org.jasig.portal.layout.StylesheetUserPreferencesServiceImpl.java Source code

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/**
 * Licensed to Apereo under one or more contributor license
 * agreements. See the NOTICE file distributed with this work
 * for additional information regarding copyright ownership.
 * Apereo 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 the following location:
 *
 *   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.jasig.portal.layout;

import java.util.Collection;
import java.util.LinkedHashSet;
import java.util.Map;
import java.util.concurrent.ConcurrentHashMap;
import java.util.concurrent.ConcurrentMap;

import javax.servlet.http.HttpServletRequest;
import javax.servlet.http.HttpSession;

import org.jasig.portal.IUserPreferencesManager;
import org.jasig.portal.IUserProfile;
import org.jasig.portal.layout.dao.IStylesheetDescriptorDao;
import org.jasig.portal.layout.dao.IStylesheetUserPreferencesDao;
import org.jasig.portal.layout.om.ILayoutAttributeDescriptor;
import org.jasig.portal.layout.om.IOutputPropertyDescriptor;
import org.jasig.portal.layout.om.IStylesheetData;
import org.jasig.portal.layout.om.IStylesheetData.Scope;
import org.jasig.portal.layout.om.IStylesheetDescriptor;
import org.jasig.portal.layout.om.IStylesheetParameterDescriptor;
import org.jasig.portal.layout.om.IStylesheetUserPreferences;
import org.jasig.portal.security.IPerson;
import org.jasig.portal.user.IUserInstance;
import org.jasig.portal.user.IUserInstanceManager;
import org.jasig.portal.utils.Populator;
import org.jasig.portal.utils.web.PortalWebUtils;
import org.slf4j.Logger;
import org.slf4j.LoggerFactory;
import org.springframework.beans.factory.annotation.Autowired;
import org.springframework.stereotype.Service;
import org.springframework.transaction.annotation.Transactional;
import org.springframework.web.util.WebUtils;

import com.google.common.base.Function;
import com.google.common.collect.Collections2;
import com.google.common.collect.ImmutableMap;
import com.google.common.collect.ImmutableMap.Builder;
import org.apache.commons.lang3.StringUtils;

/**
 * Handles retrieving and storing the various scopes of stylesheet user preference data.
 * 
 * @author Eric Dalquist
 * @version $Revision$
 */
@Service
public class StylesheetUserPreferencesServiceImpl implements IStylesheetUserPreferencesService {
    private static final String OUTPUT_PROPERTIES_KEY = StylesheetUserPreferencesServiceImpl.class.getName()
            + ".OUTPUT_PROPERTIES";
    private static final String STYLESHEET_PARAMETERS_KEY = StylesheetUserPreferencesServiceImpl.class.getName()
            + ".STYLESHEET_PARAMETERS";
    private static final String LAYOUT_ATTRIBUTES_KEY = StylesheetUserPreferencesServiceImpl.class.getName()
            + ".LAYOUT_ATTRIBUTES";

    public static final String STYLESHEET_STRUCTURE_OVERRIDE_REQUEST_ATTRIBUTE = StylesheetUserPreferencesServiceImpl.class
            .getCanonicalName() + ".STYLESHEET_STRUCTURE_NAME";
    public static final String STYLESHEET_THEME_OVERRIDE_REQUEST_ATTRIBUTE_NAME = StylesheetUserPreferencesServiceImpl.class
            .getCanonicalName() + ".STYLESHEET_THEME_NAME";

    protected final Logger logger = LoggerFactory.getLogger(getClass());

    private IUserInstanceManager userInstanceManager;
    private IStylesheetDescriptorDao stylesheetDescriptorDao;
    private IStylesheetUserPreferencesDao stylesheetUserPreferencesDao;

    @Autowired
    public void setUserInstanceManager(IUserInstanceManager userInstanceManager) {
        this.userInstanceManager = userInstanceManager;
    }

    @Autowired
    public void setStylesheetDescriptorDao(IStylesheetDescriptorDao stylesheetDescriptorDao) {
        this.stylesheetDescriptorDao = stylesheetDescriptorDao;
    }

    @Autowired
    public void setStylesheetUserPreferencesDao(IStylesheetUserPreferencesDao stylesheetUserPreferencesDao) {
        this.stylesheetUserPreferencesDao = stylesheetUserPreferencesDao;
    }

    protected static final class StylesheetPreferencesKey {
        private final IPerson person;
        private final IUserProfile userProfile;
        private final IStylesheetDescriptor stylesheetDescriptor;
        private final String str;

        private StylesheetPreferencesKey(IPerson person, IUserProfile userProfile,
                IStylesheetDescriptor stylesheetDescriptor) {
            this.person = person;
            this.userProfile = userProfile;
            this.stylesheetDescriptor = stylesheetDescriptor;

            this.str = "[" + stylesheetDescriptor.getId() + "," + person.getUserName() + ","
                    + userProfile.getProfileId() + "]";
        }

        public String toString() {
            return this.str;
        }
    }

    protected final StylesheetPreferencesKey getStylesheetPreferencesKey(HttpServletRequest request,
            PreferencesScope prefScope) {
        final IUserInstance userInstance = this.userInstanceManager.getUserInstance(request);

        final IPerson person = userInstance.getPerson();

        final IUserPreferencesManager preferencesManager = userInstance.getPreferencesManager();
        final IUserProfile userProfile = preferencesManager.getUserProfile();

        final IStylesheetDescriptor stylesheetDescriptor = getStylesheetDescriptor(request, prefScope);

        return new StylesheetPreferencesKey(person, userProfile, stylesheetDescriptor);
    }

    protected final IStylesheetUserPreferences getDistributedStylesheetUserPreferences(HttpServletRequest request,
            PreferencesScope prefScope) {
        final IUserInstance userInstance = this.userInstanceManager.getUserInstance(request);
        final IUserPreferencesManager preferencesManager = userInstance.getPreferencesManager();
        final IUserLayoutManager userLayoutManager = preferencesManager.getUserLayoutManager();
        final IUserLayout userLayout = userLayoutManager.getUserLayout();

