Journal tags: svg

I wrote a little while back about improving performance on The Session by reducing runtime JavaScript in favour of caching on the server. This is on the pages for tunes, where the SVGs for the sheetmusic are now inlined instead of being generated on the fly.

It worked. But I also wrote:

A page like that with lots of sheetmusic and plenty of comments is going to have a hefty page weight and a large DOM size. I’ve still got a fair bit of main-thread work happening, but now the bulk of it is style and layout, whereas previously I had the JavaScript overhead on top of that.

Take a tune like Out On The Ocean. It has 27 settings. That’s a lot of SVG markup that needs to be parsed, styled and rendered, even if it’s inline.

Then I remembered a very handy CSS property called content-visibility:

It enables the user agent to skip an element’s rendering work (including layout and painting) until it is needed — which makes the initial page load much faster.

Sounds great! But there are two gotchas.

The first gotcha is that if a browser doesn’t paint the element, it doesn’t know how much space the element should take up. So you need to provide dimensions. At the very least you need to provide a height value. Otherwise when the element comes into view and gets rendered, it pushes down on the content below it. You’d see a sudden jump in the scrollbar position.

The solution is to provide a value for contain-intrinsic-size. If your content is dynamic—from, say, a CMS—then you’re out of luck. You don’t know how long the content is.

Luckily, in my case, I could take a stab at it. I know how many lines of sheetmusic there are for each tune setting. Each line takes up roughly the same amount of space. If I multiply that amount of space by the number of lines then I’ve got a pretty good approximation of the height of the sheetmusic. I apply this with the contain-intrinsic-block-size property.

So each piece of sheetmusic has an inline style attribute with declarations like this:

content-visibility: auto;
contain-intrinsic-block-size: 380px;

It works a treat. I did a before-and-after check with pagespeed insights on the page for Out On The Ocean. The “style and layout” part of the main thread work went down considerably. Total blocking time went from more than 600 milliseconds to less than 400 milliseconds.

Not a bad result for a little bit of CSS!

I said there was a second gotcha. That’s browser support.

Right now content-visibility is only supported in Chrome and Edge. But that’s okay. This is a progressive enhancement. Adding this CSS has no detrimental effect on the browsers that don’t understand it (and when they do ship support for it, it’ll just start working). I’ve said it before and I’ll say it again: the forgiving error-parsing in HTML and CSS is a killer feature of the web. Browsers just ignore what they don’t understand. That’s what makes progressive enhancement like this possible.

And actually, there’s something you can do for all browsers. Even browsers that don’t support content-visibility still understand containment. So they’ll understand contain-intrinsic-size. Pair that with a contain declaration like this to tell the browser that this chunk of content isn’t going to reflow or get repainted:

contain: layout paint;

Here’s what MDN says about contain:

The contain CSS property indicates that an element and its contents are, as much as possible, independent from the rest of the document tree. Containment enables isolating a subsection of the DOM, providing performance benefits by limiting calculations of layout, style, paint, size, or any combination to a DOM subtree rather than the entire page.

So if you’ve got a chunk of static content, you might as well apply contain to it.

Again, not bad for a little bit of CSS!

I had a lot of fun making the website for Patterns Day.

If you’re interested in the tech stack, here’s what I used:

1. HTML
2. CSS

Actually, technically it’s all HTML because the styles are inside a style element rather than a separate style sheet, but you know what I mean. Also, there is technically some JavaScript but all it does is register a service worker that takes care of caching and going offline.

I didn’t use any build tools. There was no pipeline. There is no node_modules folder filling up my hard drive. Nothing was automated. The website was hand-crafted the long hard stupid way.

I started with the content. I wrote out the words and marked them up with the most appropriate HTML elements.

Time to layer on the presentation.

For the design, I turned to Michelle for help. I gave her a brief, describing the vibe of the conference, and asked her to come up with an appropriate visual language.

Crucially, I asked her not to design a website. Instead I asked her to think about other places where this design language might be used: a poster, social media, anything but a website.

