Tags: apis



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.

Tuesday, May 1st, 2018

What’s new in Microsoft Edge in the Windows 10 April 2018 Update - Microsoft Edge Dev BlogMicrosoft Edge Dev Blog

Service workers, push notifications, and variable fonts are now shipping in Edge.

Tuesday, April 3rd, 2018

Designing Progressive Web Apps by Jason Grigsby

It’s the afternoon of the second day of An Event Apart Seattle and Jason is talking about Designing Progressive Web Apps. These are my notes…

Jason wants to talk about a situation you might find yourself in. You’re in a room and in walks the boss, who says “We need a progressive web app.” Now everyone is asking themselves “What is a progressive web app?” Or maybe “How does the CEO even know about progressive web apps?”

Well, trade publications are covering progressive web apps. Lots of stats and case studies are being published. When executives see this kind of information, they don’t want to get left out. Jason keeps track of this stuff at PWA Stats.

Answering the question “What is a progressive web app?” is harder than it should be. The phrase was coined by Frances Berriman and Alex Russell. They listed ten characteristics that defined progressive web apps. The “linkable” and “progressive” characteristics are the really interesting and new characteristics. We’ve had technologies before (like Adobe Air) that tried to make app-like experiences, but they weren’t really of the web. Progressive web apps are different.

Despite this list of ten characteristics, even people who are shipping progressive web apps find it hard to define the damn thing. The definition on Google’s developer site keeps changing. They reduced the characteristics from ten to six. Then it became “reliable, fast, and engaging.” What does that mean? Craigslist is reliable, fast, and engaging—does that mean it’s a progressive web app.

The technical definition is useful (kudos to me, says Jason):

  1. HTTPS
  2. service worker
  3. manifest file

If you don’t have those three things, it’s not a progressive web app.

We should definitely use HTTPS if we want make life harder for the NSA. Also browser makers are making APIs available only under HTTPS. By July, Chrome will mark HTTP sites as insecure. Every site should be under HTTPS.

Service workers are where the power is. They act as a proxy. They allow us to say what we want to cache, what we want to go out to the network for; things that native apps have been able to do for a while. With progressive web apps we can cache the app shell and go to the network for content. Service workers can provide a real performance boost.

A manifest file is simply a JSON file. It’s short and clear. It lists information about the app: icons, colours, etc.

Once you provide those three things, you get benefits. Chrome and Opera on Android will prompt to add the app to the home screen.

So that’s what’s required for progressive web apps, but there’s more to them than that (in the same way there’s more to responsive web design than the three requirements in the baseline definition).

The hype around progressive web apps can be a bit of a turn-off. It certainly was for Jason. When he investigated the technologies, he wondered “What’s the big deal?” But then he was on a panel at a marketing conference, and everyone was talking about progressive web apps. People’s expectations of what you could do on the web really hadn’t caught up with what we can do now, and the phrase “progressive web app” gives us a way to encapsulate that. As Frances says, the name isn’t for us; it’s for our boss or marketer.

Jason references my post about using the right language for the right audience.

Should you have a progressive web app? Well, if you have a website, then the answer is almost certainly “Yes!” If you make money from that website, the answer is definitely “Yes!”

But there’s a lot of FUD around progressive web apps. It brings up the tired native vs. web battle. Remember though that not 100% of your users or customers have your app installed. And it’s getting harder to convince people to install apps. The average number of apps installed per month is zero. But your website is often a customer’s first interaction with your company. A better web experience can only benefit you.

Often, people say “The web can’t do…” but a lot of the time that information is out of date. There are articles out there with outdated information. One article said that progressive web apps couldn’t access the camera, location, or the fingerprint sensor. Yet look at Instagram’s progressive web app: it accesses the camera. And just about every website wants access to your location these days. And Jason knows you can use your fingerprint to buy things on the web because he accidentally bought socks when he was trying to take a screenshot of the J.Crew website on his iPhone. So the author of that article was just plain wrong. The web can do much more than we think it can.

Another common objection is “iOS doesn’t support progressive web apps”. Well, as of last week that is no longer true. But even when that was still true, people who had implemented progressive web apps were seeing increased conversion even on iOS. That’s probably because, if you’ve got the mindset for building a progressive web app, you’re thinking deeply about performance. In many ways, progressive web apps are a trojan horse for performance.