        return prefScope.getDistributedIStylesheetUserPreferences(userLayout);
    }

    protected final Scope getWriteScope(HttpServletRequest request, PreferencesScope prefScope,
            StylesheetPreferencesKey stylesheetPreferencesKey, IStylesheetData descriptor) {
        final Scope scope = descriptor.getScope();
        final boolean persistentScopeReadOnly = this.isPersistentScopeReadOnly(request, prefScope,
                stylesheetPreferencesKey);
        if (persistentScopeReadOnly && Scope.PERSISTENT == scope) {
            return Scope.SESSION;
        }
        return scope;
    }

    protected boolean isPersistentScopeReadOnly(HttpServletRequest request, PreferencesScope prefScope,
            StylesheetPreferencesKey stylesheetPreferencesKey) {
        return stylesheetPreferencesKey.person.isGuest();
    }

    protected final boolean compareValues(String value, String defaultValue) {
        return value == defaultValue || (value != null && value.equals(defaultValue));
    }

    protected final <T> T getDataValue(HttpServletRequest request,
            StylesheetPreferencesKey stylesheetPreferencesKey, Scope scope, String mapKey, String name) {
        switch (scope) {
        case SESSION: {
            final HttpSession session = request.getSession(false);
            if (session == null) {
                return null;
            }

            final Map<String, T> outputProperties = PortalWebUtils.getMapSessionAttribute(session,
                    mapKey + stylesheetPreferencesKey.toString(), false);
            if (outputProperties == null) {
                return null;
            }

            return outputProperties.get(name);
        }
        case REQUEST: {
            final Map<String, T> outputProperties = PortalWebUtils.getMapRequestAttribute(request,
                    mapKey + stylesheetPreferencesKey.toString(), false);
            if (outputProperties == null) {
                return null;
            }

            return outputProperties.get(name);
        }
        default: {
            return null;
        }
        }
    }

    protected final <T> T putDataValue(HttpServletRequest request,
            StylesheetPreferencesKey stylesheetPreferencesKey, Scope scope, String mapKey, String name, T value) {
        switch (scope) {
        case SESSION: {
            final HttpSession session = request.getSession();
            final Map<String, T> outputProperties = PortalWebUtils.getMapSessionAttribute(session,
                    mapKey + stylesheetPreferencesKey.toString());

            return outputProperties.put(name, value);
        }
        case REQUEST: {
            final Map<String, T> outputProperties = PortalWebUtils.getMapRequestAttribute(request,
                    mapKey + stylesheetPreferencesKey.toString());

            return outputProperties.put(name, value);
        }
        default: {
            return null;
        }
        }
    }

    protected final <T> T removeDataValue(HttpServletRequest request,
            StylesheetPreferencesKey stylesheetPreferencesKey, Scope scope, String mapKey, String name) {
        switch (scope) {
        case SESSION: {
            final HttpSession session = request.getSession(false);
            if (session == null) {
                return null;
            }

            final Map<String, T> outputProperties = PortalWebUtils.getMapSessionAttribute(session,
                    mapKey + stylesheetPreferencesKey.toString(), false);
            if (outputProperties == null) {
                return null;
            }

            return outputProperties.remove(name);
        }
        case REQUEST: {
            final Map<String, T> outputProperties = PortalWebUtils.getMapRequestAttribute(request,
                    mapKey + stylesheetPreferencesKey.toString(), false);
            if (outputProperties == null) {
                return null;
            }

            return outputProperties.remove(name);
        }
        default: {
            return null;
        }
        }
    }

    @Override
    public IStylesheetDescriptor getStylesheetDescriptor(HttpServletRequest request, PreferencesScope prefScope) {
        String stylesheetName = this.getStyleSheetName(request, prefScope);
        if (!StringUtils.isBlank(stylesheetName)) {
            return this.stylesheetDescriptorDao.getStylesheetDescriptorByName(stylesheetName);
        } else {
            final IUserInstance userInstance = this.userInstanceManager.getUserInstance(request);

            final IUserPreferencesManager preferencesManager = userInstance.getPreferencesManager();
            final IUserProfile userProfile = preferencesManager.getUserProfile();

            final int stylesheetId = prefScope.getStylesheetId(userProfile);
            return this.stylesheetDescriptorDao.getStylesheetDescriptor(stylesheetId);
        }
    }

    @Override
    public String getOutputProperty(HttpServletRequest request, PreferencesScope prefScope, String name) {
        final StylesheetPreferencesKey stylesheetPreferencesKey = this.getStylesheetPreferencesKey(request,
                prefScope);
        final IStylesheetDescriptor stylesheetDescriptor = stylesheetPreferencesKey.stylesheetDescriptor;
        final IOutputPropertyDescriptor outputPropertyDescriptor = stylesheetDescriptor
                .getOutputPropertyDescriptor(name);
        if (outputPropertyDescriptor == null) {
            logger.warn(
                    "Attempted to get output property '{}' but no such output property is defined in stylesheet descriptor '{}'. null will be returned",
                    new Object[] { name, stylesheetDescriptor.getName() });
            return null;
        }

        final String value;
        final Scope scope = outputPropertyDescriptor.getScope();
        switch (scope) {
        case PERSISTENT: {
            final IStylesheetUserPreferences stylesheetUserPreferences = this.getStylesheetUserPreferences(request,
                    stylesheetPreferencesKey);
            if (stylesheetUserPreferences == null) {
                return null;
            }

            value = stylesheetUserPreferences.getOutputProperty(name);
            break;
        }
        default: {
            value = this.getDataValue(request, stylesheetPreferencesKey, scope, OUTPUT_PROPERTIES_KEY, name);
            break;
        }
        }

        if (value == null) {
            return null;
        }

        //If the value is equal to the default value remove the property and return null
        if (this.compareValues(value, outputPropertyDescriptor.getDefaultValue())) {
            this.removeOutputProperty(request, prefScope, name);
            return null;
        }

        return value;
    }

    @Transactional
    @Override
    public String setOutputProperty(HttpServletRequest request, PreferencesScope prefScope, String name,
            String value) {
        final StylesheetPreferencesKey stylesheetPreferencesKey = this.getStylesheetPreferencesKey(request,
                prefScope);
        final IStylesheetDescriptor stylesheetDescriptor = stylesheetPreferencesKey.stylesheetDescriptor;
        final IOutputPropertyDescriptor outputPropertyDescriptor = stylesheetDescriptor
                .getOutputPropertyDescriptor(name);
        if (outputPropertyDescriptor == null) {
            logger.warn(
                    "Attempted to set output property {}={} but no such output property is defined in stylesheet descriptor {}. It will be ignored",
                    new Object[] { name, value, stylesheetDescriptor.getName() });
            return null;
        }

