org.apache.myfaces.shared_tomahawk.resource.ExternalContextResourceLoader Maven / Gradle / Ivy

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JSF components and utilities that can be used with any JSF implementation. This library is based on the JSF1.1 version of Tomahawk, but with minor source code and build changes to take advantage of JSF2.1 features. A JSF2.1 implementation is required to use this version of the Tomahawk library.
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/*
 * Licensed to the Apache Software Foundation (ASF) under one
 * or more contributor license agreements.  See the NOTICE file
 * distributed with this work for additional information
 * regarding copyright ownership.  The ASF licenses this file
 * to you 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.myfaces.shared_tomahawk.resource;

import java.io.InputStream;
import java.net.MalformedURLException;
import java.net.URL;
import java.util.Iterator;
import java.util.Set;
import java.util.regex.Pattern;

import javax.faces.context.FacesContext;

/**
 * A resource loader implementation which loads resources from the webapp root. It uses the methods on ExternalContext
 * for handle resources.
 * 
 */
public class ExternalContextResourceLoader extends ResourceLoader
{
    /**
     * It checks version like this: /1/, /1_0/, /1_0_0/, /100_100/
     * 
     * Used on getLibraryVersion to filter resource directories
     **/
    protected static final Pattern VERSION_CHECKER = Pattern.compile("/\\p{Digit}+(_\\p{Digit}*)*/");

    /**
     * It checks version like this: /1.js, /1_0.js, /1_0_0.js, /100_100.js
     * 
     * Used on getResourceVersion to filter resources
     **/
    protected static final Pattern RESOURCE_VERSION_CHECKER = Pattern.compile("/\\p{Digit}+(_\\p{Digit}*)*\\..*");

    public ExternalContextResourceLoader(String prefix)
    {
        super(prefix);
    }

    protected Set getResourcePaths(String path)
    {
        return FacesContext.getCurrentInstance().getExternalContext().getResourcePaths(getPrefix() + '/' + path);
    }

    @Override
    public String getResourceVersion(String path)
    {
        String resourceVersion = null;
        Set resourcePaths = this.getResourcePaths(path);
        if (getPrefix() != null)
        {
            path = getPrefix() + '/' + path;
        }

        if (null != resourcePaths && !resourcePaths.isEmpty())
        {
            // resourceVersion = // execute the comment
            // Look in the resourcePaths for versioned resources.
            // If one or more versioned resources are found, take
            // the one with the "highest" version number as the value
            // of resourceVersion. If no versioned libraries
            // are found, let resourceVersion remain null.
            for (String resourcePath : resourcePaths)
            {
                String version = resourcePath.substring(path.length());

                if (RESOURCE_VERSION_CHECKER.matcher(version).matches())
                {
                    version = version.substring(1, version.lastIndexOf('.'));
                    if (resourceVersion == null)
                    {
                        resourceVersion = version;
                    }
                    else if (getVersionComparator().compare(resourceVersion, version) < 0)
                    {
                        resourceVersion = version;
                    }
                }
            }
            //Since it is a directory and no version was found, set as invalid
            if (resourceVersion == null)
            {
                resourceVersion = VERSION_INVALID;
            }
        }
        return resourceVersion;
    }

    @Override
    public String getLibraryVersion(String path)
    {
        String libraryVersion = null;
        Set libraryPaths = this.getResourcePaths(path);
        path = getPrefix() + '/' + path;
        if (null != libraryPaths && !libraryPaths.isEmpty())
        {
            // Look in the libraryPaths for versioned libraries.
            // If one or more versioned libraries are found, take
            // the one with the "highest" version number as the value
            // of libraryVersion. If no versioned libraries
            // are found, let libraryVersion remain null.

            for (Iterator it = libraryPaths.iterator(); it.hasNext();)
            {
                String libraryPath = it.next();
                String version = "";
                if (path.length() < libraryPath.length())
                {
                    version = libraryPath.substring(path.length());
                }

                if (VERSION_CHECKER.matcher(version).matches())
                {
                    version = version.substring(1, version.length() - 1);
                    if (libraryVersion == null)
                    {
                        libraryVersion = version;
                    }
                    else if (getVersionComparator().compare(libraryVersion, version) < 0)
                    {
                        libraryVersion = version;
                    }
                }
            }
        }
        return libraryVersion;
    }

    @Override
    public URL getResourceURL(ResourceMeta resourceMeta)
    {
        try
        {
            return FacesContext.getCurrentInstance().getExternalContext().getResource(
                getPrefix() + '/' + resourceMeta.getResourceIdentifier());
        }
        catch (MalformedURLException e)
        {
            return null;
        }
    }

    @Override
    public InputStream getResourceInputStream(ResourceMeta resourceMeta)
    {
        return FacesContext.getCurrentInstance().getExternalContext().getResourceAsStream(
            getPrefix() + '/' + resourceMeta.getResourceIdentifier());
    }

    @Override
    public ResourceMeta createResourceMeta(String prefix, String libraryName, String libraryVersion,
                                           String resourceName, String resourceVersion)
    {
        return new ResourceMetaImpl(prefix, libraryName, libraryVersion, resourceName, resourceVersion);
    }

    @Override
    public boolean libraryExists(String libraryName)
    {
        if (getPrefix() != null && !"".equals(getPrefix()))
        {
            try
            {
                URL url =
                    FacesContext.getCurrentInstance().getExternalContext().getResource(
                        getPrefix() + '/' + libraryName);
                if (url != null)
                {
                    return true;
                }
            }
            catch (MalformedURLException e)
            {
                return false;
            }
        }
        else
        {
            try
            {

                URL url = FacesContext.getCurrentInstance().getExternalContext().getResource(libraryName);

                if (url != null)
                {
                    return true;
                }
            }
            catch (MalformedURLException e)
            {
                return false;
            }
        }
        return false;
    }
}