Tags: js

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Wednesday, December 16th, 2020

Audio

I spent the last couple of weekends rolling out a new feature on The Session. It involves playing audio in a web page. No big deal these days, right? But the history involves some old file formats…

The first venerable format is ABC notation. File extension: .abc, mime type: text/vnd.abc. It’s an ingenious text format for musical notation using ASCII. The metadata of the piece of music is defined in JSON-like key/value pairs. Then the contents are encoded with letters: A, B, C, etc. Uppercase and lowercase denote different octaves. Numbers can be used for note lengths.

The format was created by Chris Walshaw in 1997 when dial-up was the norm. With ABC, people were able to swap tunes on email lists or bulletin boards without transferring weighty image or sound files. If you had ABC software on your computer, you could convert that lightweight text file into sheet music …or audio.

That brings me to the second old format: midi files. File extension: .mid, mime-type: audio/midi. Like ABC, it’s a lightweight format for encoding the instructions for music instead of the music itself.

Think of it like SVG: instead of storing the final pixels of an image, SVG stores the instructions for drawing the image instead. The instructions in a midi file are like “play this note for this long on this instrument.” Again, as with ABC, you need some software to turn the instructions into sound.

There was a time when lots of software could play midi files. Quicktime on the Mac, for example. You could even embed midi files in web pages. I mean literally embed them …with the embed element. No Geocities page was complete without an autoplaying midi file.

On The Session, people submit tunes in ABC format. Then, using the amazing ABCJS JavaScript library, the ABC is turned into SVG on the fly! For years I’ve also offered midi files, generated on the server from the ABC notation.

But times have changed. These days it’s hard to find software that plays midi files. Quicktime doesn’t do it anymore. And you’d need to go to the app store on iOS to find a midi file player. It’s time to phase out the midi files on The Session.

I still want to provide automatically-generated audio though. Fortunately ABCJS gives me a way to do this. But instead of using the old technology of midi files, it uses a more modern browser feature: the Web Audio API.

The end result sounds like a midi file, but the underlying technique is more like a synthesiser. There’s a separate mp3 file for each note. The JavaScript figures out how long each “sample” needs to be played for, strings them all together, and outputs them with Web Audio. So you’ve got cutting-edge browser technology recreating a much older file format. Paul Rosen—the creator of ABCJS—has a presentation explaining how it all works under the hood.

Not only is there a separate short mp3 file for each note in seven octaves, but if you want the sound of a different instrument, you need samples for all seven octaves in that instrument. They’re called soundfonts.

Paul provides soundfonts for ABCJS. It’s a repo that was forked from this repo from Benjamin Gleitzman. And here’s where it gets small worldy…

The reason why Benjamin has a repo of soundfonts is because he needed to create midi-like audio in the browser. He wanted to do this for a project on September 28th and 29th, 2013 …at Science Hack Day San Francisco!

I was there too—working on my own audio-related hack—and I remember the excellent (and winning) hack that Benjamin worked on. It was called Symphony of Satellites and it’s still online along with the promo video. Here’s Benjamin’s post-hackday write-up from seven years ago.

It’s rare that the worlds of the web and Irish music cross over. When I got to meet Paul—creator of ABCJS—at a web conference a couple of years ago it kind of blew my mind. Last weekend when I set out to dabble with a feature on The Session, I certainly didn’t expect to stumble on a connection to Science Hack Day! (Aside: the first Science Hack Day was ten years ago—yowzers!)

Anyway, I was able to get that audio playback working on The Session. Except for some weirdness on iOS that I had to fix. But that’s a hack for another day.

Thursday, November 5th, 2020

Saturday, October 3rd, 2020

Monday, September 21st, 2020

Playing The Drunken Landlady (reel) on mandolin:

https://thesession.org/tunes/363

https://www.youtube.com/watch?v=QIQj3uF_Js8

Monday, June 1st, 2020

Picture 1 Picture 2 Picture 3 Picture 4

Summertime meals.

Tuesday, May 26th, 2020

Playing The Fisherman’s Island (reel) by Ed Reavey on mandolin:

https://thesession.org/tunes/181

https://www.youtube.com/watch?v=LD6Nr_X5Jso

Saturday, May 23rd, 2020

Playing The Mouse In The Mug (jig) by Tom McElvogue on mandolin:

https://thesession.org/tunes/362

https://www.youtube.com/watch?v=-mSETsqVgc8

Wednesday, May 6th, 2020

Playing No Matter The Wreckage (hornpipe) by @RowanFolk on mandolin:

https://thesession.org/tunes/16793

https://www.youtube.com/watch?v=9MxuYJsancE

Saturday, April 25th, 2020

Reading

At the beginning of the year, Remy wrote about extracting Goodreads metadata so he could create his end-of-year reading list. More recently, Mark Llobrera wrote about how he created a visualisation of his reading history. In his case, he’s using JSON to store the information.

