ECMAScript 4

John Resig has posted a whitepaper outlining the new features in ECMAScript4 (aka the Javascript standard), how it differs from ECMAScript3, and the rationale for any incompatibilities.

Many of the features have already made their way into Opera and Firefox, which is at Javascript 1.7 level. ES3 is equivalent to JS1.3, and ES4 is the basis for forthcoming JS2.

I look forward to optional strict typing, multiline strings, comprehensions, and generators making their way into browsers. A lot of the new features make Javascript more like Python without losing all the nice things tabout Javascript.

Creating Start Menu shortcuts with Javascript

While preparing the installer for the Web 2.0 Starter Toolkit for IBM DB2, I had to set up Start Menu shortcuts. The way to do that is to work through the Windows Scripting Host (WSH).

The WSH supports two built-in languages – VBScript and Jscript – and a theoretical number of third-party alternatives. VBScript is the better documented of the two in terms of examples, but I find its syntax ugly and constrained. Fortunately, Jscript can do anything VBScript can.

So here’s how we can create Start Menu shortcuts with Javascript.

Locate the Start Menu Programs folder

Most interesting Windows folders can be found by working with special folders

var shell = new ActiveXObject("WScript.Shell");
var startmenu = shell.SpecialFolders("Programs");

The shell object will be reused in code below, but you can redeclare it every time if you like.

Create a Folder

Scripting Guy has more details

var folder = "My App";
var group = startmenu + "\\" + name;

var fso = new ActiveXObject("Scripting.FileSystemObject");
if (!fso.FolderExists(folder)) fso.CreateFolder(folder);

startmenu is defined above.

Create an LNK Shortcut

The very hidden file extension of standard Windows shortcuts is LNK. This distinguishes them from website shortcuts, which have the equally hidden extension of URL.

If you are interested in something closer to the symbolic links of Unix, the NTFS equivalent is called junctions. You may find Junction Link Magic of interest.

var name = "My Shortcut";
var file = "myfile.txt";
var path = "C:\\Program Files";

var shortcut = shell.CreateShortcut(group + "\\" + name + ".lnk");
shortcut.TargetPath = path + "\\" + file;
shortcut.WorkingDirectory = path;

See the full list of properties. I recommend always setting the working directory for application links. If you don’t, your program won’t be able to load resources from it’s installation folder.

shell and group are defined above.

Create a URL Shortcut

This is very similar. The main difference is that you set the extension to URL.

var name2 = "My Other Shortcut";
var address = "";

var shortcut = shell.CreateShortcut(group + "\\" + name2 +".url");
shortcut.TargetPath = address;

See the full list of properties.

shell and group are defined above.

Locate Program Files

When creating shortcuts, it is often useful to know where a user’s Program Files directory is located. It is called different things in different versions of Windows, and some advanced users like to move it or rename it.

var REG_PF = "HKLM\\SOFTWARE\\Microsoft\\Windows\\CurrentVersion\\ProgramFilesDir";

var progFiles = null;
var process = shell.Environment("PROCESS");
if (process)
	progFiles = process("ProgramFiles");
if (!progFiles)
	progFiles = shell.RegRead(REG_PF);

shell is defined in the first code excerpt.

Rails and DB2 data types

When creating a table in a Rails migration, you have to specify data types using platform-agnostic names. The mapping of Rails types onto DB2 types is defined in ibm_db_adapter.rb:

:primary_key => @servertype.primary_key,
:string      => { :name => "varchar", :limit => 255 },
:text        => { :name => "clob" },
:integer     => { :name => "integer" },
:float       => { :name => "float" },
:datetime    => { :name => "timestamp" },
:timestamp   => { :name => "timestamp" },
:time        => { :name => "time" },
:date        => { :name => "date" },
:binary      => { :name => "blob" },

# A boolean can be represented  by a smallint,
# adopting the convention that False is 0 and True is 1
:boolean     => { :name => "smallint"},
:xml         => { :name => "xml"},
:decimal     => { :name => "decimal" }

Useful Resources

InfoCenter | DB2 Data Types
dW | DB2 and Ruby on Rails, Part 1 (May 2007)
dW | An Introduction to Ruby on Rails for DB2 Developers (June 2006)

The DB2 adapter is now called ibm_db. You can refresh your installation by typing gem install ibm_db at the command line and choosing the latest win32 release.

Choosing colours

One of the tricky things in web design is picking the right colours. They need to be easy to read, not grim, not flashy, yet somehow distinctive. Often, taking a stab in the dark and then tweaking a screenshot of the result for saturation, contrast, and the like can be very effective. At other times, you need a starting point.

These have all helped me:

Installing Pear and PECL on Zend Core for IBM


Atomized | PHP Performance Best Practices – Informative.

Installing PEAR and PECL on Zend Core for IBM

  1. Save to go-pear.php (in, say, C:\Program Files\Zend\Core for IBM\pear)
  2. Open Command Prompt
  3. % cd “C:\Program Files\Zend\Core for IBM\pear”
  4. % ../bin/php go-pear.php
  5. Follow the steps and let it modify your php.ini
  6. Restart your Apache

Installing the profiling packages mentioned in Best Practices

  1. % pear install Benchmark
  2. % pecl install apd