These are the things that people think about when it comes to progressive web apps:

  1. Making it feel like a app
  2. Installation and discovery
  3. Offline mode
  4. Push notifications
  5. Beyond progressive web app

Making it feel like a app

What is an app anyway? Nobody can define it. Once again, Jason references my posts on this topic (how “app” is like “obscenity” or “brunch”).

A lot of people think that “app-like” means making it look native. But that’s a trap. Which operating system will you choose to emulate? Also, those design systems change over time. You should define your own design. Make it an exceptional experience regardless of OS.

It makes more sense to talk in terms of goals…

Goal: a more immersive experience.

Possible solution: removing the browser chrome and going fullscreen?

You can define this in the manifest file. But as you remove the browser chrome, you start to lose things that people rely on: the back button, the address bar. Now you have to provide that functionality. If you move to a fullscreen application you need to implement sharing, printing, and the back button (and managing browser history is not simple). Remember that not every customer will add your progressive web app to their home screen. Some will have browser chrome; some won’t.

Goal: a fast fluid experience.

Possible solution: use an app shell model.

You want smooth pages that don’t jump around as the content loads in. The app shell makes things seem faster because something is available instantly—it’s perceived performance. Basically you’re building a single page application. That’s a major transition. But thankfully, you don’t have to do it! Progressive web apps don’t have to be single page apps.

Goal: an app with personality.

Possible solution: Animated transitions and other bits of UI polish.

Really, it’s all about delight.

Installation and discovery

In your manifest file you can declare a background colour for the startup screen. You can also declare a theme colour—it’s like you’re skinning the browser chrome.

You can examine the manifest files for a site in Chrome’s dev tools.

Once you’ve got a progressive web app, some mobile browsers will start prompting users to add it to their home screen. Firefox on Android displays a little explainer the first time you visit a progressive web app. Chrome and Opera have add-to-homescreen banners which are a bit more intrusive. The question of when they show up keeps changing. They use a heuristic to decide this. The heuristic has been changed a few times already. One thing you should consider is suppressing the banner until it’s an optimal time. Flipkart do this: they only allow it on the order confirmation page—the act of buying something makes it really likely that someone will add the progressive web app to their home screen.

What about app stores? We don’t need them for progressive web apps—they’re on the web. But Microsoft is going to start adding progressive web apps to their app store. They’ve built a site called PWA Builder to help you with your progressive web app.

On the Android side, there’s Trusted Web Activity which is kind of like PhoneGap—it allows you to get a progressive web app into the Android app store.

But remember, your progressive web app is your website so all the normal web marketing still applies.

Offline mode

A lot of organisations say they have no need for offline functionality. But everyone has a need for some offline capability. At the very least, you can provide a fallback page, like Trivago’s offline maze game.

You can cache content that has been recently viewed. This is what Jason does on the Cloud Four site. They didn’t want to make any assumptions about what people might want, so they only cache pages as people browse around the site.

If you display cached information, you might want to display how stale the information is e.g. for currency exchange rates.

Another option is to let people choose what they want to keep offline. The Financial Times does this. They also pre-cache the daily edition.

If you have an interactive application, you could queue tasks and then carry them out when there’s a connection.

Or, like Slack does, don’t let people write something if they’re offline. That’s better than letting someone write something and then losing it.

Workbox is a handy library for providing offline functionality.

Push notifications

The JavaScript for push notifications is relatively easy, says Jason. It’s the back-end stuff that’s hard. That’s because successful push notifications are personalised. But to do that means doing a lot more work on the back end. How do you integrate with preferences? Which events trigger notifications?

There are third-party push notification services that take care of a lot of this for you. Jason has used OneSignal.

Remember that people are really annoyed by push notifications. Don’t ask for permission immediately. Don’t ask someone to marry you on a first date. On Cloud Four’s blog, they only prompt after the user has read an article.

Twitter’s progressive web app does this really well. It’s so important that you do this well: if a user says “no” to your push notification permission request, you will never be able to ask them again. There used to be three options on Chrome: allow, block, or close. Now there are just two: allow or block.

