guru.mmp.application.web.template.components.Breadcrumbs.java Source code

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Here is the source code for guru.mmp.application.web.template.components.Breadcrumbs.java

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/*
 * Copyright 2017 Marcus Portmann
 *
 * 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
 *
 *   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 guru.mmp.application.web.template.components;

//~--- non-JDK imports --------------------------------------------------------

import guru.mmp.application.web.template.TemplateWebApplication;
import guru.mmp.application.web.template.TemplateWebSession;
import guru.mmp.application.web.template.navigation.NavigationGroup;
import guru.mmp.application.web.template.navigation.NavigationItem;
import guru.mmp.application.web.template.navigation.NavigationState;
import org.apache.wicket.Component;
import org.apache.wicket.Page;
import org.apache.wicket.Session;
import org.apache.wicket.markup.ComponentTag;
import org.apache.wicket.markup.MarkupElement;
import org.apache.wicket.markup.MarkupStream;
import org.apache.wicket.request.Response;
import org.apache.wicket.request.cycle.RequestCycle;
import org.apache.wicket.request.mapper.parameter.PageParameters;

/**
 * The <code>Breadcrumbs</code> class provides a Wicket component that renders the breadcrumbs
 * for the Web Application Template.
 *
 * @author Marcus Portmann
 */
public class Breadcrumbs extends Component {
    private static final long serialVersionUID = 1000000;

    /**
     * @param id the non-null id of this component
     *
     * @see org.apache.wicket.Component#Component(String)
     */
    public Breadcrumbs(String id) {
        super(id);
    }

    /**
     * Render the breadcrumbs.
     */
    @Override
    protected void onRender() {
        MarkupStream markupStream = findMarkupStream();
        MarkupElement element = markupStream.get();
        Response response = getResponse();

        if (element instanceof ComponentTag) {
            Session session = getSession();

            if (session instanceof TemplateWebSession) {
                TemplateWebSession webSession = ((TemplateWebSession) session);

                NavigationState navigationState = webSession.getNavigationState();

                // If we have cached breadcrumbs HTML then check if we can use it
                if (navigationState.getCachedBreadcrumbsHTML() != null) {
                    /*
                     * If we are rendering the breadcrumbs for the last page accessed in the navigation
                     * hierarchy then use the cached navigation HTML.
                     */
                    if (navigationState.isLastPageAccessedInNavigationHierarchy(getPage())) {
                        response.write(navigationState.getCachedBreadcrumbsHTML());

                        return;
                    }

                    /*
                     * If we are rendering the breadcrumbs for a page that is not in the navigation
                     * hierarchy then used the cached breadcrumbs HTML for the last page accessed in the
                     * navigation hierarchy.
                     */
                    if (!webSession.getNavigation().isPageInNavigationHierarchy(getPage())) {
                        response.write(navigationState.getCachedBreadcrumbsHTML());

                        return;
                    }
                }

                StringBuilder buffer = new StringBuilder();

                buffer.append("<ol class=\"breadcrumb\">");

                Class<? extends Page> clazz;

                if (webSession.isUserLoggedIn()) {
                    clazz = TemplateWebApplication.getTemplateWebApplication().getSecureHomePage();
                } else {
                    clazz = TemplateWebApplication.getTemplateWebApplication().getHomePage();
                }

                if (clazz.isAssignableFrom(getPage().getPageClass())) {
                    buffer.append("<li class=\"active\"><a href=\"#\"><i class=\"fa fa-home\"></i> Home</a></li>");
                } else {
                    buffer.append("<li><a href=\"");

                    buffer.append(RequestCycle.get().urlFor(clazz, new PageParameters()));

                    buffer.append("\"><i class=\"fa fa-home\"></i> Home</a></li>");

                    renderBreadcrumbs(webSession.getNavigation(), buffer);
                }

                buffer.append("</ol>");

                navigationState.setLastPageAccessedInNavigationHierarchy(getPage());

                navigationState.setCachedBreadcrumbsHTML(buffer.toString());

                response.write(navigationState.getCachedBreadcrumbsHTML());
            }
        }
    }

    private void renderBreadcrumbs(NavigationItem navigationItem, StringBuilder buffer) {
        if (navigationItem instanceof NavigationGroup) {
            NavigationGroup navigationGroup = (NavigationGroup) navigationItem;

            for (NavigationItem childNavigationItem : navigationGroup.getItems()) {
                if (childNavigationItem.isPageInNavigationHierarchy(getPage())) {
                    if (childNavigationItem instanceof NavigationGroup) {
                        buffer.append("<li>").append(childNavigationItem.getName()).append("</li>");

                        renderBreadcrumbs(childNavigationItem, buffer);

                        return;
                    } else {
                        buffer.append("<li class=\"active\">");
                        buffer.append(childNavigationItem.getName());
                        buffer.append("</li>");
                    }
                }
            }
        }
    }
}