Tags: frontend

1506

sparkline

Tuesday, November 12th, 2019

CSS for all

There have been some great new CSS properties and values shipping in Firefox recently.

Miriam Suzanne explains the difference between the newer revert value and the older inherit, initial and unset values in a video on the Mozilla Developer channel:

display: revert;

In another video, Jen describes some new properties for styling underlines (on links, for example):

text-decoration-thickness:  0.1em;
text-decoration-color: red;
text-underline-offset: 0.2em;
text-decoration-skip-ink: auto;

Great stuff!

As far as I can tell, all of these properties are available to you regardless of whether you are serving your website over HTTP or over HTTPS. That may seem like an odd observation to make, but I invite you to cast your mind back to January 2018. That’s when the Mozilla Security Blog posted about moving to secure contexts everywhere:

Effective immediately, all new features that are web-exposed are to be restricted to secure contexts. Web-exposed means that the feature is observable from a web page or server, whether through JavaScript, CSS, HTTP, media formats, etc. A feature can be anything from an extension of an existing IDL-defined object, a new CSS property, a new HTTP response header, to bigger features such as WebVR.

(emphasis mine)

Buzz Lightyear says to Woody: Secure contexts …secure contexts everywhere!

Despite that “effective immediately” clause, I haven’t observed any of the new CSS properties added in the past two years to be restricted to HTTPS. I’m glad about that. I wrote about this announcement at the time:

I am in total agreement that we should be encouraging everyone to switch to HTTPS. But requiring HTTPS in order to use CSS? The ends don’t justify the means.

If there were valid security reasons for making HTTPS a requirement, I would be all for enforcing this. But these are two totally separate areas. Enforcing HTTPS by withholding CSS support is no different to enforcing AMP by withholding search placement.

There’s no official word from the Mozilla Security Blog about any change to their two-year old “effective immediately” policy, and the original blog post hasn’t been updated. Maybe we can all just pretend it never happened.

Monday, November 11th, 2019

FF Conf 2019

Friday was FF Conf day here in Brighton. This was the eleventh(!) time that Remy and Julie have put on the event. It was, as ever, excellent.

It’s a conference that ticks all the boxes for me. For starters, it’s a single-track event. The more I attend conferences, the more convinced I am that multi-track events are a terrible waste of time for attendees (and a financially bad model for organisers). I know that sounds like a sweeping broad generalisation, but ask me about it next time we meet and I’ll go into more detail. For now, I just want to talk about this mercifully single-track conference.

FF Conf has built up a rock-solid reputation over the years. I think that’s down to how Remy curates it. He thinks about what he wants to know and learn more about, and then thinks about who to invite to speak on those topics. So every year is like a snapshot of Remy’s brain. By happy coincidence, a snapshot of Remy’s brain right now looks a lot like my own.

You could tell that Remy had grouped the talks together in themes. There was a performance-themed chunk right after lunch. There was a people-themed chunk in the morning. There was a creative-coding chunk at the end of the day. Nice work, DJ.

I think it was quite telling what wasn’t on the line-up. There were no talks about specific libraries or frameworks. For me, that was a blessed relief. The only technology-specific talk was Alice’s excellent talk on Git—a tool that’s useful no matter what you’re coding.

One of the reasons why I enjoyed the framework-free nature of the day is that most talks—and conferences—that revolve around libraries and frameworks are invariably focused on the developer experience. Think about it: next time you’re watching a talk about a framework or library, ask yourself how it impacts user experience.

At FF Conf, the focus was firmly on people. In the case of Laura’s barnstorming presentation, those people are end users (I’m constantly impressed by how calm and measured Laura remains even when talking about blood-boilingly bad behaviour from the tech industry). In the case of Amina’s talk, the people are junior developers. And for Sharon’s presentation, the people are everyone.

One of the most useful talks of the day was from Anna who took us on a guided tour of dev tools to identify performance improvements. I found it inspiring in a very literal sense—if I had my laptop with me, I think I would’ve opened it up there and then and started tinkering with my websites.

Harry also talked about performance, but at Remy’s request, it was more business focused. Specifically, it was focused on Harry’s consultancy business. I think this would’ve been the perfect talk for more of an “industry” event, whereas FF Conf is very much a community event: Harry’s semi-serious jibes about keeping his performance secrets under wraps didn’t quite match the generous tone of the rest of the line-up.

The final two talks from Charlotte and Suz were a perfect double whammy.

When I saw Charlotte speak at Material in Iceland last year, I wrote this aside in my blog post summary:

(Oh, and Remy, when you start to put together the line-up for next year’s FF Conf, be sure to check out Charlotte Dann—her talk at Material was the perfect mix of code and creativity.)

I don’t think I can take credit for Charlotte being on the line-up, but I will take credit for saying she’d be the perfect fit.

And then Suz Hinton closed out the conference with this rallying cry that resonated perfectly with Laura’s talk:

Less mass-produced surveillance bullshit and more Harry Potter magic (please)!

I think that rallying cry could apply equally well to conferences, and I think FF Conf is a good example of that ethos in action.

JavaScript | 2019 | The Web Almanac by HTTP Archive

It’s time for a look at the state of the web when it comes to JavaScript usage. Here’s the report powered by data from HTTP Archive:

JavaScript is the most costly resource we send to browsers; having to be downloaded, parsed, compiled, and finally executed. Although browsers have significantly decreased the time it takes to parse and compile scripts, download and execution have become the most expensive stages when JavaScript is processed by a web page.

Sending smaller JavaScript bundles to the browser is the best way to reduce download times, and in turn improve page performance. But how much JavaScript do we really use?

When it comes to frameworks and UI libraries, there are some interesting numbers. Given the volume of chatter in the dev world, you’d be forgiven for thinking that React is used on the majority of websites today. The real number? 4.6% of websites. That’s less than the number of websites using CSS custom properties.

This is reminding me of what I wrote about dev perception.

Thursday, November 7th, 2019

What I’ve learned about accessibility in SPAs

Nolan writes up what he learned making accessibiity improvements to a single page app. The two big takeways involve letting the browser do the work for you:

Here’s the best piece of accessibility advice for newbies: if something is a button, make it a <button>. If something is an input, make it an <input>. Don’t try to reinvent everything from scratch using <div>s and <span>s.

And then there are all the issues that crop up when you take over the task of handling navigations:

  • You need to manage focus yourself.
  • You need to manage scroll position yourself.

For classic server-rendered pages, most browser engines give you this functionality for free. You don’t have to code anything. But in an SPA, since you’re overriding the normal navigation behavior, you have to handle the focus yourself.

Wednesday, November 6th, 2019

The web is not dying | Go Make Things

A counterpart to the piece by Baldur that I linked to yesterday:

There are many challenges to face as the web grows.

Most of them are people problems. Habits. Inertia. A misalignment of priorities with user needs. Those can be overcome.

Tuesday, November 5th, 2019

Become a Front-End Master in 2020 With These 10 Project Ideas | CSS-Tricks

The title sounds clickbaity, but this is a thoughtful list of project ideas from Chris (partly prompted by the way other lists seem to involve nothing but JavaScript frameworks).

JavaScript isn’t always available and it’s not the user’s fault by Adam Silver

It’s not a matter of if your users don’t have JavaScript—it’s a matter of when and how often.

The answer to that is around 1% of the time.

If you had an application bug which occurred 1% of the time, you’d fix it. No team I’ve come across would put up with that level of reliability.

The same goes for JavaScript. It’s not about people who turn it off. It’s about the nature of the web itself.

Thursday, October 31st, 2019

Indy maps

Remember when I wrote about adding travel maps to my site at the recent Indie Web Camp Brighton? I must confess that the last line I wrote was an attempt to catch a fish from the river of the lazy web:

It’s a shame that I can’t use the lovely Stamen watercolour tiles for these static maps though.