        if (this.compareValues(value, outputPropertyDescriptor.getDefaultValue())) {
            return this.removeOutputProperty(request, prefScope, name);
        }

        final Scope scope = this.getWriteScope(request, prefScope, stylesheetPreferencesKey,
                outputPropertyDescriptor);
        switch (scope) {
        case PERSISTENT: {
            IStylesheetUserPreferences stylesheetUserPreferences = this.getStylesheetUserPreferences(request,
                    stylesheetPreferencesKey);
            if (stylesheetUserPreferences == null) {
                stylesheetUserPreferences = this.stylesheetUserPreferencesDao.createStylesheetUserPreferences(
                        stylesheetDescriptor, stylesheetPreferencesKey.person,
                        stylesheetPreferencesKey.userProfile);
                this.clearStylesheetUserPreferencesCache(request, stylesheetPreferencesKey);
            }

            final String oldValue = stylesheetUserPreferences.setOutputProperty(name, value);
            this.stylesheetUserPreferencesDao.storeStylesheetUserPreferences(stylesheetUserPreferences);
            return oldValue;
        }
        default: {
            return this.putDataValue(request, stylesheetPreferencesKey, scope, OUTPUT_PROPERTIES_KEY, name, value);
        }
        }
    }

    @Transactional
    @Override
    public String removeOutputProperty(HttpServletRequest request, PreferencesScope prefScope, String name) {
        final StylesheetPreferencesKey stylesheetPreferencesKey = this.getStylesheetPreferencesKey(request,
                prefScope);
        final IStylesheetDescriptor stylesheetDescriptor = stylesheetPreferencesKey.stylesheetDescriptor;
        final IOutputPropertyDescriptor outputPropertyDescriptor = stylesheetDescriptor
                .getOutputPropertyDescriptor(name);
        if (outputPropertyDescriptor == null) {
            logger.warn(
                    "Attempted to remove output property '{}' but no such output property is defined in stylesheet descriptor '{}'. It will be ignored",
                    new Object[] { name, stylesheetDescriptor.getName() });
            return null;
        }

        final Scope scope = this.getWriteScope(request, prefScope, stylesheetPreferencesKey,
                outputPropertyDescriptor);
        switch (scope) {
        case PERSISTENT: {
            final IStylesheetUserPreferences stylesheetUserPreferences = this.getStylesheetUserPreferences(request,
                    stylesheetPreferencesKey);
            if (stylesheetUserPreferences == null) {
                return null;
            }

            final String oldValue = stylesheetUserPreferences.removeOutputProperty(name);
            this.stylesheetUserPreferencesDao.storeStylesheetUserPreferences(stylesheetUserPreferences);
            this.clearStylesheetUserPreferencesCache(request, stylesheetPreferencesKey);
            return oldValue;
        }
        default: {
            return removeDataValue(request, stylesheetPreferencesKey, scope, OUTPUT_PROPERTIES_KEY, name);
        }
        }
    }

    @Override
    public <P extends Populator<String, String>> P populateOutputProperties(HttpServletRequest request,
            PreferencesScope prefScope, P properties) {
        final StylesheetPreferencesKey stylesheetPreferencesKey = this.getStylesheetPreferencesKey(request,
                prefScope);
        final IStylesheetDescriptor stylesheetDescriptor = stylesheetPreferencesKey.stylesheetDescriptor;

        //Get the scoped sources once
        final IStylesheetUserPreferences stylesheetUserPreferences = this.getStylesheetUserPreferences(request,
                stylesheetPreferencesKey);

        final Map<String, String> sessionOutputProperties;
        final HttpSession session = request.getSession(false);
        if (session == null) {
            sessionOutputProperties = null;
        } else {
            sessionOutputProperties = PortalWebUtils.getMapSessionAttribute(session,
                    OUTPUT_PROPERTIES_KEY + stylesheetPreferencesKey.toString(), false);
        }

        final Map<String, String> requestOutputProperties = PortalWebUtils.getMapRequestAttribute(request,
                OUTPUT_PROPERTIES_KEY + stylesheetPreferencesKey.toString(), false);

        //Try getting each output property to populate the Properties
        for (final IOutputPropertyDescriptor outputPropertyDescriptor : stylesheetDescriptor
                .getOutputPropertyDescriptors()) {
            final String name = outputPropertyDescriptor.getName();

            final String value;
            final Scope scope = outputPropertyDescriptor.getScope();
            switch (scope) {
            case PERSISTENT: {
                if (stylesheetUserPreferences == null) {
                    value = null;
                    break;
                }

                value = stylesheetUserPreferences.getOutputProperty(name);
                break;
            }
            case SESSION: {
                if (sessionOutputProperties == null) {
                    value = null;
                    break;
                }

                value = sessionOutputProperties.get(name);
                break;
            }
            case REQUEST: {
                if (requestOutputProperties == null) {
                    value = null;
                    break;
                }

                value = requestOutputProperties.get(name);
                break;
            }
            default: {
                value = null;
                break;
            }
            }

            //Don't add unset properties
            if (value == null) {
                continue;
            }

            //If the value is equal to the default value remove the property and return null
            if (this.compareValues(value, outputPropertyDescriptor.getDefaultValue())) {
                this.removeOutputProperty(request, prefScope, name);
                continue;
            }

            properties.put(name, value);
        }

        return properties;
    }

    @Transactional
    @Override
    public void clearOutputProperties(HttpServletRequest request, PreferencesScope prefScope) {
        final StylesheetPreferencesKey stylesheetPreferencesKey = this.getStylesheetPreferencesKey(request,
                prefScope);

        final IStylesheetUserPreferences stylesheetUserPreferences = this.getStylesheetUserPreferences(request,
                stylesheetPreferencesKey);
        if (stylesheetUserPreferences != null) {
            stylesheetUserPreferences.clearOutputProperties();
            this.stylesheetUserPreferencesDao.storeStylesheetUserPreferences(stylesheetUserPreferences);
        }

        final HttpSession session = request.getSession(false);
        if (session != null) {
            session.removeAttribute(OUTPUT_PROPERTIES_KEY + stylesheetPreferencesKey.toString());
        }

        request.removeAttribute(OUTPUT_PROPERTIES_KEY + stylesheetPreferencesKey.toString());
    }

