Tags: polyfill

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Tuesday, July 12th, 2022

Stop supporting Internet Explorer!

The headline is clickbaity, but the advice is solid. Use progressive enhancement and don’t worry about polyfilling.

When I say ‘Stop supporting IE’ it means to me that I won’t go the extra mile to get unsupported features working in Internet Explorer, but still make sure Internet Explorer users get the basics, and can use the site.

Wednesday, June 29th, 2022

How we think about browsers | The GitHub Blog

JavaScript doesn’t get executed on very old browsers when native syntax for new language features is encountered. However, thanks to GitHub being built following the principle of progressive enhancement, users of older browsers still get to interact with basic features of GitHub, while users with more capable browsers get a faster experience.

That’s the way to do it!

Concepts like progressive enhancement allow us to deliver the best experience possible to the majority of customers, while delivering a useful experience to those using older browsers.

Read on for the nitty-gritty details…

Tuesday, June 28th, 2022

Tuesday, December 7th, 2021

Web tech is better. Developer norms are worse. | Go Make Things

The web historically moves in waves.

Libraries are created to push complex features in an easier way. Then the libraries themselves get complicated, often more so than the benefits they provide.

Eventually, (some of) the core features of those libraries make their way into the browser itself, but the libraries linger like water on the shore, slowly receding.

And before the sand has a chance to fully dry, a new set of libraries washes in to push the web even further.

Sunday, November 28th, 2021

Modern CSS in a Nutshell - Cloud Four

I like this high-level view of the state of CSS today. There are two main takeaways:

  1. Custom properties, flexbox, and grid are game-changers.
  2. Pre- and post-processers are becoming less and less necessary.

This is exactly the direction we should be going in! More and more power from the native web technologies (while still remaining learnable), with less and less reliance on tooling. For CSS, the tools have been like polyfills that we can now start to remove.

Alas, while the same should be true of JavaScript (there’s so much you can do in native JavaScript now), people seem to have tied their entire identities to the tooling they use.

They could learn a thing or two from the trajectory of CSS: treat your frameworks as cattle, not pets.

Sunday, March 7th, 2021

Imagining native skip links | Kitty Giraudel

I like this proposal, and I like that it’s polyfillable (which is a perfectly cromulent word).

Saturday, January 2nd, 2021

Loading and replacing HTML parts with HTML

I like this proposal for a declarative Ajax pattern. It’s relatively straightforward to polyfill, although backward-compatibility is an issue because of existing browser behaviour with the target attribute.

Wednesday, November 11th, 2020

Upgrades and polyfills

I started getting some emails recently from people having issues using The Session. The issues sounded similar—an interactive component that wasn’t, well …interacting.

When I asked what device or browser they were using, the answer came back the same: Safari on iPad. But not a new iPad. These were older iPads running older operating systems.

Now, remember, even if I wanted to recommend that they use a different browser, that’s not an option:

Safari is the only browser on iOS devices.

I don’t mean it’s the only browser that ships with iOS devices. I mean it’s the only browser that can be installed on iOS devices.

You can install something called Chrome. You can install something called Firefox. Those aren’t different web browsers. Under the hood they’re using Safari’s rendering engine. They have to.

It gets worse. Not only is there no choice when it comes to rendering engines on iOS, but the rendering engine is also tied to the operating system.

If you’re on an old Apple laptop, you can at least install an up-to-date version of Firefox or Chrome. But you can’t install an up-to-date version of Safari. An up-to-date version of Safari requires an up-to-date version of the operating system.

It’s the same on iOS devices—you can’t install a newer version of Safari without installing a newer version of iOS. But unlike the laptop scenario, you can’t install any version of Firefox of Chrome.

It’s disgraceful.

It’s particularly frustrating when an older device can’t upgrade its operating system. Upgrades for Operating system generally have some hardware requirements. If your device doesn’t meet those requirements, you can’t upgrade your operating system. That wouldn’t matter so much except for the Safari issue. Without an upgraded operating system, your web browsing experience stagnates unnecessarily.

For want of a nail

  • A website feature isn’t working so
  • you need to upgrade your browser which means
  • you need to upgrade your operating sytem but
  • you can’t upgrade your operating system so
  • you need to buy a new device.

Apple doesn’t allow other browsers to be installed on iOS devices so people have to buy new devices if they want to use the web. Handy for Apple. Bad for users. Really bad for the planet.

