org.apache.myfaces.tomahawk.application.ResourceViewHandlerWrapper Maven / Gradle / Ivy

Show more of this group Show more artifacts with this name
Show all versions of tomahawk21 Show documentation
JSF components and utilities that can be used with any JSF implementation. This library is based on the JSF1.1 version of Tomahawk, but with minor source code and build changes to take advantage of JSF2.1 features. A JSF2.1 implementation is required to use this version of the Tomahawk library.
The newest version!
/*
 * 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.myfaces.tomahawk.application;

import java.io.IOException;
import java.util.Map;

import javax.faces.FacesException;
import javax.faces.application.ViewHandler;
import javax.faces.application.ViewHandlerWrapper;
import javax.faces.component.UIComponent;
import javax.faces.component.UIOutput;
import javax.faces.component.UIViewRoot;
import javax.faces.context.FacesContext;
import javax.faces.event.PostAddToViewEvent;
import javax.faces.event.SystemEvent;
import javax.faces.event.SystemEventListener;

import org.apache.myfaces.custom.autoscroll.AutoscrollBehaviorTagHandler;
import org.apache.myfaces.custom.autoscroll.AutoscrollBodyScript;
import org.apache.myfaces.custom.autoscroll.AutoscrollHiddenField;
import org.apache.myfaces.renderkit.html.util.AddResource;
import org.apache.myfaces.renderkit.html.util.AddResourceFactory;
import org.apache.myfaces.shared_tomahawk.config.MyfacesConfig;
import org.apache.myfaces.shared_tomahawk.renderkit.JSFAttr;
import org.apache.myfaces.tomahawk.util.TomahawkResourceUtils;

public class ResourceViewHandlerWrapper extends ViewHandlerWrapper
{
    private static final String SET_RESOURCE_CONTAINER_DUMMY_COMPONENT_ID = 
            "oam_autoscroll_setResourceContainer";
    private static final String BODY_SCRIPT_COMPONENT_ID =
            "oam_autoscroll_body_script";
    private static final String HIDDEN_FIELD_COMPONENT_ID =
            "oam_autoscroll_hidden_field";
    
    private ViewHandler _delegate;

    public ResourceViewHandlerWrapper(ViewHandler delegate)
    {
        super();
        _delegate = delegate;
    }

    @Override
    public ViewHandler getWrapped()
    {
        return _delegate;
    }

    @Override
    public UIViewRoot createView(FacesContext context, String viewId)
    {
        UIViewRoot root = super.createView(context, viewId);
        // This listener just ensures that the locations for autoscroll component are
        // set before call markInitialState(). In this way, the state size is reduced when
        // partial state saving is used.
        root.subscribeToViewEvent(PostAddToViewEvent.class, new SystemEventListener() {

            public boolean isListenerForSource(Object o)
            {
                return o instanceof UIViewRoot;
            }

            public void processEvent(SystemEvent se)
            {
                FacesContext context = FacesContext.getCurrentInstance();
                UIViewRoot viewToRender = (UIViewRoot) se.getSource();
                if (MyfacesConfig.getCurrentInstance(context.getExternalContext()).isAutoScroll() ||
                    viewToRender.getAttributes().containsKey(AutoscrollBehaviorTagHandler.AUTOSCROLL_TAG_ON_PAGE))
                {
                    UIOutput test = new UIOutput();
                    test.setId(SET_RESOURCE_CONTAINER_DUMMY_COMPONENT_ID);
                    test.setTransient(true);
                    UIComponent facet = null;
                    facet = viewToRender.getFacet(TomahawkResourceUtils.FORM_LOCATION);
                    if (facet == null)
                    {
                        viewToRender.addComponentResource(context, test, TomahawkResourceUtils.FORM_LOCATION);
                        facet = viewToRender.getFacet(TomahawkResourceUtils.FORM_LOCATION);
                        if (facet != null)
                        {
                            facet.getChildren().remove(test);
                        }
                    }
                    
                    facet = viewToRender.getFacet(TomahawkResourceUtils.BODY_LOCATION);
                    if (facet == null)
                    {
                        viewToRender.addComponentResource(context, test, TomahawkResourceUtils.BODY_LOCATION);
                        facet = viewToRender.getFacet(TomahawkResourceUtils.BODY_LOCATION);
                        if (facet != null)
                        {
                            facet.getChildren().remove(test);
                        }
                    }

                    facet = viewToRender.getFacet(TomahawkResourceUtils.HEAD_LOCATION);
                    if (facet == null)
                    {
                        viewToRender.addComponentResource(context, test, TomahawkResourceUtils.HEAD_LOCATION);
                        facet = viewToRender.getFacet(TomahawkResourceUtils.HEAD_LOCATION);
                        if (facet != null)
                        {
                            facet.getChildren().remove(test);
                        }
                    }
                }
            }
        });
        return root;
    }

    @Override
    public void renderView(FacesContext context, UIViewRoot viewToRender)
            throws IOException, FacesException
    {
        if (MyfacesConfig.getCurrentInstance(context.getExternalContext()).isAutoScroll() ||
            viewToRender.getAttributes().containsKey(AutoscrollBehaviorTagHandler.AUTOSCROLL_TAG_ON_PAGE))
        {
            AddResource addResource = AddResourceFactory.getInstance(context);

            if (!addResource.requiresBuffer())
            {
                //If the response is buffered, addResource instance takes
                //the responsability of render this script.
                AutoscrollBodyScript autoscrollBodyScript = (AutoscrollBodyScript) 
                    context.getApplication().createComponent(context, 
                        AutoscrollBodyScript.COMPONENT_TYPE,
                        AutoscrollBodyScript.DEFAULT_RENDERER_TYPE);
                autoscrollBodyScript.setId(BODY_SCRIPT_COMPONENT_ID);
                autoscrollBodyScript.setTransient(true);
                autoscrollBodyScript.getAttributes().put(
                        JSFAttr.TARGET_ATTR, 
                        TomahawkResourceUtils.BODY_LOCATION);
                viewToRender.addComponentResource(context, autoscrollBodyScript);
            }
            
            AutoscrollHiddenField autoscrollHiddenField = (AutoscrollHiddenField) context.getApplication().
                createComponent(context, 
                        AutoscrollHiddenField.COMPONENT_TYPE,
                        AutoscrollHiddenField.DEFAULT_RENDERER_TYPE);
            autoscrollHiddenField.setId(HIDDEN_FIELD_COMPONENT_ID);
            autoscrollHiddenField.setTransient(true);
            autoscrollHiddenField.getAttributes().put(JSFAttr.TARGET_ATTR, TomahawkResourceUtils.FORM_LOCATION);
            viewToRender.addComponentResource(context, autoscrollHiddenField);
        }
        
        //Reset the added resource 
        TomahawkResourceUtils.resetAddedResources(context);
        
        _publishPreRenderViewAddResourceEvent(context, viewToRender);
        super.renderView(context, viewToRender);
    }
    
    private void _publishPreRenderViewAddResourceEvent(FacesContext context, UIComponent component)
    {
        context.getApplication().publishEvent(context,  PreRenderViewAddResourceEvent.class, UIComponent.class, component);
        
        //Scan children
        if (component.getChildCount() > 0)
        {
            for (UIComponent child : component.getChildren())
            {
                _publishPreRenderViewAddResourceEvent(context, child);
            }
        }

        //Scan facets
        if (component.getFacetCount() > 0)
        {
            for (Map.Entry entry : component.getFacets().entrySet())
            {
                _publishPreRenderViewAddResourceEvent(context, entry.getValue());
            }
        }
    }
}