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.core.util.string; import org.apache.wicket.request.Response; import org.apache.wicket.util.string.Strings; /** * Provide some helpers to write javascript related tags to the response object. * * @author Juergen Donnerstag */ public class JavaScriptUtils { /** * Prefix for JavaScript CDATA content. If this is changed, also update * Wicket.Head.Contributor.processScript() function from wicket-ajax-jquery.js */ public final static String SCRIPT_CONTENT_PREFIX = "\n/*<![CDATA[*/\n"; /** * Suffix for JavaScript CDATA content. If this is changed, also update * Wicket.Head.Contributor.processScript() function from wicket-ajax-jquery.js */ public final static String SCRIPT_CONTENT_SUFFIX = "\n/*]]>*/\n"; /** Script open tag including content prefix */ public final static String SCRIPT_OPEN_TAG = "<script type=\"text/javascript\">" + SCRIPT_CONTENT_PREFIX; /** Script close tag including content suffix */ public final static String SCRIPT_CLOSE_TAG = SCRIPT_CONTENT_SUFFIX + "</script>\n"; /** The response object */ private final Response response; /** * Construct. * * @param response * The response object * @param id */ public JavaScriptUtils(final Response response, String id) { this.response = response; writeOpenTag(response, id); } /** * Constructor without id for backward compatibility * * @param response * The response object */ public JavaScriptUtils(final Response response) { this.response = response; writeOpenTag(response); } /** * Escape single and double quotes so that they can be part of e.g. an alert call. * * Note: JSON values need to escape only the double quote, so this method wont help. * * @param input * the JavaScript which needs to be escaped * @return Escaped version of the input */ public static CharSequence escapeQuotes(final CharSequence input) { CharSequence s = input; if (s != null) { s = Strings.replaceAll(s, "'", "\\'"); s = Strings.replaceAll(s, "\"", "\\\""); } return s; } /** * Write a reference to a javascript file to the response object * * @param response * The HTTP response * @param url * The javascript file URL * @param id * Unique identifier of element */ public static void writeJavaScriptUrl(final Response response, final CharSequence url, final String id) { writeJavaScriptUrl(response, url, id, false, null, false); } /** * Write a reference to a javascript file to the response object * * @param response * The HTTP response * @param url * The javascript file URL * @param id * Unique identifier of element * @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 */ public static void writeJavaScriptUrl(final Response response, final CharSequence url, final String id, boolean defer, String charset) { writeJavaScriptUrl(response, url, id, defer, charset, false); } /** * Write a reference to a javascript file to the response object * * @param response * The HTTP response * @param url * The javascript file URL * @param id * Unique identifier of element * @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 async * specifies that the script can be loaded asynchronously by the browser */ public static void writeJavaScriptUrl(final Response response, final CharSequence url, final String id, boolean defer, String charset, boolean async) { response.write("<script type=\"text/javascript\" "); if (id != null) { response.write("id=\"" + Strings.escapeMarkup(id) + "\" "); } if (defer) { response.write("defer=\"defer\" "); } if (async) { response.write("async=\"async\" "); } if (charset != null) { response.write("charset=\"" + Strings.escapeMarkup(charset) + "\" "); } response.write("src=\""); response.write(url); response.write("\"></script>"); response.write("\n"); } /** * Write a reference to a javascript file to the response object * * @param response * The HTTP response * @param url * The javascript file URL */ public static void writeJavaScriptUrl(final Response response, final CharSequence url) { writeJavaScriptUrl(response, url, null); } /** * Write the simple text to the response object surrounded by a script tag. * * @param response * The HTTP: response * @param text * The text to added in between the script tags * @param id * Unique identifier of element */ public static void writeJavaScript(final Response response, final CharSequence text, String id) { writeOpenTag(response, id); response.write(Strings.replaceAll(text, "</", "<\\/")); writeCloseTag(response); } /** * Write the simple text to the response object surrounded by a script tag. * * @param response * The HTTP: response * @param text * The text to added in between the script tags */ public static void writeJavaScript(final Response response, final CharSequence text) { writeJavaScript(response, text, null); } /** * * @param response * @param id */ public static void writeOpenTag(final Response response, String id) { response.write("<script type=\"text/javascript\" "); if (id != null) { response.write("id=\"" + Strings.escapeMarkup(id) + "\""); } response.write(">"); response.write(SCRIPT_CONTENT_PREFIX); } /** * * @param response */ public static void writeOpenTag(final Response response) { writeOpenTag(response, null); } /** * * @param response */ public static void writeCloseTag(final Response response) { response.write(SCRIPT_CONTENT_SUFFIX); response.write("</script>\n"); } /** * @see Response#write(java.lang.CharSequence) * @param script */ public void write(final CharSequence script) { response.write(script); } /** * @see Response#write(CharSequence) * @param script */ public void println(final CharSequence script) { response.write(script); } /** * Write the script close tag to the response. The response output stream remains open. */ public void close() { writeCloseTag(response); } }