Beyond progressive web apps

There are a lot of APIs that aren’t technically part of progressive web apps but get bundled in with them. Like the Credentials Management API or the Payment Request API (which is converging with ApplePay).

So how should you plan your progressive web app launch? Remember it’s progressive. You can keep adding features. Each step along the way, you’re providing value to people.

Start with some planning and definition. Get everyone in a room and get a common definition of what the ideal progressive web app would look like. Remember there’s a continuum of features for all five of the things that Jason has outlined here.

Benchmark your existing site. It will help you later on.

Assess your current website. Is the site reasonably fast? Is it responsive? Fix those usability issues first.

Next, do the baseline. Switch to HTTPS. Add a manifest file. Add a service worker. Apart from the HTTPS switch, this can all be done on the front end. Don’t wait for all three: ship each one when they’re ready.

Then do front-end additions: pre-caching pages, for example.

Finally, there are the larger initiatives (with more complex APIs). This is where your initial benchmarking really pays off. You can demonstrate the value of what you’re proposing.

Every step on the path to a progressive web app makes sense on its own. Figure out where you want to go and start that journey.

See also:

Tuesday, February 13th, 2018

XML is 20

XML 1.0 was released on February 10th, 1998. I remember the hype around XML at the time—it was our saviour, the chosen one, prophesied to bring balance to data exchange. Things didn’t quite work out that way, but still…

Twenty years later, it seems obvious that the most important thing about XML is that it was the first. The first data format that anyone could pack anything up into, send across the network to anywhere, and unpack on the other end, without asking anyone’s permission or paying for software, or for the receiver to have to pay attention to what the producer thought they’d produced it for or what it meant.

Friday, January 26th, 2018

The Power of Serverless

Chris has set up a whole site dedicated to someone-else’s-server sites with links to resources and services (APIs), along with ideas of what you could build in this way.

Here’s one way to think about it: you can take your front-end skills and do things that typically only a back-end can do. You can write a JavaScript function that you run and receive a response from by hitting a URL. That’s sometimes also called Cloud Functions or Functions as a Service, which are perhaps better names, but just a part of the whole serverless thing.

Tuesday, January 16th, 2018

How To Make A Drag-and-Drop File Uploader With Vanilla JavaScript — Smashing Magazine

A step-by-step guide to implementing drag’n’drop, and image previews with the Filereader API. No libraries or frameworks were harmed in the making of this article.

Friday, December 29th, 2017

Raindrops on roses, whiskers on kittens, declarative web APIs and truly serverless web endpoints

Three technologies that Ada is excited about:

  1. a service: IndieAuth,
  2. a front end library: Comlink,
  3. a pattern: APIs as Web Components.

Monday, June 12th, 2017

Design in the Era of the Algorithm | Big Medium

The transcript of Josh’s fantastic talk on machine learning, voice, data, APIs, and all the other tools of algorithmic design:

The design and presentation of data is just as important as the underlying algorithm. Algorithmic interfaces are a huge part of our future, and getting their design right is critical—and very, very hard to do.

Josh put together ten design principles for conceiving, designing, and managing data-driven products. I’ve added them to my collection.

  1. Favor accuracy over speed
  2. Allow for ambiguity
  3. Add human judgment
  4. Advocate sunshine
  5. Embrace multiple systems
  6. Make it easy to contribute (accurate) data
  7. Root out bias and bad assumptions
  8. Give people control over their data
  9. Be loyal to the user
  10. Take responsibility

Tuesday, May 23rd, 2017

Service Worker Security FAQ - The Chromium Projects

Got questions about the security of service workers? This document probably has the answer.

Tuesday, January 3rd, 2017

Exciting times: 2017 and the web - Tales of a Developer Advocate by Paul Kinlan

Paul takes a look at the year ahead on the web and likes what he sees. There’s plenty of new browser features and APIs of course, but more interesting:

The web reaching more people as they come online with Mobile. There is still a huge amount of potential and growth in India, Indonesia, China, Thailand, Vietnam, all of Africa. You name it, mobile is growing massively still and the web is accessible on all of these devices.

Friday, December 30th, 2016

Data on the Web Best Practices

This document provides Best Practices related to the publication and usage of data on the Web designed to help support a self-sustaining ecosystem. Data should be discoverable and understandable by humans and machines.

Monday, December 19th, 2016

The (Not So) Secret Powers Of The Mobile Browser – Smashing Magazine

A run-down of all the functionality that you get in browsers these days. One small quibble with the title: most of the features and APIs described here aren’t limited to mobile browsers. Still, this is a great reminder that you probably don’t need to create a native app to get the most out of a mobile device.

Friday, October 28th, 2016

Working with mobile technology - Digital Service Manual - GOV.UK

Excellent guidelines from GDS on providing services that work well on mobile. The watchwords are:

  • responsive design,
  • progressive enhancement,
  • open data, and
  • emerging technology (service workers, notifications, etc.).

Native and hybrid apps are rarely justified.

Saturday, May 28th, 2016

State of the gap

Remy looks at the closing gap between native and web. Things are looking pretty damn good for the web, with certain caveats:

The web is the long game. It will always make progress. Free access to both consumers and producers is a core principle. Security is also a core principle, and sometimes at the costs of ease to the developer (but if it were easy it wouldn’t be fun, right?).

That’s why there’ll always be some other technology that’s ahead of the web in terms of features, but those features give the web something to aim for:

Flash was the plugin that was ahead of the web for a long time, it was the only way to play video for heavens sake!

Whereas before we needed polyfills like PhoneGap (whose very reason for existing is to make itself obsolete), now with progressive web apps, we’re proving the philosophy behind PhoneGap:

If the web doesn’t do something today it’s not because it can’t, or won’t, but rather it is because we haven’t gotten around to implementing that capability yet.

Friday, April 1st, 2016


This is a very handy resource—a collection of minimum viable implementations of HTML5 features and JavaScript APIs.

Thursday, March 24th, 2016

toddmotto/public-apis: A collective list of public JSON APIs for use in web development.

Remember mashups? Mashups were cool.

If you fancy partying like it’s nineteen ninety web 2.0, here’s a growing list of public APIs that return JSON.

Monday, March 14th, 2016

Web Progressions

This looks a good (free!) event in London all about the latest browser goodies, all wrapped in the “progressive apps” buzzword.

Alas, I’ll be making my way back from Indie Web Camp Düsseldorf the day this is on.

Saturday, December 5th, 2015

Native or Not? The Untapped Power of Web Apps | Viget

Following on from that last link, here’s an in-depth run-down of what you can do in mobile browsers today. I think a lot of people internalised “what you can’t do on the web” a while back—it’s well worth periodically revisiting the feature landscape to revise that ever-shrinking list.

Perhaps the biggest advantage the web has over native apps is how quickly users are able to engage. All that’s between the user and your content is one click.

What Web Can Do Today

Visit this site using different browsers on different devices to get a feel for what you can do with web technologies.

Native will always be ahead, but the feature gap is closing impressively fast.

Monday, November 3rd, 2014

Just what is it that you want to do?

The supersmart Scott Jenson just gave a talk at The Web Is in Cardiff, which was by all accounts, excellent. I wish I could have seen it, but I’m currently chilling out in Florida and I haven’t mastered the art of bilocation.

Last week, Scott wrote a blog post called My Issue with Progressive Enhancement (he wrote it on Google+, which is why you might not have seen it).

In it, he takes to task the idea that—through progressive enhancement—you should be able to offer all functionality to all browsers, thereby foregoing the use of newer technologies that aren’t universally supported.

If that were what progressive enhancement meant, I’d be with him all the way. But progressive enhancement is not about offering all functionality; progressive enhancement is about making sure that your core functionality is available to everyone. Everything after that is, well, an enhancement (the clue is in the name).

The trick to doing this well is figuring out what is core functionality, and what is an enhancement. There are no hard and fast rules.

Sometimes it’s really obvious. Web fonts? They’re an enhancement. Rounded corners? An enhancement. Gradients? An enhancement. Actually, come to think of it, all of your CSS is an enhancement. Your content, on the other hand, is not. That should be available to everyone. And in the case of task-based web thangs, that means the fundamental tasks should be available to everyone …but you can still layer more tasks on top.

If you’re building an e-commerce site, then being able to add items to a shopping cart and being able to check out are your core tasks. Once you’ve got that working with good ol’ HTML form elements, then you can go crazy with your enhancements: animating, transitioning, swiping, dragging, dropping …the sky’s the limit.

This is exactly what Orde Saunders describes:

I’m not suggesting that you try and replicate all your JavaScript functionality when it’s disabled, above all that’s just not practical. What you should be aiming for is being able to complete the basics - for example adding a product to a shopping cart and then checking out. This is necessarily going to be clunky as judged by current standards and I suggest you don’t spend much time on optimising this process.

Scott asked about building a camera app with progressive enhancement:

Here again, the real question to ask is “what is the core functionality?” Building a camera app is a means to an end, not the end itself. You need to ask what the end goal is. Perhaps it’s “enable people to share photos with their friends.” Going back to good ol’ HTML, you can accomplish that task with:

<input type="file" accept="image/*">

Now that you’ve got that out of the way, you can spend the majority of your time making the best damn camera app you can, using all the latest browser technologies. (Perhaps WebRTC? Maybe use a canvas element to display the captured image data and apply CSS filters on top?)

Scott says:

My point is that not everything devolves to content. Sometimes the functionality is the point.

I agree wholeheartedly. In fact, I would say that even in the case of “content” sites, functionality is still the point—the functionality would be reading/hearing/accessing content. But I think that Scott is misunderstanding progressive enhancement if he think it means providing all the functionality that one can possibly provide.

Mat recently pointed out that there are plenty of enhancements on the Boston Globe site that require JavaScript, but the core functionality is available to everyone:

Scott again:

What I’m chaffing at is the belief that when a page is offering specific functionality, Let’s say a camera app or a chat app, what does it mean to progressively enhance it?

Again, a realtime chat app is a means to an end. What is it enabling? The ability for people to talk to each other over the web? Okay, we can do that using good ol’ HTML—text and form elements—with full page refreshes. That won’t be realtime. That’s okay. The realtime part is an enhancement. Use Web Sockets and WebRTC (in the browsers that support them) to provide the realtime experience. But everyone gets the core functionality.

Like I said, the trick is figuring out what’s core functionality and what’s an enhancement.

Ethan provides another example. Let’s say you’re building a browser-based rich text editor, that uses JavaScript to do all sorts of formatting on the fly. The core functionality is not the formatting on the fly; the core functionality is being able to edit text:

If progressive enhancement truly meant making all functionality available to everyone, then it would be unworkable. I think that’s a common misconception around progressive enhancement; there’s this idea that using progressive enhancement means that you’re going to spend all your time making stuff work in older browsers. In fact, it’s the exact opposite. As long as you spend a little bit of time at the start making sure that the core functionality works with good ol’ fashioned HTML, then you can spend most of your time trying out the latest and greatest browser technologies.

As Orde put it:

What you are going to be spending the majority of your time and effort on is the enhanced JavaScript version as that is how the majority of your customers will be experiencing your site.

The other Scott—Scott Jehl—wrote a while back:

For us, building with Progressive Enhancement moves almost all of our development time and costs to newer browsers, not older ones.

Progressive Enhancement frees us to focus on the costs of building features for modern browsers, without worrying much about leaving anyone out. With a strongly qualified codebase, older browser support comes nearly for free.

Approaching browser support this way requires a different way of thinking. For everything you’re building, you need to ask “is this core functionality, or is it an enhancment?” and build accordingly. It takes a bit of getting used to, but it gets easier the more you do it (until, after a while, it becomes second nature).

But if you’re thinking about progressive enhancement as “devolving” down—as Scott Jenson describes in his post—then I think you’re on the wrong track. Instead it’s about taking care of the core functionality quickly and then spending your time “enhancing” up.

Scott asks:

Shouldn’t we be allowed to experiment? Isn’t it reasonable to build things that push the envelope?

Absolutely! And the best and safest way to do that is to make sure that you’re providing your core functionality for everyone. Once you do that, you can go nuts with the latest and greatest experimental envelope-pushing technologies, secure in the knowledge that you don’t even need to worry about the fact that they don’t work in older browsers. Geolocation! Offline storage! Device APIs! Anything you can think of, you can use as a powerful enhancement on top of your core tasks.

Once you realise this, it’s immensely liberating to use progressive enhancement. You can have the best of both worlds: universal access to core functionality, combined with all the latest cuting-edge technology too.