javascript page 8 - Dave's Blog

Old Miscellaneous Thoughts

2007 Dec 26, 5:45Miscellaneous thoughts I had that would have been relevant many months ago:

• A History Channel program had a reenactment of a 1920's archaeologist discovering a stone tablet, sending the tablet to a warehouse, etc. all behind the voice over giving the dry facts. The reenactor hammed it up a bit and I would have rather had clips from Indiana Jones in the background. If they're already not showing me the archaeologist who discovered the tablet, they may as well show me one who will be entertaining.
• There are many parodies of the Get a Mac ads and so when I saw a UK Get a Mac ad I payed attention to see what the joke was. I was disappointed by the 'parody' because it was a conventional Get a Mac ad with different actors. Apple localized their Get a Mac ad campaign in this fashion in the UK and in Japan. I've got a playlist of the US, UK, and Japan's version of the Piechart ad. Ranking the lovable bumblingness of the PC I give the order UK, Japan, then US and ranking the sumgness of the Mac I give the order UK, US, then Japan. But don't take my word for it, view the ads for yourself.
  
• Yahoo Pipes lets users generate an RSS feed altering service that runs on Yahoo's server using a GUI. This is very different from Microsoft's Popfly which allows users to component-ize and share javascript utilities that run client side on a webbrowser. Both have the awesome power of buzzword associations like 'Web 2.0' and 'Mashup' but in my mind Yahoo Pipes is for server side RSS feed modification and Popfly is about client side javascript webpages. And neither will allow me to run an arbitrary XSLT =).

popfly apple personal history-channel indiana-jones pipes mac technical microsoft mashup yahoo nontechnical

XSL Transforms in JavaScript

2007 Oct 7, 4:12In a previous post I mentioned an xsltproc like js file I made. As noted in that post, on Windows you can write console script files in JavaScript, name them foo.js, and execute them from the command prompt. I later found that MSDN has an XSLT javascript sample which looks similar to mine, but I like mine better for the XSLT parameter support and having a non-ridiculous way of interpreting filenames. The code for my xsltproc.js follows. The script is very simple and demonstrates the ease with which you can manipulate these system objects and all it takes is opening up notepad.

var createNewXMLObj = function() {
   var result = new ActiveXObject("MSXML2.FreeThreadedDOMDocument");
   result.validateOnParse = false;
   result.async = false;
   return result;
}

var args = WScript.arguments;
var ofs = WScript.CreateObject("Scripting.FileSystemObject");

var xslParams = [];
var xmlStyle = null;
var xmlInput = null;
var inputFile = null;
var outputFile = null;
var error = false;

for (var idx = 0; idx < args.length && !error; ++idx)
   if (args.item(idx) == "-o") {
      if (idx + 1 < args.length) {
         outputFile = ofs.GetAbsolutePathName(args.item(idx + 1));
         ++idx;
      }
      else
         error = true;
   }
   else if (args.item(idx) == "--param" || args.item(idx) == "-param") {
      if (idx + 2 < args.length) {
         xslParams[args.item(idx + 1)] = args.item(idx + 2);
         idx += 2;
      }
      else
         error = true;
   }
   else if (xmlStyle == null) {
      xmlStyle = createNewXMLObj();
      xmlStyle.load(ofs.GetAbsolutePathName(args.item(idx)));
   }
   else if (xmlInput == null) {
      inputFile = ofs.GetAbsolutePathName(args.item(idx));
      xmlInput = createNewXMLObj();
      xmlInput.load(inputFile);
   }

if (xmlStyle == null || xmlInput == null || error) {
   WScript.Echo('Usage:\n\t"xsltproc" xsl-stylesheet input-file\n\t\t["-o" output-file] *["--param" name value]');
}
else {
   var xslt = new ActiveXObject("MSXML2.XSLTemplate.3.0");
   xslt.stylesheet = xmlStyle;
   var xslProc = xslt.createProcessor();
   xslProc.input = xmlInput;

   for (var keyVar in xslParams)
      xslProc.addParameter(keyVar, xslParams[keyVar]);

   xslProc.transform();

