Optimizing long lists of yes/no values with JavaScript

My newest article on Smashing Magazine’s coding section is for the geekiest among you. It’s about how you can pack long lists of boolean values into a string in the most space-efficient way. Hope you enjoy it 🙂

Articles Personal

Help the community: report browser bugs

Thought I’d let you know that my Smashing Magazine article with that title was published today. It discusses why, how, when and where to report browser bugs, as well as how to make a good bug report.

Get comfortable and make a big cup of coffee before you dive in, as it’s quite long (4000 words).


Tag editing UIs

I had to build the edit tags interface for an application I’m working on, so I took a good look at how these are implemented across many popular applications nowadays. It seems there are a few patterns that are used over and over, and I’m unsure which one is the most preferable by users, they all have their advantages and disadvantages. In this post I’m going to describe these patterns and list some of the pros and cons I think they have. For simplicity, I will focus on the tag editing interface itself, ignoring any tag suggestions and other extra features.


The curious case of border-radius:50%

Admittedly, percentages in border-radius are not one of the most common use cases. Some even consider them an edge case, since most people seem to set border-radius in pixels or –rarely– ems. And since it’s not used very frequently, it’s still quite buggy. A bit of a chicken and egg case actually: Is it buggy because it’s used rarely or is it used rarely because it’s buggy? My vote would go to the first, so the purpose of this post is to let people know about why percentages in border-radius are incredibly useful and to highlight the various browser whims when it comes to rendering them.

Articles Original Personal

Organizing a university course on modern Web development

About a year ago, prof. Vasilis Vassalos of Athens University of Economics and Business approached me and asked for my help in a new course they were preparing for their Computer Science department, which would introduce 4th year undergrads to various web development aspects. Since I was always complaining about how outdated higher education is when it comes to web development, I saw it as my chance to help things change for the better, so I agreed without a second thought.

This is one of the main reasons I didn’t have time to write many blog posts for the past months: This activity took up all my spare time. However, it proved to be an interesting and enlightening experience, in more than one ways. In this blog post I’ll describe the dilemmas we faced, the decisions we made and the insights I gained throughout these 6 months, with the hope that they’ll prove to be useful for anyone involved in something similar.

Table of contents

  1. Content
  2. Homework
  3. Labs
  4. Personal aftermath

Articles Original

On CSS counters plus a CSS3 Reversi UI

CSS Counters have a lot more potential than most web developers seem to think. The common use case consists of something like:

somecontainer { counter-reset: foocount; }
Ε { counter-increment: foocount; }
Ε::before { content: counter(foocount) ". "; }

commonly used to add numbering to section headings or re-create an <ol>’s counters in order to style them (since browser support for ::marker is ridiculous).

Have you ever thought of applying the counter to different elements than the ones being counted? This way we’re able to count elements and display their total count somewhere with CSS alone! (and with the variety of selectors in CSS3, I see great potential here…). I’m referring to something like:

ul { counter-reset:foo; }
li { counter-increment:foo; }
p::after { content:counter(foo); }

From my tests, this works flawlessly in Firefox, Safari, Opera and Chrome (I’ve only checked the latest stable though), as long as the element that displays the count comes after the elements being counted (in the markup).

Another underutilized aspect of CSS counters (well, far less underused than the above, but still) is how we can combine multiple in the same pseudoelement. For instance, to count rows and cells of a table and display the count inside each cell:

table {

tr {

td {

td::after {
	content:counter(row, upper-alpha) counter(cell);

Which displays counters like A1, A2, A3, B1, B2, B3, etc in the cells. When the content property is more properly implemented, you wouldn’t even need the last rule.

Last but not least, a CSS3 Reversi UI (no images used!) I created a while ago that demonstrates the above (and various other things, like –finally– a use case for :empty 😛 ). Looks fine only in Firefox and Opera 10.5, due to lack of support for inset box shadows in Safari and buggy support in Chrome. Works fine in all 4 of them (IE is out of the question anyway).

Screenshot of the UI

The displayed counts of each player’s pieces (top right corner) are just CSS counters. Same goes for every cell’s name. This is mostly a proof of concept, since it’s impossible to determine if someone won by CSS alone, so we would have to count the pieces in JS too.

As a game it’s not finalized, you are basically only able to play against yourself and it doesn’t know when somebody won, so it’s not very useful or enjoyable. If someone wants to take it up and develop it further be my guest.

Note to avoid confusion: CSS Counters are not CSS 3. They are perfectly valid CSS 2.1. The “CSS3” in the title (“CSS3 Reversi”) is due to other techniques used in it’s UI.

Articles Original

Exploring browser-supported Unicode characters and a tweet shortening experiment

I recently wanted to post something on twitter that was just slightly over the 140 chars limit and I didn’t want to shorten it by cutting off characters (some lyrics from Pink Floyd’s “Hey You” that expressed a particular thought I had at the moment — it would be barbaric to alter Roger Waters’ lyrics in any way, wouldn’t it? ;-)). I always knew there were some ligatures and digraphs in the Unicode table, so I thought that these might be used to shorten tweets, not only that particular one of course, but any tweet. So I wrote a small script (warning: very rough around the edges) to explore the Unicode characters that browsers supported, find the replacement pairs and build the tweet shortening script (I even thought of a name for it: ligatweet, LOL I was never good at naming).


Exploring CSS3 text-shadow

I consider CSS3’s text-shadow one of the most exciting CSS3* properties, which offers us a lot more effects than it’s name suggests. Of course, it can be used for creating drop shadows for text, and it carries out that task very well, but it’s inherent flexibility allows it to be also used for glow effects, outlines, bevels, extruded text, inset text, fuzzy text and many others (until browser bugs and backwards compatibility come into play… :(). This post is about various findings of mine (and others’, where a source is provided) regarding this property, including browser bugs and inconsistencies, effects that can be achieved with it, compatibility woes etc.

Articles Tips

On password masking and usability

I just read Jakob Nielsen’s recent post in which he urged web designers/developers to stop password masking due to it’s inherent usability issues. I found it an interesting read. Hey, at last, someone dared to talk about the elephant in the room!

In most cases password masking is indeed useless, but still, there are several cases where you need that kind of protection. He also points that out, suggesting a checkbox to enable the user to mask their entered password if they wish to do so. He also suggests that checkbox being enabled by default on sites that require high security.

I think the checkbox idea is really good, as long as it works in the opposite way: Password masking should always be the default and you should check the checkbox to show the characters you typed. This is in line with what Windows (Vista or newer) users are already accustomed to anyway

Articles Tips

Tip: Multi-step form handling

First of all, sorry for my long absence! I haven’t abandoned this blog, I was just really, really busy. I’m still busy, and this probably won’t change soon. However, I will still blog when I get too fed up with work or studying (this is one of these moments…). Now, let’s get to the meat.

The situation

In most web applications, even the simplest ones, the need for form handling will arise. There will be forms that need to be submitted, checked, processed or returned to the user informing them about any errors. A good empirical rule I try to follow is “Try not to produce URLs that don’t have a meaning if accessed directly”. It sounds simple and common-sense, doesn’t it? However, as Francois Voltaire said, “common sense is not so common”. I’ve seen variations of the following scenario several times, in several websites or even commercial web application software: