Java tutorial
/* * 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.Objects; import org.apache.wicket.core.request.handler.IPartialPageRequestHandler; import org.apache.wicket.core.util.string.JavaScriptUtils; import org.apache.wicket.request.Response; import org.apache.wicket.request.cycle.RequestCycle; import org.apache.wicket.request.mapper.parameter.PageParameters; import org.apache.wicket.request.resource.ResourceReference; import org.apache.wicket.util.lang.Args; import org.apache.wicket.util.string.Strings; /** * Base class for all {@link HeaderItem}s that represent javascripts. This class mainly contains * factory methods. * * @author papegaaij */ public abstract class JavaScriptHeaderItem extends HeaderItem { /** * The condition to use for Internet Explorer conditional comments. E.g. "IE 7". * {@code null} or empty string for no condition. */ private final String condition; /** * An optional markup id to set on the rendered <script> HTML element for * this header item */ private String markupId; protected JavaScriptHeaderItem(String condition) { this.condition = condition; } /** * @return unique id for the javascript element. */ public String getId() { return markupId; } /** * Sets the markup id for this header item * @param markupId * the markup id * @return {@code this} object, for method chaining */ public JavaScriptHeaderItem setId(String markupId) { this.markupId = markupId; return this; } /** * @return the condition to use for Internet Explorer conditional comments. E.g. "IE 7". */ public String getCondition() { return condition; } /** * Creates a {@link JavaScriptReferenceHeaderItem} for the given reference. * * @param reference * resource reference pointing to the javascript resource * @return A newly created {@link JavaScriptReferenceHeaderItem} for the given reference. */ public static JavaScriptReferenceHeaderItem forReference(ResourceReference reference) { return forReference(reference, null); } /** * Creates a {@link JavaScriptReferenceHeaderItem} for the given reference. * * @param reference * resource reference pointing to the javascript resource * @param id * id that will be used to filter duplicate reference (it's still filtered by URL * too) * @return A newly created {@link JavaScriptReferenceHeaderItem} for the given reference. */ public static JavaScriptReferenceHeaderItem forReference(ResourceReference reference, String id) { return forReference(reference, null, id); } /** * Creates a {@link JavaScriptReferenceHeaderItem} for the given reference. * * @param reference * resource reference pointing to the javascript resource * @param pageParameters * the parameters for this Javascript resource reference * @param id * id that will be used to filter duplicate reference (it's still filtered by URL * too) * @return A newly created {@link JavaScriptReferenceHeaderItem} for the given reference. */ public static JavaScriptReferenceHeaderItem forReference(ResourceReference reference, PageParameters pageParameters, String id) { return forReference(reference, pageParameters, id, false); } /** * Creates a {@link JavaScriptReferenceHeaderItem} for the given reference. * * @param reference * resource reference pointing to the javascript resource * @param pageParameters * the parameters for this Javascript resource reference * @param id * id that will be used to filter duplicate reference (it's still filtered by URL * too) * @param defer * specifies that the execution of a script should be deferred (delayed) until after * the page has been loaded. * @return A newly created {@link JavaScriptReferenceHeaderItem} for the given reference. */ public static JavaScriptReferenceHeaderItem forReference(ResourceReference reference, PageParameters pageParameters, String id, boolean defer) { return forReference(reference, pageParameters, id, defer, null); } /** * Creates a {@link JavaScriptReferenceHeaderItem} for the given reference. * * @param reference * resource reference pointing to the JavaScript resource * @param id * id that will be used to filter duplicate reference (it's still filtered by URL * too) * @param defer * specifies that the execution of a script should be deferred (delayed) until after * the page has been loaded. * @return A newly created {@link JavaScriptReferenceHeaderItem} for the given reference. */ public static JavaScriptReferenceHeaderItem forReference(ResourceReference reference, String id, boolean defer) { return forReference(reference, null, id, defer, null); } /** * Creates a {@link JavaScriptReferenceHeaderItem} for the given reference. * * @param reference * resource reference pointing to the JavaScript resource * @param defer * specifies that the execution of a script should be deferred (delayed) until after * the page has been loaded. * @return A newly created {@link JavaScriptReferenceHeaderItem} for the given reference. */ public static JavaScriptReferenceHeaderItem forReference(ResourceReference reference, boolean defer) { return forReference(reference, null, null, defer, null); } /** * Creates a {@link JavaScriptReferenceHeaderItem} for the given reference. * * @param reference * resource reference pointing to the javascript resource * @param pageParameters * the parameters for this Javascript resource reference * @param id * id that will be used to filter duplicate reference (it's still filtered by URL * too) * @param defer * specifies that the execution of a script should be deferred (delayed) until after * the page has been loaded. * @param charset * a non null value specifies the charset attribute of the script tag * @return A newly created {@link JavaScriptReferenceHeaderItem} for the given reference. */ public static JavaScriptReferenceHeaderItem forReference(ResourceReference reference, PageParameters pageParameters, String id, boolean defer, String charset) { return new JavaScriptReferenceHeaderItem(reference, pageParameters, id, defer, charset, null); } /** * Creates a {@link JavaScriptReferenceHeaderItem} for the given reference. * * @param reference * resource