Partly I was doing this for my own benefit. If you give me a pixel-perfect design for a web page and tell me to code it up, either I won’t do it or I won’t enjoy it. I just don’t get any motivation out of that kind of direct one-to-one translation.

But give me guardrails, give me constraints, give me boundary conditions, and off I go!

Michelle was very gracious in dealing with such a finicky client as myself (“Can you try this other direction?”, “Hmm… I think I preferred the first one after all!”) She delivered a colour palette, a type scale, typeface choices, and some wonderful tiling patterns …it is Patterns Day after all!

With just a few extra lines of CSS, the basic typography was in place.

I started layering on the colours. Even though this was a one-page site, I still made liberal use of custom properties in the CSS. It just feels good to be able to update one value and see the results, well …cascade.

I had a lot of fun with the tiling background images. SVG was the perfect format for these. And because the tiles were so small in file size, I just inlined them straight into the CSS.

By this point, I felt like I was truly designing in the browser. Adjusting spacing, playing around with layout, and all that squishy stuff. Some of the best results came from happy accidents—the way that certain elements behaved at certain screen sizes would lead me into little experiments that yielded interesting results.

I’m not sure it’s possible to engineer that kind of serendipity in Figma. Figma was the perfect tool for exploring ideas around the visual vocabulary, and for handing over design decisions around colour, typography, and texture. But when it comes to how the content is going to behave on the World Wide Web, nothing beats a browser for fidelity.

By this point I was really sweating the details, like getting the logo just right and adjusting the type scale for different screen sizes. Needless to say, Utopia was a godsend for that.

I was also checking back in with Michelle to get her take on design decisions I was making.

I could’ve kept tinkering but the diminishing returns were a sign that it was time to put this out into the world.

It felt really good to work on a web page like this. It felt like I was getting my hands into the soil of the web. I don’t think it’s an accident that the result turned out to be very performant.

Getting hands-on like this stops me from getting rusty. And honestly, working with CSS these days is a joy. There’s such power to be had from using var() in combination with functions like calc() and clamp(). Layout is a breeze with flexbox and grid. Browser differences are practically non-existent. We’ve never had it so good.

Here’s something I noticed about my relationship to CSS; my brain has finally made the switch to logical properties. Now if I’m looking at some CSS and I see left, right, top, or bottom, it looks like a bug to me. Those directional properties feel loaded with assumptions whereas logical properties feel much more like working with the grain of the web.

Performance is a high priority for me with The Session. It needs to work for people all over the world using all kinds of devices.

My main strategy for ensuring good performance is to diligently apply progressive enhancement. The core content is available to any device that can render HTML.

To keep things performant, I’ve avoided as many assets (or, more accurately, liabilities) as possible. No uneccessary images. No superfluous JavaScript libraries. Not even any web fonts (gasp!). And definitely no third-party resources.

The pay-off is a speedy site. If you want to see lab data, run a page from The Session through lighthouse. To see field data, take a look at data from Chrome UX Report (Crux).

But the devil is in the details. Even though most pages on The Session are speedy, the outliers have bothered me for a while.

Take a typical tune page on the site. The data is delivered from the server as HTML, which loads nice and quick. That data includes the notes for the tune settings, written in ABC notation, a nice lightweight text format.

Then the enhancement happens. Using Paul Rosen’s brilliant abcjs JavaScript library, those ABCs are converted into SVG sheetmusic.

So on tune pages there’s an additional download for that JavaScript library. That’s not so bad though—I’m using a service worker to cache that file so there’ll only ever be one initial network request.

If a tune has just a few different versions, the page remains nice and zippy. But if a tune has lots of settings, the computation starts to add up. Converting all those settings from ABC to SVG starts to take a cumulative toll on the main thread.

I pondered ways to avoid that conversion step. Was there some way of pre-generating the SVGs on the server rather than doing it all on the client?

