extscript-core-root/extscript-myfaces2-extensions/src/main/java/org/apache/myfaces/extensions/scripting/jsf/dynamicdecorators/implemetations/RenderkitProxy.java

/*
 * 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.extensions.scripting.jsf.dynamicdecorators.implemetations;

import org.apache.myfaces.extensions.scripting.api.Decorated;
import org.apache.myfaces.extensions.scripting.api.ScriptingConst;
import org.apache.myfaces.extensions.scripting.core.util.WeavingContext;
import org.apache.myfaces.extensions.scripting.jsf2.annotation.purged.PurgedRenderer;
import org.apache.myfaces.extensions.scripting.jsf2.annotation.purged.PurgedClientBehaviorRenderer;

import javax.faces.context.FacesContext;
import javax.faces.render.RenderKit;
import javax.faces.render.Renderer;
import javax.faces.render.ResponseStateManager;
import javax.faces.render.ClientBehaviorRenderer;
import javax.faces.context.ResponseWriter;
import javax.faces.context.ResponseStream;
import javax.faces.FacesException;
import java.io.Writer;
import java.io.OutputStream;
import java.util.Iterator;
import java.util.Map;

/**
 * Weaving renderkit which
 * acts as a proxy factory for
 * our internal reloading referers
 *
 * @author Werner Punz
 */
public class RenderkitProxy extends RenderKit implements Decorated {

    RenderKit _delegate = null;

    public RenderkitProxy(RenderKit delegate) {
        _delegate = delegate;
    }

    public void addRenderer(String componentFamily, String rendererType, Renderer renderer) {
        weaveDelegate();
        //wo do it brute force here because we have sometimes casts and hence cannot rely on proxies
        //renderers itself are flyweight patterns which means they are shared over objects

        renderer = (Renderer) reloadInstance(renderer, ScriptingConst.ARTIFACT_TYPE_RENDERER);

        _delegate.addRenderer(componentFamily, rendererType, renderer);
    }

    public Renderer getRenderer(String componentFamily, String rendererType) {
        weaveDelegate();
        Renderer rendr = _delegate.getRenderer(componentFamily, rendererType);
        Renderer rendr2 = (Renderer) reloadInstance(rendr, ScriptingConst.ARTIFACT_TYPE_RENDERER);
        if (rendr != rendr2) {
            Renderer tempRenderer = _delegate.getRenderer(componentFamily, rendererType);
            if (tempRenderer instanceof PurgedRenderer) {
                return handleAnnotationChange(componentFamily, rendererType);
            }

            _delegate.addRenderer(componentFamily, rendererType, rendr2);
            return rendr2;
        }
        return rendr;
    }

    private ClientBehaviorRenderer handleAnnotationChangeBehaviorRenderer(String s) {
        ClientBehaviorRenderer rendr2;

        rendr2 = _delegate.getClientBehaviorRenderer(s);
        if (rendr2 instanceof PurgedClientBehaviorRenderer) {
            throw new FacesException("Renderer not found");
        }
        rendr2 = _delegate.getClientBehaviorRenderer(s);
        return rendr2;
    }

    private Renderer handleAnnotationChange(String s, String s1) {
        Renderer rendr2;

        //WeavingContext.getWeaver().fullClassScan();
        rendr2 = _delegate.getRenderer(s, s1);
        if (rendr2 instanceof PurgedRenderer) {
            throw new FacesException("Renderer not found");
        }
        rendr2 = _delegate.getRenderer(s, s1);
        return rendr2;
    }

    public ResponseStateManager getResponseStateManager() {
        weaveDelegate();
        return _delegate.getResponseStateManager();
    }

    public ResponseWriter createResponseWriter(Writer writer, String s, String s1) {
        weaveDelegate();
        return (ResponseWriter) reloadInstance(_delegate.createResponseWriter(writer, s, s1), ScriptingConst.ARTIFACT_TYPE_RESPONSEWRITER);
    }

    public ResponseStream createResponseStream(OutputStream outputStream) {
        weaveDelegate();
        return (ResponseStream) reloadInstance(_delegate.createResponseStream(outputStream), ScriptingConst.ARTIFACT_TYPE_RESPONSESTREAM);
    }

    @Override
    public void addClientBehaviorRenderer(String s, ClientBehaviorRenderer renderer) {

        weaveDelegate();
        renderer = (ClientBehaviorRenderer) reloadInstance(renderer, ScriptingConst.ARTIFACT_TYPE_CLIENTBEHAVIORRENDERER);
        _delegate.addClientBehaviorRenderer(s, renderer);
    }

    @Override
    public ClientBehaviorRenderer getClientBehaviorRenderer(String s) {
        weaveDelegate();
        ClientBehaviorRenderer rendr = _delegate.getClientBehaviorRenderer(s);
        ClientBehaviorRenderer rendr2 = (ClientBehaviorRenderer) reloadInstance(rendr, ScriptingConst.ARTIFACT_TYPE_CLIENTBEHAVIORRENDERER);
        if (rendr != rendr2) {

            rendr2 = _delegate.getClientBehaviorRenderer(s);
            if (rendr2 instanceof PurgedClientBehaviorRenderer) {
                return handleAnnotationChangeBehaviorRenderer(s);
            }
            return rendr2;
        }
        return rendr;
    }

    @Override
    public Iterator<String> getClientBehaviorRendererTypes() {
        weaveDelegate();
        return _delegate.getClientBehaviorRendererTypes();
    }

    @Override
    public Iterator<String> getComponentFamilies() {
        weaveDelegate();
        return _delegate.getComponentFamilies();
    }

    @Override
    public Iterator<String> getRendererTypes(String s) {
        weaveDelegate();
        return _delegate.getRendererTypes(s);
    }

    public Object getDelegate() {
        return _delegate;
    }

    private void weaveDelegate() {
        _delegate = (RenderKit) WeavingContext.getWeaver().reloadScriptingInstance(_delegate, ScriptingConst.ARTIFACT_TYPE_RENDERKIT);
    }

    private Object reloadInstance(Object instance, int artefactType) {
        if (instance == null) {
            return null;
        }
        if (WeavingContext.isDynamic(instance.getClass()) && !alreadyWovenInRequest(instance.getClass().getName())) {
            alreadyWovenInRequest(instance.getClass().getName());
            instance = WeavingContext.getWeaver().reloadScriptingInstance(instance, artefactType);

            //now the add should be done properly if possible
        }
        return instance;
    }

    private boolean alreadyWovenInRequest(String clazz) {
        try {//portlets now can be enabled thanks to the jsf2 indirections regarding the external context

            //portlets now can be enabled thanks to the jsf2 indirections regarding the external context
            Map<String, Object> req = FacesContext.getCurrentInstance().getExternalContext().getRequestMap();
            if (req.get(ScriptingConst.SCRIPTING_REQUSINGLETON + clazz) == null) {
                req.put(ScriptingConst.SCRIPTING_REQUSINGLETON + clazz, "");
                return false;
            }
            return true;
        } catch (UnsupportedOperationException ex) {
            //still in startup no additional weaving here
            return true;
        }
    }

}