Tags: api

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Tuesday, November 13th, 2018

Inlining or Caching? Both Please! | Filament Group, Inc., Boston, MA

This just blew my mind! A fiendishly clever pattern that allows you to inline resources (like critical CSS) and cache that same content for later retrieval by a service worker.

Crazy clever!

Thursday, October 4th, 2018

Declaration

I like the robustness that comes with declarative languages. I also like the power that comes with imperative languages. Best of all, I like having the choice.

Take the video and audio elements, for example. If you want, you can embed a video or audio file into a web page using a straightforward declaration in HTML.

<audio src="..." controls><!-- fallback goes here --></audio>

Straightaway, that covers 80%-90% of use cases. But if you need to do more—like, provide your own custom controls—there’s a corresponding API that’s exposed in JavaScript. Using that API, you can do everything that you can do with the HTML element, and a whole lot more besides.

It’s a similar story with animation. CSS provides plenty of animation power, but it’s limited in the events that can trigger the animations. That’s okay. There’s a corresponding JavaScript API that gives you more power. Again, the CSS declarations cover 80%-90% of use cases, but for anyone in that 10%-20%, the web animation API is there to help.

Client-side form validation is another good example. For most us, the HTML attributes—required, type, etc.—are probably enough most of the time.

<input type="email" required />

When we need more fine-grained control, there’s a validation API available in JavaScript (yes, yes, I know that the API itself is problematic, but you get the point).

I really like this design pattern. Cover 80% of the use cases with a declarative solution in HTML, but also provide an imperative alternative in JavaScript that gives more power. HTML5 has plenty of examples of this pattern. But I feel like the history of web standards has a few missed opportunities too.

Geolocation is a good example of an unbalanced feature. If you want to use it, you must use JavaScript. There is no declarative alternative. This doesn’t exist:

<input type="geolocation" />

That’s a shame. Anyone writing a form that asks for the user’s location—in order to submit that information to a server for processing—must write some JavaScript. That’s okay, I guess, but it’s always going to be that bit more fragile and error-prone compared to markup.

(And just in case you’re thinking of the fallback—which would be for the input element to be rendered as though its type value were text—and you think it’s ludicrous to expect users with non-supporting browsers to enter latitude and longitude coordinates by hand, I direct your attention to input type="color": in non-supporting browsers, it’s rendered as input type="text" and users are expected to enter colour values by hand.)

Geolocation is an interesting use case because it only works on HTTPS. There are quite a few JavaScript APIs that quite rightly require a secure context—like service workers—but I can’t think of a single HTML element or attribute that requires HTTPS (although that will soon change if we don’t act to stop plans to create a two-tier web). But that can’t have been the thinking behind geolocation being JavaScript only; when geolocation first shipped, it was available over HTTP connections too.

Anyway, that’s just one example. Like I said, it’s not that I’m in favour of declarative solutions instead of imperative ones; I strongly favour the choice offered by providing declarative solutions as well as imperative ones.

In recent years there’s been a push to expose low-level browser features to developers. They’re inevitably exposed as JavaScript APIs. In most cases, that makes total sense. I can’t really imagine a declarative way of accessing the fetch or cache APIs, for example. But I think we should be careful that it doesn’t become the only way of exposing new browser features. I think that, wherever possible, the design pattern of exposing new features declaratively and imperatively offers the best of the both worlds—ease of use for the simple use cases, and power for the more complex use cases.

Previously, it was up to browser makers to think about these things. But now, with the advent of web components, we developers are gaining that same level of power and responsibility. So if you’re making a web component that you’re hoping other people will also use, maybe it’s worth keeping this design pattern in mind: allow authors to configure the functionality of the component using HTML attributes and JavaScript methods.

Infovore » Pouring one out for the Boxmakers

This is a rather beautiful piece of writing by Tom (especially the William Gibson bit at the end). This got me right in the feels:

Web 2.0 really, truly, is over. The public APIs, feeds to be consumed in a platform of your choice, services that had value beyond their own walls, mashups that merged content and services into new things… have all been replaced with heavyweight websites to ensure a consistent, single experience, no out-of-context content, and maximising the views of advertising. That’s it: back to single-serving websites for single-serving use cases.

A shame. A thing I had always loved about the internet was its juxtapositions, the way it supported so many use-cases all at once. At its heart, a fundamental one: it was a medium which you could both read and write to. From that flow others: it’s not only work and play that coexisted on it, but the real and the fictional; the useful and the useless; the human and the machine.

Sunday, September 2nd, 2018

Sapiens

I finally got around to reading Sapiens by Yuval Noah Harari. It’s one of those books that I kept hearing about from smart people whose opinions I respect. But I have to say, my reaction to the book reminded me of when I read Matt Ridley’s The Rational Optimist:

It was an exasperating read.

At first, I found the book to be a rollicking good read. It told the sweep of history in an engaging way, backed up with footnotes and references to prime sources. But then the author transitions from relaying facts to taking flights of fancy without making any distinction between the two (the only “tell” is that the references dry up).

Just as Matt Ridley had personal bugbears that interrupted the flow of The Rational Optimist, Yuval Noah Harari has fixated on some ideas that make a mess of the narrative arc of Sapiens. In particular, he believes that the agricultural revolution was, as he describes it, “history’s biggest fraud.” In the absence of any recorded evidence for this, he instead provides idyllic descriptions of the hunter-gatherer lifestyle that have as much foundation in reality as the paleo diet.