In theory, yes. I could spin up a headless browser, run the JavaScript and take a snapshot. But that’s a bit beyond my backend programming skills, so I’ve taken a slightly different approach.

The first time anyone hits a tune page, the ABCs getting converted to SVGs as usual. But now there’s one additional step. I grab the generated markup and send it as an Ajax payload to an endpoint on my server. That endpoint stores the sheetmusic as a file in a cache.

Next time someone hits that page, there’s a server-side check to see if the sheetmusic has been cached. If it has, send that down the wire embedded directly in the HTML.

The idea is that over time, most of the sheetmusic on the site will transition from being generated in the browser to being stored on the server.

So far it’s working out well.

Take a really popular tune like The Lark In The Morning. There are twenty settings, and each one has four parts. Previously that would have resulted in a few seconds of parsing and rendering time on the main thread. Now everything is delivered up-front.

I’m not out of the woods. A page like that with lots of sheetmusic and plenty of comments is going to have a hefty page weight and a large DOM size. I’ve still got a fair bit of main-thread work happening, but now the bulk of it is style and layout, whereas previously I had the JavaScript overhead on top of that.

I’ll keep working on it. But overall, the speed improvement is great. A typical tune page is now very speedy indeed.

It’s like a microcosm of web performance in general: respect your users’ time, network connection and battery life. If that means shifting the work from the browser to the server, do it!

While I’m talking about the SVGs on The Session, I thought I’d share something else related to the rendering of the sheet music.

Like I said, I use the brilliant abcjs JavaScript library. It converts ABC notation into sheet music on the fly, which still blows my mind.

If you view source on the rendered SVG, you’ll see that the path and rect elements have been hard-coded with a colour value of #000000. That makes sense. You’d want to display sheet music on a light background, probably white. So it seems like a safe assumption.

Ah, but when it comes to front-end development, assumptions are like little hidden bombs just waiting to go off!

I got an email the other day:

Hi Jeremy,

I have vision problems, so I need to use high-contrast mode (using Windows 11). In high-contrast mode, the sheet-music view is just black!

Doh! All my CSS adapts just fine to high-contrast mode, but those hardcoded hex values in the SVG aren’t going to be affected by high-contrtast mode.

Stepping back, the underlying problem was that I didn’t have a full separation of concerns. Most of my styling information was in my CSS, but not all. Those hex values in the SVG should really be encoded in my style sheet.

I couldn’t remove the hardcoded hex values—not without messing around with JavaScript beyond my comprehension—so I made the fix in CSS:

[fill="#000000"] {
  fill: currentColor;
}
[stroke="#000000"] {
  stroke: currentColor;
}

That seemed to do the trick. I wrote back to the person who had emailed me, and they were pleased as punch:

Well done, Thanks!  The staff, dots, etc. all appear as white on a black background.  When I click “Print”, it looks like it still comes out black on a white background, as expected.

I’m very grateful that they brought the issue to my attention. If they hadn’t, that assumption would still be lying in wait, preparing to ambush someone else.

Two weeks ago, I wrote:

I woke up today to a very annoying new bug in Firefox. The browser shits the bed in an unpredictable fashion when rounding up single pixel line widths in SVG. That’s quite a problem on The Session where all the sheet music is rendered in SVG. Those thin lines in sheet music are kind of important.

Paul Rosen, who makes abcjs, the JavaScript library that renders sheet music on The Session, managed to get a fix out pretty quickly. But I use an older version of the library and updating it would introduce some side-effects that would take me a while to work around. So that option wasn’t available to me.

In this situation, when the problem is caused by a browser bug, the correct course of action is to file a bug with the browser. That had already been done. Now all I could do was twiddle my thumbs and wait for the next release of the browser, which would hopefully ship with the fix.

But I figured I may as well try to find a temporary workaround in the meantime.

At first, I looked at diving into the internals of the JavaScript—that’s where the instructions are given for drawing the SVGs.

But then I stopped and thought, “If the problem is with the rendering of the SVG, maybe CSS can help.”

