001: /*
002: * Copyright 2002-2005 the original author or authors.
003: *
004: * Licensed under the Apache License, Version 2.0 (the "License");
005: * you may not use this file except in compliance with the License.
006: * You may obtain a copy of the License at
007: *
008: * http://www.apache.org/licenses/LICENSE-2.0
009: *
010: * Unless required by applicable law or agreed to in writing, software
011: * distributed under the License is distributed on an "AS IS" BASIS,
012: * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
013: * See the License for the specific language governing permissions and
014: * limitations under the License.
015: */
016:
017: package org.springframework.web.servlet.theme;
018:
019: import javax.servlet.http.Cookie;
020: import javax.servlet.http.HttpServletRequest;
021: import javax.servlet.http.HttpServletResponse;
022:
023: import org.springframework.web.servlet.ThemeResolver;
024: import org.springframework.web.util.CookieGenerator;
025: import org.springframework.web.util.WebUtils;
026:
027: /**
028: * Implementation of ThemeResolver that uses a cookie sent back to the user
029: * in case of a custom setting, with a fallback to the default theme.
030: * This is particularly useful for stateless applications without user sessions.
031: *
032: * <p>Custom controllers can thus override the user's theme by calling
033: * <code>setThemeName</code>, e.g. responding to a certain theme change request.
034: *
035: * @author Jean-Pierre Pawlak
036: * @author Juergen Hoeller
037: * @since 17.06.2003
038: * @see #setThemeName
039: */
040: public class CookieThemeResolver extends CookieGenerator implements
041: ThemeResolver {
042:
043: public final static String ORIGINAL_DEFAULT_THEME_NAME = "theme";
044:
045: /**
046: * Name of the request attribute that holds the theme name. Only used
047: * for overriding a cookie value if the theme has been changed in the
048: * course of the current request! Use RequestContext.getTheme() to
049: * retrieve the current theme in controllers or views.
050: * @see org.springframework.web.servlet.support.RequestContext#getTheme
051: */
052: public static final String THEME_REQUEST_ATTRIBUTE_NAME = CookieThemeResolver.class
053: .getName()
054: + ".THEME";
055:
056: public static final String DEFAULT_COOKIE_NAME = CookieThemeResolver.class
057: .getName()
058: + ".THEME";
059:
060: private String defaultThemeName = ORIGINAL_DEFAULT_THEME_NAME;
061:
062: public CookieThemeResolver() {
063: setCookieName(DEFAULT_COOKIE_NAME);
064: }
065:
066: /**
067: * Set the name of the default theme.
068: */
069: public void setDefaultThemeName(String defaultThemeName) {
070: this .defaultThemeName = defaultThemeName;
071: }
072:
073: /**
074: * Return the name of the default theme.
075: */
076: public String getDefaultThemeName() {
077: return defaultThemeName;
078: }
079:
080: public String resolveThemeName(HttpServletRequest request) {
081: // Check request for preparsed or preset theme.
082: String theme = (String) request
083: .getAttribute(THEME_REQUEST_ATTRIBUTE_NAME);
084: if (theme != null) {
085: return theme;
086: }
087:
088: // Retrieve cookie value from request.
089: Cookie cookie = WebUtils.getCookie(request, getCookieName());
090: if (cookie != null) {
091: return cookie.getValue();
092: }
093:
094: // Fall back to default theme.
095: return getDefaultThemeName();
096: }
097:
098: public void setThemeName(HttpServletRequest request,
099: HttpServletResponse response, String themeName) {
100: if (themeName != null) {
101: // Set request attribute and add cookie.
102: request.setAttribute(THEME_REQUEST_ATTRIBUTE_NAME,
103: themeName);
104: addCookie(response, themeName);
105: }
106:
107: else {
108: // Set request attribute to fallback theme and remove cookie.
109: request.setAttribute(THEME_REQUEST_ATTRIBUTE_NAME,
110: getDefaultThemeName());
111: removeCookie(response);
112: }
113: }
114:
115: }
|