It’s particularly galling when it comes to iPads. Those are exactly the kind of casual-use devices that shouldn’t need to be caught in the wasteful cycle of being used for a while before getting thrown away. I mean, I get why you might want to have a relatively modern phone—a device that’s constantly with you that you use all the time—but an iPad is the perfect device to just have lying around. You shouldn’t feel pressured to have the latest model if the older version still does the job:

An older tablet makes a great tableside companion in your living room, an effective e-book reader, or a light-duty device for reading mail or checking your favorite websites.

Hang on, though. There’s another angle to this. Why should a website demand an up-to-date browser? If the website has been built using the tried and tested approach of progressive enhancement, then everyone should be able to achieve their goals regardless of what browser or device or operating system they’re using.

On The Session, I’m using progressive enhancement and feature detection everywhere I can. If, for example, I’ve got some JavaScript that’s going to use querySelectorAll and addEventListener, I’ll first test that those methods are available.

if (!document.querySelectorAll || !window.addEventListener) {
  // doesn't cut the mustard.
  return;
}

I try not to assume that anything is supported. So why was I getting emails from people with older iPads describing an interaction that wasn’t working? A JavaScript error was being thrown somewhere and—because of JavaScript’s brittle error-handling—that was causing all the subsequent JavaScript to fail.

I tracked the problem down to a function that was using some DOM methods—matches and closest—as well as the relatively recent JavaScript forEach method. But I had polyfills in place for all of those. Here’s the polyfill I’m using for matches and closest. And here’s the polyfill I’m using for forEach.

Then I spotted the problem. I was using forEach to loop through the results of querySelectorAll. But the polyfill works on arrays. Technically, the output of querySelectorAll isn’t an array. It looks like an array, it quacks like an array, but it’s actually a node list.

So I added this polyfill from Chris Ferdinandi.

That did the trick. I checked with the people with those older iPads and everything is now working just fine.

For the record, here’s the small collection of polyfills I’m using. Polyfills are supposed to be temporary. At some stage, as everyone upgrades their browsers, I should be able to remove them. But as long as some people are stuck with using an older browser, I have to keep those polyfills around.

I wish that Apple would allow other rendering engines to be installed on iOS devices. But if that’s a hell-freezing-over prospect, I wish that Safari updates weren’t tied to operating system updates.

Apple may argue that their browser rendering engine and their operating system are deeply intertwingled. That line of defence worked out great for Microsoft in the ‘90s.

Thursday, October 1st, 2020

share-button-type/explainer.md

If you’ve been following my recent blog posts about a declarative option for the Web Share API, you might be interested in this explainer document I’ve put together. It outlines the use case for button type="share".

Wednesday, September 16th, 2020

A polyfill for button type=”share”

After writing about a declarative Web Share API here yesterday I thought I’d better share the idea (see what I did there?).

I opened an issue on the Github repo for the spec.

(I hope that’s the right place for this proposal. I know that in the past ideas were kicked around on the Discourse site for Web platform Incubator Community Group but I can’t stand Discourse. It literally requires JavaScript to render anything to the screen even though the entire content is text. If it turns out that that is the place I should’ve posted, I guess I’ll hold my nose and do it using the most over-engineered reinvention of the browser I’ve ever seen. But I believe that the plan is for WICG to migrate proposals to Github anyway.)

I also realised that, as the JavaScript Web Share API already exists, I can use it to polyfill my suggestion for:

<button type="share">

The polyfill also demonstrates how feature detection could work. Here’s the code.

This polyfill takes an Inception approach to feature detection. There are three nested levels:

  1. This browser supports button type="share". Great! Don’t do anything. Otherwise proceed to level two.
  2. This browser supports the JavaScript Web Share API. Use that API to share the current page URL and title. Otherwise proceed to level three.
  3. Use a mailto: link to prefill an email with the page title as the subject and the URL in the body. Ya basic!

The idea is that, as long as you include the 20 lines of polyfill code, you could start using button type="share" in your pages today.

I’ve made a test page on Codepen. I’m just using plain text in the button but you could use a nice image or SVG or combination. You can use the Codepen test page to observe two of the three possible behaviours browsers could exhibit:

  1. A browser supports button type="share". Currently that’s none because I literally made this shit up yesterday.
  2. A browser supports the JavaScript Web Share API. This is Safari on Mac, Edge on Windows, Safari on iOS, and Chrome, Samsung Internet, and Firefox on Android.
  3. A browser supports neither button type="share" nor the existing JavaScript Web Share API. This is Firefox and Chrome on desktop (and Edge if you’re on a Mac).

