Tags: progressive enhancement

313

sparkline

Saturday, February 15th, 2020

Same HTML, Different CSS

Like a little mini CSS Zen Garden, here’s one compenent styled five very different ways.

Crucially, the order of the markup doesn’t consider the appearance—it’s concerned purely with what makes sense semantically. And now with CSS grid, elements can be rearranged regardless of source order.

CSS is powerful and capable of doing amazingly beautiful things. Let’s embrace that and keep the HTML semantical instead of adapting it to the need of the next design change.

Thursday, February 6th, 2020

Local First, Undo Redo, JS-Optional, Create Edit Publish - Tantek

Tantek documents the features he wants his posting interface to have.

Hydration

As you may have noticed, I’m a fan of progressive enhancement.

It’s not cool. It’s often at odds with “modern” web development, so I end up looking like an old man yelling at a cloud to get off my lawn. Or something.

At its heart though, progressive enhancement seems fairly uncontroversial and inoffensive to me. It’s an approach. A mindset. Here’s how I describe it in Resilient Web Design:

  1. Identify core functionality.
  2. Make that functionality available using the simplest possible technology.
  3. Enhance!

Progressive enhancement makes use of the principle of least power:

Choose the least powerful language suitable for a given purpose.

That’s step two of the three-step process. But the third step is vital.

I think a lot of the hostility towards progressive enhancement comes from a misunderstanding of that three-step process, perhaps thinking that it stops at step two. I’m sure that some have intrepreted progressive enhancement as preventing developers from using the latest and greatest technology. Nothing could be further from the truth!

Taking a layered approach to building on the web gives you permission to try cutting‐edge JavaScript APIs, regardless of how many or how few browsers currently implement them.

The most common misunderstanding of progressive enhancement is that it’s inherently about JavaScript. That’s not true. You can apply progressive enhancement at every step of front-end development: HTML, CSS, and JavaScript.

But because of JavaScript’s strict error-handling model (at least compared to HTML and CSS), it’s in the JavaScript layer that the lack of a progressive enhancement mindset is most often felt.

That’s why I was saddened by the rise of frameworks and mindsets that assume the availability of JavaScript. Single page apps generally follow this assumption. Everything is delivered via JavaScript: content, markup, styles, and behaviour.

This leads to a terrible situation for performance. The user is left staring at a blank screen, waiting for something—anything!—to appear. Browsers are optimised to stream HTML as soon as they can. Delivering your content via JavaScript rather than HTML means you’re not taking advantage of that optimisation. Your users suffer.

But I was very heartened when I saw the pendulum start to swing back the other way a bit…

Let’s say you’re using a JavaScript framework like React. But the reason you’re using it isn’t because you’re doing anything particularly complex in the browser involving state management. You might be using React because you really like the way it encourages modularity and componentisation.

A few years ago, making a single page app was pretty much the only way you could use React. For you as a developer to experience the benefits of modularity and componentisation, users had to pay the price in the payload (and fragility) of client-side JavaScript.

That’s no longer the case. Now that we can run JavaScript on the server, it’s possible to build in a modular, componentised way and still use progressive enhancement.

When I first heard about Gatsby and Next.js, I thought that was the selling point. Run React on the server; send pre-generated HTML down the wire to the user; then enhance with client-side JavaScript.

But that’s not exactly how it works. The pre-generated HTML isn’t functional. It still needs a bucketload of JavaScript before it can do anything. The actual process is: Run React on the server; send pre-generated HTML down the wire to the user; then send everything again but this time in JavaScript, bundled with the entire React library.

This leads to a situation for users that’s almost worse than before. Instead of staring at a blank screen, now they get HTML lickety-split—excellent! But if they try to interact with what’s on screen, they’ll find that nothing is working yet. Even worse, once the JavaScript is delivered, and is being parsed, they probably can’t even scroll—their device is too busy interpreting all that JavaScript. Your users suffer.

All your content is sent twice. First HTML is sent from the server. These days this is called “server-side rendering”, even though for decades the technical term was “serving a web page” (I’m pretty sure the rendering part happens in a browser). Then a JavaScript library—plus all your bespoke JavaScript—is loaded. Then all your content is loaded again as JSON.

So you’ve got a facade of an interface that you can’t actually interact with until a deluge of JavaScript has been loaded, parsed and executed. The term used for this stage of the process is “hydration”, which makes it sound more like a relaxing treatment from Gwyneth Paltrow than the horrible user experience it is.

