org.apache.wicket.ajax.AjaxRequestTarget.java Source code

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Here is the source code for org.apache.wicket.ajax.AjaxRequestTarget.java

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/*
 * 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.wicket.ajax;

import java.util.Map;

import org.apache.wicket.Component;
import org.apache.wicket.Page;
import org.apache.wicket.ajax.attributes.AjaxRequestAttributes;
import org.apache.wicket.core.request.handler.IPartialPageRequestHandler;
import org.apache.wicket.request.ILoggableRequestHandler;

/**
 *
 * @since 6.0
 */
public interface AjaxRequestTarget extends IPartialPageRequestHandler, ILoggableRequestHandler {
    /**
     * An {@link AjaxRequestTarget} listener that can be used to respond to various target-related
     * events
     *
     */
    interface IListener {
        /**
         * Triggered before ajax request target begins its response cycle
         *
         * @param map
         *            modifiable map (markupId -> component) of components already added to the target
         * @param target
         *            the target itself. Could be used to add components or to append/prepend
         *            javascript
         *
         */
        default void onBeforeRespond(Map<String, Component> map, AjaxRequestTarget target) {
        }

        /**
         * Triggered after ajax request target is done with its response cycle. At this point only
         * additional javascript can be output to the response using the provided
         * {@link AjaxRequestTarget.IJavaScriptResponse} object
         *
         * NOTE: During this stage of processing any calls to target that manipulate the response
         * (adding components, javascript) will have no effect
         *
         * @param map
         *            read-only map:markupId->component of components already added to the target
         * @param response
         *            response object that can be used to output javascript
         */
        default void onAfterRespond(Map<String, Component> map, AjaxRequestTarget.IJavaScriptResponse response) {
        }

        /**
         * Triggered for every Ajax behavior. Can be used to configure common settings.
         * 
         * @param behavior
         *            the behavior the attributes are updated for
         * @param attributes
         *            The attributes for the Ajax behavior
         * @since 7.0.0
         */
        default void updateAjaxAttributes(AbstractDefaultAjaxBehavior behavior, AjaxRequestAttributes attributes) {
        }
    }

    /**
     * Empty implementation of an {@link IListener} useful as a starting point for your own
     * custom listener.
     *
     * @deprecated This class will be removed in Wicket 9.0.0. Use {@link IListener} instead
     */
    @Deprecated
    class AbstractListener implements IListener {
    }

    /**
     * An ajax javascript response that allows users to add javascript to be executed on the client
     * side
     *
     * @author ivaynberg
     */
    @FunctionalInterface
    interface IJavaScriptResponse {
        /**
         * Adds more javascript to the ajax response that will be executed on the client side
         *
         * @param script
         *            javascript
         */
        void addJavaScript(String script);
    }

    /**
     * Components can implement this interface to get a notification when AjaxRequestTarget begins
     * to respond. This can be used to postpone adding components to AjaxRequestTarget until the
     * response begins.
     *
     * @author Matej Knopp
     */
    @FunctionalInterface
    interface ITargetRespondListener {
        /**
         * Invoked when AjaxRequestTarget is about the respond.
         *
         * @param target
         */
        void onTargetRespond(AjaxRequestTarget target);
    }

    /**
     * Adds a listener to this target
     *
     * @param listener
     * @throws IllegalStateException
     *             if {@link AjaxRequestTarget.IListener}'s events are currently being fired or have both been fired
     *             already
     */
    void addListener(AjaxRequestTarget.IListener listener);

    /**
     * Register the given respond listener. The listener's
     * {@link org.apache.wicket.ajax.AjaxRequestTarget.ITargetRespondListener#onTargetRespond} method will be invoked when
     * the {@link AjaxRequestTarget} starts to respond.
     *
     * @param listener
     */
    void registerRespondListener(ITargetRespondListener listener);

    /**
     * Returns the HTML id of the last focused element.
     *
     * @return markup id of last focused element, <code>null</code> if none
     */
    String getLastFocusedElementId();

    /**
     * Returns the page. Be aware that the page can be instantiated if this wasn't the case already.
     *
     * @return page instance
     */
    @Override
    Page getPage();
}