See the Pen Polyfill for button type=”share" by Jeremy Keith (@adactio) on CodePen.

The polyfill doesn’t support Internet Explorer 11 or lower because it uses the DOM closest() method. Feel free to fork and rewrite if you need to support old IE.

Monday, August 17th, 2020

Mind the gap

In May 2012, Brian LeRoux, the creator of PhoneGap, wrote a post setting out the beliefs, goals and philosophy of the project.

The beliefs are the assumptions that inform everything else. Brian stated two core tenets:

  1. The web solved cross platform.
  2. All technology deprecates with time.

That second belief then informed one of the goals of the PhoneGap project:

The ultimate purpose of PhoneGap is to cease to exist.

Last week, PhoneGap succeeded in its goal:

Since the project’s beginning in 2008, the market has evolved and Progressive Web Apps (PWAs) now bring the power of native apps to web applications.

Today, we are announcing the end of development for PhoneGap.

I think Brian was spot-on with his belief that all technology deprecates with time. I also think it was very astute of him to tie the goals of PhoneGap to that belief. Heck, it’s even in the project name: PhoneGap!

I recently wrote this about Sass and clamp:

I’ve said it before and I’ll say it again, the goal of any good library should be to get so successful as to make itself redundant. That is, the ideas and functionality provided by the tool are so useful and widely adopted that the native technologies—HTML, CSS, and JavaScript—take their cue from those tools.

jQuery is the perfect example of this. jQuery is no longer needed because cross-browser DOM Scripting is now much easier …thanks to jQuery.

Successful libraries and frameworks point the way. They show what developers are yearning for, and that’s where web standards efforts can then focus. When a library or framework is no longer needed, that’s not something to mourn; it’s something to celebrate.

That’s particularly true if the library of code needs to be run by a web browser. The user pays a tax with that extra download so that the developer gets the benefit of the library. When web browsers no longer need the library in order to provide the same functionality, it’s a win for users.

In fact, if you’re providing a front-end library or framework, I believe you should be actively working towards making it obselete. Think of your project as a polyfill. If it’s solving a genuine need, then you should be looking forward to the day when your code is made redundant by web browsers.

One more thing…

I think it was great that Brian documented PhoneGap’s beliefs, goals and philosophy. This is exactly why design principles can be so useful—to clearly set out the priorities of a project, so that there’s no misunderstanding or mixed signals.

If you’re working on a project, take the time to ask yourself what assumptions and beliefs are underpinning the work. Then figure out how those beliefs influence what you prioritise.

Ultimately, the code you produce is the output generated by your priorities. And your priorities are driven by your purpose.

You can make those priorities tangible in the form of design principles.

You can make those design principles visible by publishing them.

Sunday, July 21st, 2019

The Simplest Way to Load CSS Asynchronously | Filament Group, Inc.

Scott re-examines the browser support for loading everything-but-the-critical-CSS asynchronously and finds that it might now be as straightforward as this one declaration:

<link rel="stylesheet" href="/path/to/my.css" media="print" onload="this.media='all'">

I love the fact the Filament Group are actively looking at how deprecate their loadCSS polyfill—exactly the right attitude for polyfills in general.

Friday, March 22nd, 2019

I Used The Web For A Day On Internet Explorer 8 — Smashing Magazine

A fascinating look at the web today with IE8. And it’s worth remembering who might be experiencing the web like this:

Whoever they are, you can bet they’re not using an old browser just to annoy you. Nobody deliberately chooses a worse browsing experience.

The article also outlines two possible coping strategies:

  1. Polyfilling Strive for feature parity for all by filling in the missing browser functionality.
  2. Progressive Enhancement Start from a core experience, then use feature detection to layer on functionality.

Take a wild guess as to which strategy I support.

There’s a bigger point made at the end of all this:

IE8 is today’s scapegoat. Tomorrow it’ll be IE9, next year it’ll be Safari, a year later it might be Chrome. You can swap IE8 out for ‘old browser of choice’. The point is, there will always be some divide between what browsers developers build for, and what browsers people are using. We should stop scoffing at that and start investing in robust, inclusive engineering solutions. The side effects of these strategies tend to pay dividends in terms of accessibility, performance and network resilience, so there’s a bigger picture at play here.

Sunday, June 3rd, 2018

AMPstinction

I’ve come to believe that the goal of any good framework should be to make itself unnecessary.