When the book avoids that particular historical conspiracy theory, it fares better. But even then, the author seems to think he’s providing genuinely new insights into matters of religion, economics, and purpose, when in fact, he’s repeating the kind of “college thoughts” that have been voiced by anyone who’s ever smoked a spliff.

I know I’m making it sound terrible, and it’s not terrible. It’s just …generally not that great. And when it is great, it only makes the other parts all the more frustrating. There’s a really good book in Sapiens, but unfortunately it’s interspersed with some pretty bad editorialising. I have to agree with Galen Strawson’s review:

Much of Sapiens is extremely interesting, and it is often well expressed. As one reads on, however, the attractive features of the book are overwhelmed by carelessness, exaggeration and sensationalism.

Towards the end of Sapiens, Yuval Noah Harari casts his eye on our present-day world and starts to speculate on the future. This is the point when I almost gave myself an injury with the amount of eye-rolling I was doing. His ideas on technology, computers, and even science fiction are embarrassingly childish and incomplete. And the bad news is that his subsequent books—Home Deus and 21 Lessons For The 21st Century—are entirely speculations about humanity and technology. I won’t be touching those with all the ten foot barge poles in the world.

In short, although there is much to enjoy in Sapiens, particularly in the first few chapters, I can’t recommend it.

If you’re looking for a really good book on the fascinating history of our species, read A Brief History of Everyone Who Ever Lived by Adam Rutherford . That’s one I can recommend without reservation.

Thursday, August 16th, 2018

How to build a simple Camera component - Frontend News #4

A step-by-step guide to wrapping up a self-contained bit of functionality (a camera, in this case) into a web component.

Mind you, it would be nice if there were some thought given to fallbacks, like say:

<simple-camera>
<input type="file" accept="image/*">
</simple-camera>

Thursday, August 2nd, 2018

New Facebook Platform Product Changes and Policy Updates - Facebook for Developers

Welp! As of today, none of my posts, links, or notes can be syndicated to Facebook:

The publish_actions permission will be deprecated. This permission granted apps access to publish posts to Facebook as the logged in user. Apps created from today onwards will not have access to this permission. Apps created before today that have been previously approved to request publish_actions can continue to do so until August 1, 2018.

If you’re reading this on Facebook: so long, it’s been good to know ya.

Wednesday, July 25th, 2018

Badging API Explainer

Here’s an intriguing proposal that would allow web apps to indicate activity in an icon (like an unread count) in the same way that native apps can.

This is an interesting one because, in this case, it’s not just browsers that would have to implement it, but operating systems as well.

Saturday, June 16th, 2018

Artificial Intelligence for more human interfaces | Christian Heilmann

An even-handed assessment of the benefits and dangers of machine learning.

Tuesday, June 5th, 2018

CORS

A thorough explanation of the history and inner workings of Cross-Origin Resource Sharing.

Like tales of a mythical sea beast, every developer has a story to tell about the day CORS seized upon one of their web requests, dragging it down into the inexorable depths, never to be seen again.

Sunday, May 6th, 2018

HTML5 Constraint Validation

The slides from a presentation by Drew on all the functionality that browsers give us for free when it comes to validating form inputs.

Half the battle of the web platform is knowing what technology is out there, ready to use. We’re all familiar with the ability to declare validation constraints in our HTML5 forms, but were you aware there’s a JavaScript API that goes along with it?

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.

Friday, April 20th, 2018

Cancelling Requests with Abortable Fetch

This is a really good use-case for cancelling fetch requests: making API calls while autocompleting in search.

Tuesday, April 10th, 2018

Fantasies of the Future: Design in a World Being Eaten by Software / Paul Robert Lloyd

The transcript of a terrific talk by Paul, calling for a more thoughtful, questioning approach to digital design. It covers the issues I’ve raised about Booking.com’s dark patterns and a post I linked to a while back about the shifting priorities of designers working at scale.

Drawing inspiration from architectural practice, its successes and failures, I question the role of design in a world being eaten by software. When the prevailing technocratic culture permits the creation of products that undermine and exploit users, who will protect citizens within the digital spaces they now inhabit?

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:

Saturday, March 31st, 2018

Sessions Map

This is nifty—a map of all the Irish music sessions and events happening around the world, using the data from TheSession.org.

If you’re interested in using data from The Session, there’s a read-only API and regularly-updated data dumps.

Wednesday, March 21st, 2018

Facebook and the end of the world

I’d love to see some change, and some introspection. A culture of first, do no harm. A recognition that there are huge dangers if you just do what’s possible, or build a macho “fail fast” culture that promotes endangerment. It’s about building teams that know they’ll make mistakes but also recognize the difference between great businesses opportunities and gigantic, universe-sized fuck ups.

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, February 2nd, 2018

Privacy could be the next big thing

A brilliant talk by Stuart on how privacy could be a genuinely disruptive angle for companies looking to gain competitive advantage over the businesses currently in the ascendent.

How do you end up shaping the world? By inventing a thing that the current incumbents can’t compete against. By making privacy your core goal. Because companies who have built their whole business model on monetising your personal information cannot compete against that. They’d have to give up on everything that they are, which they can’t do. Facebook altering itself to ensure privacy for its users… wouldn’t exist. Can’t exist. That’s how you win.

The beauty of this is that it’s a weapon which only hurts bad people. A company who are currently doing creepy things with your data but don’t actually have to can alter themselves to not be creepy, and then they’re OK! A company who is utterly reliant on doing creepy things with your data and that’s all they can do, well, they’ll fail. But, y’know, I’m kinda OK with that.

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.