lessons learned this morning:
a) Even if it’s simple code you “know” will work you must test it. No excuses.
b) In programming, nothing happens by “magic”. There is a tangible reason that that thing that should be working isn’t.
c) Don’t assume something couldn’t be true simply because it doesn’t make any sense.

my-mistakes-let-me-show-you-them · oh-crap

I’ve been focusing more and more on my port of Ling-to-Objects, Jsoq the past few weeks. It’s still in really early stages and I’m not quite sure about it’s actual usefulness but I’m learning a lot about JavaScript and having a ton of fun along the way!

Jsoq deals with arrays a lot. About 95% of it’s use cases involve either looping through, altering, or creating arrays. Having a ton of for loops in my code just seems so… not right. For loops have always seemed dirty to me. They just aren’t elegant enough.

Here is your normal, average, everyday for loop in Javascript.

var array = "1,2,3,4,5,6,7,8,9,10".split(',');

for(var i = -1, l = array.length; ++i < l;) {
    alert(array[i]);
}

This works. It’s reliable and gets the message across. But what if we needed to loop over an array and get all the items that matched a condition? Using a for loop the code could look something like:

var array = [ 1, 2, 3, 4, 5, 1, 2, 3, 4 ];
var results = [];
var condition = function(i) { return i%2 == 0; };

for(var itt = -1, len = array.length; ++itt < len;) {
	if( condition(array[itt]) ) {
		results.push(array[itt]);
	}
}

This does work, I’ve written code like this many times before, and while technically there isn’t anything wrong with it I think there is still room for improvement.

Jsoq is going to be handling arrays all over the place so the solution to this problem needs to be simple.

Here’s what I need:

• to loop over an entire collection and perform an action on each item.
• If that action produces a result, the item is to be pushed into an array and returned to after the loop is done

.

• Also: it needs to be readable, someone else coming along should be able to determine what this thing is doing without too much difficulty. So I had my work cut out for me.

A few hours later I had a decent function that I could use to replace a lot of the for loops I had. After some more refactoring I was able to wipe them all out and replace them with calls to enumerateOver(). Here is the latest version from source control:

function enumerateOver(collection, work) {
	var result = [], val = [];

	if (isArray(collection)) {
		try {
			for (var i = -1, l = collection.length; ++i < l;) {
				result = work(collection[i], i);
				if (typeof result !== "undefined" && result != null) {
					val.push(result);
				}
			}
		}catch (e) {
			if (e != jsoq.$break) throw(e);
		}

		if (val.length > 0) {
			return val;
		}
	}else {
		try {
			val = work(collection, 0);
		}
		catch (e) {
			if (e != jsoq.$break) throw(e);
		}
		if (typeof val !== 'undefined') {
			return val;
		}
	}
	return result == null ? [] : result;
}

And here is the code to replace the for loops above, re-written to use enumerateOver()

var results2 = enumerateOver(array, function(i, c) {
     return i%2 == 0;
});

So by implmenting this function I was able to come up with a more readable, testable and streamlined codebase. Is this suitable for everyone? Definitely not, but I did it for a few reasons:

1. Like I mentioned before. I’ve never been at ease with for loops and being able to replace them all with calls to a single function was a huge win for me
2. The normal use-case didn’t fit right. I needed to not only iterate over arrays but also return the results of work performed on those items. Doing this the “regular” way just wouldn’t work (see previous reason)
3. I thought this was a fun problem to solve

If you have any feedback, good, bad, or indifferent add a comment!

code · Javascript · jsoq · Open Source

The other day I had to alter the stylesheets in a child IFrame when a user selected an item from a drop-down. My first draft was pretty ugly, it ivolved getting the DOM from the child IFrame (by getting it’s contentWindow or contentDocument property) then getting the of the DOM and looping over all the child items… yuck!

I coded up this jQuery extension method which will return a jQuery-wrapped DOM instance for any of the matched IFrames.

(function($) {
    $.fn.extend({
        dom: function () {
            var $this = $(this);
            var getDom = function(o) {
                if( !o || (!o.contentWindow && !o.contentDocument) ) {
                    return null;
                }

                var doc = (o.contentWindow || o.contentDocument);

                return doc.document || doc;
            };

            var dom = getDom($this[0]);

            return dom === null ? $this : $(dom);
        }
    });
})(jQuery);

So with this, getting the styles for a child IFrame is as easy as:

$('iframe').dom().find('head link').each(function(index, item) {
    alert(item.href);
});

Unfortunately, this code will only work if your IFrame is hosting content that is on the same domain as its parent.

Javascript · jquery · jquery-extensions

Has this ever happened to you: you’ve been working on a customer’s site, writing some really awesome jQuery flashy, fadey, scrolly, interactivey thing, you deploy it, and everything is awesome. The customer rejoices and the customer’s customers rejoice. Rejoicing is had by everyone.

And then you get an email one day:

“Everything is broken. We’ve kidnapped your dog. Fix our site or you’ll never see Spartacus again.”

