Tags: progressive

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Friday, July 20th, 2018

Introducing ‘My Browser’ - Andy Bell - Front-End Developer

Andy describes the technical approach he took building his handy reporting tool, My Browser:

Although the site is built with bleeding edge technology such as web components, it’s built with a progressive-first approach. This means that in order to get the best experience, you need to be on a modern browser, but to do the most basic function—reporting data, you can still do it by pressing a “generate report” button, which is the default state.

Not only is this a liberating way to work, it really pays off in performance:

We’re given so much for free to make a progressively enhanced website or web app. We’ve got feature detection and @supports in CSS which means that “My Browser” ships with no polyfills, fallbacks or hacks like Autoprefixer. The app degrades gracefully instead.

This has been a very refreshing way to work that I’ve enjoyed a lot. The fact that the whole thing comes in around 25kb tells you how effective progressive enhancement can be for performance too.

Short note on progressive ARIA by The Paciello Group

Léonie makes a really good point here: if you’re adding aria attributes to indicate interactions you’re making available through JavaScript, then make sure you also use JavaScript to add those aria attributes.

Tuesday, July 10th, 2018

Twitter and Instagram progressive web apps

Since support for service workers landed in Mobile Safari on iOS, I’ve been trying a little experiment. Can I replace some of the native apps I use with progressive web apps?

The two major candidates are Twitter and Instagram. I added them to my home screen, and banished the native apps off to a separate screen. I’ve been using both progressive web apps for a few months now, and I have to say, they’re pretty darn great.

There are a few limitations compared to the native apps. On Twitter, if you follow a link from a tweet, it pops open in Safari, which is fine, but when you return to Twitter, it loads anew. This isn’t any fault of Twitter—this is the way that web apps have worked on iOS ever since they introduced their weird web-app-capable meta element. I hope this behaviour will be fixed in a future update.

Also, until we get web notifications on iOS, I need to keep the Twitter native app around if I want to be notified of a direct message (the only notification I allow).

Apart from those two little issues though, Twitter Lite is on par with the native app.

Instagram is also pretty great. It too suffers from some navigation issues. If I click through to someone’s profile, and then return to the main feed, it also loads it anew, losing my place. It would be great if this could be fixed.

For some reason, the Instagram web app doesn’t allow uploading multiple photos …which is weird, because I can upload multiple photos on my own site by adding the multiple attribute to the input type="file" in my posting interface.

Apart from that, though, it works great. And as I never wanted notifications from Instagram anyway, the lack of web notifications doesn’t bother me at all. In fact, because the progressive web app doesn’t keep nagging me about enabling notifications, it’s a more pleasant experience overall.

Something else that was really annoying with the native app was the preponderance of advertisements. It was really getting out of hand.

Well …(looks around to make sure no one is listening)… don’t tell anyone, but the Instagram progressive web app—i.e. the website—doesn’t have any ads at all!

Here’s hoping it stays that way.

Components and concerns

We tend to like false dichotomies in the world of web design and web development. I’ve noticed one recently that keeps coming up in the realm of design systems and components.

It’s about separation of concerns. The web has a long history of separating structure, presentation, and behaviour through HTML, CSS, and JavaScript. It has served us very well. If you build in that order, ensuring that something works (to some extent) before adding the next layer, the result will be robust and resilient.

But in this age of components, many people are pointing out that it makes sense to separate things according to their function. Here’s the Diana Mounter in her excellent article about design systems at Github:

Rather than separating concerns by languages (such as HTML, CSS, and JavaScript), we’re are working towards a model of separating concerns at the component level.

This echoes a point made previously in a slidedeck by Cristiano Rastelli.

Separating interfaces according to the purpose of each component makes total sense …but that doesn’t mean we have to stop separating structure, presentation, and behaviour! Why not do both?

There’s nothing in the “traditonal” separation of concerns on the web (HTML/CSS/JavaScript) that restricts it only to pages. In fact, I would say it works best when it’s applied on smaller scales.

In her article, Pattern Library First: An Approach For Managing CSS, Rachel advises starting every component with good markup:

Your starting point should always be well-structured markup.

This ensures that your content is accessible at a very basic level, but it also means you can take advantage of normal flow.

That’s basically an application of starting with the rule of least power.

In chapter 6 of Resilient Web Design, I outline the three-step process I use to build on the web:

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

That chapter is filled with examples of applying those steps at the level of an entire site or product, but it doesn’t need to end there:

We can apply the three‐step process at the scale of individual components within a page. “What is the core functionality of this component? How can I make that functionality available using the simplest possible technology? Now how can I enhance it?”

