ScriptFamily.java

/*
 * Copyright OmniFaces
 *
 * Licensed 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
 *
 *     https://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.omnifaces.component.script;

import static org.omnifaces.util.Renderers.writeAttribute;

import java.io.IOException;

import jakarta.faces.component.UIComponentBase;
import jakarta.faces.component.UIViewRoot;
import jakarta.faces.context.FacesContext;
import jakarta.faces.context.ResponseWriter;
import jakarta.faces.event.ComponentSystemEvent;
import jakarta.faces.event.PostAddToViewEvent;
import jakarta.faces.event.PostRestoreStateEvent;

/**
 * Base class which is to be shared between all components of the Script family.
 *
 * @author Bauke Scholtz
 */
public abstract class ScriptFamily extends UIComponentBase {

    // Public constants -----------------------------------------------------------------------------------------------

    /** The standard component family. */
    public static final String COMPONENT_FAMILY = "org.omnifaces.component.script";

    // UIComponent overrides ------------------------------------------------------------------------------------------

    /**
     * Returns {@link #COMPONENT_FAMILY}.
     */
    @Override
    public String getFamily() {
        return COMPONENT_FAMILY;
    }

    /**
     * Returns <code>true</code>.
     */
    @Override
    public boolean getRendersChildren() {
        return true;
    }

    /**
     * If this component is rendered, then start the <code>&lt;script&gt;</code> element.
     */
    @Override
    public void encodeBegin(FacesContext context) throws IOException {
        if (getRendererType() != null) {
            super.encodeBegin(context);
            return;
        }

        pushComponentToEL(context, this);

        if (isRendered()) {
            ResponseWriter writer = context.getResponseWriter();

            if (getId() != null || !getClientBehaviors().isEmpty()) {
                writer.startElement("input", this);
                writeAttribute(writer, "type", "hidden");
                writeAttribute(writer, "id", getClientId(context));
                writer.endElement("input");
            }

            writer.startElement("script", this);
            writeAttribute(writer, "type", "text/javascript");
        }
    }

    /**
     * If this component is rendered, then end the <code>&lt;script&gt;</code> element.
     */
    @Override
    public void encodeEnd(FacesContext context) throws IOException {
        if (getRendererType() != null) {
            super.encodeEnd(context);
            return;
        }

        if (isRendered()) {
            context.getResponseWriter().endElement("script");
        }

        popComponentFromEL(context);
    }

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

    /**
     * Move this ScriptFamily component to end of body and returns <code>true</code> if done so. This method
     * needs to be called from {@link #processEvent(ComponentSystemEvent)} during {@link PostAddToViewEvent} or
     * {@link PostRestoreStateEvent}. This has basically the same effect as setting <code>target="body"</code> on a
     * component resource.
     * @param event The involved event, which can be either {@link PostAddToViewEvent} or {@link PostRestoreStateEvent}.
     * @return <code>true</code> if the move has taken place.
     */
    protected boolean moveToBody(ComponentSystemEvent event) {
        if (!(event instanceof PostAddToViewEvent || event instanceof PostRestoreStateEvent)) {
            return false;
        }

        FacesContext context = event.getFacesContext();
        UIViewRoot view = context.getViewRoot();

        if (context.isPostback() ? !view.getComponentResources(context, "body").contains(this) : event instanceof PostAddToViewEvent) {
            view.addComponentResource(context, this, "body");
            return true;
        }
        else {
            return false;
        }
    }

}