org.apache.wicket.markup.head.OnDomReadyHeaderItem.java Source code

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Here is the source code for org.apache.wicket.markup.head.OnDomReadyHeaderItem.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.markup.head;

import java.util.Collections;
import java.util.List;
import java.util.Objects;

import org.apache.wicket.Application;
import org.apache.wicket.core.util.string.JavaScriptUtils;
import org.apache.wicket.request.Response;
import org.apache.wicket.request.resource.ResourceReference;
import org.apache.wicket.settings.JavaScriptLibrarySettings;
import org.apache.wicket.util.string.Strings;

/**
 * {@link HeaderItem} for scripts that need to be executed directly after the DOM has been built,
 * but before external resources, such as images, are loaded.
 *
 * @author papegaaij
 */
public class OnDomReadyHeaderItem extends HeaderItem {
    private static final long serialVersionUID = 1L;

    /**
     * Creates a {@link OnDomReadyHeaderItem} for the script.
     *
     * @param javaScript
     *            The script to execute on the DOM ready event.
     *
     * @return A newly created {@link OnDomReadyHeaderItem}.
     */
    public static OnDomReadyHeaderItem forScript(CharSequence javaScript) {
        return new OnDomReadyHeaderItem(javaScript);
    }

    private final CharSequence javaScript;

    /**
     * Constructor.
     *
     * The JavaScript should be provided by overloaded #getJavaScript
     */
    public OnDomReadyHeaderItem() {
        this(null);
    }

    /**
     * Construct.
     *
     * @param javaScript
     */
    public OnDomReadyHeaderItem(CharSequence javaScript) {
        this.javaScript = javaScript;
    }

    /**
     * @return the script that gets executed on the DOM ready event.
     */
    public CharSequence getJavaScript() {
        return javaScript;
    }

    @Override
    public void render(Response response) {
        CharSequence js = getJavaScript();
        if (Strings.isEmpty(js) == false) {
            JavaScriptUtils.writeJavaScript(response,
                    "Wicket.Event.add(window, \"domready\", " + "function(event) { " + js + ";});");
        }
    }

    @Override
    public Iterable<?> getRenderTokens() {
        return Collections.singletonList("javascript-domready-" + getJavaScript());
    }

    @Override
    public String toString() {
        return "OnDomReadyHeaderItem('" + getJavaScript() + "')";
    }

    @Override
    public int hashCode() {
        return Objects.hash(javaScript);
    }

    @Override
    public boolean equals(Object o) {
        if (this == o)
            return true;
        if (o == null || getClass() != o.getClass())
            return false;
        OnDomReadyHeaderItem that = (OnDomReadyHeaderItem) o;
        return Objects.equals(javaScript, that.javaScript);
    }

    @Override
    public List<HeaderItem> getDependencies() {
        JavaScriptLibrarySettings ajaxSettings = Application.get().getJavaScriptLibrarySettings();
        ResourceReference wicketAjaxReference = ajaxSettings.getWicketAjaxReference();
        List<HeaderItem> dependencies = super.getDependencies();
        dependencies.add(JavaScriptHeaderItem.forReference(wicketAjaxReference));
        return dependencies;
    }
}