This kind of JSON storage is exactly what Tom Critchlow proposes in his post, Library JSON - A Proposal for a Decentralized Goodreads:

Thinking through building some kind of “web of books” I realized that we could use something similar to RSS to build a kind of decentralized GoodReads powered by indie sites and an underlying easy to parse format.

His proposal looks kind of similar to what Mark came up with. There’s a title, an author, an image, and some kind of date for when you started and/or finished reading the book.

Matt then points out that RSS gets close to the data format being suggested and asks how about using RSS?:

Rather than inventing a new format, my suggestion is that this is RSS plus an extension to deal with books. This is analogous to how the podcast feeds are specified: they are RSS plus custom tags.

Like Matt, I’m in favour of re-using existing wheels rather than inventing new ones, mostly to avoid a 927 situation.

But all of these proposals—whether JSON or RSS—involve the creation of a separate file, and yet the information is originally published in HTML. Along the lines of Matt’s idea, I could imagine extending the h-entry collection of class names to allow for books (or films, or other media). It already handles images (with u-photo). I think the missing fields are the date-related ones: when you start and finish reading. Those fields are present in a different microformat, h-event in the form of dt-start and dt-end. Maybe they could be combined:


<article class="h-entry h-event h-review">
<h1 class="p-name p-item">Book title</h1>
<img class="u-photo" src="image.jpg" alt="Book cover.">
<p class="p-summary h-card">Book author</p>
<time class="dt-start" datetime="YYYY-MM-DD">Start date</time>
<time class="dt-end" datetime="YYYY-MM-DD">End date</time>
<div class="e-content">Remarks</div>
<data class="p-rating" value="5">★★★★★</data>
<time class="dt-published" datetime="YYYY-MM-DDThh:mm">Date of this post</time>
</article>

That markup is simultaneously a post (h-entry) and an event (h-event) and you can even throw in h-card for the book author (as well as h-review if you like to rate the books you read). It can be converted to RSS and also converted to .ics for calendars—those parsers are already out there. It’s ready for aggregation and it’s ready for visualisation.

I publish very minimal reading posts here on adactio.com. What little data is there isn’t very structured—I don’t even separate the book title from the author. But maybe I’ll have a little play around with turning these h-entries into combined h-entry/event posts.

Tuesday, September 17th, 2019

NoJS Side-by-Side

Drag this to your browser’s bookmark bar now!

Such a useful quick check for resilience—this bookmarklet shows you a side-by-side comparison of a site with JavaScript enabled and disabled.

Wednesday, May 22nd, 2019

Bruce Lawson’s personal site  : Structured data and Google

Bruce wonders why Google seems to prefer separate chunks of JSON-LD in web pages instead of interwoven microdata attributes:

I strongly feel that metadata that is separated from the user-visible data associated with it highly susceptible to metadata partial copy-paste necrosis. User-visible text is also developer-visible text. When devs copy/ paste that, it’s very easy to forget to copy any associated metadata that’s not interleaved, leading to errors.

Sunday, April 14th, 2019

Pork!

Pork!

Wednesday, April 10th, 2019

Split

When I talk about evaluating technology for front-end development, I like to draw a distinction between two categories of technology.

On the one hand, you’ve got the raw materials of the web: HTML, CSS, and JavaScript. This is what users will ultimately interact with.

On the other hand, you’ve got all the tools and technologies that help you produce the HTML, CSS, and JavaScript: pre-processors, post-processors, transpilers, bundlers, and other build tools.

Personally, I’m much more interested and excited by the materials than I am by the tools. But I think it’s right and proper that other developers are excited by the tools. A good balance of both is probably the healthiest mix.

I’m never sure what to call these two categories. Maybe the materials are the “external” technologies, because they’re what users will interact with. Whereas all the other technologies—that mosty live on a developer’s machine—are the “internal” technologies.

Another nice phrase is something I heard during Chris’s talk at An Event Apart in Seattle, when he quoted Brad, who talked about the front of the front end and the back of the front end.

I’m definitely more of a front-of-the-front-end kind of developer. I have opinions on the quality of the materials that get served up to users; the output should be accessible and performant. But I don’t particularly care about the tools that produced those materials on the back of the front end. Use whatever works for you (or whatever works for your team).

As a user-centred developer, my priority is doing what’s best for end users. That’s not to say I don’t value developer convenience. I do. But I prioritise user needs over developer needs. And in any case, those two needs don’t even come into conflict most of the time. Like I said, from a user’s point of view, it’s irrelevant what text editor or version control system you use.

