com.sun.webui.jsf.util.WidgetUtilities Maven / Gradle / Ivy

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/*
 * The contents of this file are subject to the terms
 * of the Common Development and Distribution License
 * (the License).  You may not use this file except in
 * compliance with the License.
 * 
 * You can obtain a copy of the license at
 * https://woodstock.dev.java.net/public/CDDLv1.0.html.
 * See the License for the specific language governing
 * permissions and limitations under the License.
 * 
 * When distributing Covered Code, include this CDDL
 * Header Notice in each file and include the License file
 * at https://woodstock.dev.java.net/public/CDDLv1.0.html.
 * If applicable, add the following below the CDDL Header,
 * with the fields enclosed by brackets [] replaced by
 * you own identifying information:
 * "Portions Copyrighted [year] [name of copyright owner]"
 * 
 * Copyright 2007 Sun Microsystems, Inc. All rights reserved.
 */
package com.sun.webui.jsf.util;

import java.io.IOException;
import java.io.Writer;
import java.util.Iterator;

import javax.faces.component.UIComponent;
import javax.faces.context.ExternalContext;
import javax.faces.context.FacesContext;
import javax.faces.context.ResponseWriter;
import javax.faces.FactoryFinder;
import javax.faces.render.Renderer;
import javax.faces.render.RenderKitFactory;
import javax.faces.render.RenderKit;
import javax.servlet.ServletRequest;

import org.json.JSONArray;
import org.json.JSONException;
import org.json.JSONObject;

/**
 * This class provides common methods for widget renderers.
 */
public class WidgetUtilities {
    // ~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~
    // JSON methods
    // ~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~

    /**
     * Helper method to add component properties.
     *
     * @param json The JSONArray to append value to.
     * @param value A string containing JSON or HTML text.
     */
    public static void addProperties(JSONArray json, String value) 
            throws JSONException {
        if (value != null) {
            try {
                // If JSON text is given, append a new JSONObject.
                json.put(new JSONObject(value));
            } catch (JSONException e) {
                // Append HTML string.
                json.put(value);
            }
        }
    }

    /**
     * Helper method to add component properties.
     *
     * @param json The JSONObject to append value to.
     * @param key A key string.
     * @param value A string containing JSON or HTML text.
     */
    public static void addProperties(JSONObject json, String key,
            String value) throws JSONException {
        if (value != null) {
            try {
                // If JSON text is given, append a new JSONObject.
                json.put(key, new JSONObject(value));
            } catch (JSONException e) {
                // Append HTML string.
                json.put(key, value);
            }
        }
    }

    // ~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~
    // Renderer methods
    // ~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~

    /**
     * Helper method to capture rendered component properties for client-side
     * rendering. Based on the component renderer, either JSON or HTML text may 
     * be returned.
     *
     * @param context FacesContext for the current request.
     * @param component UIComponent to be rendered.
     *
     * @returns An HTML or JSON string.
     */
    public static String renderComponent(FacesContext context,
            UIComponent component) throws IOException, JSONException {
        if (component == null || !component.isRendered()) {
            return null;
        }

        // Initialize Writer to buffer rendered output.
        ResponseWriter oldWriter = context.getResponseWriter();
        Writer strWriter = initStringWriter(context);

        // Render component and restore writer.
        RenderingUtilities.renderComponent(component, context);
        context.setResponseWriter(oldWriter);

        return strWriter.toString(); // Return buffered output.
    }

    // ~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~
    // Writer methods
    // ~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~

    /**
     * Helper method to initialize a writer used to buffer rendered output.
     * 
     * Note: Be certain to save the old writer pior to invoking this method. The
     * writer in the given context is replaced with a new writer.
     *
     * @param context FacesContext for the current request.
     *
     * @returns The Writer used to buffer rendered output.
     */
    protected static Writer initStringWriter(FacesContext context) {
        if (context == null) {
            return null;
        }

        // Get render kit.
        RenderKitFactory renderFactory = (RenderKitFactory)
        FactoryFinder.getFactory(FactoryFinder.RENDER_KIT_FACTORY);
        RenderKit renderKit = renderFactory.getRenderKit(context,
            context.getViewRoot().getRenderKitId());

        // Get writers.
        ResponseWriter oldWriter = context.getResponseWriter();
        Writer strWriter = new FastStringWriter(1024);
        ResponseWriter newWriter = null;

        // Initialize new writer.
        if (null != oldWriter) {
            newWriter = oldWriter.cloneWithWriter(strWriter);
        } else {
            ExternalContext extContext = context.getExternalContext();
            ServletRequest request = (ServletRequest) extContext.getRequest();
            newWriter = renderKit.createResponseWriter(strWriter, null,
                request.getCharacterEncoding());
        }
        // Set new writer in context.
        context.setResponseWriter(newWriter);
        return strWriter;
    }

    // ~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~
    // Private methods
    // ~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~
}