Tabbing Through Fields Vertically

Sometimes it’s useful to switch the browser’s default tabbing behavior (left to right) to the opposite (top to bottom) when your input fields are in a grid layout instead the of the usual single column layout. Having to do this manually is a real pain, especially for large grids; So here is a solution in javascript, using mootools:

window.addEvent('domready', function(){
    var trs = $$('#mytable tr')
    var accum = 0
    trs.each(function(tr, trindex){
        accum = trindex + 1
        tr.getChildren().each(function(td, tdindex){
            td.getChildren('input')[0].tabIndex = accum
            accum = accum + trs.length

Why MooTools (or Why Not JQuery)

UPDATE 2012: this post is dumb and angsty, dont read

I’ve been toying around with MooTools a bit lately, and I’ve found the experience quite enjoyable and refreshing. Naturally, I twittered about it and went along my merry way. Moments later (and much to my surprise), I had a direct message from John Resig himself asking “Why, what’s wrong with jQuery?”. I was pretty taken aback that he would take time from his surely busy day to message a total stranger in an effort to improve his project or at least gain an insight in the everyday life of a js developer (it’s not like DHH would personally message people that are dumping rails to use merb). I figured he deserved a straight, honest answer; One that at least would be longer than 140 characters (even though I managed to use every single one). So it begs the question, Why MooTools?

  • Class support. JQuery’s SQL-like syntax is fine for quick and dirty javascripting, but eventually you’ll want real classes to structure your UI logic.

  • It smells, feels and tastes like regular javascript. JQuery doesn’t even look like javascript, which isn’t necessarily a bad thing, since that’s kind of their goal. MooTools however, feels like just an extension of the language

  • Faster. ‘Nuff Said EDIT: This was pointed out to be false; It is only faster in certain cases (such as mine, WebKit nightly on OS X).

  • Robert Penner’s easing equations baked right in.This could just be me, but I find the animations that mootools creates are alot smoother than JQuery’s (especially the easing).

  • Creating new DOM elements is a snap.Need to create a dom element? var el = new Element(‘a’, { ‘href’: ‘’}); Done.

  • Modular. I like that I can just build and pull down a moo.js that only contains the functionality I need.

  • Better Documented.Or at least, its faster to find what you need.

  • Easier to hack on and extend. While I haven’t personally delved into the internals of either system, the consensus seems to be that jquery is an unintelligible mess when it comes to modifying how it works.

  • Prototype Approach (versus a namespaced approach) This is really just matter of preference; MooTools achieves it’s magic by just extending the prototypes of common objects (Array, String, etc); While this is obstrusive, it makes for shorter, more natural code. JQuery does its thing via a main object (which you can name, hence the namespace), that you wrap around whatever you want to make magical; This is unobstrusive, but you pay for that by having to wrap anything you want to use (which ends up being everything). It basically boils down to arr.each(fn) vs $.each(arr, fn)

  • It’s not a revolution. It feels as if JQuery is trying to take on the world (it seems like it too, since its now included with visual studio and the nokia sdk). However, I’m not; I’m just trying to write some javascript here.

It’s not like I’m never going to use JQuery again; It simply isn’t my default js framework any longer.

Highlight Link Based on Current Page in Rails

This is common pattern in website navigation, where it highlights the link (usually by setting class=”active”) that took you to the current page while you are on that page.

First, define a helper:

def is_active?(page_name)
  "active" if params[:action] == page_name

Then call it in your link_to’s in your layout as such:

link_to 'Home', '/', :class => is_active?("index")
link_to 'About', '/about', :class => is_active?("about")
link_to 'contact', '/contact', :class => is_active?("contact")

This effect is achieved due to how link_to handles being passed nil for its :class, so when is_active? returns nil (because its not the current page), link_to outputs nothing as its class (not class=”” as you might expect).