I see more and more posts like this or this recently and I always see that when people are telling about how poor the Prototype framework is they really don't know even half of it's possibilities.
As it always happens, the code comparison in those posts is written by person who is not experienced in one framework or another.
I agree, that jQuery has some nice features: 1) actions on groups of objects (that you have mentioned), 2) more powerful selectors: prototype has support for css3 selectors only, but jQuery can handle more sophisticated queries like selecting hidden elements or inputs of particular type.
I haven't dug into what it takes to write custom effect or plugin (plan to do it soon), but I don't see how you can base your effects on existing ones in a way other than aggregating/compositing (the thing with Prototype effects is that you can inherit your effect from some base effect and have some nice features like configurable 'easing' function, which can control effect speed over time, or some other stuff for free).
But seeing syntax comparisons like that just makes me mad.
First, adding a class name to element in Prototype is just as easy as in jQuery:
$('element').addClassName('className')
$('element').removeClassName('classsName')
Second, the Ajax syntax. Prototype's variant is designed to do POST requests by default. You don't need to specify 'method' parameter if you do POST request. As for GET requests, in Prototype you can do just as in jQuery:
new Ajax.Updater('element', url + '&' + parameters)
(I believe, the '&' thing is needed in jQuery also, but author of code comparison just 'forgot' to mention that)
Moreover, if you don't like the wordy syntax of Ajax.Updater, you can extend Element to support whatever syntax you like:
Element.addMethods({
load: function(element, url) {
new Ajax.Updater(element, url)
}
})
and then you can do
$('element').load(url + params)
just as in jQuery.
And, yes, Prototype doesn't handle working with sets of elements by default. To add a particular class to a set of elements in Prototype you need to do some extra stuff, but not as it is mentioned in code comparison:
$$('.element').invoke('addClassName', 'className')
And yes, I agree, that Prototype and Scriptaculous have bad documentation and I personally have bought a book on them (see Pragmatic Programmers bookshelf) and my problems with Prototype and Scripaculous have gone since then.
I don't see any big reason to switch to jQuery.
PS There are lots of other javascript frameworks like mooTools (if I spell it correctly), Dojo, Rhino and such and I always haven't paid much attention to those, because usually my web application require custom solutions, not those that are present in such frameworks. But recently I came across some book ("Mastering Dojo" published by Pragmatic Programmers) and a podcast on it and it got my attention. They say that lot's of fortune 500 companies are using their framework because it is very solid and stable. And I'm curious about what particular features of Dojo make them think so. I have visited Dojo's site and tried to see at some of the examples (e.g. fish eye component) and they were running way too slow on my latest Firefox 2.x (which I consider as rather modern web browser). Probably, I need to give it one more chance and, probably, read that book.
