com.sun.faces.renderkit.html_basic.WebsocketRenderer Maven / Gradle / Ivy

Go to download
Show more of this group Show more artifacts with this name
Show all versions of jakarta.faces Show documentation
EE4J Compatible Implementation for Jakarta Faces API
The newest version!
/*
 * Copyright (c) 1997, 2020 Oracle and/or its affiliates. All rights reserved.
 *
 * This program and the accompanying materials are made available under the
 * terms of the Eclipse Public License v. 2.0, which is available at
 * http://www.eclipse.org/legal/epl-2.0.
 *
 * This Source Code may also be made available under the following Secondary
 * Licenses when the conditions for such availability set forth in the
 * Eclipse Public License v. 2.0 are satisfied: GNU General Public License,
 * version 2 with the GNU Classpath Exception, which is available at
 * https://www.gnu.org/software/classpath/license.html.
 *
 * SPDX-License-Identifier: EPL-2.0 OR GPL-2.0 WITH Classpath-exception-2.0
 */

// CommandScriptRenderer.java

package com.sun.faces.renderkit.html_basic;

import static com.sun.faces.cdi.CdiUtils.getBeanReference;
import static jakarta.faces.component.behavior.ClientBehaviorContext.createClientBehaviorContext;

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

import com.sun.faces.push.WebsocketChannelManager;
import com.sun.faces.push.WebsocketFacesListener;
import com.sun.faces.renderkit.RenderKitUtils;

import jakarta.faces.component.UIComponent;
import jakarta.faces.component.UIWebsocket;
import jakarta.faces.component.behavior.ClientBehavior;
import jakarta.faces.context.FacesContext;
import jakarta.faces.context.ResponseWriter;
import jakarta.faces.event.AbortProcessingException;
import jakarta.faces.event.ComponentSystemEvent;
import jakarta.faces.event.ComponentSystemEventListener;
import jakarta.faces.event.ListenerFor;
import jakarta.faces.event.PostAddToViewEvent;

/**
 * WebsocketRenderer is a class that renders the faces.push.init() script and decodes any client
 * behaviors triggered by {@link UIWebsocket}.
 *
 * @author Bauke Scholtz
 * @since 2.3
 * @see UIWebsocket
 */
@ListenerFor(systemEventClass = PostAddToViewEvent.class)
public class WebsocketRenderer extends HtmlBasicRenderer implements ComponentSystemEventListener {

    // Constants ------------------------------------------------------------------------------------------------------

    public static final String RENDERER_TYPE = "jakarta.faces.Websocket";

    private static final String SCRIPT_INIT = "faces.push.init('%s','%s','%s',%s,%s,%s);";

    // Actions --------------------------------------------------------------------------------------------------------

    /**
     * After adding component to view, subscribe {@link WebsocketFacesListener} if necessary.
     */
    @Override
    public void processEvent(ComponentSystemEvent event) throws AbortProcessingException {
        WebsocketFacesListener.subscribeIfNecessary(event.getFacesContext());
    }

    /**
     * Decode all client behaviors.
     */
    @Override
    public void decode(FacesContext context, UIComponent component) {
        decodeBehaviors(context, component);
    }

    /**
     * Render faces.push.init() function if necessary.
     */
    @Override
    public void encodeEnd(FacesContext context, UIComponent component) throws IOException {
        UIWebsocket websocket = (UIWebsocket) component;

        if (WebsocketFacesListener.isNew(context, websocket)) {
            WebsocketChannelManager websocketChannelManager = getBeanReference(WebsocketChannelManager.class);

            String clientId = websocket.getClientId(context);
            String channel = websocket.getChannel();
            String url = websocketChannelManager.register(context, channel, websocket.getScope(), websocket.getUser());
            String functions = websocket.getOnopen() + "," + websocket.getOnmessage() + "," + websocket.getOnerror() + "," + websocket.getOnclose();
            String behaviors = getBehaviorScripts(context, websocket);
            boolean connected = websocket.isConnected();

            RenderKitUtils.renderFacesJsIfNecessary(context);

            ResponseWriter writer = context.getResponseWriter();
            writer.startElement("script", component);
            writer.writeAttribute("id", clientId, "id");
            writer.write(String.format(SCRIPT_INIT, clientId, url, channel, functions, behaviors, connected));
            writer.endElement("script");
        }
    }

    // Helpers --------------------------------------------------------------------------------------------------------

    /**
     * Helper to collect all client behavior scripts of websocket into a string representing a JS object.
     */
    private static String getBehaviorScripts(FacesContext context, UIWebsocket websocket) {
        Map> clientBehaviorsByEvent = websocket.getClientBehaviors();

        if (clientBehaviorsByEvent.isEmpty()) {
            return "{}";
        }

        String clientId = websocket.getClientId(context);
        StringBuilder scripts = new StringBuilder("{");

        for (Entry> entry : clientBehaviorsByEvent.entrySet()) {
            String event = entry.getKey();
            List clientBehaviors = entry.getValue();
            scripts.append(scripts.length() > 1 ? "," : "").append(event).append(":[");

            for (int i = 0; i < clientBehaviors.size(); i++) {
                scripts.append(i > 0 ? "," : "").append("function(event){");
                scripts.append(clientBehaviors.get(i).getScript(createClientBehaviorContext(context, websocket, event, clientId, null)));
                scripts.append("}");
            }

            scripts.append("]");
        }

        return scripts.append("}").toString();
    }

}