinder#bind(Class, Class)} and {@link ServiceBindingOptions#withMarker(Class...)} to construct the
035 * service, then use the marker annotation to inject the service when contributing the service into to the
036 * {@link JavaScriptStackSource}.
037 * <p/>
038 * A limitation of this implementation is that the contributed assets are not localized at all.
039 *
040 * @see StackExtension
041 * @since 5.3
042 */
043@UsesOrderedConfiguration(StackExtension.class)
044public class ExtensibleJavaScriptStack implements JavaScriptStack
045{
046    private final AssetSource assetSource;
047
048    private final List<Asset> libraries;
049
050    private final List<StylesheetLink> stylesheets;
051
052    private final List<String> stacks;
053
054    private final List<String> modules;
055
056    private final String initialization;
057
058    private final Predicate<StackExtension> by(final StackExtensionType type)
059    {
060        return new Predicate<StackExtension>()
061        {
062            public boolean accept(StackExtension element)
063            {
064                return element.type == type;
065            }
066        };
067    }
068
069    private final Mapper<StackExtension, String> extractValue = new Mapper<StackExtension, String>()
070    {
071        public String map(StackExtension element)
072        {
073            return element.value;
074        }
075
076        ;
077    };
078
079    private final Mapper<String, Asset> stringToAsset = new Mapper<String, Asset>()
080    {
081        public Asset map(String value)
082        {
083            return assetSource.getExpandedAsset(value);
084        }
085
086        ;
087    };
088
089    private final Mapper<Asset, StylesheetLink> assetToStylesheetLink = new Mapper<Asset, StylesheetLink>()
090    {
091        public StylesheetLink map(Asset asset)
092        {
093            return new StylesheetLink(asset);
094        }
095
096        ;
097    };
098
099    public ExtensibleJavaScriptStack(AssetSource assetSource, List<StackExtension> configuration)
100    {
101        this.assetSource = assetSource;
102
103        Flow<StackExtension> extensions = F.flow(configuration);
104
105        libraries = extensions.filter(by(StackExtensionType.LIBRARY)).map(extractValue).map(stringToAsset).toList();
106
107        stacks = extensions.filter(by(StackExtensionType.STACK)).map(extractValue).toList();
108
109        modules = extensions.filter(by(StackExtensionType.MODULE)).map(extractValue).toList();
110
111        stylesheets = extensions.filter(by(StackExtensionType.STYLESHEET)).map(extractValue).map(stringToAsset)
112                .map(assetToStylesheetLink).toList();
113
114        List<String> initializations = extensions.filter(by(StackExtensionType.INITIALIZATION)).map(extractValue)
115                .toList();
116
117        initialization = initializations.isEmpty() ? null : InternalUtils.join(initializations, "\n");
118    }
119
120    public List<String> getStacks()
121    {
122        return stacks;
123    }
124
125    public List<Asset> getJavaScriptLibraries()
126    {
127        return libraries;
128    }
129
130    public List<StylesheetLink> getStylesheets()
131    {
132        return stylesheets;
133    }
134
135    public String getInitialization()
136    {
137        return initialization;
138    }
139
140    public List<String> getModules()
141    {
142        return modules;
143    }
144}