I started messing around with SVG-specific CSS properties like stroke, fill, and so on. With dev tools open, I started targeting the paths that acted as bar lines in the sheet music, playing around with widths, opacities, and fills.

It was the debugging equivalent of throwing spaghetti at the wall. Remarkably, it actually worked.

I found a solution with this nonsensical bit of CSS:

stroke: currentColor;
stroke-opacity: 0;

For some reason, rather than making all the barlines disappear, this ensured they were visible.

It’s the worst kind of hacky fix—the kind where you have no idea why it works, but it does.

So I shipped it.

And at pretty much exactly the same time, a new version of Firefox dropped …with the bug fixed.

I can’t deny that there was a certain satisfaction in being able to work around a browser bug. But there’s much more satisfaction in deleting the hacky workaround when it’s no longer needed.

I added a dark mode to my site last year. Since then I’ve been idly toying with the addition of a dark mode to The Session too.

As with this site, the key to adding a dark mode was switching to custom properties for color and background-color declarations. But my plans kept getting derailed by the sheet music on the site. The sheet music is delivered as SVG generated by ABCJS which hard-codes the colour in stroke and fill attributes:

fill="#000000" stroke="#000000"

When I was describing CSS recently I mentioned the high specifity of inline styles:

Whereas external CSS and embedded CSS don’t have any effect on specificity, inline styles are positively radioactive with specificity.

Given that harsh fact of life, I figured it would be nigh-on impossible to over-ride the colour of the sheetmusic. But then I realised I was an idiot.

The stroke and fill attributes in SVG are presentational but they aren’t inline styles. They’re attributes. They have no affect on specifity. I can easily over-ride them in an external style sheet.

In fact, if I had actually remembered what I wrote when I was adding a dark mode to adactio.com, I could’ve saved myself some time:

I have SVGs of sparklines on my homepage. The SVG has a hard-coded colour value in the stroke attribute of the path element that draws the sparkline. Fortunately, this can be over-ridden in the style sheet:

svg.activity-sparkline path {
  stroke: var(--text-color);
}

I was able to do something similar on The Session. I used the handy currentColor keyword in CSS so that the sheet music matched the colour of the text:

svg path {
  fill: currentColor;
}
svg path:not(stroke="none") {
  stroke: currentColor;
}

Et voila! I now had light-on-dark sheet music for The Session’s dark mode all wrapped up in a prefers-color-scheme: dark media query.

I pushed out out the new feature and started getting feedback. It could be best summarised as “Thanks. I hate it.”

It turns out that while people were perfectly fine with a dark mode that inverts the colours of text, it felt really weird and icky to do the same with sheet music.

On the one hand, this seems odd. After all, sheet music is a writing system like any other. If you’re fine with light text on a dark background, why doesn’t that hold for light sheet music on a dark background?

But on the other hand, sheet music is also like an image. And we don’t invert the colours of our images when we add a dark mode to our CSS.

With that in mind, I went back to the drawing board and this time treated the sheet music SVGs as being intrinsicly dark-on-light, rather than a stylistic choice. It meant a few more CSS rules, but I’m happy with the final result. You can see it in action by visiting a tune page and toggling your device’s “appearance” settings between light and dark.

If you’re a member of The Session, I also added a toggle switch to your member profile so you can choose dark or light mode regardless of your device settings.

Here’s a tiny lesson that I picked up from Trys that I’d like to share with you…

I was working on some upcoming changes to the Clearleft site recently. One particular component needed some SVG background images. I decided I’d inline the SVGs in the CSS to avoid extra network requests. It’s pretty straightforward:

.myComponent {
    background-image: url('data:image/svg+xml;utf8,<svg> ... </svg>');
}

You can basically paste your SVG in there, although you need to a little bit of URL encoding: I found that converting # to %23 to was enough for my needs.