The idea is that subsequent navigations—which will happen with Ajax—should be snappy. But the price has already been paid by then. The initial loading experience is jagged and frustrating.

Don’t get me wrong: server-side rendering is great …if what you’re sending from the server is functional. It’s the combination of hollow HTML sent from the server, followed by a huge browser-freezing dump of JavaScript that is an anti-pattern.

This use of server-side rendering followed by hydration feels like progressive enhancement, because it separates out the delivery of markup and scripts. But it’s missing the mindset.

The layered approach of progressive enhancement echoes the separation of concerns in the front-end stack: HTML, CSS, and JavaScript—each layer expressing more power. But while these concepts are related, they’re not interchangable. Separating out the layers of your tech stack isn’t necessarily progressive enhancement. If you have some HTML that relies on JavaScript to be useful, then there’s no benefit in separating that HTML into a separate payload. The HTML that you initially send down the wire needs to be functional (at least at a basic level) before the JavaScript arrives.

I was a little disappointed to see Kyle Simpson—who I admire greatly—conflate separation of concerns with progressive enhancement in his talk from JSCamp 2019:

This content is here. I can see it, and it’s even styled. But I can’t click on the damn button because nothing has loaded in the JavaScript layer yet.

Anybody experienced that where you’ve been on a web page and it’s not really fully functional yet? I can see something but I can’t actually make any usage of it yet.

These are all things that cropped out of our thought process that said: “Let’s build the web in layers. Let’s deliver it progressively in layers. Because that’s morally right. We call this progressive enhancement. And let’s not worry too much about all these potential user experience flaws that may happen.”

That’s a spot-on description of server-side rendering and hydration, but it’s a gross mischaracterisation of progressive enhancement.

That button that requires JavaScript to work? That should’ve been generated with JavaScript. (For example, if you’re building a complex web app, consider sending a read-only view down the wire in HTML—then add any interactive interface elements with JavaScript in the browser.)

If people are equating progressive enhancement with thoughtless server-side rendering and hydration, then I can see why they’d be hostile towards it.

Users would be better served with unprogressive non-enhancement:

You take some structured content, which follows the vertical flow of the document in a way that everyone understands.

Which people traverse easily by either dragging their scroll bar with their mouse, or operating the keyboard using the up and down keys, or using the spacebar.

Or if they’re using a touch device, simply flicking backwards and forwards in that easy way that we’ve all become used to. What you do is you take that, and you fucking well leave it alone.

Alas, that’s not what tools like Gatsby offer. The latest post on their blog is called Why Gatsby is better with JavaScript:

But what about sites or pages where there is no client-side interactivity? Even for those pages, Gatsby offers performance benefits by including JavaScript.

I beg to differ.

(By the way, that same blog post also initially tried to equate the performance hit of client-side JavaScript with the performance hit of images. Andy explains why that’s disingenuous.)

Hope is on the horizon for React in the form of partial hydration. I sincerely hope that it will become the default way of balancing server-side rendering with just-in-time client-side interaction.

The situation we have now is the worst of both worlds: server-side rendering followed by a tsunami of hydration. It has a whiff of progressive enhancement to it (because there’s a cosmetic separation of concerns) but it has none of the user benefits.

Monday, February 3rd, 2020

Progressive enhancement doesn’t have to be hard - Levi McGranahan

It’s wild because in engineering terms this question, how does it fail?, should be the first one we ask, but oftentimes it is never even considered in front-end development. A good example is most client-side JS frameworks that render the entire UI in the browser, how would your app or site fail in that situation?

N26 and lack of JavaScript | Hugo Giraudel

JavaScript is fickle. It can fail to load. It can be disabled. It can be blocked. It can fail to run. It probably is fine most of the time, but when it fails, everything tends to go bad. And having such a hard point of failure is not ideal.

This is a very important point:

It’s important not to try making the no-JS experience work like the full one. The interface has to be revisited. Some features might even have to be removed, or dramatically reduced in scope. That’s also okay. As long as the main features are there and things work nicely, it should be fine that the experience is not as polished.

Monday, January 13th, 2020

Smaller HTML Payloads with Service Workers — Philip Walton

This is a great progressive enhancement for performance that uses a service worker to combine reusable bits of a page with fresh content. The numbers are very convincing!

