org.springframework.web.servlet.ThemeResolver Maven / Gradle / Ivy
/*
* Copyright 2002-2017 the original author or authors.
*
* Licensed 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
*
* https://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.springframework.web.servlet;
import javax.servlet.http.HttpServletRequest;
import javax.servlet.http.HttpServletResponse;
import org.springframework.lang.Nullable;
/**
* Interface for web-based theme resolution strategies that allows for
* both theme resolution via the request and theme modification via
* request and response.
*
* This interface allows for implementations based on session,
* cookies, etc. The default implementation is
* {@link org.springframework.web.servlet.theme.FixedThemeResolver},
* simply using a configured default theme.
*
*
Note that this resolver is only responsible for determining the
* current theme name. The Theme instance for the resolved theme name
* gets looked up by DispatcherServlet via the respective ThemeSource,
* i.e. the current WebApplicationContext.
*
*
Use {@link org.springframework.web.servlet.support.RequestContext#getTheme()}
* to retrieve the current theme in controllers or views, independent
* of the actual resolution strategy.
*
* @author Jean-Pierre Pawlak
* @author Juergen Hoeller
* @since 17.06.2003
* @see org.springframework.ui.context.Theme
* @see org.springframework.ui.context.ThemeSource
*/
public interface ThemeResolver {
/**
* Resolve the current theme name via the given request.
* Should return a default theme as fallback in any case.
* @param request the request to be used for resolution
* @return the current theme name
*/
String resolveThemeName(HttpServletRequest request);
/**
* Set the current theme name to the given one.
* @param request the request to be used for theme name modification
* @param response the response to be used for theme name modification
* @param themeName the new theme name ({@code null} or empty to reset it)
* @throws UnsupportedOperationException if the ThemeResolver implementation
* does not support dynamic changing of the theme
*/
void setThemeName(HttpServletRequest request, @Nullable HttpServletResponse response, @Nullable String themeName);
}