But here’s the thing. My component had some variations. One of the variations had multiple background images. There was a second background image in addition to the first. There’s no way in CSS to add an additional background image without writing a whole background-image declaration:

.myComponent--variant {
    background-image: url('data:image/svg+xml;utf8,<svg> ... </svg>'), url('data:image/svg+xml;utf8,<svg> ... </svg>');
}

So now I’ve got the same SVG source inlined in two places. That negates any performance benefits I was getting from inlining in the first place.

That’s where Trys comes in. He shared a nifty technique he uses in this exact situation: put the SVG source into a custom property!

:root {
    --firstSVG: url('data:image/svg+xml;utf8,<svg> ... </svg>');
    --secondSVG: url('data:image/svg+xml;utf8,<svg> ... </svg>');
}

Then you can reference those in your background-image declarations:

.myComponent {
    background-image: var(--firstSVG);
}
.myComponent--variant {
    background-image: var(--firstSVG), var(--secondSVG);
}

Brilliant! Not only does this remove any duplication of the SVG source, it also makes your CSS nice and readable: no more big blobs of SVG source code in the middle of your style sheet.

You might be wondering what will happen in older browsers that don’t support CSS custom properties (that would be Internet Explorer 11). Those browsers won’t get any background image. Which is fine. It’s a background image. Therefore it’s decoration. If it were an important image, it wouldn’t be in the background.

Progressive enhancement, innit?

I’ve seen some lovely examples of the Web Audio API recently.

At the Material conference, Halldór Eldjárn demoed his Poco Apollo project. It generates music on the fly in the browser to match a random image from NASA’s Apollo archive on Flickr. Brian Eno, eat your heart out!

At Codebar Brighton a little while back, local developer Luke Twyman demoed some of his audio-visual work, including the gorgeous Solarbeat—an audio orrery.

The latest issue of the Clearleft newsletter has some links on sound design in interfaces:

• Why strong sound design is critical to successful products by Amber Case and Aaron Day,
• UI Sounds: From Zero To Hero by Roman Zimarev, and
• Form Validation with Web Audio by Ruth John.

I saw Ruth give a fantastic talk on the Web Audio API at CSS Day this year. It had just the right mixture of code and inspiration. I decided there and then that I’d have to find some opportunity to play around with web audio.

As ever, my own website is the perfect playground. I added an audio Easter egg to adactio.com a while back, and so far, no one has noticed. That’s good. It’s a very, very silly use of sound.

In her talk, Ruth emphasised that the Web Audio API is basically just about dealing with numbers. Lots of the examples of nice usage are the audio equivalent of data visualisation. Data sonification, if you will.

I’ve got little bits of dataviz on my website: sparklines. Each one is a self-contained SVG file. I added a script element to the SVG with a little bit of JavaScript that converts numbers into sound (I kind of wish that the script were scoped to the containing SVG but that’s not the way JavaScript in SVG works—it’s no different to putting a script element directly in the body). Clicking on the sparkline triggers the sound-playing function.

It sounds terrible. It’s like a theremin with hiccups.

Still, I kind of like it. I mean, I wish it sounded nicer (and I’m open to suggestions on how to achieve that—feel free to fork the code), but there’s something endearing about hearing a month’s worth of activity turned into a wobbling wave of sound. And it’s kind of fun to hear how a particular tag is used more frequently over time.

Anyway, it’s just a silly little thing, but anywhere you spot a sparkline on my site, you can tap it to hear it translated into sound.

I’ve noticed a few nice examples of motion design on the web lately.

The Cloud Four gang recently redesigned their site, including a nice little animation on the home page.

Malcolm Gladwell has a new podcast called Revisionist History. The website for the podcast is quite lovely. Each episode is illustrated with an animated image. Lovely!

If you want to see some swishy animations triggered by navigation, the waaark websites has them a-plenty. Personally I find the scroll-triggered animations on internal pages too much to take (I have yet to find an example of scrolljacking that doesn’t infuriate me). But the homepage illustrations have some lovely subtle movement.

