org.apache.wicket.markup.html.TransparentWebMarkupContainer.java Source code

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Here is the source code for org.apache.wicket.markup.html.TransparentWebMarkupContainer.java

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/*
 * Licensed to the Apache Software Foundation (ASF) under one or more
 * contributor license agreements.  See the NOTICE file distributed with
 * this work for additional information regarding copyright ownership.
 * The ASF licenses this file to You 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 org.apache.wicket.markup.html;

import org.apache.wicket.Component;
import org.apache.wicket.MarkupContainer;
import org.apache.wicket.markup.ComponentTag;
import org.apache.wicket.markup.MarkupElement;
import org.apache.wicket.markup.MarkupStream;
import org.apache.wicket.markup.WicketTag;
import org.apache.wicket.markup.html.internal.HtmlHeaderContainer;
import org.apache.wicket.markup.resolver.ComponentResolvers;
import org.apache.wicket.markup.resolver.IComponentResolver;
import org.apache.wicket.request.Request;
import org.apache.wicket.request.cycle.RequestCycle;
import org.apache.wicket.request.http.WebRequest;

/**
 * A simple "transparent" markup container.
 * 
 * @author Juergen Donnerstag
 */
public class TransparentWebMarkupContainer extends WebMarkupContainer implements IComponentResolver {
    private static final long serialVersionUID = 1L;

    /**
     * Construct.
     * 
     * @param id
     *          The component id
     */
    public TransparentWebMarkupContainer(String id) {
        super(id);
    }

    /**
     * @see org.apache.wicket.markup.resolver.IComponentResolver#resolve(org.apache.wicket.MarkupContainer,
     *      org.apache.wicket.markup.MarkupStream, org.apache.wicket.markup.ComponentTag)
     */
    @Override
    public Component resolve(MarkupContainer container, MarkupStream markupStream, ComponentTag tag) {
        if (tag instanceof WicketTag && ((WicketTag) tag).isFragmentTag()) {
            // even having a wicket:id it isn't a component's markup
            return null;
        }

        Component resolvedComponent = getParent().get(tag.getId());
        if (resolvedComponent != null && getPage().wasRendered(resolvedComponent)) {
            /*
             * Means that parent container has an associated homonymous tag to this grandchildren
             * tag in markup. The parent container wants render it and it should be not resolved to
             * their grandchildren.
             */
            return null;
        }
        return resolvedComponent;
    }

    @Override
    public void internalRenderHead(HtmlHeaderContainer container) {
        /*
         * https://issues.apache.org/jira/browse/WICKET-5941
         * 
         * if this component is updated via AJAX and is the root
         * one, then render head also for embedded components.
         */
        if (isAjaxRequest() && !isParentRendering()) {
            renderHeadForInnerSiblings(container);
        }

        super.internalRenderHead(container);
    }

    /**
     * Says if parent container is rendering or not.
     * 
     * @return true if parent is rendering, false otherwise.
     */
    private boolean isParentRendering() {
        MarkupContainer parent = getParent();

        return parent != null && parent.isRendering();
    }

    /**
     * Says if the current request is an AJAX one.
     * 
     * @return true if the current request is an AJAX one, false otherwise.
     */
    private boolean isAjaxRequest() {
        Request request = RequestCycle.get().getRequest();

        if (request instanceof WebRequest) {
            WebRequest webRequest = (WebRequest) request;
            return webRequest.isAjax();
        }

        return false;
    }

    /**
     * Renders head for embedded component, i.e. those who are not added 
     * directly to this container but have the markup inside it.
     * 
     * @param container
     *             The HtmlHeaderContainer
     */
    private void renderHeadForInnerSiblings(HtmlHeaderContainer container) {
        MarkupStream stream = new MarkupStream(getMarkup());

        while (stream.isCurrentIndexInsideTheStream()) {
            MarkupElement childOpenTag = stream.nextOpenTag();

            if ((childOpenTag instanceof ComponentTag) && !stream.atCloseTag()) {
                // Get element as tag
                final ComponentTag tag = (ComponentTag) childOpenTag;

                // Get component id
                final String id = tag.getId();

                Component component = null;

                if (get(id) == null) {
                    component = ComponentResolvers.resolveByComponentHierarchy(this, stream, tag);
                }

                if (component != null) {
                    component.internalRenderHead(container);
                }

                //consider just direct children
                stream.skipToMatchingCloseTag(tag);
            }
        }
    }

    @Override
    protected Component findChildComponent(ComponentTag tag) {
        Component childComponent = super.findChildComponent(tag);

        return childComponent != null ? childComponent : resolve(this, null, tag);
    }
}