In the spirit of Cunningham’s Law, I was hoping that somebody was going to respond with “It’s totally possible to use Stamen’s watercolour tiles for static maps, dumbass—look!” (to which my response would have been “thank you very much!”).

Alas, no such response was forthcoming. The hoped-for schooling never forthcame.

Still, I couldn’t quite let go of the idea of using those lovely watercolour maps somewhere on my site. But I had decided that dynamic maps would have been overkill for my archive pages:

Sure, it looked good, but displaying the map required requests for a script, a style sheet, and multiple map tiles.

Then I had a thought. What if I keep the static maps on my archive pages, but make them clickable? Then, on the other end of that link, I can have the dynamic version. In other words, what if I had a separate URL just for the dynamic maps?

These seemed like a good plan to me, so while I was travelling by Eurostar—the only way to travel—back from the lovely city of Antwerp where I had been speaking at Full Stack Europe, I started hacking away on making the dynamic maps even more dynamic. After all, now that they were going to have their own pages, I could go all out with any fancy features I wanted.

I kept coming back to my original goal:

I was looking for something more like the maps in Indiana Jones films—a line drawn from place to place to show the movement over time.

I found a plug-in for Leaflet.js that animates polylines—thanks, Iván! With a bit of wrangling, I was able to get it to animate between the lat/lon points of whichever archive section the map was in. Rather than have it play out automatically, I also added a control so that you can start and stop the animation. While I was at it, I decided to make that “play/pause” button do something else too. Ahem.

If you’d like to see the maps in action, click the “play” button on any of these maps:

You get the idea. It’s all very silly really. It’s right up there with the time I made my sparklines playable. But that’s kind of the point. It’s my website so I can do whatever I want with it, no matter how silly.

First of all, the research department for adactio.com (that’s me) came up with the idea. Then that had to be sold in to upper management (that’s me too). A team was spun up to handle design and development (consisting of me and me). Finally, the finished result went live thanks to the tireless efforts of the adactio.com ops group (that would be me). Any feedback should be directed at the marketing department (no idea who that is).

Wednesday, October 30th, 2019

Interactive web animation with SVG by Cassie Evans | CSSCAMP 2019 - YouTube

Cassie’s excellent talk on SVG animation is well worth your time.

Tuesday, October 29th, 2019

Periodic background sync

Yesterday I wrote about how much I’d like to see silent push for the web:

I’d really like silent push for the web—the ability to update a cache with fresh content as soon as it’s published; that would be nifty! At the same time, I understand the concerns. It feels more powerful than other permission-based APIs like notifications.

Today, John Holt Ripley responded on Twitter:

hi there, just read your blog post about Silent Push for acthe web, and wondering if Periodic Background Sync would cover a few of those use cases?

Periodic background sync looks very interesting indeed!

It’s not the same as silent push. As the name suggests, this is about your service worker waking up periodically and potentially fetching (and caching) fresh content from the network. So the service worker is polling rather than receiving a push. But I’ll take it! It’s definitely close enough for the kind of use-cases I’ve been thinking about.

Interestingly, periodic background sync also ties into the other part of what I was writing about: permissions. I mentioned that adding a site the home screen could be interpreted as a signal to potentially allow more permissions (or at least allow prompts for more permissions).

Well, Chromium has a document outlining metrics for attempting to gauge site engagement. There’s some good thinking in there.

Using the Platform | TimKadlec.com

Tim ponders the hard work that goes into adding standards to browsers, giving us a system with remarkable longevity.

So much care and planning has gone into creating the web platform, to ensure that even as new features are added, they’re added in a way that doesn’t break the web for anyone using an older device or browser. Can you say the same for any framework out there?

