org.springframework.web.servlet.view.tiles3.TilesView.java Source code

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Here is the source code for org.springframework.web.servlet.view.tiles3.TilesView.java

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/*
 * 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.view.tiles3;

import java.util.Locale;
import java.util.Map;
import javax.servlet.ServletContext;
import javax.servlet.http.HttpServletRequest;
import javax.servlet.http.HttpServletResponse;

import org.apache.tiles.TilesContainer;
import org.apache.tiles.access.TilesAccess;
import org.apache.tiles.renderer.DefinitionRenderer;
import org.apache.tiles.request.AbstractRequest;
import org.apache.tiles.request.ApplicationContext;
import org.apache.tiles.request.Request;
import org.apache.tiles.request.render.Renderer;
import org.apache.tiles.request.servlet.ServletRequest;
import org.apache.tiles.request.servlet.ServletUtil;

import org.springframework.lang.Nullable;
import org.springframework.util.Assert;
import org.springframework.web.context.request.RequestAttributes;
import org.springframework.web.context.request.RequestContextHolder;
import org.springframework.web.context.request.ServletRequestAttributes;
import org.springframework.web.servlet.support.JstlUtils;
import org.springframework.web.servlet.support.RequestContext;
import org.springframework.web.servlet.support.RequestContextUtils;
import org.springframework.web.servlet.view.AbstractUrlBasedView;

/**
 * {@link org.springframework.web.servlet.View} implementation that renders
 * through the Tiles Request API. The "url" property is interpreted as name of a
 * Tiles definition.
 *
 * @author Nicolas Le Bas
 * @author mick semb wever
 * @author Rossen Stoyanchev
 * @author Sebastien Deleuze
 * @since 3.2
 */
public class TilesView extends AbstractUrlBasedView {

    @Nullable
    private Renderer renderer;

    private boolean exposeJstlAttributes = true;

    private boolean alwaysInclude = false;

    @Nullable
    private ApplicationContext applicationContext;

    /**
     * Set the {@link Renderer} to use.
     * If not set, by default {@link DefinitionRenderer} is used.
     */
    public void setRenderer(Renderer renderer) {
        this.renderer = renderer;
    }

    /**
     * Whether to expose JSTL attributes. By default set to {@code true}.
     * @see JstlUtils#exposeLocalizationContext(RequestContext)
     */
    protected void setExposeJstlAttributes(boolean exposeJstlAttributes) {
        this.exposeJstlAttributes = exposeJstlAttributes;
    }

    /**
     * Specify whether to always include the view rather than forward to it.
     * <p>Default is "false". Switch this flag on to enforce the use of a
     * Servlet include, even if a forward would be possible.
     * @since 4.1.2
     * @see TilesViewResolver#setAlwaysInclude
     */
    public void setAlwaysInclude(boolean alwaysInclude) {
        this.alwaysInclude = alwaysInclude;
    }

    @Override
    public void afterPropertiesSet() throws Exception {
        super.afterPropertiesSet();

        ServletContext servletContext = getServletContext();
        Assert.state(servletContext != null, "No ServletContext");
        this.applicationContext = ServletUtil.getApplicationContext(servletContext);

        if (this.renderer == null) {
            TilesContainer container = TilesAccess.getContainer(this.applicationContext);
            this.renderer = new DefinitionRenderer(container);
        }
    }

    @Override
    public boolean checkResource(final Locale locale) throws Exception {
        Assert.state(this.renderer != null, "No Renderer set");

        HttpServletRequest servletRequest = null;
        RequestAttributes requestAttributes = RequestContextHolder.getRequestAttributes();
        if (requestAttributes instanceof ServletRequestAttributes) {
            servletRequest = ((ServletRequestAttributes) requestAttributes).getRequest();
        }

        Request request = new ServletRequest(this.applicationContext, servletRequest, null) {
            @Override
            public Locale getRequestLocale() {
                return locale;
            }
        };

        return this.renderer.isRenderable(getUrl(), request);
    }

    @Override
    protected void renderMergedOutputModel(Map<String, Object> model, HttpServletRequest request,
            HttpServletResponse response) throws Exception {

        Assert.state(this.renderer != null, "No Renderer set");

        exposeModelAsRequestAttributes(model, request);
        if (this.exposeJstlAttributes) {
            JstlUtils.exposeLocalizationContext(new RequestContext(request, getServletContext()));
        }
        if (this.alwaysInclude) {
            request.setAttribute(AbstractRequest.FORCE_INCLUDE_ATTRIBUTE_NAME, true);
        }

        Request tilesRequest = createTilesRequest(request, response);
        this.renderer.render(getUrl(), tilesRequest);
    }

    /**
     * Create a Tiles {@link Request}.
     * <p>This implementation creates a {@link ServletRequest}.
     * @param request the current request
     * @param response the current response
     * @return the Tiles request
     */
    protected Request createTilesRequest(final HttpServletRequest request, HttpServletResponse response) {
        return new ServletRequest(this.applicationContext, request, response) {
            @Override
            public Locale getRequestLocale() {
                return RequestContextUtils.getLocale(request);
            }
        };
    }

}