Now, you could make the argument that anything that is good for developer convenience is automatically good for user experience because faster, more efficient development should result in better output. While that’s true in theory, I highly recommend Alex’s post, The “Developer Experience” Bait-and-Switch.

Where it gets interesting is when a technology that’s designed for developer convenience is made out of the very materials being delivered to users. For example, a CSS framework like Bootstrap is made of CSS. That’s different to a tool like Sass which outputs CSS. Whether or not a developer chooses to use Sass is irrelevant to the user—the final output will be CSS either way. But if a developer chooses to use a CSS framework, that decision has a direct impact on the user experience. The user must download the framework in order for the developer to get the benefit.

So whereas Sass sits at the back of the front end—where I don’t care what you use—Bootstrap sits at the front of the front end. For tools like that, I don’t think saying “use whatever works for you” is good enough. It’s got to be weighed against the cost to the user.

Historically, it’s been a similar story with JavaScript libraries. They’re written in JavaScript, and so they’re going to be executed in the browser. If a developer wanted to use jQuery to make their life easier, the user paid the price in downloading the jQuery library.

But I’ve noticed a welcome change with some of the bigger JavaScript frameworks. Whereas the initial messaging around frameworks like React touted the benefits of state management and the virtual DOM, I feel like that’s not as prevalent now. You’re much more likely to hear people—quite rightly—talk about the benefits of modularity and componentisation. If you combine that with the rise of Node—which means that JavaScript is no longer confined to the browser—then these frameworks can move from the front of the front end to the back of the front end.

We’ve certainly seen that at Clearleft. We’ve worked on multiple React projects, but in every case, the output was server-rendered. Developers get the benefit of working with a tool that helps them. Users don’t pay the price.

For me, this question of whether a framework will be used on the client side or the server side is crucial.

Let me tell you about a Clearleft project that sticks in my mind. We were working with a big international client on a product that was going to be rolled out to students and teachers in developing countries. This was right up my alley! We did plenty of research into network conditions and typical device usage. That then informed a tight performance budget. Every design decision—from web fonts to images—was informed by that performance budget. We were producing lean, mean markup, CSS, and JavaScript. But we weren’t the ones implementing the final site. That was being done by the client’s offshore software team, and they insisted on using React. “That’s okay”, I thought. “React can be used server-side so we can still output just what’s needed, right?” Alas, no. These developers did everything client side. When the final site launched, the log-in screen alone required megabytes of JavaScript just to render a form. It was, in my opinion, entirely unfit for purpose. It still pains me when I think about it.

That was a few years ago. I think that these days it has become a lot easier to make the decision to use a framework on the back of the front end. Like I said, that’s certainly been the case on recent Clearleft projects that involved React or Vue.

It surprises me, then, when I see the question of server rendering or client rendering treated almost like an implementation detail. It might be an implementation detail from a developer’s perspective, but it’s a key decision for the user experience. The performance cost of putting your entire tech stack into the browser can be enormous.

Alex Sanders from the development team at The Guardian published a post recently called Revisiting the rendering tier . In it, he describes how they’re moving to React. Now, if this were a move to client-rendered React, that would make a big impact on the user experience. The thing is, I couldn’t tell from the article whether React was going to be used in the browser or on the server. The article talks about “rendering”—which is something that browsers do—and “the DOM”—which is something that only exists in browsers.

So I asked. It turns out that this plan is very much about generating HTML and CSS on the server before sending it to the browser. Excellent!

With that question answered, I’m cool with whatever they choose to use. In this case, they’re choosing to use CSS-in-JS (although, to be pedantic, there’s no C anymore so technically it’s SS-in-JS). As long as the “JS” part is JavaScript on a server, then it makes no difference to the end user, and therefore no difference to me. Not my circus, not my monkeys. For users, the end result is the same whether styling is applied via a selector in an external stylesheet or, for example, via an inline style declaration (and in some situations, a server-rendered CSS-in-JS solution might be better for performance). And so, as a user-centred developer, this is something that I don’t need to care about.

Except…

I have misgivings. But just to be clear, these misgivings have nothing to do with users. My misgivings are entirely to do with another group of people: the people who make websites.

There’s a second-order effect. By making React—or even JavaScript in general—a requirement for styling something on a web page, the barrier to entry is raised.