His parting advice is perfect:

Use the platform until you can’t, then augment what’s missing. And when you augment, do so with care because the responsibility of ensuring the security, accessibility, and performance that the platform tries to give you by default now falls entirely on you.

Using ES6 modules for progressive enhancement | Blog | Decade City

It looks like modules could be a great way to serve modern JavaScript to modern browsers, and serve polyfills or older code to older browsers.

Monday, October 28th, 2019

Silent push for the web

After Indie Web Camp in Berlin last year, I wrote about Seb’s nifty demo of push without notifications:

While I’m very unwilling to grant permission to be interrupted by intrusive notifications, I’d be more than willing to grant permission to allow a website to silently cache timely content in the background. It would be a more calm technology.

Phil Nash left a comment on the Medium copy of my post explaining that Seb’s demo of using the Push API without showing a notification wouldn’t work for long:

The browsers allow a certain number of mistakes(?) before they start to show a generic notification to say that your site sent a push notification without showing a notification. I believe that after ~10 or so notifications, and that’s different between browsers, they run out of patience.

He also provided me with the name to describe what I’m after:

You’re looking for “silent push” as are many others.

Silent push is something that is possible in native apps. It isn’t (yet?) available on the web, presumably because of security concerns.

It’s an API that would ripe for abuse. I mean, just look at the mess we’ve made with APIs like notifications and geolocation. Sure, they require explicit user opt-in, but these opt-ins are seen so often that users are sick of seeing them. Silent push would be one more permission-based API to add to the stack of annoyances.

Still, I’d really like silent push for the web—the ability to update a cache with fresh content as soon as it’s published; that would be nifty! At the same time, I understand the concerns. It feels more powerful than other permission-based APIs like notifications.

Maybe there could be another layer of permissions. What if adding a site to your home screen was the first step? If a site is running on HTTPS, has a service worker, has a web app manifest, and has been added to the homescreen, maybe then and only then should it be allowed to prompt for permission to do silent push.

In other words, what if certain very powerful APIs were only available to progressive web apps that have successfully been added to the home screen?

Frankly, I’d be happy if the same permissions model applied to web notifications too, but I guess that ship has sailed.

Anyway, all this is pure conjecture on my part. As far as I know, silent push isn’t on the roadmap for any of the browser vendors right now. That’s fair enough. Although it does annoy me that native apps have this capability that web sites don’t.

It used to be that there was a long list of features that only native apps could do, but that list has grown shorter and shorter. The web’s hare is catching up to native’s tortoise.

Friday, October 25th, 2019

Offline Page Descriptions | Erik Runyon

Here’s a nice example of showing pages offline. It’s subtly different from what I’m doing on my own site, which goes to show that there’s no one-size-fits-all recipe when it comes to offline strategies.

The difference between HTML, CSS, and JavaScript | Zell Liew

HTML lets you create the structure of a website.

CSS lets you make the website look nice.

JavaScript lets you change HTML and CSS. Because it lets you change HTML and CSS, it can do tons of things.

Why Are Accessible Websites so Hard to Build? | CSS-Tricks

I reckon a lot of websites have bad accessibility not because folks don’t care, but because they don’t know there’s an issue in the first place.

The headline is begging the question (I don’t think accessible websites are so hard to build), but I agree with Robin’s idea:

What if our text editors caught accessibility issues and showed them to us during development?

This is something that Hidde has been talking about recently too, looking at content management systems.

Tuesday, October 22nd, 2019

203221 – Web Share API: should prefer URL to text when both available

That unusual behaviour I wrote about with the Web Share API in Safari on iOS is now officially a bug—thanks, Tess!

Monday, October 21st, 2019

Indy web

It was Indie Web Camp Brighton on the weekend. After a day of thought-provoking discussions, I thoroughly enjoyed spending the second day tinkering on my website.

