Mercurial > jdk8-mips64-public > nashorn / file revision

 #// Usage: jjs -scripting jsadapter_dom.js

 /*

  * Copyright (c) 2014, Oracle and/or its affiliates. All rights reserved.

  * 

  * Redistribution and use in source and binary forms, with or without

  * modification, are permitted provided that the following conditions

  * are met:

  * 

  *   - Redistributions of source code must retain the above copyright

  *     notice, this list of conditions and the following disclaimer.

  * 

  *   - Redistributions in binary form must reproduce the above copyright

  *     notice, this list of conditions and the following disclaimer in the

  *     documentation and/or other materials provided with the distribution.

  * 

  *   - Neither the name of Oracle nor the names of its

  *     contributors may be used to endorse or promote products derived

  *     from this software without specific prior written permission.

  * 

  * THIS SOFTWARE IS PROVIDED BY THE COPYRIGHT HOLDERS AND CONTRIBUTORS "AS

  * IS" AND ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO,

  * THE IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR

  * PURPOSE ARE DISCLAIMED.  IN NO EVENT SHALL THE COPYRIGHT OWNER OR

  * CONTRIBUTORS BE LIABLE FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL,

  * EXEMPLARY, OR CONSEQUENTIAL DAMAGES (INCLUDING, BUT NOT LIMITED TO,

  * PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES; LOSS OF USE, DATA, OR

  * PROFITS; OR BUSINESS INTERRUPTION) HOWEVER CAUSED AND ON ANY THEORY OF

  * LIABILITY, WHETHER IN CONTRACT, STRICT LIABILITY, OR TORT (INCLUDING

  * NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT OF THE USE OF THIS

  * SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF SUCH DAMAGE.

  */

 // Simple example that demonstrates reading XML Rss feed

 // to generate a HTML file from script and show it by browser

 // Uses XML DOM parser and DOM element wrapped by script 

 // "proxy" (JSAdapter constructor)

 // Java classes used

 var DocBuilderFac = Java.type("javax.xml.parsers.DocumentBuilderFactory");

 var Node = Java.type("org.w3c.dom.Node");

 var File = Java.type("java.io.File");

 var FileWriter = Java.type("java.io.FileWriter");

 var PrintWriter = Java.type("java.io.PrintWriter");

 // constants from Node class

 var ELEMENT_NODE = Node.ELEMENT_NODE;

 var TEXT_NODE = Node.TEXT_NODE;

 // parse XML from uri and return Document

 function parseXML(uri) {

     var docBuilder = DocBuilderFac.newInstance().newDocumentBuilder();

     return docBuilder["parse(java.lang.String)"](uri);

 }

 // get child Elements of given name of the parent element given

 function getChildElements(elem, name) {

     var nodeList = elem.childNodes;

     var childElems = [];

     var len = nodeList.length;

     for (var i = 0; i < len; i++) {

         var node = nodeList.item(i);

         if (node.nodeType == ELEMENT_NODE &&

             node.tagName == name) {

             childElems.push(wrapElement(node));

         }

     }

     return childElems;

 }

 // get concatenated child text content of an Element

 function getElemText(elem) {

     var nodeList = elem.childNodes;

     var len = nodeList.length;

     var text = '';

     for (var i = 0; i < len; i++) {

         var node = nodeList.item(i);

         if (node.nodeType == TEXT_NODE) {

             text += node.nodeValue;

         } 

     }

     return text;

 }

 // Wrap DOM Element object as a convenient script object

 // using JSAdapter. JSAdapter is like java.lang.reflect.Proxy

 // in that it allows property access, method calls be trapped

 // by 'magic' methods like __get__, __call__.

 function wrapElement(elem) {

     if (! elem) {

         return elem;

     }

     return new JSAdapter() {

         // getter to expose child elements and attributes by name

         __get__: function(name) {

             if (typeof name == 'string') {

                 if (name.startsWith('@')) {

                     var attr = elem.getAttributeNode(name.substring(1));

                     return !attr? undefined : attr.value;

                 }

                 var arr = getChildElements(elem, name);

                 if (arr.length == 1) {

                     // single child element, expose as single element

                     return arr[0];

                 } else {

                     // multiple children of given name, expose as array

                     return arr;

                 }

             }

             return undefined;

         },

         __call__: function(name) {

             // toString override to get text content of this Element

             if (name == 'toString' || name == 'valueOf') {

                 return getElemText(elem);

             }

             return undefined;

         }

     }

 }

 // generate HTML using here-doc and string interpolation

 function getBooksHtml() {

     var doc = parseXML("http://www.gutenberg.org/cache/epub/feeds/today.rss");

     // wrap document root Element as script convenient object

     var rss = wrapElement(doc.documentElement);

     print("rss file version " + rss['@version']);

     var str = <<HEAD

 <html>

 <title>${rss.channel.title}</title>

 <body>

 <h1>${rss.channel.description}</h1>

 <p>

 Published on ${rss.channel.pubDate}

 </p>

 HEAD

     var items = rss.channel.item;

     for each (var i in items) {

         str += <<LIST

 <dl>

 <dt><a href="${i.link}">${i.title}</a></dt>

 <dd>${i.description}</dd>

 </dl>

 LIST

     }

     str += <<END

 </body>

 </html>

 END

     return str;

 }

 // write the string to the given file

 function writeTo(file, str) {

     var w = new PrintWriter(new FileWriter(file));

     try {

         w.print(str);

     } finally {

         w.close();

     }

 }

 // generate books HTML

 var str = getBooksHtml();

 // write to file. __DIR__ is directory where

 // this script is stored.

 var file = new File(__DIR__ + "books.html");

 writeTo(file, str);

 // show it by desktop browser

 try {

     var Desktop = Java.type("java.awt.Desktop");

     Desktop.desktop.browse(file.toURI());

 } catch (e) {

     print(e);

 }