At least, I think that the barrier to entry is raised. I completely acknowledge that this is a subjective judgement. In fact, the reason why a team might decide to make JavaScript a requirement for participation might well be because they believe it makes it easier for people to participate. Let me explain…

It wasn’t that long ago that devs coming from a Computer Science background were deriding CSS for its simplicity, complaining that “it’s broken” and turning their noses up at it. That rhetoric, thankfully, is waning. Nowadays they’re far more likely to acknowledge that CSS might be simple, but it isn’t easy. Concepts like the cascade and specificity are real head-scratchers, and any prior knowledge from imperative programming languages won’t help you in this declarative world—all your hard-won experience and know-how isn’t fungible. Instead, it seems as though all this cascading and specificity is butchering the modularity of your nicely isolated components.

It’s no surprise that programmers with this kind of background would treat CSS as damage and find ways to route around it. The many flavours of CSS-in-JS are testament to this. From a programmer’s point of view, this solution has made things easier. Best of all, as long as it’s being done on the server, there’s no penalty for end users. But now the price is paid in the diversity of your team. In order to participate, a Computer Science programming mindset is now pretty much a requirement. For someone coming from a more declarative background—with really good HTML and CSS skills—everything suddenly seems needlessly complex. And as Tantek observed:

Complexity reinforces privilege.

The result is a form of gatekeeping. I don’t think it’s intentional. I don’t think it’s malicious. It’s being done with the best of intentions, in pursuit of efficiency and productivity. But these code decisions are reflected in hiring practices that exclude people with different but equally valuable skills and perspectives.

Rachel describes HTML, CSS and our vanishing industry entry points:

If we make it so that you have to understand programming to even start, then we take something open and enabling, and place it back in the hands of those who are already privileged.

I think there’s a comparison here with toxic masculinity. Toxic masculinity is obviously terrible for women, but it’s also really shitty for men in the way it stigmatises any male behaviour that doesn’t fit its worldview. Likewise, if the only people your team is interested in hiring are traditional programmers, then those programmers are going to resent having to spend their time dealing with semantic markup, accessibility, styling, and other disciplines that they never trained in. Heydon correctly identifies this as reluctant gatekeeping:

By assuming the role of the Full Stack Developer (which is, in practice, a computer scientist who also writes HTML and CSS), one takes responsibility for all the code, in spite of its radical variance in syntax and purpose, and becomes the gatekeeper of at least some kinds of code one simply doesn’t care about writing well.

This hurts everyone. It’s bad for your team. It’s even worse for the wider development community.

Last year, I was asked “Is there a fear or professional challenge that keeps you up at night?” I responded:

My greatest fear for the web is that it becomes the domain of an elite priesthood of developers. I firmly believe that, as Tim Berners-Lee put it, “this is for everyone.” And I don’t just mean it’s for everyone to use—I believe it’s for everyone to make as well. That’s why I get very worried by anything that raises the barrier to entry to web design and web development.

I’ve described a number of dichotomies here:

  • Materials vs. tools,
  • Front of the front end vs. back of the front end,
  • User experience vs. developer experience,
  • Client-side rendering vs. server-side rendering,
  • Declarative languages vs. imperative languages.

But the split that worries the most is this:

  • The people who make the web vs. the people who are excluded from making the web.

Thursday, June 7th, 2018

Picture 1 Picture 2 Picture 3 Picture 4

Pre-ballet tapas

Thursday, April 5th, 2018

setInterval(_=>{ document.body.innerHTML = [ …”😮😀😁😐😑😬” ][~~(Math.random()*6)] },95)

A tiny snippet of JavaScript for making an animation of a talking emoji face.

Friday, February 9th, 2018

Href Tools - Free online web tools

Handy web-based tools—compress HTML, CSS, and JavaScript, and convert files from one format to another.

Saturday, December 2nd, 2017

JSRobot

Learn JavaScript by playing/programming a platform game.

Friday, September 22nd, 2017

CloseBrace | A Brief, Incomplete History of JavaScript

Another deep dive into web history, this time on JavaScript. The timeline of JS on the web is retroactively broken down into four eras:

  • the early era: ~1996 – 2004,
  • the jQuery era: ~2004 – 2010,
  • the Single Page App era: ~2010 - 2014, and
  • the modern era: ~2014 - present.

Nice to see “vanilla” JavaScript making a resurgence in that last one.

It’s 2017, the JavaScript ecosystem is both thriving and confusing as all hell. No one seems to be quite sure where it’s headed, only that it’s going to continue to grow and change. The web’s not going anywhere, which means JS isn’t going anywhere, and I’m excited to see what future eras bring us.

Friday, September 1st, 2017

Categories land in the Web App Manifest | Aaron Gustafson

Manifest files can have categories now. Time to update those JSON files.

Thursday, August 3rd, 2017

Attachment #317095 for bug #175115

I’ve never been so excited by a single diff in a JSON file.

Service workers are coming to Safari.