For a while now, I’ve wanted to add maps to my monthly archive pages (to accompany the calendar heatmaps I added at a previous Indie Web Camp). Whenever I post anything to my site—a blog post, a note, a link—it’s timestamped and geotagged. I thought it would be fun to expose that in a glanceable way. A map seems like the right medium for that, but I wanted to avoid the obvious route of dropping a load of pins on a map. Instead I was looking for something more like the maps in Indiana Jones films—a line drawn from place to place to show the movement over time.

I talked to Aaron about this and his advice was that a client-side JavaScript embedded map would be the easiest option. But that seemed like overkill to me. This map didn’t need to be pannable or zoomable; just glanceable. So I decided to see if how far I could get with a static map. I timeboxed two hours for it.

After two hours, I admitted defeat.

I was able to find the kind of static maps I wanted from Mapbox—I’m already using them for my check-ins. I could even add a polyline, which is exactly what I wanted. But instead of passing latitude and longitude co-ordinates for the points on the polyline, the docs explain that I needed to provide …cur ominous thunder and lightning… The Encoded Polyline Algorithm Format.

Go to that link. I’ll wait.

Did you read through the eleven steps of instructions? Did you also think it was a piss take?

  1. Take the initial signed value.
  2. Multiply it by 1e5.
  3. Convert that decimal value to binary.
  4. Left-shift the binary value one bit.
  5. If the original decimal value is negative, invert this encoding.
  6. Break the binary value out into 5-bit chunks.
  7. Place the 5-bit chunks into reverse order.
  8. OR each value with 0x20 if another bit chunk follows.
  9. Convert each value to decimal.
  10. Add 63 to each value.
  11. Convert each value to its ASCII equivalent.

This was way beyond my brain’s pay grade. But surely someone else had written the code I needed? I did some Duck Duck Going and found a piece of PHP code to do the encoding. It didn’t work. I Ducked Ducked and Went some more. I found a different piece of PHP code. That didn’t work either.

At this point, my allotted time was up. If I wanted to have something to demo by the end of the day, I needed to switch gears. So I did.

I used Leaflet.js to create the maps I wanted using client-side JavaScript. Here’s the JavaScript code I wrote.

It waits until the page has finished loading, then it searches for any instances of the h-geo microformat (a way of encoding latitude and longitude coordinates in HTML). If there are three or more, it generates a script element to pull in the Leaflet library, and a corresponding style element. Then it draws the map with the polyline on it. I ended up using Stamen’s beautiful watercolour map tiles.

Had some fun at Indie Web Camp Brighton on the weekend messing around with @Stamen’s lovely watercolour map tiles. (I was trying to create Indiana Jones style travel maps for my site …a different kind of Indy web.)

That’s what I demoed at the end of the day.

But I wasn’t happy with it.

Sure, it looked good, but displaying the map required requests for a script, a style sheet, and multiple map tiles. I made sure that it didn’t hold up the loading of the rest of the page, but it still felt wasteful.

So after Indie Web Camp, I went back to investigate static maps again. This time I did finally manage to find some PHP code for encoding lat/lon coordinates into a polyline that worked. Finally I was able to construct URLs for a static map image that displays a line connecting multiple points with a line.

I’ve put this maps on any of the archive pages that also have calendar heat maps. Some examples:

If you go back much further than that, the maps start to trail off. That’s because I wasn’t geotagging everything from the start.

I’m pretty happy with the final results. It’s certainly far more responsible from a performance point of view. Oh, and I’ve also got the maps inside a picture element so that I can swap out the tiles if you switch to dark mode.

It’s a shame that I can’t use the lovely Stamen watercolour tiles for these static maps though.

Wednesday, October 16th, 2019

IndieWeb Link Sharing | Max Böck - Frontend Web Developer

Max describes how he does bookmarking on his own site—he’s got a bookmarklet for sharing links, like I do. But he goes further with a smart use of the “share target” section in his web app manifest, as described by Aaron.

By the way, Max’s upcoming talk at the Web Clerks conference in Vienna sounds like it’s going to be unmissable!