Alas, the code is using the Workbox library, but figuring out the vanilla code to write shouldn’t be too tricky seeing as Philip talks through his logic step by step.

Sunday, December 29th, 2019

Move Fast & Don’t Break Things | Filament Group, Inc.

This is the transcript of a brilliant presentation by Scott—read the whole thing! It starts with a much-needed history lesson that gets to where we are now with the dismal state of performance on the web, and then gives a whole truckload of handy tips and tricks for improving performance when it comes to styles, scripts, images, fonts, and just about everything on the front end.

Essential!

Thursday, November 21st, 2019

A Non-Business Case for Supporting Old Browsers « Texte | ovl – code & design

Supporting Internet Explorer 11 doesn’t mean you need to give it the same experience as a modern browser:

Making sure (some of) your code works in older browsers, does not mean all functionality has to work everywhere. But, mind you, ninety percent of web development means putting text and images in boxes.

And to be honest, there is no reason to not enable this everywhere. Same for form submissions. Make it boring. Make it solid. And sprinkle delight on it.

Saturday, November 16th, 2019

The Layers Of The Web - Jeremy Keith on Vimeo

Thanks to the quick work of Marc and his team, the talk I gave at Beyond Tellerrand on Thursday was online within hours!

I’m really pleased with how this turned out. I wasn’t sure if anybody was going to be interested in the deep dive into history that I took for the first 15 or 20 minutes, but lots of people told me that they really enjoyed that part, so that makes me happy.

Tuesday, November 5th, 2019

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.

Tuesday, October 29th, 2019

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.

Sunday, October 13th, 2019

The “P” in Progressive Enhancement stands for “Pragmatism” - Andy Bell

With a Progressive Enhancement mindset, support actually means support. We’re not trying to create an identical experience: we’re creating a viable experience instead.

Also with Progressive Enhancement, it’s incredibly likely that your IE11 user, or your user on a low-powered device, or even your user on a poor connection won’t notice that they’re experiencing a “minor” experience because it’ll just work for them. This is the magic, right there. Everyone’s a winner.

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.

Monday, September 16th, 2019

The Book | The Lean Web

This is such a great little web book from Chris Ferdinandi that you can read online for free.

  1. Intro
  2. Modern Best Practices
  3. How did we get here?
  4. Lean Web Principles
  5. What now?

Saturday, August 31st, 2019

Less Data Doesn’t Mean a Lesser Experience| TimKadlec.com

If you treat data as a constraint in your design and development process, you’ll likely be able to brainstorm a large number of different ways to keep data usage to a minimum while still providing an excellent experience. Doing less doesn’t mean it has to feel broken.

Friday, August 9th, 2019

Redux: Lazy loading youtube embeds

Remy has an excellent improvement on that article I linked to yesterday on using srcdoc with iframes. Rather than using srcdoc instead of src, you can use srcdoc as well as src. That way you can support older browsers too!

Wednesday, July 24th, 2019

Progressive Enhancement

This post was originally written in 2015, but upon re-reading it today, it still (just about) holds up, so I finally hit publish.

Tuesday, June 25th, 2019

In defence of graceful degradation and where progressive enhancement comes in by Adam Silver

This does a really good job of describing the difference between progressive enhancement and graceful degradation …but I don’t buy the conclusion: I don’t think that feature detection equates to graceful degradation. I do agree though that, when it comes to JavaScript, the result of progressive enhancement is that the language degrades gracefully.

This is progressive enhancement. An approach to making interfaces that ensures JavaScript degrades gracefully—something that HTML and CSS do automatically.

But there’s a difference between something degrading gracefully (the result) and graceful degradation (the approach).

Friday, June 7th, 2019

Building on Vimeo

Here’s the video of the opening talk I gave at New Adventures earlier this year. I think it’s pretty darn good!

Thursday, June 6th, 2019

Designing for actual performance by Adam Silver

This is something I’ve been thinking about a lot lately. The justification for single page apps feels like circular thinking to me. A JavaScript framework is needed to avoid full page refreshes because full page refreshes are expensive because that means assets will be reloaded …assets like the JavaScript framework that only exists to avoid the full page refresh.

This is how it goes. We put a load of shit into a single web page. This makes the page slow. Slow to load, slow to render. Slow.

Instead of getting rid of the shit, we blame the page refresh.