There’s another shared benefit to separating concerns when building pages and building components. In the case of pages, asking “what is the core functionality?” will help you come up with a good URL. With components, asking “what is the core functionality?” will help you come up with a good name …something that’s at the heart of a good design system. In her brilliant Design Systems book, Alla advocates asking “what is its purpose?” in order to get a good shared language for components.

My point is this:

  • Separating structure, presentation, and behaviour is a good idea.
  • Separating an interface into components is a good idea.

Those two good ideas are not in conflict. Presenting them as though they were binary choices is like saying “I used to eat Italian food, but now I drink Italian wine.” They work best when they’re done in combination.

Tuesday, June 26th, 2018

10 Progressive Web App Examples that Brand Owners can Learn From - Iflexion

Adriana Blum lists progressive web apps that are doing very, very well from Twitter, Trivago, Starbucks, Forbes, Debebhams, West Elm, Washington Post, Pinterest, AliExpress, and Lancôme.

Instead of choosing between the immediacy of a mobile website and the rich experience offered by native apps, you can now offer your target audiences the best of both and improve the commercial performance of your business to boot.

Monday, June 18th, 2018

User agent as a runtime | Blog | Decade City

Ultimately you can’t control when and how things go wrong but you do have some control over what happens. This is why progressive enhancement exists.

Tuesday, June 12th, 2018

Any Site can be a Progressive Web App - Jeremy Keith | DeltaV 2018 - YouTube

Here’s a really quick (ten minute) talk about the offline user experience that I gave at the Delta V conference recently. I’m quite happy with how it turned out—there’s something to be said for having a short and snappy time slot.

There’s a common misconception that making a Progressive Web App means creating a Single Page App with an app-shell architecture. But the truth is that literally any website can benefit from the performance boost that results from the combination of HTTPS + Service Worker + Web App Manifest.

Any Site can be a Progressive Web App - Jeremy Keith | DeltaV 2018

Tuesday, June 5th, 2018

Clearleft.com is a progressive web app

What’s that old saying? The cobbler’s children have no shoes that work offline. Or something.

It’s been over a year since the Clearleft site relaunched and I listed some of the next steps I had planned:

Service worker. It’s a no-brainer. Now that the Clearleft site is (finally!) running on HTTPS, having a simple service worker to cache static assets like CSS, JavaScript and some images seems like the obvious next step.

You know how it is. Those no-brainer tasks are exactly the kind of thing that end up on a to-do list without ever quite getting to-done. Meanwhile I’ve been writing and speaking about how any website can be a progressive web app. I think Alanis Morissette used to sing about this sort of situation.

Enough is enough! Clearleft.com is now a progressive web app. It has a manifest file and a service worker script.

The service worker logic is fairly straightforward, and taken almost verbatim from Going Offline. As you navigate around the site, the service worker applies different logic depending on the kind of file you’re requesting:

  • Pages are served fresh from the network, falling back to the cache when there’s a problem.
  • Everything else is served from the cache where possible, resorting to the network only if there’s no match in the cache—quite the performance boost!

In both cases, if a page or a file is retrieved from the network, it’s gets put into a cache. I’ve got one cache for pages, and another for everything else. And even if a file is retrieved from that cache, I still fire off a fetch request to grab a fresh copy for the cache. So while there’s a chance that a stale file might be served up, it will only ever be slightly stale, and the next time it’s requested, it’ll be fresh.

In the worst-case scenario, when a page can’t be retrieved from the network or the cache, you end up seeing a custom offline page. There you can see a list of any pages that are cached (meaning you can revisit them even without an internet connection).

A custom offline page showing a list of URLs.

It’s not ideal—page titles would be friendlier than URLs—but it’s a start. I’m sure I’ll revisit it soon. Honest.

Oh, and after a year of procrastinating about doing this, guess how long it took? About half a day. Admittedly, this isn’t my first progressive web app, and the more you build ‘em, the easier it gets. Still, it’s a classic example of a small investment of time leading to a big improvement in performance and user experience.

If you think your company’s website could benefit from being a progressive web app (and believe me, it definitely could), you have a couple of options:

  1. Arm yourself with a copy of Going Offline and give it a go yourself. Or
  2. Get in touch with Clearleft. We can help you. (See, I can say that with a straight face now that we’re practicing what we preach.)

Either way, don’t dilly dally …like I did.

Monday, June 4th, 2018

Progressive Web Games – Mozilla Hacks – the Web developer blog

I was just talking about how browser-based games are the perfect use-case for service workers. Andrzej Mazur breaks down how that would work:

  • Add to Home screen
  • Offline capabilities
  • Progressive loading

Saturday, May 19th, 2018

The Slow Death of Internet Explorer and the Future of Progressive Enhancement · An A List Apart Article

Oliver Williams makes the case—and shows the code—for delivering only HTML to old versions of Internet Explorer, sparing them from the kind of CSS and JavaScript that they can’t deal with it. Seems like a sensible approach to me (assuming you’re correctly building in a layered way so that your core content is delivered in markup).

