Raimund Meyer's personal blog

JavaScript clone object

nospam@example.com (Raimund Meyer) — Wed, 12 Aug 2009 11:38:14 +0200

Since I did not easily find a good all browser, all kinds of object cloning funtion on the net, here's my one

function cloneObject (obj)
{
  if ( !obj )
  {
    return null;
  }

  // check for function, RegExp, and Date objects, and non-object types
  if ( typeof obj != 'object' || obj instanceof Function || obj instanceof RegExp || obj instanceof Date)
  {
    newObj = obj; // just copy reference to it
  }
  else
  {
    var newObj = (obj instanceof Array) ? [] : {};
    for ( var n in obj )
    {
      var node = obj[n];
      if ( typeof node == 'object' )
      {
        newObj[n] = cloneObject(node);
      }
      else
      {
        newObj[n] = node;
      }
    }
  }

  return newObj;
};

var x = {a: 1, b : "OK", c : /test$/, d: [1,2], e : {a:'OK'}, f: function(arg){alert(arg)}};
var y = cloneObject(x);

alert(typeof y.a +': '+y.a);
alert(typeof y.b +': '+y.b);
alert('RegExp: ' +'true: '+y.c.test("test") + ' false: '+y.c.test("testx"));
alert('Array: ' + y.d.join(' joinedWith '));
alert('Object: ' + y.e.a);

y.f('Function: OK');

function myClass(a, b)
{
  this.prop = 'Custom Class method call: OK';
}

myClass.prototype.func = function()
{
  alert(this.prop)
}

var t = new myClass();
tClone = cloneObject(t);

tClone.func();
alert('instanceof myClass: ' + (tClone instanceof myClass)); //unfortunately this does not work

Javascript class inheritance

nospam@example.com (Raimund Meyer) — Sat, 30 May 2009 14:00:40 +0200

I always believed there was no such thing as class inheritance in Javascript. As I'm just working on a rather large Javascript application I thought I might well use a derived class an discovered that there is really a way to do it.

function a()
{
	
}

a.prototype.propA = 'Hello';

a.prototype.methodA = function()
{
	this.thisPropA = 'World';
}

function b()
{
	a.apply(this, arguments);
  this.methodA();
	this.thisPropB = 'works!'
}

b.prototype = new a();
b.prototype.propB = 'It';
b.prototype.method2 = function()
{
	alert(this.thisPropA + ' ' + this.propA + ' ' + this.propB + ' ' + this.thisPropB)
}


o = new b();
o.method2();

To inherit from one class, you have to assign an instance of it to the protopype of the derived class. It seems not very explicit, but it works as expected. To call the parent constructor you have to use its apply() method to execute it in the this-context of the derived class.

JavaScript Array sort function for umlauts and numbers

nospam@example.com (Raimund Meyer) — Wed, 17 Sep 2008 18:01:16 +0200

Array.prototype.jsCoreSort = Array.prototype.sort;
Array.prototype.sort = function(comparisonFunction)
{
	if(typeof comparisonFunction != 'function')
	{
		comparisonFunction = function(a, b){
			if (typeof parseInt(a,10) == 'number' && typeof parseInt(b,10) == 'number')
			{
				return parseInt(a,10)-parseInt(b,10);
			}
			else 
			{
				if (typeof a != 'string') a = a.toString();
				var r = function (str){
					str = str.toLowerCase();
					str = str.replstrce(/ä/g,"a");
					str = str.replstrce(/ö/g,"o");
					str = str.replstrce(/ü/g,"u");
					str = str.replstrce(/ß/g,"s");
					
					return str;
				}
				a = r(a);
			
				if (typeof b != 'string') b = b.toString();
				b = r(b);
			
				return(a==b)?0:(a>b)?1:-1;
			}
		}
	}
	this.jsCoreSort(comparisonFunction);
}

Thanks to http://www.brain4.de/programmierecke/js/arraySort.php for the comparison function

Compiz Fusion and two monitors

nospam@example.com (Raimund Meyer) — Fri, 25 Jul 2008 10:22:16 +0200

If you have two monitors on a nvidia card and want to enable desktop effects, use TwinView and not Xinerama!

Open images in Photoshop in Linux with wine

nospam@example.com (Raimund Meyer) — Thu, 29 May 2008 21:59:34 +0200

I'm glad that it's possible using Photoshop in Linux, but the lack of desktop integration is so irritating. Placing this script in /usr/bin as photoshop makes it possible to open images with double click or context menu

#!/bin/sh
wine "C:\Programme\Adobe\Photoshop CS\Photoshop.exe"  "`winepath -w $*`"

And don't forget to make it executable:

chmod +x /usr/bin/photoshop

Use Xinha instead of HTMLArea in Serendipity

nospam@example.com (Raimund Meyer) — Thu, 29 May 2008 19:03:12 +0200

Just installed Serendipity and saw, omg, they use HTMLArea. Of course I instantly uploaded Xinha in the very htmlarea folder and voilà, works like a charm. Very content with backward compatibility