Today I tried to help a friend who is a great computer scientist, but not a JS person use a JS module he found on Github. Since for the past 6 years my day job is doing usability research & teaching at MIT, I couldn’t help but cringe at the slog that this was. Lo and behold, a pile of unnecessary er...

I was always interested in color science. In 2014, I gave a talk about CSS Color 4 at various conferences around the world called “The Chroma Zone”. Even before that, in 2009, I wrote a color picker that used a hidden Java applet to support ICC color profiles to do CMYK properly, a first on the Web ...

tl;dr: If you just want to quickly get stats for a repo, you can find the app here. The rest of this post explains how it’s built with Mavo HTML, CSS, and 0 lines of JS. Or, if you’d prefer, you can just View Source — it’s all there! The finished app we’re going to make, find it at https://projects....

I like hand-editing my SVGs. Often I will create an initial version in Illustrator, and then export and continue with hand editing. Not only is it a bit of a meditative experience and it satisfies my obsessive-compulsive tendencies to clean up the code, it has actual practical benefits when you need...

Today for a bit of code I was writing, I needed to be able to distinguish “x is not defined” ReferenceErrors from any other error within a try...catch block and handle them differently. Now I know what you’re thinking. Trying to figure out exactly what kind of error you have programmatically is a we...

Almost 11 years ago, Paul Irish posted this brilliant bookmarklet to refresh all stylesheets on the current page. Despite the amount of tools, plugins, servers to live reload that have been released over the years, I’ve always kept coming back to it. It’s incredibly elegant in its simplicity. It wor...

If you use regular expressions a lot, you probably also create them from existing strings that you first need to escape in case they contain special characters that need to be matched literally, like $ or +. Usually, a helper function is defined (hopefully this will soon change as RegExp.escape() is...

I just dealt with one of the weirdest bugs and thought you may find it amusing too. In one of my slides for my upcoming talk “Even More CSS Secrets”, I had a Mavo app on a <form>, and the app included a collection to quickly create a UI to manage pairs of values for something I wanted to calculate i...

Many people have explored responsive tables. The usual idea is turning the table into key-value pairs so that cells become rows and there are only 2 columns total, which fit in any screen. However, this means table headers need to now be repeated for every row. The current ways to do that are: Dupli...

If you’ve used Storify, you probably know by now it’s closing down soon. They have an FAQ up to help people with the transition which explains that to export your content you need to… Log in to Storify at www.storify.com. Mouse over the story that contains content you would like to export and select...

This semester I’m teaching 6.813 User Interface Design and Implementation at MIT, as an instructor. Many of the assignments of this course include Web development and the course included two 2-hour labs to introduce students to these technologies. Since I’m involved this year, I decided to make new ...

I often run into this issue where I want a different URL remotely and a different one locally so I can test my local changes to a library. Sure, relative URLs work a lot of the time, but are often not an option. Developing Mavo is yet another example of this: since Mavo is in a separate repo from ma...

Today I finally released the project I’ve been working on for the last two years at MIT CSAIL: An HTML-based language for creating (many kinds of) web applications without programming or a server backend. It’s named Mavo after my late mother (Maria Verou), and is Open Source of course (yes, getting ...

I’m a strong believer in lowering the barrier of what it takes to create rich, interactive experiences and improving the user experience of programming. I wrote an article over at Smashing Magazine aimed at JavaScript library developers that want their libraries to be usable via HTML (i.e. without w...

Today I needed a quick tool to compare the loading progression (not just loading time, but also incremental rendering) of two websites, one remote and one in my localhost. Just have them side by side and see how they load relative to each other. Maybe even record the result on video and study it aft...

Those of us who use promises heavily, have often wished there was a Promise.prototype.resolve() method, that would force an existing Promise to resolve. However, for architectural reasons (throw safety), there is no such thing and probably never will be. Therefore, a Promise can only resolve or reje...

I adore Github Pages. I use them for everything I can, and try to avoid server-side code like the plague, exactly so that I can use them. The convenience of pushing to a repo and having the changes immediately reflected on the website with no commit hooks or any additional setup, is awesome. The fre...

Recently, when I was making the minisite for markapp.io, I realized a neat trick one can do with CSS variables, precisely due to their dynamic nature. Let’s say you want to use a property that has multiple versions: an unprefixed one and one or more prefixed ones. In this example we are going to use...

I have often lamented how many JavaScript developers don’t realize that a large percentage of HTML & CSS authors are not comfortable writing JS, and struggle to use their libraries. To encourage libraries with HTML APIs, i.e. libraries that can be used without writing a line of JS, I made a website ...

As part of my preparation for my talk at CSSDay HTML Special, I was perusing the most recent HTML specs (WHATWG Living Standard, W3C HTML 5.1) to see what undiscovered gems lay there. It turns out that HTML sliders have a lot of cool features specced that aren’t very well implemented: Ticks that sna...

Women speaking up about the sexism they have experienced in tech is great for raising awareness about the issues. However, when no positive stories get out, the overall picture painted is bleak, which could scare even more women away. Lucky for me, I fell in love with programming a decade before I e...

Anyone who follows this blog, my twitter, or my work probably is aware that I’m not a huge fan of big libraries. I think wrapper objects are messy, and big libraries are overkill for smaller projects. On large projects, one uses frameworks like React or Angular anyway, not libraries. Anyone who writ...

If, like me, you try to avoid using heavy libraries when not needed, you must have definitely written a helper to copy properties from one object to another at some point. It’s needed so often that it’s just silly to write the same loops over and over again. These days, most of my time is spent work...

Over the last couple of years, blind reviews have been popularized as the ultimate method for fair talk selection in industry conferences. While I don’t really submit proposals myself, I have served several times on the other side of the process, doing speaker selection in conference committees, and...

As you might be aware, these days a good chunk of my time is spent working on research, at MIT. Although it’s still too early to talk about my research project, I can say that it’s related to the Web and it will be open source, both of which are pretty awesome (getting paid to work on cool open sour...

After getting fed up with too many “promotional” emails and newsletters with incredibly obscure unsubscribe links, I decided to make this tumblr to point out such examples of digital douchebaggery. This annoying dark pattern is so widespread that Google even added a feature to Gmail for making those...

It’s no secret that I like conical gradients. In as early as 2011, I wrote a draft for conical-gradient() in CSS, that Tab later said helped him when he added them in CSS Image Values Level 4 in 2012. However, almost three years later, no progress has been made in implementing them. Sure, the spec i...

As I pointed out in yesterday’s blog post, one of the reasons why I don’t like using jQuery is its wrapper objects. For jQuery, this was a wise decision: Back in 2006 when it was first developed, IE releases had a pretty icky memory leak bug that could be easily triggered when one added properties t...

Heh, I always wanted to do one of those “X considered harmful” posts*. :D Before I start, let me say that I think jQuery has helped tremendously to move the Web forward. It gave developers power to do things that were previously unthinkable, and pushed the browser manufacturers to implement these th...

Sorry for the lack of posts for the past 7 (!) months, I’ve been super busy working on my book, which up to a certain point, I couldn’t even imagine finishing, but I’m finally there! I’ve basically tried to cram all the CSS wisdom I’ve accumulated over the years in it :P (which is partly why it took...