    @Override
    public String getStylesheetParameter(HttpServletRequest request, PreferencesScope prefScope, String name) {
        final StylesheetPreferencesKey stylesheetPreferencesKey = this.getStylesheetPreferencesKey(request,
                prefScope);
        final IStylesheetDescriptor stylesheetDescriptor = stylesheetPreferencesKey.stylesheetDescriptor;
        final IStylesheetParameterDescriptor stylesheetParameterDescriptor = stylesheetDescriptor
                .getStylesheetParameterDescriptor(name);
        if (stylesheetParameterDescriptor == null) {
            logger.warn(
                    "Attempted to get stylesheet parameter '{}' but no such stylesheet parameter is defined in stylesheet descriptor '{}'. null will be returned",
                    new Object[] { name, stylesheetDescriptor.getName() });
            return null;
        }

        final String value;
        final Scope scope = stylesheetParameterDescriptor.getScope();
        switch (scope) {
        case PERSISTENT: {
            final IStylesheetUserPreferences stylesheetUserPreferences = this.getStylesheetUserPreferences(request,
                    stylesheetPreferencesKey);
            if (stylesheetUserPreferences == null) {
                return null;
            }

            value = stylesheetUserPreferences.getStylesheetParameter(name);
            break;
        }
        default: {
            value = this.getDataValue(request, stylesheetPreferencesKey, scope, STYLESHEET_PARAMETERS_KEY, name);
            break;
        }
        }

        if (value == null) {
            return null;
        }

        //If the value is equal to the default value remove the property and return null
        if (this.compareValues(value, stylesheetParameterDescriptor.getDefaultValue())) {
            this.removeStylesheetParameter(request, prefScope, name);
            return null;
        }

        return value;
    }

    @Transactional
    @Override
    public String setStylesheetParameter(HttpServletRequest request, PreferencesScope prefScope, String name,
            String value) {

        logger.trace("Setting stylesheet parameter {} with scope {} to {}.", name, prefScope, value);

        final StylesheetPreferencesKey stylesheetPreferencesKey = this.getStylesheetPreferencesKey(request,
                prefScope);
        final IStylesheetDescriptor stylesheetDescriptor = stylesheetPreferencesKey.stylesheetDescriptor;
        final IStylesheetParameterDescriptor stylesheetParameterDescriptor = stylesheetDescriptor
                .getStylesheetParameterDescriptor(name);
        if (stylesheetParameterDescriptor == null) {
            logger.warn(
                    "Attempted to set stylesheet parameter {}={} but no such stylesheet parameter is defined in stylesheet descriptor {}. It will be ignored",
                    new Object[] { name, value, stylesheetDescriptor.getName() });
            return null;
        }

        if (this.compareValues(value, stylesheetParameterDescriptor.getDefaultValue())) {
            return this.removeStylesheetParameter(request, prefScope, name);
        }

        final Scope scope = this.getWriteScope(request, prefScope, stylesheetPreferencesKey,
                stylesheetParameterDescriptor);
        switch (scope) {
        case PERSISTENT: {
            IStylesheetUserPreferences stylesheetUserPreferences = this.getStylesheetUserPreferences(request,
                    stylesheetPreferencesKey);
            if (stylesheetUserPreferences == null) {
                stylesheetUserPreferences = this.stylesheetUserPreferencesDao.createStylesheetUserPreferences(
                        stylesheetDescriptor, stylesheetPreferencesKey.person,
                        stylesheetPreferencesKey.userProfile);
                this.clearStylesheetUserPreferencesCache(request, stylesheetPreferencesKey);
            }

            final String oldValue = stylesheetUserPreferences.setStylesheetParameter(name, value);
            this.stylesheetUserPreferencesDao.storeStylesheetUserPreferences(stylesheetUserPreferences);
            return oldValue;
        }
        default: {
            return this.putDataValue(request, stylesheetPreferencesKey, scope, STYLESHEET_PARAMETERS_KEY, name,
                    value);
        }
        }
    }

    @Transactional
    @Override
    public String removeStylesheetParameter(HttpServletRequest request, PreferencesScope prefScope, String name) {
        final StylesheetPreferencesKey stylesheetPreferencesKey = this.getStylesheetPreferencesKey(request,
                prefScope);
        final IStylesheetDescriptor stylesheetDescriptor = stylesheetPreferencesKey.stylesheetDescriptor;
        final IStylesheetParameterDescriptor stylesheetParameterDescriptor = stylesheetDescriptor
                .getStylesheetParameterDescriptor(name);
        if (stylesheetParameterDescriptor == null) {
            logger.warn(
                    "Attempted to remove stylesheet parameter {} but no such stylesheet parameter is defined in stylesheet descriptor {}. It will be ignored",
                    new Object[] { name, stylesheetDescriptor.getName() });
            return null;
        }

        final Scope scope = this.getWriteScope(request, prefScope, stylesheetPreferencesKey,
                stylesheetParameterDescriptor);
        switch (scope) {
        case PERSISTENT: {
            final IStylesheetUserPreferences stylesheetUserPreferences = this.getStylesheetUserPreferences(request,
                    stylesheetPreferencesKey);
            if (stylesheetUserPreferences == null) {
                return null;
            }

            final String oldValue = stylesheetUserPreferences.removeStylesheetParameter(name);
            this.stylesheetUserPreferencesDao.storeStylesheetUserPreferences(stylesheetUserPreferences);
            return oldValue;
        }
        default: {
            return removeDataValue(request, stylesheetPreferencesKey, scope, STYLESHEET_PARAMETERS_KEY, name);
        }
        }
    }

    @Override
    public Iterable<String> getStylesheetParameterNames(HttpServletRequest request, PreferencesScope prefScope) {
        final StylesheetPreferencesKey stylesheetPreferencesKey = this.getStylesheetPreferencesKey(request,
                prefScope);
        final IStylesheetDescriptor stylesheetDescriptor = stylesheetPreferencesKey.stylesheetDescriptor;
        final Collection<IStylesheetParameterDescriptor> stylesheetParameterDescriptors = stylesheetDescriptor
                .getStylesheetParameterDescriptors();

        return Collections2.transform(stylesheetParameterDescriptors,
                new Function<IStylesheetParameterDescriptor, String>() {
                    @Override
                    public String apply(IStylesheetParameterDescriptor input) {
                        return input.getName();
                    }
                });
    }

    @Override
    public <P extends Populator<String, String>> P populateStylesheetParameters(HttpServletRequest request,
            PreferencesScope prefScope, P stylesheetParameters) {
        final StylesheetPreferencesKey stylesheetPreferencesKey = this.getStylesheetPreferencesKey(request,
                prefScope);
        final IStylesheetDescriptor stylesheetDescriptor = stylesheetPreferencesKey.stylesheetDescriptor;

        //Get the scoped sources once
        final IStylesheetUserPreferences stylesheetUserPreferences = this.getStylesheetUserPreferences(request,
                stylesheetPreferencesKey);
        final Map<String, String> sessionStylesheetParameters;
        final HttpSession session = request.getSession(false);
        if (session == null) {
            sessionStylesheetParameters = null;
        } else {
            sessionStylesheetParameters = PortalWebUtils.getMapSessionAttribute(session,
                    STYLESHEET_PARAMETERS_KEY + stylesheetPreferencesKey.toString(), false);
        }
        final Map<String, String> requestStylesheetParameters = PortalWebUtils.getMapRequestAttribute(request,
                STYLESHEET_PARAMETERS_KEY + stylesheetPreferencesKey.toString(), false);

        //Try getting each stylesheet parameter to populate the Map
        for (final IStylesheetParameterDescriptor stylesheetParameterDescriptor : stylesheetDescriptor
                .getStylesheetParameterDescriptors()) {
            final String name = stylesheetParameterDescriptor.getName();

            final String value;
            final Scope scope = stylesheetParameterDescriptor.getScope();
            switch (scope) {
            case PERSISTENT: {
                if (stylesheetUserPreferences == null) {
                    value = null;
                    break;
                }

                value = stylesheetUserPreferences.getStylesheetParameter(name);
                break;
            }
            case SESSION: {
                if (sessionStylesheetParameters == null) {
                    value = null;
                    break;
                }

                value = sessionStylesheetParameters.get(name);
                break;
            }
            case REQUEST: {
                if (requestStylesheetParameters == null) {
                    value = null;
                    break;
                }

                value = requestStylesheetParameters.get(name);
                break;
            }
            default: {
                value = null;
                break;
            }
            }

            //Don't add unset properties
            if (value == null) {
                continue;
            }

            //If the value is equal to the default value remove the property and return null
            if (this.compareValues(value, stylesheetParameterDescriptor.getDefaultValue())) {
                this.removeStylesheetParameter(request, prefScope, name);
                continue;
            }

            stylesheetParameters.put(name, value);
        }

        return stylesheetParameters;
    }

    @Transactional
    @Override
    public void clearStylesheetParameters(HttpServletRequest request, PreferencesScope prefScope) {
        final StylesheetPreferencesKey stylesheetPreferencesKey = this.getStylesheetPreferencesKey(request,
                prefScope);

        final IStylesheetUserPreferences stylesheetUserPreferences = this.getStylesheetUserPreferences(request,
                stylesheetPreferencesKey);
        if (stylesheetUserPreferences != null) {
            stylesheetUserPreferences.clearStylesheetParameters();
            this.stylesheetUserPreferencesDao.storeStylesheetUserPreferences(stylesheetUserPreferences);
        }

        final HttpSession session = request.getSession(false);
        if (session != null) {
            session.removeAttribute(STYLESHEET_PARAMETERS_KEY + stylesheetPreferencesKey.toString());
        }

        request.removeAttribute(STYLESHEET_PARAMETERS_KEY + stylesheetPreferencesKey.toString());
    }

    @Override
    public String getLayoutAttribute(HttpServletRequest request, PreferencesScope prefScope, String nodeId,
            String name) {
        final StylesheetPreferencesKey stylesheetPreferencesKey = this.getStylesheetPreferencesKey(request,
                prefScope);
        final IStylesheetDescriptor stylesheetDescriptor = stylesheetPreferencesKey.stylesheetDescriptor;
        final ILayoutAttributeDescriptor layoutAttributeDescriptor = stylesheetDescriptor
                .getLayoutAttributeDescriptor(name);
        if (layoutAttributeDescriptor == null) {
            logger.warn(
                    "Attempted to get layout attribute {} for ID=\"{}\" but no such stylesheet parameter is defined in stylesheet descriptor {}. Null will be returned",
                    new Object[] { name, nodeId, stylesheetDescriptor.getName() });
            return null;
        }

        //Load the default value
        String defaultValue = null;
        final IStylesheetUserPreferences distributedStylesheetUserPreferences = this
                .getDistributedStylesheetUserPreferences(request, prefScope);
        if (distributedStylesheetUserPreferences != null) {
            defaultValue = distributedStylesheetUserPreferences.getLayoutAttribute(nodeId, name);

            if (this.compareValues(defaultValue, layoutAttributeDescriptor.getDefaultValue())) {
                //DLM attribute value matches the stylesheet descriptor default, remove the DLM value
                distributedStylesheetUserPreferences.removeLayoutAttribute(nodeId, name);
                defaultValue = null;
            }
        }

        final String value;
        final Scope scope = layoutAttributeDescriptor.getScope();
        switch (scope) {
        case PERSISTENT: {
            final IStylesheetUserPreferences stylesheetUserPreferences = this.getStylesheetUserPreferences(request,
                    stylesheetPreferencesKey);
            if (stylesheetUserPreferences == null) {
                value = null;
                break;
            }

            value = stylesheetUserPreferences.getLayoutAttribute(nodeId, name);
            break;
        }
        default: {
            final Map<String, String> nodeAttributes = this.getDataValue(request, stylesheetPreferencesKey, scope,
                    LAYOUT_ATTRIBUTES_KEY, nodeId);
            if (nodeAttributes == null) {
                value = null;
                break;
            }

            value = nodeAttributes.get(name);
            break;
        }
        }

        if (value == null) {
            return defaultValue;
        }

        if (this.compareValues(value, layoutAttributeDescriptor.getDefaultValue()) || //Value is equal to stylesheet descriptor default
                (defaultValue != null && this.compareValues(value, defaultValue))) { //Value is equal to DLM stylesheet preferences default

