ENTRIES TAGGED "polyfill"
The changing landscape of web platform extensibility
From its nascent days, the growth of the web has been marked by the waxing and waning of technologies, frameworks and ideas. Old ideas and technologies expire and fade away, and new ones arise in their place. Much as the cicada molts and leaves behind an old shell as it moves into adulthood, the web has seen countless ideas come and go as it has evolved.
Relics (and Catalysts) of the Web
Remember XHTML? More specifically, do you remember caring deeply about XHTML? You likely do. Do you still care about XHTML? Chances are, the answer is no. The same goes for Flash, DHTML, HTML Components and countless other buzzwords of the web that once felt so alive and important, and now feel like relics of another time.
Occasionally, however, we collectively stumble upon ideas and technologies that stand the test of time. These are ideas that don’t just evolve with the web–they are often a catalyst for the evolution of the web itself. Ideas like Cascading Style Sheets and XMLHTTPRequest, the vendor hack that spurred the AJAX revolution, are two examples among many.
On both front and back end, the Web challenges conventional wisdom
The Web is different, and I can see why programmers might have little tolerance for the paths it chose, but this time the programmers are wrong. It’s not that the Web is perfect – it certainly has glitches. It’s not that success means something is better. Many terrible things have found broad audiences, and there are infinite levels to the Worse is Better conversations. And of course, the Web doesn’t solve every programming need. Many problems just don’t fit, and that’s fine.
So why is the Web better?
The standard for mathematical content in publishing work flows, technical writing, and math software
20 years into the web, math and science are still second class citizens on the web. While MathML is part of HTML 5, its adoption has seen ups and downs but if you look closely you can see there is more light than shadow and a great opportunity to revolutionize educational, scientific and technical communication.
Somebody once compared the first 20 years of the web to the first 100 years of the printing press. It has become my favorite perspective when thinking about web standards, the web platform and in particular browser development. 100 years after Gutenberg the novel had yet to be invented, typesetting quality was crude at best and the main products were illegally copied pamphlets. Still, the printing press had revolutionized communication and enabled social change on a massive scale.
In the near future, all our current web technology will look like Gutenberg’s original press sitting next to an offset digital printing machine.
With faster and faster release cycles it is sometimes hard to keep in mind what is important in the long run—enabling and revolutionizing human communication.
Since I joined the MathJax team in 2012, I have gained many new perspectives on MathML, the web standard for display of mathematical content, and its role in making scientific content a first class citizen on the web. But it is rather useless to talk about MathML’s potential without knowing about the state of MathML on the web. So let’s tackle that in this post.
Creating flexible expectations
“Expect the unexpected” has long been a maxim of web development. New browsers and devices arrive, technologies change, and things break. The lore of web development isn’t just the technology: it addresses the many challenges of dealing with customers who want to lock everything down.
Is there room for programmers to tell a similar story?
I don’t mean agile. Agile development is difficult enough to explain to clients, but applications that adapt to their circumstances are a separate set of complications. Iterating on adaptable behaviors may be more difficult than iterating on adaptable designs, but it opens new possibilities both for applications and for the evolution of the Web.
Responsive Web Design is (slowly) becoming the new baseline, giving designers a set of tools for building pages that (usually) provide the same functionality while adapting to different circumstances. Programmers sometimes provide different functionality to different users, but it’s more often about cases where users have different privileges than about different devices and contexts.
Adjusting how content displays is complex enough, but modifying application behavior to respond to different circumstances is more unusual. The goal of most web development has been to provide a single experience across a variety of devices, filling in gaps whenever possible to support uniformity. The history of “this page best viewed on my preferred browser” is mostly ugly. Polyfills, which I think have a bright future, emerged to create uniformity where browsers didn’t.
Browsers, though, now provide a huge shared context. Variations exist, of course, and cause headaches, but many HTML5 APIs and CSS3 features can work nicely as supplements to a broader site. Yes, you could build a web app around WebRTC and Media Capture and Streams, and it would only run on Firefox and Chrome right now. But you could also use WebRTC to help users talk about content that’s visible across browsers, and only the users on Firefox and Chrome would have the extra video option. The Web Audio API is also a good candidate for this, as might be some graphics features.
This is harder, of course, with things like WebSockets that provide basic functionality. For those cases, polyfills seem like a better option. Something that seems as complicated and foundational as IndexedDB could be made optional, though, by switching whether data is stored locally or remotely (or both).
HTML5 and CSS3 have re-awakened Web development. I’m hoping that we can develop new practices that let us take advantage of these tools without having to wait for them to work everywhere. In the long run, I hope that will create a more active testing and development process to give browser vendors feedback earlier—but getting there will require changing the expectations of our users and customers as well.
Evolving enhancements for web developers
You thought CSS was weak? Think again.
After years of complaints about Cascading Style Sheets, many stemming from their deliberately declarative nature, it’s time to recognize their power. For developers coming from imperative programming styles, it might seem hard to lose the ability to specify more complex logical flow. That loss, though, is discipline leading toward the ability to create vastly more flexible systems, a first step toward the pattern matching model common to functional programming.
Way back when I was writing about styling XML in browsers, I didn’t even have to stop to think about how difficult it would be to repurpose CSS selectors for XML documents. Since they weren’t tightly bound to assumptions about HTML beyond the existence of elements and attributes, they just worked.
The tool that most vividly demonstrated the real power of selectors, though, was jQuery. I may have annoyed some people by referring to jQuery as “that framework that lets you use CSS selectors instead of DOM tree walking” for a while, but Remy Sharp makes clear the power of that:
The ease in which jQuery could be learnt was the appeal to me. All the DOM navigation was done using CSS expression using some insane black box magic that John Resig had come up [with] – saving my limited brain power, and once I had those DOM nodes, I could do what I wanted to them (usually some combinations of showing, hiding, fading and so on).
Over time, as Sharp notes, Web browsers learned from jQuery, building this basic lesson deeper into their tools and making it work more efficiently:
In those 7 years, quite a bit has happened. Probably one of the most important steps forward was the introduction of querySelectorAll.
Being able to give a native function of a browser a CSS expression, and it doing the work to navigate the DOM is a huge (literally) part of jQuery.
It's time for developers to create their own vocabularies
When HTML first appeared, it offered a coherent if limited vocabulary for sharing content on the newly created World Wide Web. Today, after HTML has handed off most of its actual work to other specifications, it’s time to stop worrying about this central core and let developers choose their own markup vocabularies and processing.
When the W3C first formed, it formed around HTML, the core standard of content on the Web, defining the structure, appearance, and behavior of content. Over the next few years, however, it became clear that HTML was doing too much, and the W3C and other groups refactored appearance, behavior, and many semantics into separate specifications:
Cascading Style Sheets (CSS) took responsibility for presentation and layout.
WAI-ARIA took responsibility for accessibility semantics, ensuring that content remained available to a broad audience even if developers pushed the current boundaries of markup.