Basically, because of the Object type. Extension of native objects is
done in javascript through the "prototype" method. This adds
functionality to each native object, allowing you to do things like:
"".trim()
The problem arises with the Object native. This encompasses a large
portion of the structures (all objects, classes, arrays, etc) in
Javascript, and cannot be prototyped easily. The reason being, if you
do something like:
Object.prototype.myMethod = function(){
alert('Foo');
}
You can no longer iterate through the object safely. Now:
var a = {a:1,b:2,c:3};
$.each(a, function(key){ alert(key) }); // a,b,c,myMethod
Also, keeping jQuery in the global namespace helps prevent conflict
with libraries who go directly for native extension, like prototype.js
On Jan 14, 8:19 pm, atwork8 <atwo...@hotmail.co.uk> wrote:
> First post on here so hello everybody :o)
>
> I've been looking at different javascript libraries for a while now to
> see what one suits best. The 2 I'm interested in are jQuery and
> mooTools. I've been messing with both and I really like them, however,
> the way they get the job done is completely different. I have to
> admit, I prefer the mooTools syntax as it is how javascript intended
> e.g.
>
> " lots of spaces before and after ".trim(); //mooTools
> $.trim(" lots of spaces before and after "); //jQuery
>
> But I hate how it pollutes and extends native objects, as it has
> caused us problems in the past with other scripts.
>
> Now jQuery's one global symbol method is excellent and stops all the
> compatibility problems with other scripts, which is why I think we'll
> be going with jQuery. So my question is this, why doesn't jQuery apply
> the same compatibility method to Native types (exc Object) as it does
> to the global namespace? e.g.
>
> var natives = {
> extend: function(sType,sAlias) {
> for(var e in this[sType]) {
> String.prototype[sAlias + e] = this[sType][e];
> }
> },
> 'String': {
> trim: function() {
> return (this || "").replace(/^\s+|\s+$/g,"");
> },
> repeat: function(iCount) {
> for(var i = 0,str = '';i < iCount;i++) { str +=
> this; }
> return str
> },
> format: function() {
> var a = arguments,i = -1;
> return this.replace(/#/g,function() { return a[+
> +i] });
> }
> },
> 'Array': {
> //extend array
> },
> 'Date': {
> //extend date
> }
> //bla bla bla
> }
>
> natives.extend('String','$');
> alert(' lots of spaces before and after '.$trim());
> alert('I love you ' + 'x'.$repeat(5));
> alert('hi #, want to go to the ##'.$format('John','foo','bar'));
>
> In terms of the global namespace it's a tried and tested method so I'm
> sure it could work on Natives too, plus, it would mean jQuery
> javascript is more like javascript. It would be good to get some
> feedback on why this sort of thing isn't employed.
>
> Thanks,
>
> Reiss