And before you have time to wonder why you ever named your dog “Spartacus” to begin with (i mean come. on.), you’re off in debug hell. You load the site and see all sorts of weird errors:

“$().ready is not a function”

“$(document) doesn’t support this property or method”

Or my personal favorite:

“null is null or not an object”

You open up FireFox, activate FireBug, load the console, and type “alert($)”, press run, and instead of seeing the expected jQuery function:

function (E, F) {
    return new (o.fn.init)(E, F);
}

You instead get:

function $(element) {
    if (arguments.length > 1) {
        for (var i = 0, elements = [], length = arguments.length; i < length; i++) {
            elements.push($(arguments[i]));
        }
        return elements;
    }
    if (Object.isString(element)) {
        element = document.getElementById(element);
    }
    return Element.extend(element);
}

Or even:

function $(id) {
    return document.getElementById(id);
}

DOH! Looks like another javascript library has been loaded and has overwritten the $() shortcut for jQuery. Woe is I. Why can’t we all just get along?!?

Well, we can’t stop people from including their favorite javascript libraries, but what we can do is prevent our code from suffering as a result. We’ll need a nice, big beefy, bodyguard to make sure our code isn’t messed with while it’s out clubbing with Prototype, Scriptaculous or even MooTools (who invited him??!?).

Here’s what our bodyguard function will look like

( function($) {

} ) ( jQuery );

So what this does is call our anonymous function and pass the jQuery object. This will scope ‘$’ to within our little function so we won’t step on anyone else’s toes (and they won’t bump into us while we’re on the dance floor and spill our drink everywhere). Okay, I think I've taken the clubbing metaphor far enough.

Basically this will allow our code to run and use the $ shortcut for JQuery as if it were loaded without any of these other libraries on the page.

Here is what the completed code would look like:

<script src="http://ajax.googleapis.com/ajax/libs/jquery/1.4.1/jquery.min.js" type="text/javascript">
</script>

<script src="http://ajax.googleapis.com/ajax/libs/prototype/1.6.1.0/prototype.js" type="text/javascript">
</script>
<script src="http://ajax.googleapis.com/ajax/libs/scriptaculous/1.8.3/scriptaculous.js" type="text/javascript">
</script>

<script type="text/javascript">
( function($) {
    // we can now rely on $ within the safety of our “bodyguard” function
    $(document).ready( function() { alert("nyah nyah! I’m able to use '$'!!!!");  } );
} ) ( jQuery );

//this will fail
$(document).ready( function() { alert('fail?'); } );
</script>

I love using this simple self-calling anonymous function style when working with jQuery because it saves me from typing jQuery(), which really does look a lot more ugly than using the $() shortcut. It also protects my code from any scoping issues and lets the code function normally when jQuery is put into no conflict mode.

My opinion, if you're doing work in jQuery on sites that you don't control 100%, you should be using this method to protect your code and your clients.

Updated: changed link for jquery to use 1.4.1 at the google CDN (tsk, tsk, tsk I was using the googlecode.com link)

code-style · Javascript · jquery

I’ve spent the last few days going over what I want to accomplish this year, what I think I definitely could do, what might challenge me and what is just this side of impossible. Whenever I’ve made my resolutions known in the past its always been in a passing conversation with a friend of family member. I never wrote them down or tried to keep track of them once the conversation was over so this year I decided to post them publicly to give me that extra bit of motivation, and also I’ll be able to check back here throughout the year and see how I’m measuring up.

These are in no particular order.

I need to grow more as a professional. Last year I went to my first conference (MSDEVCON) and it was a total blast. I met a lot of truly awesome and intelligent people and learned a billion things that I didn’t know before. After that I attended Stack Overflows Dev Days in Boston and it was the same experience all over again. This year My goal is to start attending more conferences/events (as many as I can afford with time and $$$) to grow myself as a professional.

Make more mistakes. I made my fair share of mistakes in 2009 and (more importantly) I learned a lot from them: about myself, my skills, and what I am capable of. I’m addicted. I’m going to put myself more out in the open and make some more mistakes so I can learn a lot more in 2010.

I need to lose at least 25lbs this year. I’ve let myself go over the past few years and it’s time to take my health more seriously. 25lbs probably doesn’t sound like a lot and honestly it’s a lot less than I need to lose but I’ve never been good at staying fit so hopefully I achieve this goal relatively early and am able to keep the weight off the rest of the year.

No more sugary drinks, especially soda. I’m looking at you Mt. Dew. I’m not sure what happened but between the end of the year work rush and the holiday (fr)antics I’ve been downing soda like it’s going out of style. Time for that to end.

Eliminate debt. This goal is a bit lofty but my goal is to eliminate 80% of all my debts this year. This is going to be a tough one to pull off, what with the recent job change and our new house but it’s needed.

Finish something. I started way too many side projects last year, and I finished… none. Not one project I started in 2009 saw what I would call a 1.0 release. Time to crap or get off the pot. I aim to crap. My goal will be to promote at least 2 of the projects I started in 2009 to a 1.0 release this year.

More play. Tamara and I didn’t get a vacation last year and we are dying for some time away. This is going to be tough with all my debt elimination going on but the more debt I get rid of the more I can save.

More sleep. Tamara reminds me all the time how little sleep I get ( about 4-5 hours a night at most ) and it really started to show during the holidays. I simply ran myself into the ground. Time to recharge and see what I can really do.

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