reference pointing to the javascript resource * @param pageParameters * the parameters for this Javascript resource reference * @param id * id that will be used to filter duplicate reference (it's still filtered by URL * too) * @param defer * specifies that the execution of a script should be deferred (delayed) until after * the page has been loaded. * @param charset * a non null value specifies the charset attribute of the script tag * @param condition * the condition to use for Internet Explorer conditional comments. E.g. "IE 7". * @return A newly created {@link JavaScriptReferenceHeaderItem} for the given reference. */ public static JavaScriptReferenceHeaderItem forReference(ResourceReference reference, PageParameters pageParameters, String id, boolean defer, String charset, String condition) { return new JavaScriptReferenceHeaderItem(reference, pageParameters, id, defer, charset, condition); } /** * Creates a {@link JavaScriptContentHeaderItem} for the given content. * * @param javascript * javascript content to be rendered. * @param id * unique id for the javascript element. This can be null, however in that case the * ajax header contribution can't detect duplicate script fragments. * @return A newly created {@link JavaScriptContentHeaderItem} for the given content. */ public static JavaScriptContentHeaderItem forScript(CharSequence javascript, String id) { return forScript(javascript, id, null); } /** * Creates a {@link JavaScriptContentHeaderItem} for the given content. * * @param javascript * javascript content to be rendered. * @param id * unique id for the javascript element. This can be null, however in that case the * ajax header contribution can't detect duplicate script fragments. * @param condition * the condition to use for Internet Explorer conditional comments. E.g. "IE 7". * @return A newly created {@link JavaScriptContentHeaderItem} for the given content. */ public static JavaScriptContentHeaderItem forScript(CharSequence javascript, String id, String condition) { return new JavaScriptContentHeaderItem(javascript, id, condition); } /** * Creates a {@link JavaScriptUrlReferenceHeaderItem} for the given url. * * @param url * context-relative url of the the javascript resource * @return A newly created {@link JavaScriptUrlReferenceHeaderItem} for the given url. */ public static JavaScriptUrlReferenceHeaderItem forUrl(String url) { return forUrl(url, null); } /** * Creates a {@link JavaScriptUrlReferenceHeaderItem} for the given url. * * @param url * context-relative url of the the javascript resource * @param id * id that will be used to filter duplicate reference (it's still filtered by URL * too) * @return A newly created {@link JavaScriptUrlReferenceHeaderItem} for the given url. */ public static JavaScriptUrlReferenceHeaderItem forUrl(String url, String id) { return forUrl(url, id, false); } /** * Creates a {@link JavaScriptUrlReferenceHeaderItem} for the given url. * * @param url * context-relative url of the the javascript resource * @param id * id that will be used to filter duplicate reference (it's still filtered by URL * too) * @param defer * specifies that the execution of a script should be deferred (delayed) until after * the page has been loaded. * @return A newly created {@link JavaScriptUrlReferenceHeaderItem} for the given url. */ public static JavaScriptUrlReferenceHeaderItem forUrl(String url, String id, boolean defer) { return forUrl(url, id, defer, null); } /** * Creates a {@link JavaScriptUrlReferenceHeaderItem} for the given url. * * @param url * context-relative url of the the javascript resource * @param id * id that will be used to filter duplicate reference (it's still filtered by URL * too) * @param defer * specifies that the execution of a script should be deferred (delayed) until after * the page has been loaded. * @param charset * a non null value specifies the charset attribute of the script tag * @return A newly created {@link JavaScriptUrlReferenceHeaderItem} for the given url. */ public static JavaScriptUrlReferenceHeaderItem forUrl(String url, String id, boolean defer, String charset) { return forUrl(url, id, defer, charset, null); } /** * Creates a {@link JavaScriptUrlReferenceHeaderItem} for the given url. * * @param url * context-relative url of the the javascript resource * @param id * id that will be used to filter duplicate reference (it's still filtered by URL * too) * @param defer * specifies that the execution of a script should be deferred (delayed) until after * the page has been loaded. * @param charset * a non null value specifies the charset attribute of the script tag * @return A newly created {@link JavaScriptUrlReferenceHeaderItem} for the given url. */ public static JavaScriptUrlReferenceHeaderItem forUrl(String url, String id, boolean defer, String charset, String condition) { return new JavaScriptUrlReferenceHeaderItem(url, id, defer, charset, condition); } protected final void internalRenderJavaScriptReference(Response response, String url, String id, boolean defer, String charset, String condition, boolean async) { Args.notEmpty(url, "url"); boolean hasCondition = Strings.isEmpty(condition) == false; if (hasCondition) { response.write("<!--[if "); response.write(condition); response.write("]>"); } boolean isAjax = RequestCycle.get().find(IPartialPageRequestHandler.class).isPresent(); // the url needs to be escaped when Ajax, because it will break the Ajax Response XML (WICKET-4777) CharSequence escapedUrl = isAjax ? Strings.escapeMarkup(url) : url; JavaScriptUtils.writeJavaScriptUrl(response, escapedUrl, id, defer, charset, async); if (hasCondition) { response.write("<![endif]-->\n"); } } @Override public boolean equals(Object o) { if (this == o) return true; if (o == null || getClass() != o.getClass()) return false; JavaScriptHeaderItem that = (JavaScriptHeaderItem) o; return Objects.equals(condition, that.condition) && Objects.equals(markupId, that.markupId); } @Override public int hashCode() { return Objects.hash(condition, markupId); } }