jdk8-mips64-public/nashorn: samples/jsadapter_dom.js@2f1b9f4daec1 (annotated)

samples/jsadapter_dom.js@2f1b9f4daec1 (annotated)

samples/jsadapter_dom.js

Fri, 05 Jun 2015 12:38:53 +0200

author: mhaupt
date: Fri, 05 Jun 2015 12:38:53 +0200
changeset 1398: 2f1b9f4daec1
parent 962: ac62e33a99b0
permissions: -rw-r--r--

8080087: Nashorn $ENV.PWD is originally undefined
Summary: On Windows, the PWD environment variable does not exist and cannot be imported in scripting mode, so it is set explicitly.
Reviewed-by: lagergren, sundar

 #// 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);
 }