            //Remove the user's customized value
            this.removeLayoutAttribute(request, prefScope, nodeId, name);
            return null;
        }

        return value;
    }

    private static final String NO_PERSISTENT_IStylesheetUserPreferences = StylesheetUserPreferencesServiceImpl.class
            .getName() + ".NO_PERSISTENT_IStylesheetUserPreferences";

    private String getCacheKey(StylesheetPreferencesKey stylesheetPreferencesKey) {
        return NO_PERSISTENT_IStylesheetUserPreferences + "." + stylesheetPreferencesKey.toString();
    }

    private IStylesheetUserPreferences getStylesheetUserPreferences(HttpServletRequest request,
            StylesheetPreferencesKey stylesheetPreferencesKey) {
        final String key = getCacheKey(stylesheetPreferencesKey);

        if (request.getAttribute(key) != null) {
            return null;
        }

        final HttpSession session = request.getSession();
        if (session.getAttribute(key) != null) {
            request.setAttribute(key, Boolean.TRUE);
            return null;
        }

        final IStylesheetUserPreferences stylesheetUserPreferences = this.stylesheetUserPreferencesDao
                .getStylesheetUserPreferences(stylesheetPreferencesKey.stylesheetDescriptor,
                        stylesheetPreferencesKey.person, stylesheetPreferencesKey.userProfile);

        if (stylesheetUserPreferences == null) {
            session.setAttribute(key, Boolean.TRUE);
            request.setAttribute(key, Boolean.TRUE);
        }

        return stylesheetUserPreferences;
    }

    private void clearStylesheetUserPreferencesCache(HttpServletRequest request,
            StylesheetPreferencesKey stylesheetPreferencesKey) {
        final String key = getCacheKey(stylesheetPreferencesKey);

        request.removeAttribute(key);

        final HttpSession session = request.getSession();
        session.removeAttribute(key);
    }

    /**
     * @return Map<nodeId, Map<name, value>>
     */
    protected ConcurrentMap<String, Map<String, String>> getRequestLayoutAttributes(HttpServletRequest request,
            StylesheetPreferencesKey stylesheetPreferencesKey) {
        return PortalWebUtils.getMapRequestAttribute(request,
                LAYOUT_ATTRIBUTES_KEY + stylesheetPreferencesKey.toString(), false);
    }

    /**
     * @return Map<nodeId, Map<name, value>>
     */
    protected ConcurrentMap<String, Map<String, String>> getSessionLayoutAttributes(HttpSession session,
            StylesheetPreferencesKey stylesheetPreferencesKey) {
        return PortalWebUtils.getMapSessionAttribute(session,
                LAYOUT_ATTRIBUTES_KEY + stylesheetPreferencesKey.toString(), false);
    }

    @Transactional
    @Override
    public String setLayoutAttribute(HttpServletRequest request, PreferencesScope prefScope, String nodeId,
            String name, String value) {
        final StylesheetPreferencesKey stylesheetPreferencesKey = this.getStylesheetPreferencesKey(request,
                prefScope);
        final IStylesheetDescriptor stylesheetDescriptor = stylesheetPreferencesKey.stylesheetDescriptor;
        final ILayoutAttributeDescriptor layoutAttributeDescriptor = stylesheetDescriptor
                .getLayoutAttributeDescriptor(name);
        if (layoutAttributeDescriptor == null) {
            logger.warn(
                    "Attempted to set layout attribute {}={} on node with ID=\"{}\" but no such stylesheet parameter is defined in stylesheet descriptor {}. It will be ignored.",
                    new Object[] { name, value, nodeId, stylesheetDescriptor.getName() });
            return null;
        }

        if (this.compareValues(value, layoutAttributeDescriptor.getDefaultValue())) {
            //Value matches the default value, remove the attribute
            return this.removeLayoutAttribute(request, prefScope, nodeId, name);
        }

        final IStylesheetUserPreferences distributedStylesheetUserPreferences = this
                .getDistributedStylesheetUserPreferences(request, prefScope);
        if (distributedStylesheetUserPreferences != null) {
            final String defaultValue = distributedStylesheetUserPreferences.getLayoutAttribute(nodeId, name);
            if (this.compareValues(value, defaultValue)) {
                //Value matches the DLM preferences value, remove the value
                return this.removeLayoutAttribute(request, prefScope, nodeId, name);
            }
        }

        final Scope scope = this.getWriteScope(request, prefScope, stylesheetPreferencesKey,
                layoutAttributeDescriptor);
        switch (scope) {
        case PERSISTENT: {
            IStylesheetUserPreferences stylesheetUserPreferences = this.getStylesheetUserPreferences(request,
                    stylesheetPreferencesKey);
            if (stylesheetUserPreferences == null) {
                stylesheetUserPreferences = this.stylesheetUserPreferencesDao.createStylesheetUserPreferences(
                        stylesheetDescriptor, stylesheetPreferencesKey.person,
                        stylesheetPreferencesKey.userProfile);
                this.clearStylesheetUserPreferencesCache(request, stylesheetPreferencesKey);
            }

            final String oldValue = stylesheetUserPreferences.setLayoutAttribute(nodeId, name, value);
            this.stylesheetUserPreferencesDao.storeStylesheetUserPreferences(stylesheetUserPreferences);
            return oldValue;
        }
        default: {

            //Determine the mutex to use for accessing the nodeAttributes map
            final Object mutex;
            switch (scope) {
            case REQUEST: {
                mutex = PortalWebUtils.getRequestAttributeMutex(request);
                break;
            }
            case SESSION: {
                final HttpSession session = request.getSession();
                mutex = WebUtils.getSessionMutex(session);
                break;
            }
            default: {
                mutex = new Object();
                break;
            }
            }

