How to extend javascript classes
The intrinsec objects of javascript (String, Number, Date, etc) are missing a lot of handy methods. God knows why. Example, you don’t have a trim() function on a String object. Maybe the developers thought that it was easy enough to write theString.replace(/^\s*|\s*$/g, “”) to trim a string but that’s not the kind of ugly code I want to see everywhere in my projects. It’s unesthetical. To do this, I have to use prototype.
So I want to add a trim() method to all my objects that are String class.
[source:javascript]
String.prototype.trim = function()
{
return this.replace(/^\s*|\s*$/g, “”);
}
[/source]
Easy.
Special note : I don’t want you to copy/paste that code. It’s for the purpose of the demonstration only.
I can do the same thing for every objects wheter they are intrinsic javascript classes, third-party classes or my own classes.
RSS without the echo chamber
Hi,
Thanks for all your info.
I tried to make something similar, but not with strings, with objects. I wanted a function to set the alpha for a DIV.
It sounds like this:
Object.prototype.setAlpha = function (alpha) {
this.style.filter = ‘alpha(opacity: ‘ + alpha + ‘)’;
this.style.MozOpacity = alpha / 100;
this.style.KhtmlOpacity = alpha / 100;
this.style.opacity = alpha / 100;
}
and I call it with: bgDiv.setAlpha(80);
Works in FF but doesn’t in IE (6).
Anyway, the content of the function is irrelevant, as the call of the function itself is the problem and gives the error in IE.
Any ideas?