To most Web developers, it sounds controversial until you hear the punchline: Last summer, the developers in charge of Google’s Chrome browser floated a proposal that went virtually unnoticed by the technology press, which was to remove support for an established W3C standard that every other browser vendor still supports. The standard in question? Extensible Stylesheet Language Transformations, otherwise known as XSLT.
In reaction to this news, most Web developers would likely shrug and say “So what?” That’s unfortunate.
Transformations are a simple yet powerful technique for separating content and presentation in Web applications. Yet, outside of enterprise and data-processing circles, transformations have failed to gain popularity through XSLT. As a result, Web developers are liable to think that transformations “don’t apply to me,” even though they work with HTML, a structured format ripe for transformation. Thankfully, new transformation frameworks are on the horizon, including work by the inventor of Sass, that hold the promise of a revival.
In this article, we will reintroduce transformations and explore their applications to mobile and responsive design. We will not only teach the old dog new tricks, but show that transformations are relevant to everyone who deals with HTML.
For more on Enlive, I recommend David Nolen’s excellent tutorial. But the key point is that content and presentation have been decoupled. Website changes, A/B tests and even a redesign could be as easy as getting new HTML from your designer and dropping it in. In addition, the designer doesn’t need to know anything about the templating language and may use HTML classes and IDs, concepts that they already know.
While you don’t need to build a website in this way, the situation is analogous to building a Web page without a style sheet. True, you could design a page purely with inline styles (that is, using only the
style attribute), and novice developers often code this way out of expediency. But experienced developers know that a style sheet improves workflow and productivity at scale.
Similarly, by separating content and presentation, you will unlock more productivity and agility for your team. In effect, transformations truly separate the front end from the back end and create a new workspace for the visual design team to operate independently of the rest of the system. In an industry where even simple things like the color of a button can affect conversion rates, enabling your visual design team to iterate more quickly and continually could deliver tremendous value to the bottom line.
Transformations are not just useful in a templating system. This decoupling of content and presentation can also be applied to an existing website, enabling developers to apply a new presentation regardless of how the original website was built. This combination of separating content and presentation and its applicability to existing websites is what makes transformations so powerful and useful to a broader audience than currently use them. I’ll illustrate this by responsively retrofitting an existing website using a transformation technology that’s in every browser today (at least for now), XSLT.
XSLT was introduced in the late 1990s as a language for transforming XML and XHTML documents. During the ascendency of XML, XSLT was seen as a solution for separating content and presentation in Web applications built on XML data formats. The W3C recommended XSLT as a standard, and almost every major browser incorporated support for some form of the language.
Responsive retrofitting is the process of grafting responsive Web design techniques onto an existing website that was not built to be responsive. Although a lot of resources and tutorials on building a responsive website from scratch are out there, retrofitting has curiously received far less attention, despite its enormous value. A lot more old websites exist than new ones, and significant capital and effort have been invested in them.
The natural first step would be to retrofit the website purely in CSS. Ben Callahan’s bookmarkletfor example, inserts a custom CSS file to make a given website more responsive. However, adding CSS gets you only so far. Eventually, the layout, nesting and order of elements in the original HTML will restrict your design options. John Shirrel describes this as an inherent flaw of CSS: