Comments on: Advancing JavaScript with Libraries

By: foriniswrong

foriniswrong — Mon, 16 Apr 2007 12:19:49 +0000

@cdr – Extending the ‘Object object’s prototype is bad news because loads of things use it. For-in loops ARE supposed to be used with ‘Object objects’. That is not the case with Arrays. For example, Prototype Framework does NOT extend the ‘object Object’ prototype but is cool extending the Array prototype. If you don’t dig that don’t use frameworks that support doing that. What is your hand up on wanting to use a for-in loop with an Array? That is mis-use! I think your consensus is wrong. Extending basic data types can be a great thing. myString.capitalize() or myString.toJSON(), myArray.toJSON(), myArray.each() and other really cool extensions are great and offer a quick and easy to read programming solution.

By: Kelly Storm

Kelly Storm — Mon, 16 Apr 2007 02:51:40 +0000

It does not cease to amaze me that, while covering a variety of fresh web applications and frameworks, you can still write up a viciously thorough, yet strikingly simplistic, article like this one.

Keep up the *great* work.

By: Giggle Platypus

Giggle Platypus — Mon, 16 Apr 2007 02:47:26 +0000

Sho’ nuff, yo.

By: cdr

cdr — Mon, 16 Apr 2007 02:35:18 +0000

im pretty sure theres a concensus that its not kosher for libraries to modify basic object type prototypes, especially the ones with literal syntax help, for precisely that kind of issue.

not being able to use for..in and extended Array/Object prototypes at the same time sounds like something that could be fixed. i’m interested in your thoughts on how to do that (introducing the unwritten, hidden ‘archetype’ vs ‘prototype’ distinctino into the syntax would make the inheritance system even more crazy than it already is..)

By: foriniswrong

foriniswrong — Mon, 16 Apr 2007 01:58:18 +0000

@cdr – you should know good and well by now that using a for-in loop on an array is bad practice. A for-in loop iterates over all properties and methods in an object and the Array object is no different. Just because some people do it doesn’t make it good practice or correct. For Arrays you should stick with regular for loops iterating over the indexes of the array.

Frameworks are meant to be used from the ground up in a project. The code you make shouldn’t contain the for-in loop array pit-fall. If you are concerned with 3rd party JavaScript code using the for-in loop wrong, most text editors allow you to do a search through files for a ‘for-in’ loop (At least I know Zend IDE allows it).

Some interesting information on array sandboxing can be found here:
http://dean.edwards.name/weblog/2006/11/hooray/

By: cdr

cdr — Mon, 16 Apr 2007 00:54:53 +0000

Rizqi: how do you extend Array literals globally without polluting the ‘for..in’ and similar iteration? are they fixing that in JS2?

By: cdr

cdr — Mon, 16 Apr 2007 00:52:58 +0000

heres the link if you happen to have Flash:

http://video.yahoo.com/video/play?ei=UTF-8&b=0&vid=410472&gid=133414

By: cdr

cdr — Mon, 16 Apr 2007 00:52:28 +0000

if any of the folks from Yahoo! are reading this, any chance you are planning to put a mp4 version of this talk on the YUI Theatre website? flash-impaired on 64bit OSes out here in the dev jungle..

By: carmen

carmen — Mon, 16 Apr 2007 00:45:38 +0000

with apologizes for mispelling crockford,

as for the Ruby code. youd need a browser running on the JVM – afaik netscape was working on it at one point – it would be nice, for sure.

By: carmen

carmen — Mon, 16 Apr 2007 00:44:33 +0000

ok..the first half of the article is pretty straightforward ‘abstraction away from buggy/broken implementations is good, presents common API’, etc.

then it jumps off the deep end (is this summarizing another article?)

ajaxian is JQuery2? the syntax is not JS-style, eh..

and whats this about LISP in firefox?? you mean crockfordgs scheme.js?

By: Kevinin

Kevinin — Sat, 14 Apr 2007 22:56:55 +0000

In “Waiting for the document to load”, I’m sure that “document.getElementById”test”.docus();” should be “document.getElementById(“test”).focus();”

By: Andy

Andy — Sat, 14 Apr 2007 10:58:21 +0000

@remiss, Actually both of you are wrong.
Technically, the syntax should be:
“document.body.setAttribute(“class”,”home”);”. HOWEVER, this doesn’t work properly in IE. The content gets added to the body, however it doesn’t render. Therefore you should use “document.body.className = ‘home’;”.

By: remiss

remiss — Sat, 14 Apr 2007 07:51:42 +0000

Hmm..
“document.body.setAttribute(“className”, “home”);”

Sure you don’t mean document.body.class = “home”; ?
The last one would break, the first one just doesn’t make sense..

Another thing, what about browsers like konqueror that doesn’t support xpath?

By: Rizqi Ahmad

Rizqi Ahmad — Fri, 13 Apr 2007 23:40:26 +0000

You’re rock john! But I think jquery lacks of array extensions