When it comes to subtlety in animation, my favourite example comes from Charlotte. She recently refactored the homepage of the website for the Leading Design conference. It originally featured one big background image. Switching over to SVG saved a lot of bandwidth. But what I really love is that the shapes in the background are now moving …ever so gently.

It’s like gazing at a slow-motion lava lamp of geometry.

I was in Nuremberg last weekend for Indie Web Camp. It was great.

At some point I really should stop being surprised by just how much gets done in one weekend, but once again, I was blown away by the results.

On the first day we had very productive BarCamp-like discussion sessions, and on the second day it was heads-down hacking. But it was hacking with help. Being in the same room as other people who each have their own areas of expertise is so useful. It really turbo-charges the amount that you can get accomplished.

For example, I was helping Tom turn his website into a progressive web app with the addition of a service worker and a manifest file. Meanwhile Tom was helping somebody else get a Wordpress site up and running.

Actually, that was what really blew me away: two people began the second day of Indie Web Camp Nuremberg without websites and by the end of the day, they both had their own sites up and running. For me, that’s the real spirit of the indie web—I know we tend to go on about the technologies like h-card, h-entry, webmentions, micropub, and IndieAuth, but really it’s not about the technologies; it’s about having your own place on the web so that you have control over what you put out in the world.

For my part, I was mostly making some cosmetic changes to my site. There was a really good discussion on the first page about home pages. What’s the purpose of a home page? For some, it’s about conveying information about the person. For others, it’s a stream of activity.

My site used to have a splash-like homepage; just a brief bio and a link to the latest blog post. Then I changed it into a stream a few years ago. But that means that the home page of my site doesn’t feel that different from sections of the site like the journal or the link list.

During the discussion at Indie Web Camp, we started looking at how silos design their profile pages to see what we could learn from them. Looking at my Twitter profile, my Instagram profile, my Untappd profile, or just about any other profile, it’s a mixture of bio and stream, with the addition of stats showing activity on the site—signs of life.

I decided I’d add signs of life to my home page. Once again, I reached for my favourite little data visualisation helper: sparklines

A sparkline is a small intense, simple, word-sized graphic with typographic resolution.

I’ve already got sparklines on Huffduffer and on The Session so I suppose it was only a matter of time before they showed up here.

I’ve been tweaking them ever since I got back from Germany. Now I’ve added in a little h-card bio as well.

Initially I was using the fantastic little scripted SVG that Stuart made , the same one that I’m using on Huffduffer and The Session. But Kevin pointed out that a straightforward polyline would be more succinct. And in the case of my own site, there’s only four sparklines so it wouldn’t be a huge overhead to hard-code the values straight into the SVGs.

Yesterday was the first day of Render Conference in Oxford (I’ll be speaking later today). Sara gave a blisteringly great talk on (what else?) SVGs and I got so inspired I started refactoring my code right there and then. I’m pretty happy with how the sparklines are working now, although I’m sure I’ll continue to play around with them some more.

There’s another activity visualisation that I’m eager to play around with. I really like the calendar heatmap on my Github profile. I could imagine using something like that for an archive view on my own site.

Luckily for me, I’ll have a chance to play around with my website a bit more very soon. There’s going to be another Indie Web Camp in Germany very soon.

Indie Web Camp Düsseldorf will take place on May 7th and 8th, right before Beyond Tellerrand. Last year’s event was really inspiring. If there’s any chance you can make it, you should come along. You won’t regret it.

Jake gave a great talk at Responsive Day Out 3 all about nuanced progressive enhancement, with a look at service workers in particular (a technology designed with progressive enhancement at its heart).

To illustrate the performance gains, Jake used his SVGOMG site as an example—a really terrific resource for optimising SVGs.

SVGOMG requires JavaScript for its core functionality (optimising an SVG file). That was a deliberate choice. Jake could’ve made the barrier-to-entry as low as any browser that supports input type="file" but he decided that for this audience (developers) it was a safe assumption that JavaScript would be available.

