Upgrades and polyfills
Tags: apple, ios, browsers, safari
Published: 2020-11-26 23:08:04

---
title: Upgrades and polyfills
published: true
date: 2020-11-11 12:44:56 UTC
tags: apple,ios,browsers,safari
canonical_url: https://adactio.com/journal/17605
---

I started getting some emails recently from people having issues using [The Session](https://thesession.org/). 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](https://adactio.com/journal/17428):

> 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](https://en.wikipedia.org/wiki/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](https://developer.apple.com/app-store/review/guidelines/#2.5.6) 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](https://www.lifewire.com/obsolete-ipad-4138570):

> 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](https://thesession.org/), 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—becuase 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](https://remysharp.com/2010/10/08/what-is-a-polyfill/) in place for all of those. Here’s [the polyfill I’m using for `matches` and `closest`](https://github.com/jonathantneal/closest/blob/master/src/index.js). And here’s [the polyfill I’m using for `forEach`](https://gist.github.com/hufyhang/c303ce1b80c7b6f8a73e).

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](https://vanillajstoolkit.com/polyfills/nodelistforeach/).

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](https://gist.github.com/adactio/e2bcd49379d4385e577924ec3339aeb1). 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.