Rather than transpiling and polyfilling and hoping for the best, we can deliver what the person came for, in the most resilient, performant, and robust form possible: unadulterated HTML. No company has the resources to actively test their site on every old version of every browser. Malfunctioning JavaScript can ruin a web experience and make a simple page unusable. Rather than leaving users to a mass of polyfills and potential JavaScript errors, we give them a basic but functional experience.

Friday, May 18th, 2018

How to display a “new version available” of your Progressive Web App

This is a good walkthrough of the flow you’d need to implement if you want to notify users of an updated service worker.

Wednesday, May 16th, 2018

HTTPS + service worker + web app manifest = progressive web app

I gave a quick talk at the Delta V conference in London last week called Any Site can be a Progressive Web App. I had ten minutes, but frankly I only needed enough time to say the title of the talk because, well, that was also the message.

There’s a common misconception that making a Progressive Web App means creating a Single Page App with an app-shell architecture. But the truth is that literally any website can benefit from the performance boost that results from the combination of HTTPS + Service Worker + Web App Manifest.

See how I define a progressive web app as being HTTPS + service worker + web app manifest? I’ve been doing that for a while. Here’s a post from last year called Progressing the web:

Literally any website can be a progressive web app:

That last step can be tricky if you’re new to service workers, but it’s not unsurmountable. It’s certainly a lot easier than completely rearchitecting your existing website to be a JavaScript-driven single page app.

Later I wrote a post called What is a Progressive Web App? where I compared the definition to responsive web design.

Regardless of the specifics of the name, what I like about Progressive Web Apps is that they have a clear definition. It reminds me of Responsive Web Design. Whatever you think of that name, it comes with a clear list of requirements:

  1. A fluid layout,
  2. Fluid images, and
  3. Media queries.

Likewise, Progressive Web Apps consist of:

  1. HTTPS,
  2. A service worker, and
  3. A Web App Manifest.

There’s more you can do in addition to that (just as there’s plenty more you can do on a responsive site), but the core definition is nice and clear.

But here’s the thing. Outside of the confines of my own website, it’s hard to find that definition anywhere.

On Google’s developer site, their definition uses adjectives like “reliable”, “fast”, and “engaging”. Those are all great adjectives, but more useful to a salesperson than a developer.

Over on the Mozilla Developer Network, their section on progressive web apps states:

Progressive web apps use modern web APIs along with traditional progressive enhancement strategy to create cross-platform web applications. These apps work everywhere and provide several features that give them the same user experience advantages as native apps. 

Hmm …I’m not so sure about that comparison to native apps (and I’m a little disturbed that the URL structure is /Apps/Progressive). So let’s click through to the introduction:

PWAs are web apps developed using a number of specific technologies and standard patterns to allow them to take advantage of both web and native app features.

Okay. Specific technologies. That’s good to hear. But instead of then listing those specific technologies, we’re given another list of adjectives (discoverable, installable, linkable, etc.). Again, like Google’s chosen adjectives, they’re very nice and desirable, but not exactly useful to someone who wants to get started making a progressive web app. That’s why I like to cut to the chase and say:

  • You need to be running on HTTPS,
  • Then you can add a service worker,
  • And don’t forget to add a web app manifest file.

If you do that, you’ve got a progressive web app. Now, to be fair, there’a lot that I’m leaving out. Your site should be fast. Your site should be responsive (it is, after all, on the web). There’s not much point mucking about with service workers if you haven’t sorted out the basics first. But those three things—HTTPS + service worker + web app manifest—are specifically what distinguishes a progressive web app. You can—and should—have a reliable, fast, engaging website before turning it into a progressive web app.

Jason has been thinking about progressive web apps a lot lately (he should write a book or something), and he said to me:

I agree with you on the three things that comprise a PWA, but as far as I can tell, you’re the first to declare it as such.

I was quite surprised by that. I always assumed that I was repeating the three ingredients of a progressive web app, not defining them. But looking through all the docs out there, Jason might be right. It’s surprising because I assumed it was obvious why those three things comprise a progressive web app—it’s because they’re testable.

Lighthouse, PWA Builder, Sonarwhal and other tools that evaluate your site will measure its progressive web app score based on the three defining factors (HTTPS, service worker, web app manifest). Then there’s Android’s Add to Home Screen prompt. Here finally we get a concrete description of what your site needs to do to pass muster:

  • Includes a web app manifest…
  • Served over HTTPS (required for service workers)
  • Has registered a service worker with a fetch event handler

(Although, as of this month, Chrome will no longer show the prompt automatically—you also have to write some JavaScript to handle the beforeinstallprompt  event).

Anyway, if you’re looking to turn your website into a progressive web app, here’s what you need to do (assuming it’s already performant and responsive):

  1. Switch over to HTTPS. Certbot can help you here.
  2. Add a web app manifest.
  3. Add a service worker to your site so that it responds even when there’s no network connection.

That last step might sound like an intimidating prospect, but help is at hand: I wrote Going Offline for exactly this situation.

Saturday, May 12th, 2018

I Used The Web For A Day With JavaScript Turned Off — Smashing Magazine

Following on from Charlie’s experiment last year, Chris Ashton has been assessing which sites rely on JavaScript, and which sites use it in a more defensive, resilient way. Some interesting results in here.

A good core experience is indicative of a well-structured web page, which, in turn, is usually a good sign for SEO and for accessibility. It’s usually a well designed web page, as the designer and developer have spent time and effort thinking about what’s truly core to the experience. Progressive enhancement means more robust experiences, with fewer bugs in production and fewer individual browser quirks, because we’re letting the platform do the job rather than trying to write it all from scratch.

Thursday, May 10th, 2018

A Book Apart, Get to Know Jeremy Keith

My publishers asked me some questions. My answers turned out to be more revealing of my inner demons than I was expecting. I hope this isn’t too much oversharing, but I found it quite cathartic.

My greatest fear for the web is that it becomes the domain of an elite priesthood of developers. I firmly believe that, as Tim Berners-Lee put it, “this is for everyone.” And I don’t just mean it’s for everyone to use—I believe it’s for everyone to make as well. That’s why I get very worried by anything that raises the barrier to entry to web design and web development.

It’s ironic that, at the same time as we can do so much more with less when it comes to the HTML, CSS, and JavaScript in browsers, many developers are choosing to make things more complicated by introducing complex tool chains, frameworks and processes.

Thursday, May 3rd, 2018

Building Progressive Web Apps | nearForm

It is very disheartening to read misinformation like this:

A progressive web app is an enhanced version of a Single Page App (SPA) with a native app feel.

To quote from The Last Jedi, “Impressive. Everything you just said in that sentence is wrong.”

But once you get over that bit of misinformation at the start, the rest of this article is a good run-down of planning and building a progressive web app using one possible architectural choice—the app shell model. Other choices are available.

Saturday, April 28th, 2018

The Illusion of Control in Web Design · An A List Apart Article

Aaron gives a timely run-down of all the parts of a web experience that are out of our control. But don’t despair…

Recognizing all of the ways our carefully-crafted experiences can be rendered unusable can be more than a little disheartening. No one likes to spend their time thinking about failure. So don’t. Don’t focus on all of the bad things you can’t control. Focus on what you can control.

Start simply. Code defensively. User-test the heck out of it. Recognize the chaos. Embrace it. And build resilient web experiences that will work no matter what the internet throws at them.

Wednesday, April 25th, 2018

Grid to Flex

Una has put together this handy one-pager of flexbox fallbacks for some common grid layouts.

Monday, April 23rd, 2018

Sara Soueidan: Going Offline

Sara describes the process of turning her site into a progressive web app, and has some very kind words to say about my new book:

Jeremy covers literally everything you need to know to write and install your first Service Worker, tweak it to your site’s needs, and then write the Web App Manifest file to complete the offline experience, all in a ridiculously easy to follow style. It doesn’t matter if you’re a designer, a junior developer or an experienced engineer — this book is perfect for anyone who wants to learn about Service Workers and take their Web application to a whole new level.

Too, too kind!

I highly recommend it. I read the book over the course of two days, but it can easily be read in half a day. And as someone who rarely ever reads a book cover to cover (I tend to quit halfway through most books), this says a lot about how good it is.

Sunday, April 15th, 2018

Service Workers | Build Progressive

This is a really nice explanation of adding a service worker to your site to make it more resilient. This tutorial is part of an ongoing series that I’m really looking forward to reading more of.

Tuesday, April 10th, 2018

Why Suffolk Libraries chose to build their own self-service app.

It’s so great to see the initial UX work that James and I prototyped in a design sprint come to fruition in the form of a progressive web app!

In the case of this web-app, if the tablets go offline, they will still store all the transactions that are made by customers. Once the tablet comes back online, it will sync it back up to the server. That is, essentially, what a Progressive Web App is — a kind of a website with a few more security and, most importantly, offline features.