            //Get/Create the nodeAttributes map
            Map<String, String> nodeAttributes;
            synchronized (mutex) {
                nodeAttributes = this.getDataValue(request, stylesheetPreferencesKey, scope, LAYOUT_ATTRIBUTES_KEY,
                        nodeId);
                if (nodeAttributes == null) {
                    nodeAttributes = new ConcurrentHashMap<String, String>();
                    this.putDataValue(request, stylesheetPreferencesKey, scope, LAYOUT_ATTRIBUTES_KEY, nodeId,
                            nodeAttributes);
                }
            }

            return nodeAttributes.put(name, value);
        }
        }
    }

    @Transactional
    @Override
    public String removeLayoutAttribute(HttpServletRequest request, PreferencesScope prefScope, String nodeId,
            String name) {
        final StylesheetPreferencesKey stylesheetPreferencesKey = this.getStylesheetPreferencesKey(request,
                prefScope);
        final IStylesheetDescriptor stylesheetDescriptor = stylesheetPreferencesKey.stylesheetDescriptor;
        final ILayoutAttributeDescriptor layoutAttributeDescriptor = stylesheetDescriptor
                .getLayoutAttributeDescriptor(name);
        if (layoutAttributeDescriptor == null) {
            logger.warn(
                    "Attempted to remove layout attribute {} for ID=\"{}\" but no such stylesheet parameter is defined in stylesheet descriptor {}. It will be ignored.",
                    new Object[] { name, nodeId, stylesheetDescriptor.getName() });
            return null;
        }

        final Scope scope = this.getWriteScope(request, prefScope, stylesheetPreferencesKey,
                layoutAttributeDescriptor);
        switch (scope) {
        case PERSISTENT: {
            final IStylesheetUserPreferences stylesheetUserPreferences = this.getStylesheetUserPreferences(request,
                    stylesheetPreferencesKey);
            if (stylesheetUserPreferences == null) {
                break;
            }

            final String oldValue = stylesheetUserPreferences.removeLayoutAttribute(nodeId, name);
            if (oldValue != null) {
                this.stylesheetUserPreferencesDao.storeStylesheetUserPreferences(stylesheetUserPreferences);
                return oldValue;
            }
        }
        default: {
            final Map<String, String> nodeAttributes = this.getDataValue(request, stylesheetPreferencesKey, scope,
                    LAYOUT_ATTRIBUTES_KEY, nodeId);
            if (nodeAttributes == null) {
                break;
            }

            final String oldValue = nodeAttributes.remove(name);
            if (oldValue != null) {
                return oldValue;
            }
        }
        }

        final IStylesheetUserPreferences distributedStylesheetUserPreferences = this
                .getDistributedStylesheetUserPreferences(request, prefScope);
        if (distributedStylesheetUserPreferences != null) {
            return distributedStylesheetUserPreferences.removeLayoutAttribute(nodeId, name);
        }

        return null;
    }

    @Override
    public Iterable<String> getAllLayoutAttributeNodeIds(HttpServletRequest request, PreferencesScope prefScope) {
        final StylesheetPreferencesKey stylesheetPreferencesKey = this.getStylesheetPreferencesKey(request,
                prefScope);

        final LinkedHashSet<String> allNodeIds = new LinkedHashSet<String>();

        final IStylesheetUserPreferences stylesheetUserPreferences = this.getStylesheetUserPreferences(request,
                stylesheetPreferencesKey);
        if (stylesheetUserPreferences != null) {
            allNodeIds.addAll(stylesheetUserPreferences.getAllLayoutAttributeNodeIds());
        }

        final HttpSession session = request.getSession(false);
        if (session != null) {
            final Map<String, Map<String, String>> sessionLayoutAttributes = getSessionLayoutAttributes(session,
                    stylesheetPreferencesKey);
            if (sessionLayoutAttributes != null) {
                allNodeIds.addAll(sessionLayoutAttributes.keySet());
            }

        }

        final Map<String, Map<String, String>> requestLayoutAttributes = getRequestLayoutAttributes(request,
                stylesheetPreferencesKey);
        if (requestLayoutAttributes != null) {
            allNodeIds.addAll(requestLayoutAttributes.keySet());
        }

        final IStylesheetUserPreferences distributedStylesheetUserPreferences = this
                .getDistributedStylesheetUserPreferences(request, prefScope);
        if (distributedStylesheetUserPreferences != null) {
            allNodeIds.addAll(distributedStylesheetUserPreferences.getAllLayoutAttributeNodeIds());
        }

        return allNodeIds;
    }

    @Override
    public Map<String, String> getAllNodesAndValuesForAttribute(HttpServletRequest request,
            PreferencesScope prefScope, String name) {
        final StylesheetPreferencesKey stylesheetPreferencesKey = this.getStylesheetPreferencesKey(request,
                prefScope);
        final IStylesheetUserPreferences stylesheetUserPreferences = this.getStylesheetUserPreferences(request,
                stylesheetPreferencesKey);

        final Builder<String, String> result = ImmutableMap.builder();

        final IStylesheetUserPreferences distributedStylesheetUserPreferences = this
                .getDistributedStylesheetUserPreferences(request, prefScope);
        if (distributedStylesheetUserPreferences != null) {
            final Map<String, String> allNodesAndValuesForAttribute = distributedStylesheetUserPreferences
                    .getAllNodesAndValuesForAttribute(name);
            result.putAll(allNodesAndValuesForAttribute);
        }

        if (stylesheetUserPreferences != null) {
            final Map<String, String> allNodesAndValuesForAttribute = stylesheetUserPreferences
                    .getAllNodesAndValuesForAttribute(name);
            result.putAll(allNodesAndValuesForAttribute);
        }

        final HttpSession session = request.getSession(false);
        if (session != null) {
            //nodeId, name, value
            final Map<String, Map<String, String>> sessionLayoutAttributes = getSessionLayoutAttributes(session,
                    stylesheetPreferencesKey);
            getAllNodesAndValuesForAttribute(sessionLayoutAttributes, name, result);
        }

        final Map<String, Map<String, String>> requestLayoutAttributes = getRequestLayoutAttributes(request,
                stylesheetPreferencesKey);
        if (requestLayoutAttributes != null) {
            getAllNodesAndValuesForAttribute(requestLayoutAttributes, name, result);
        }

        return result.build();
    }

    protected void getAllNodesAndValuesForAttribute(Map<String, Map<String, String>> layoutAttributes, String name,
            Builder<String, String> result) {
        if (layoutAttributes == null) {
            return;
        }

        for (Map.Entry<String, Map<String, String>> layoutNodeAttributesEntry : layoutAttributes.entrySet()) {
            //name, value
            final Map<String, String> layoutNodeAttribute = layoutNodeAttributesEntry.getValue();
            final String value = layoutNodeAttribute.get(name);
            if (value != null) {
                final String nodeId = layoutNodeAttributesEntry.getKey();
                result.put(nodeId, value);
            }
        }
    }

    @Override
    public <P extends Populator<String, String>> P populateLayoutAttributes(HttpServletRequest request,
            PreferencesScope prefScope, String nodeId, P layoutAttributes) {
        final StylesheetPreferencesKey stylesheetPreferencesKey = this.getStylesheetPreferencesKey(request,
                prefScope);
        final IStylesheetDescriptor stylesheetDescriptor = stylesheetPreferencesKey.stylesheetDescriptor;

