001/*
002 * Copyright 2002-2020 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 *      https://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
017package org.springframework.web.servlet.view;
018
019/**
020 * Abstract base class for template view resolvers,
021 * in particular for Velocity and FreeMarker views.
022 *
023 * <p>Provides a convenient way to specify {@link AbstractTemplateView}'s
024 * exposure flags for request attributes, session attributes,
025 * and Spring's macro helpers.
026 *
027 * @author Juergen Hoeller
028 * @since 1.1
029 * @see AbstractTemplateView
030 * @see org.springframework.web.servlet.view.velocity.VelocityViewResolver
031 * @see org.springframework.web.servlet.view.freemarker.FreeMarkerViewResolver
032 */
033public abstract class AbstractTemplateViewResolver extends UrlBasedViewResolver {
034
035        private boolean exposeRequestAttributes = false;
036
037        private boolean allowRequestOverride = false;
038
039        private boolean exposeSessionAttributes = false;
040
041        private boolean allowSessionOverride = false;
042
043        private boolean exposeSpringMacroHelpers = true;
044
045
046        @Override
047        protected Class<?> requiredViewClass() {
048                return AbstractTemplateView.class;
049        }
050
051        /**
052         * Set whether all request attributes should be added to the
053         * model prior to merging with the template. Default is "false".
054         * @see AbstractTemplateView#setExposeRequestAttributes
055         */
056        public void setExposeRequestAttributes(boolean exposeRequestAttributes) {
057                this.exposeRequestAttributes = exposeRequestAttributes;
058        }
059
060        /**
061         * Set whether HttpServletRequest attributes are allowed to override (hide)
062         * controller generated model attributes of the same name. Default is "false",
063         * which causes an exception to be thrown if request attributes of the same
064         * name as model attributes are found.
065         * @see AbstractTemplateView#setAllowRequestOverride
066         */
067        public void setAllowRequestOverride(boolean allowRequestOverride) {
068                this.allowRequestOverride = allowRequestOverride;
069        }
070
071        /**
072         * Set whether all HttpSession attributes should be added to the
073         * model prior to merging with the template. Default is "false".
074         * @see AbstractTemplateView#setExposeSessionAttributes
075         */
076        public void setExposeSessionAttributes(boolean exposeSessionAttributes) {
077                this.exposeSessionAttributes = exposeSessionAttributes;
078        }
079
080        /**
081         * Set whether HttpSession attributes are allowed to override (hide)
082         * controller generated model attributes of the same name. Default is "false",
083         * which causes an exception to be thrown if session attributes of the same
084         * name as model attributes are found.
085         * @see AbstractTemplateView#setAllowSessionOverride
086         */
087        public void setAllowSessionOverride(boolean allowSessionOverride) {
088                this.allowSessionOverride = allowSessionOverride;
089        }
090
091        /**
092         * Set whether to expose a RequestContext for use by Spring's macro library,
093         * under the name "springMacroRequestContext". Default is "true".
094         * @see AbstractTemplateView#setExposeSpringMacroHelpers
095         */
096        public void setExposeSpringMacroHelpers(boolean exposeSpringMacroHelpers) {
097                this.exposeSpringMacroHelpers = exposeSpringMacroHelpers;
098        }
099
100
101        @Override
102        protected AbstractUrlBasedView buildView(String viewName) throws Exception {
103                AbstractTemplateView view = (AbstractTemplateView) super.buildView(viewName);
104                view.setExposeRequestAttributes(this.exposeRequestAttributes);
105                view.setAllowRequestOverride(this.allowRequestOverride);
106                view.setExposeSessionAttributes(this.exposeSessionAttributes);
107                view.setAllowSessionOverride(this.allowSessionOverride);
108                view.setExposeSpringMacroHelpers(this.exposeSpringMacroHelpers);
109                return view;
110        }
111
112}