Jake talked about this in an interview with Paul about the site:

I’m a strong believer in progressive enhancement, but also that each phase of the enhancement needs a user.

I agree completely with this approach. It makes sense to have a valid reason for adding any enhancement. But there’s something about this particular example that wasn’t sitting right with me. It took me a while to figure it out, but I now realise what it is.

Jake is talking about making it work on the server as an enhancement. But that’s not an enhancement, it’s a fallback.

Thinking in terms of fallbacks is more of a “graceful degradation” approach (i.e. for every “full” feature, thinking of a corresponding fallback). That’s not how I like to think of progressive enhancement. I like to think in terms of a baseline. And that baseline, in my mind, does not require a user to justify its existence. That’s because the baseline isn’t there to cover the use cases we can think of, it’s there to cover the use cases we can’t predict.

That might seem like a minor difference in wording to the graceful degradation approach but I think it’s actually a fundamentally different way of approaching the situation.

When I was on the progressive enhancement panel at Edge Conf, Lyza asked how low the baseline should be. I said “as low as possible.” Some of my fellow panelists took issue with this saying it varies from project to project, and that’s completely true, but I think I should’ve clarified that when I talk about a baseline, I’m not talking about browsers. I don’t think about a baseline in terms of “IE4 and above, Android 2.1 and above, etc.”—I think about a baseline in terms of “the minimum required technology to allow a user to accomplish the core task” (that qualification about core tasks is important—the baseline does not need to cover tasks that are nice-to-have; those can safely require more sophisticated technology).

That “minimum required technology” often turns out to be a combination of a web server, HTTP, and some HTML.

So to take SVGOMG as an example, I would begin with the baseline of “allowing a user to optimise an SVG file”. The minimum required technology is a web server running a programme that does the optimisation, and an HTML document that contains a form element with input type="file". Once that’s in place, then I can start applying Jake’s very sensible approach of thinking about enhancements in terms of specific user benefits. In this case, it’s pretty clear that 99.99% of the users would benefit from not having that round-trip to the server and have the SVG optimisation happen in the browser using JavaScript.

There’s an enhancement provided for the use case that I can imagine. But—and this is the subtle but important distinction—there’s a baseline for all the use cases that I can’t think of. I need to recognise that I won’t be able to predict all the possible use cases, and that’s okay—as long there’s a solid baseline in place, I’ve got an insurance policy for unforeseen circumstances. It’s still not perfect, but it lowers the risk somewhat by reducing the number of assumptions being built in at that baseline level.

Going back to Jake’s chat with Paul, he says:

I thought about making the site work without JS by doing the SVG work on the server, but this would be slow and a maintenance burden.

The maintenance burden is a very valid point. This is something that Stuart talked about a while back:

It is in theory possible to write a web app which does processing on the server and is entirely robust against its client-side scripting being broken or missing, and which does processing on the client so that it works when the server’s unavailable or uncontactable or expensive or slow. But let’s be honest here. That’s not an app. That’s two apps.

Leaving aside the promise of isomorphic/universal/whatever JavaScript, this issue of developer convenience is big issue. When I use the term “developer convenience” to label this problem, I am not belittling it in any way—developer convenience is incredibly important (hence the appeal of so many tools and frameworks that make life easier for developers). I still believe that developer convenience should be lower on the list of priorities than having a rock-solid baseline, but I can totally understand if someone doesn’t share that opinion. It’s a personal decision and if the pain involved in making a more universal baseline is greater than the perceived—and, let’s face it, somewhat abstract—benefit, I can totally understand that.

Anyway, that’s my little brain dump about progressive enhancement and baseline experiences. Something about treating the baseline experience as an enhancement was itching at my brain and now that I’ve managed to scratch it, I can see what was troubling me: thinking about the baseline experience in the same way as thinking about enhancements doesn’t work for me.

Personally, I’m going to strive to keep the baseline as low as possible. I’m also going to strive to apply Jake’s maxim about every enhancement requiring a user.