        //Get the scoped sources once
        final IStylesheetUserPreferences stylesheetUserPreferences = this.getStylesheetUserPreferences(request,
                stylesheetPreferencesKey);
        final Map<String, Map<String, String>> sessionLayoutAttributes;
        final HttpSession session = request.getSession(false);
        if (session == null) {
            sessionLayoutAttributes = null;
        } else {
            sessionLayoutAttributes = getSessionLayoutAttributes(session, stylesheetPreferencesKey);
        }
        final Map<String, Map<String, String>> requestLayoutAttributes = getRequestLayoutAttributes(request,
                stylesheetPreferencesKey);

        final IStylesheetUserPreferences distributedStylesheetUserPreferences = this
                .getDistributedStylesheetUserPreferences(request, prefScope);
        if (distributedStylesheetUserPreferences != null) {
            distributedStylesheetUserPreferences.populateLayoutAttributes(nodeId, layoutAttributes);
        }

        //Try getting each layout attribute to populate the Map
        for (final ILayoutAttributeDescriptor layoutAttributeDescriptor : stylesheetDescriptor
                .getLayoutAttributeDescriptors()) {
            final String name = layoutAttributeDescriptor.getName();

            String value;
            final Scope scope = layoutAttributeDescriptor.getScope();
            switch (scope) {
            case PERSISTENT: {
                if (stylesheetUserPreferences == null) {
                    value = null;
                    break;
                }

                value = stylesheetUserPreferences.getLayoutAttribute(nodeId, name);
                break;
            }
            case SESSION: {
                if (sessionLayoutAttributes == null) {
                    value = null;
                    break;
                }

                final Map<String, String> nodeAttributes = sessionLayoutAttributes.get(nodeId);
                if (nodeAttributes == null) {
                    value = null;
                    break;
                }

                value = nodeAttributes.get(name);
                break;
            }
            case REQUEST: {
                if (requestLayoutAttributes == null) {
                    value = null;
                    break;
                }

                final Map<String, String> nodeAttributes = requestLayoutAttributes.get(nodeId);
                if (nodeAttributes == null) {
                    value = null;
                    break;
                }

                value = nodeAttributes.get(name);
                break;
            }
            default: {
                value = null;
                break;
            }
            }

            //Don't add unset properties
            if (value == null) {
                continue;
            }

            //If the value is equal to the default value remove the property and return null
            if (this.compareValues(value, layoutAttributeDescriptor.getDefaultValue())) {
                this.removeLayoutAttribute(request, prefScope, nodeId, name);
                continue;
            }

            layoutAttributes.put(name, value);
        }

        return layoutAttributes;
    }

    @Transactional
    @Override
    public void clearLayoutAttributes(HttpServletRequest request, PreferencesScope prefScope, String nodeId) {
        final StylesheetPreferencesKey stylesheetPreferencesKey = this.getStylesheetPreferencesKey(request,
                prefScope);

        final IStylesheetUserPreferences stylesheetUserPreferences = this.getStylesheetUserPreferences(request,
                stylesheetPreferencesKey);
        if (stylesheetUserPreferences != null) {
            stylesheetUserPreferences.clearLayoutAttributes(nodeId);
            this.stylesheetUserPreferencesDao.storeStylesheetUserPreferences(stylesheetUserPreferences);
        }

        final HttpSession session = request.getSession(false);
        if (session != null) {
            final Map<String, Map<String, String>> sessionLayoutAttributes = getSessionLayoutAttributes(session,
                    stylesheetPreferencesKey);
            if (sessionLayoutAttributes != null) {
                sessionLayoutAttributes.remove(nodeId);
            }

        }

        final Map<String, Map<String, String>> requestLayoutAttributes = getRequestLayoutAttributes(request,
                stylesheetPreferencesKey);
        if (requestLayoutAttributes != null) {
            requestLayoutAttributes.remove(nodeId);
        }
    }

    @Transactional
    @Override
    public void clearAllLayoutAttributes(HttpServletRequest request, PreferencesScope prefScope) {
        final StylesheetPreferencesKey stylesheetPreferencesKey = this.getStylesheetPreferencesKey(request,
                prefScope);

        final IStylesheetUserPreferences stylesheetUserPreferences = this.getStylesheetUserPreferences(request,
                stylesheetPreferencesKey);
        if (stylesheetUserPreferences != null) {
            stylesheetUserPreferences.clearAllLayoutAttributes();
            this.stylesheetUserPreferencesDao.storeStylesheetUserPreferences(stylesheetUserPreferences);
        }

        final HttpSession session = request.getSession(false);
        if (session != null) {
            session.removeAttribute(LAYOUT_ATTRIBUTES_KEY + stylesheetPreferencesKey.toString());
        }

        request.removeAttribute(LAYOUT_ATTRIBUTES_KEY + stylesheetPreferencesKey.toString());
    }

    @Override
    public void setStructureStylesheetOverride(HttpServletRequest request, String override) {
        request.setAttribute(StylesheetUserPreferencesServiceImpl.STYLESHEET_STRUCTURE_OVERRIDE_REQUEST_ATTRIBUTE,
                override);
    }

    @Override
    public void setThemeStyleSheetOverride(HttpServletRequest request, String override) {
        request.setAttribute(StylesheetUserPreferencesServiceImpl.STYLESHEET_THEME_OVERRIDE_REQUEST_ATTRIBUTE_NAME,
                override);
    }

    /**
     * Returns the stylesheet name if overridden in the request object.
     * @param request HttpRequest
     * @param scope Scope (Structure or Theme)
     * @return Stylesheet name if set as an override in the request, else null if it was not.
     */
    protected String getStyleSheetName(final HttpServletRequest request, PreferencesScope scope) {
        final String stylesheetNameFromRequest;

        if (scope.equals(PreferencesScope.STRUCTURE)) {
            stylesheetNameFromRequest = (String) request
                    .getAttribute(STYLESHEET_STRUCTURE_OVERRIDE_REQUEST_ATTRIBUTE);
        } else {
            stylesheetNameFromRequest = (String) request
                    .getAttribute(STYLESHEET_THEME_OVERRIDE_REQUEST_ATTRIBUTE_NAME);
        }

        return stylesheetNameFromRequest;
    }
}