   if (outputFile == null)
      WScript.Echo(xslProc.output);
   else {
      var xmlOutput = createNewXMLObj();
      xmlOutput.loadXML(xslProc.output);
      xmlOutput.save(outputFile);
   }
}

js xml jscript windows xslt technical xsltproc wscript xsl javascript

Two-for Script File

2007 Aug 6, 5:40I was messing with the XSLT to XSL Converter source which is a javascript file that can be run with cscript.exe. I've changed it to be like a very basic version of xsltproc that simply runs an XML file through an XSLT. I also wanted to run this from the command prompt without writing "cscript ..." everytime. I decided to make like perl programmers I've seen and make a JS file that works as a batch file and a JS file at the same time.

Here's a basic version of what I ended doing applied to a 'hello world' script named helloworld.cmd:

/* 2> NUL
@echo off
cscript /e:javascript /nologo "%~f0" %*
@goto :eof

    Hello World
        Says 'Hello world.' when you run it.
*/

var outText = 'Hello world.';
WScript.Echo(outText);

Running this on a command prompt gives the following:

C:\Users\davris>helloworld

C:\Users\davris>/*  2>NUL
Hello world.

However, after a little more experimentation I found this was slightly overkill for my purposes since if I rename the file to helloworld.js and just type its name like a command it is run by cscript:

C:\Users\davris>helloworld
Microsoft (R) Windows Script Host Version 5.7
Copyright (C) Microsoft Corporation. All rights reserved.

Hello world.

So this time I didn't need all that but if ever in the future I need to run a batch file then a JS file I can do it with one file...cmd js technical cscript batch xslt xsl javascript

New XSLT - IE7 XML Source View Upgrade Part 2

2007 May 11, 8:55Last time, I had written some resource tools to allow me to view and modify Windows module resources in my ultimate and noble quest to implement the XML content-type fragment in IE7. Using the resource tools I found that MSXML3.DLL isn't signed and that I can replace the XSLT embedded resource with my own, which is great news and means I could continue in my endevour. In the following I discuss how I came up with this replacement for IE7's XML source view.

At first I thought I could just modify the existing XSLT but it turns out that it isn't exactly an XSLT, rather its an IE5 XSL. I tried using the XSL to XSLT converter linked to on MSDN, however the resulting document still requires manual modification. But I didn't want to muck about in their weird language and I figured I could write my own XSLT faster than I could figure out how theirs worked.

I began work on the new XSLT and found it relatively easy to produce. First I got indenting working with all the XML nodes represented appropriately and different CSS classes attached to them to make it easy to do syntax highlighting. Next I added in some javascript to allow for closing and opening of elements. At this point my XSLT had the same features as the original XSL.

Next was the XML mimetype fragment which uses XPointer, a framework around various different schemes for naming parts of an XML document. I focused on the XPointer scheme which is an extended version of XPath. So I named my first task as getting XPaths working. Thankfully javascript running in the HTML document produced by running my XSLT on an XML document has access to the original XML document object via the document.XMLDocument property. From this this I can execute XPaths, however there's no builtin way to map from the XML nodes selected by the XPath to the HTML elements that I produced to represent them. So I created a recursive javascript function and XSLT named-template that both produce the same unique strings based on an XML node's position in the document. For instance 'a3-e2-e' is the name produced for the 3rd attribute of the second element of the root element of the XML document. When producing the HTML for an XML node, I add an 'id' attribute to the HTML with the unique string of the XML node. Then in javascript when I execute an XPath I can discover the unique string of each node in the selected set and map each of them to their corresponding positions in the HTML.

With the hard part out of the way I changed the onload to get the fragment of the URI of the current document, interpret it as an XPath and highlight and navigate to the selected nodes. I also added an interactive floating bar from which you can enter your own XPaths and do the same. On a related note, I found that when accessing XML files via the file URI scheme the fragment is stripped off and not available to the javascript.

The next steps are of course to actually implement XPointer framework parsing as well as the limited number of schemes that the XPointer framework specifies.xml xpointer msxml res xpath xslt resource ie7 technical browser ie xsl