org.apache.wicket.ajax.form.OnChangeAjaxBehavior.java Source code

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Here is the source code for org.apache.wicket.ajax.form.OnChangeAjaxBehavior.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.form;

import org.apache.wicket.Component;
import org.apache.wicket.ajax.AjaxRequestTarget;
import org.apache.wicket.ajax.attributes.AjaxRequestAttributes;
import org.apache.wicket.markup.html.form.FormComponent;
import org.apache.wicket.markup.html.form.TextArea;
import org.apache.wicket.markup.html.form.TextField;
import org.apache.wicket.util.lang.Args;
import org.danekja.java.util.function.serializable.SerializableConsumer;

/**
 * A behavior that updates the hosting {@link FormComponent} via Ajax when value of the component is
 * changed.
 * <p>
 * This behavior uses best available method to track changes on different types of form components.
 * To accomplish this for text input form components it uses a custom event, named 'inputchange',
 * that is handled in the best way for the specific browser. For other form component types the
 * 'change' event is used.
 * </p>
 * 
 * @author Janne Hietam&auml;ki (janne)
 * 
 * @since 1.3
 * @see org.apache.wicket.ajax.form.AjaxFormComponentUpdatingBehavior#onUpdate(org.apache.wicket.ajax.AjaxRequestTarget)
 * @see org.apache.wicket.ajax.form.AjaxFormComponentUpdatingBehavior#onError(org.apache.wicket.ajax.AjaxRequestTarget, RuntimeException)
 */
public abstract class OnChangeAjaxBehavior extends AjaxFormComponentUpdatingBehavior {
    private static final long serialVersionUID = 1L;

    /**
     * 'inputchange' event delegates to 'input', 'keyup', 'cut' and 'paste' events
     * for text input form component depending on the browser.
     * 'change' is used as a fallback for all other form component types.
     */
    public static final String EVENT_NAME = "inputchange change";

    /**
     * the change event
     */
    public static final String EVENT_CHANGE = "change";

    /**
     * Constructor.
     */
    public OnChangeAjaxBehavior() {
        super(EVENT_NAME);
    }

    @Override
    protected void updateAjaxAttributes(AjaxRequestAttributes attributes) {
        super.updateAjaxAttributes(attributes);

        Component component = getComponent();

        // textfiels and textareas will trigger this behavior with either 'inputchange' or 'change' events
        // all the other components will use just 'change'
        if (!(component instanceof TextField || component instanceof TextArea)) {
            attributes.setEventNames(EVENT_CHANGE);
        }
    }

    /**
     * Creates an {@link OnChangeAjaxBehavior} based on lambda expressions
     * 
     * @param onChange
     *            the {@code SerializableConsumer} which accepts the {@link AjaxRequestTarget}
     * @return the {@link OnChangeAjaxBehavior}
     */
    public static OnChangeAjaxBehavior onChange(SerializableConsumer<AjaxRequestTarget> onChange) {
        Args.notNull(onChange, "onChange");

        return new OnChangeAjaxBehavior() {
            private static final long serialVersionUID = 1L;

            @Override
            protected void onUpdate(AjaxRequestTarget target) {
                onChange.accept(target);
            }
        };
    }
}