Brian said it explicitly of his PhoneGap project:

The ultimate purpose of PhoneGap is to cease to exist.

That makes total sense, especially if your code is a polyfill—those solutions are temporary by design. Autoprefixer is another good example of a piece of code that becomes less and less necessary over time.

But I think it’s equally true of any successful framework or library. If the framework becomes popular enough, it will inevitably end up influencing the standards process, thereby becoming dispensible.

jQuery is the classic example of this. There’s very little reason to use jQuery these days because you can accomplish so much with browser-native JavaScript. But the reason why you can accomplish so much without jQuery is because of jQuery. I don’t think we would have querySelector without jQuery. The library proved the need for the feature. The same is true for a whole load of DOM scripting features.

The same process is almost certain to occur with React—it’s a good bet there will be a standardised equivalent to the virtual DOM at some point.

When Google first unveiled AMP, its intentions weren’t clear to me. I hoped that it existed purely to make itself redundant:

As well as publishers creating AMP versions of their pages in order to appease Google, perhaps they will start to ask “Why can’t our regular pages be this fast?” By showing that there is life beyond big bloated invasive web pages, perhaps the AMP project will work as a demo of what the whole web could be.

Alas, as time has passed, that hope shows no signs of being fulfilled. If anything, I’ve noticed publishers using the existence of their AMP pages as a justification for just letting their “regular” pages put on weight.

Worse yet, the messaging from Google around AMP has shifted. Instead of pitching it as a format for creating parallel versions of your web pages, they’re now also extolling the virtues of having your AMP pages be the only version you publish:

In fact, AMP’s evolution has made it a viable solution to build entire websites.

On an episode of the Dev Mode podcast a while back, AMP was a hotly-debated topic. But even those defending AMP were doing so on the understanding that it was more a proof-of-concept than a long-term solution (and also that AMP is just for news stories—something else that Google are keen to change).

But now it’s clear that the Google AMP Project is being marketed more like a framework for the future: a collection of web components that prioritise performance …which is kind of odd, because that’s also what Google’s Polymer project is. The difference being that pages made with Polymer don’t get preferential treatment in Google’s search results. I can’t help but wonder how the Polymer team feels about AMP’s gradual pivot onto their territory.

If the AMP project existed in order to create a web where AMP was no longer needed, I think I could get behind it. But the more it’s positioned as the only viable solution to solving performance, the more uncomfortable I am with it.

Which, by the way, brings me to one of the most pernicious ideas around Google AMP—positioning anyone opposed to it as not caring about web performance. Nothing could be further from the truth. It’s precisely because performance on the web is so important that it deserves a long-term solution, co-created by all of us: not some commandents delivered to us from on-high by one organisation, enforced by preferential treatment by that organisation’s monopoly in search.

It’s the classic logical fallacy:

  1. Performance! Something must be done!
  2. AMP is something.
  3. Now something has been done.

By marketing itself as the only viable solution to the web performance problem, I think the AMP project is doing itself a great disservice. If it positioned itself as an example to be emulated, I would welcome it.

I wish that AMP were being marketed more like a temporary polyfill. And as with any polyfill, I look forward to the day when AMP is no longer necesssary.

I want AMP to become extinct. I genuinely think that the Google AMP team should share that wish.

Sunday, January 14th, 2018

Meet the New Dialog Element

Move over, JavaScript alerts; HTML dialogs are here.

Wednesday, February 8th, 2017

Polyfills and the evolution of the web - TAG finding

Really good advice for anyone thinking of releasing a polyfill into the world.

Saturday, December 24th, 2016

10 things I learned making the fastest site in the world

Behind the amusing banter there’s some really solid performance advice in here. Good stuff.

Client Side Rendering (CSR), or as I call it “setting money on fire and throwing it in a river” has its uses, but for this site would have been madness.

Monday, October 10th, 2016

The Web is not Fashionable. - The blog of Ada Rose Edwards

This is such a great perspective on what it’s like to build for the web over the long term. The web will always be a little bit broken, and that’s okay—we can plan for that.

The Web has history. If you build with web technology it will stick around. We try not to break the web even if it means the mistakes and bad decisions we have made in the past (and will make in the future) get set in stone.

Saturday, June 25th, 2016

Wednesday, June 1st, 2016

Introducing Multirange: A tiny polyfill for HTML5.1 two-handle sliders | Lea Verou

You’re supposed to be able to create two-handled sliders with input type="range" but the browser support isn’t there yet. In the meantime, Lea has created a nice lightweight polyfill.