org.gbif.portal.web.view.WidgetControllerSupport.java Source code

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Here is the source code for org.gbif.portal.web.view.WidgetControllerSupport.java

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/***************************************************************************
 * Copyright (C) 2005 Global Biodiversity Information Facility Secretariat.  
 * All Rights Reserved.
 *
 * The contents of this file are subject to the Mozilla Public
 * License Version 1.1 (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.mozilla.org/MPL/
 *
 * Software distributed under the License is distributed on an "AS
 * IS" basis, WITHOUT WARRANTY OF ANY KIND, either express or
 * implied. See the License for the specific language governing
 * rights and limitations under the License.
 ***************************************************************************/
package org.gbif.portal.web.view;

import javax.servlet.http.HttpServletRequest;
import javax.servlet.http.HttpServletResponse;

import org.apache.commons.beanutils.MethodUtils;
import org.apache.commons.lang.StringUtils;
import org.apache.commons.logging.Log;
import org.apache.commons.logging.LogFactory;
import org.apache.struts.tiles.ComponentContext;
import org.gbif.portal.web.view.map.MapWidgetController;
import org.springframework.web.context.WebApplicationContext;
import org.springframework.web.servlet.support.RequestContextUtils;
import org.springframework.web.servlet.view.tiles.ComponentControllerSupport;

/**
 * Abstract class to be subclassed by Controllers providing Widget functionality. A WidgetController consist of one or more
 * methods adding content to a request to be rendered by a view technology downstream. Methods providing this content
 * follow the method name convention of add<Widget-Name>. 
 * 
 * Implements the tiles interface ComponentController to allow tiles to use the controllerClass attribute to provide content for
 * a tile prior to it being rendered.
 * 
 * Also implements WidgetController interface to provide a common interface for allowing implementations
 * to populate artefacts outside of tiles.
 *
 * @see MapWidgetController
 * 
 * @author dmartin
 */
public abstract class WidgetControllerSupport extends ComponentControllerSupport implements WidgetController {

    protected static Log logger = LogFactory.getLog(WidgetControllerSupport.class);
    /**
     * The web application context used to access beans in the spring context. 
     * Added because the super instance of the application context isnt initialised when
     * this class is accessed as a spring reference.
     */
    private WebApplicationContext webAppContext;

    /**
     * This delegates to the correct widget method. 
     * @todo move to a superclass
     * @see org.springframework.web.servlet.view.tiles.ComponentControllerSupport#doPerform(org.apache.struts.tiles.ComponentContext, javax.servlet.http.HttpServletRequest, javax.servlet.http.HttpServletResponse)
     */
    protected void doPerform(ComponentContext componentContext, HttpServletRequest request,
            HttpServletResponse response) throws Exception {
        //widget is null in the case of entire page
        String widget = (String) componentContext.getAttribute("widget");
        if (logger.isDebugEnabled())
            logger.debug("widget name:" + widget);
        if (StringUtils.isNotEmpty(widget)) {
            doPerform(widget, request, response);
        }
    }

    /**
     * @see org.gbif.portal.web.view.WidgetController#doPerform(java.lang.String, javax.servlet.http.HttpServletRequest, javax.servlet.http.HttpServletResponse)
     */
    public void doPerform(String widgetName, HttpServletRequest request, HttpServletResponse response)
            throws Exception {
        Object[] args = new Object[] { request, response };
        widgetName = StringUtils.capitalize(widgetName);
        try {
            if (logger.isDebugEnabled())
                logger.debug("widget name:" + widgetName);
            MethodUtils.invokeMethod(this, "add" + widgetName, args);
        } catch (NoSuchMethodException e) {
            logger.error("Unable to find method for widget: " + widgetName);
            logger.error("Missing method: add" + widgetName);
            logger.error(e.getMessage(), e);
        }
    }

    /**
     * Retrieves the web application context to allow implementations to access spring configured beans.
     * @param request
     * @return WebApplicationContext
     */
    protected WebApplicationContext getWebAppContext(HttpServletRequest request) {
        if (webAppContext == null) {
            webAppContext = getWebApplicationContext();
            if (webAppContext == null)
                webAppContext = RequestContextUtils.getWebApplicationContext(request);
        }
        return webAppContext;
    }
}