tech.ablegray.com

Wishlist: window.alert() Shouldn't Take Over The Application

2007-10-30T20:38:27Z

I’m tired of having my browser hijacked by window.alert(). Before the advent of tabbed browsing, I’m sure that taking over the application wasn’t that bad, but now that I have multiple web pages and applications open in different tabs it’s a different situation. I don’t see why my browser won’t let me do anything (I can’t even close it!) when some website wants to tell me something.

Is this feature listed for FF3? If not, it should be. Or maybe an extension could take care of this? Any takers?

Rails Gotcha: Calling Attribute Methods From the Model Instance

2007-10-30T20:33:23Z

Here’s a little one that got me in the past. When you’re writing a method of a model, you have to be careful about how you set attributes.

Let’s say for example that you have a model Country, with attributes population, area, and government. When you want to use this property in a method, you can say:

Country
  def population_density
    area / population
  end
end

And this will work just fine. So, it seems like you can use the area and population in your code when you need to deal with these attributes.

Watch Out!

Look out that you don’t do this in the method:

Country
  def plague
    government = 'anarchy'
    population = 0
    save
  end
end

The problem is that population = 0 will only set a local variable to 0, and not your population attribute. Instead, you have to use self.population = 0. So, your #plague method would look like this:

def plague
  self.government = 'anarchy'
  self.population = 0
  save
end

Disclaimer:

Yes, I know, #plague would really look like this:

def plague
  update_attributes :government => 'anargy', :population => 0

end

I used the example above to demonstrate the concept.

A Killer Combo: SASS and Styler

2007-09-12T16:11:28Z

They work together out of the box.

SASS
Styler

Why we use i, j, and k in for loops

2007-08-18T04:04:00Z

Let this quote explain:

In Fortran, all variables starting with the letters I, J, K, L, M and N are integers... (This is the source of the long tradition of using "i", "j", "k" etc as the loop indexes of "for loops" in many programming languages -- few of which have implicit typing).

Wikipedia - Sigil (computer programming)

I guess you learn something new everyday.

Running Individual Tests in Textmate

2007-05-08T13:33:00Z

I just found out that you can run a single test in TextMate with Apple+Shift+R when you’re editing a test in Ruby on Rails mode. No more scrolling in my test window!

Can you guess what this button does?

2006-08-31T17:26:00Z

We use Lotus Notes at work. We’re the government, so you can’t expect us to always be on the cutting edge, or even within 5 years of it. That’s just how it is.

Anyways, if you are familiar with Lotus Notes, you know that it can do everything, poorly. I have many complaints about Notes, but today I just wanted to share one example that could give you a feel for the general quality (or lack there of) of the application. Let’s look at the main toolbar (I shortened it by cutting some uninteresting parts.) that I see while when I’m reading my email:

Can you guess what these buttons do? Go through each one and guess what each button does. Below are the answers.

Stumped? Obviously this button brings up a little window that shows the properties of the page you’re currently viewing. What else would “two squares, one superimposed on the other and rotated 45 degrees” mean?!

Save. Ok, that was too easy. But don’t get cocky. This next one will get you for sure.

Well, let’s see, an open folder, with an arrow gesturing to open it. Could this be Open? WRONG! It’s New. It brings up a menu where you can choose to make a new email, new calendar entry, new contact, or a new todo item.

Yeah, these are all boring. Edit, Forward Email, Print, Back, Forward, Stop, Refresh.

Ok, now this one was kind of a trick question. You would think it means either Search (which is the right answer) or Magnify. However, clicking on it brings up a friendly little dialog box that says “Cannot execute the specified command”. A button that does nothing? That’s pretty dumb. At the very least it should be greyed-out like the Save button.

Yeah, Lotus Notes is pretty terrible. However, in its defense, I may be holding it to a higher standard than it deserves. After all, they’ve only had 15 or so years to perfect it.

Well, I hope you learned something today. Maybe you learned that you should avoid Lotus Notes. Or perhaps you need to take a look at your own application and make sure you aren’t making the same mistakes. Or maybe you’ve now have a better appreciation for the software you use that doesn’t suck.

Where is Dreamweaver + Subversion?

2006-08-11T20:21:00Z

If you’ve ever looked for a way to use Subversion from within Dreamweaver, you know that there are only 2 or 3 products that do this, and they are all closed source, and they are all pretty much inadequate for actual work. How come there are no good products? Well, I have a few guesses.

Firefox for Web Developers

2006-08-10T21:12:00Z

Firefox: a web developer's best friend. Armed with the right extensions, Firefox really is the most powerful tool a web develop has these days. In this article, I want to highlight the web development extensions that I find particularly useful.

getChildrenByTagName

2006-08-03T18:51:00Z

Until the day we can use javascript select elements with XPath (natively) this script will be useful.

Select all children (not descendants) that have a specified tag name.

E.g. getChildrenByTagName( $('navigation'), 'li' ) will only select li elements that are children of your <ul id="navigation"> element. Note that the $(..) function is provided by the Prototype library.

function getChildrenByTagName(root_element, tag) {
  var kids = root_element.childNodes

  var kids_w_tag = new Array()
  
  for (var i=0; i<kids.length; i++)
    if (kids.item(i).tagName == tag.toUpperCase())
      kids_w_tag.push(kids.item(i))
      
  return kids_w_tag
}

This is useful because some browsers (including FF) correctly include white-space between elements in the DOM as TextNodes.

For example:

<ul>
 <li>Harry</li>
 <li>Susan</li>
</ul>

The child nodes of the ul above are [ TextNode, LIElement:Harry, TextNode, LIElement:Susan, TextNode ]

<ul><li>Harry</li><li>Susan</li></ul>

But in this example, the childnodes of the ul are [ LIElement:Harry, LIElement:Susan ]

getElementsByTagAndClass

2006-08-03T18:20:00Z

This is a nice little utility function that I want to save.

getElementsByTagAndClass(document, 'div', 'product') will return an Array of div elements with class name exactly equal to "product".

function getElementsByTagAndClass(root_element, tag, className) {
  var tags_with_class = new Array()
  
  var tags = root_element.getElementsByTagName(tag)
  
  for (var i=0; i<tags.length; i++)
    if (tags[i].className == className)
      tags_with_class.push(tags[i])
      
  return tags_with_class
}

Enjoy.

Caveat: this may not work in IE. I'm not sure if IE supports someElement.getElementsByTagName(..) when someElement is not document.