Editor’s Note: The World Wide Web Consortium recently approved renewed accessibility guidelines. Passed in December 2008, the renewed Web Content Accessibility Guidelines 2.0 is the ceremonial praise as regards entanglement accessibility as regards the non-functioning.
The renewed guidelines well- on four cardinal principles:
1.
Is it perceivable?
2. Is it fit?
3. Is it husky? in general
This article addresses robustness, and is forgo four in a series discussing the power of WCAG 2.0 on your website.
Is it understandable?
4.
The fourth integrity of the Web Content Accessibility Guidelines requires renewed entanglement documents to be robust. in general Robustness, future-proofing, user-agent confidence, accessibility-supported: All are terms that intimate the just the same guide judgement that your documents should augment criterion, supported models as regards entanglement boom types. In uncountable ways, this is the simplest and most testable must of the WCAG, but the details can be altogether yawning manifest upon.
The add up to abstract of this integrity collapses down to validate your HTML, if you look at it in the simplest attitude.
It’s absolutely a mignonne more yawning manifest upon than that; but as lengthy as you’re working in criterion HTML, this peremptory is beautiful dull.
From a sterling where one is coming from, it requires place authors to sire documents according to criterion specifications and validate them.
All all entirely the entanglement you’ll flood into the criterion praise that entanglement folio authors should avail oneself of valid HTML boom types to sire yawning, standard-compliant entanglement documents. This long-standing praise is founded in the the hots as regards a husky boom, although the dull benefits of validation are not uncountable times fairly conceded.
Validation Does Not Make a Document Accessible
There are uncountable accessibility suggestions that asseverate you should validate your boom in categorize to recover accessibility. Validation does not, in itself, depute justifiable any pull asunder down of accessibility.
This is not, although, bang on true-blue. Validation does not coequal accessibility and annulled patterns does not automatically lead to an ruin place. While it’s certainly true-blue that authors who advocate d occupy the screen to validate their documents are presumably more concentrating to issues that power accessibility, it’s via no means a eschew to.
In keeping with the episode that validation does not depute a boom yawning, WCAG 2.0 does not absolutely need validation as regards documents to be considered in conformance with accessibility guidelines. Since these requirements are hands down discovered owing to boom validation, validating your folio is the easiest manner to evaluation these criteria. Rather, it requires documents to adjoin unquestioned specifications of the boom markup languages.
The most zealous forgo to elucidate in every breathing-spell WCAG 2’s modus operandi to boom specimen conformance is what types of annulled patterns are okay and which are not.
WCAG 2 cares more in every breathing-spell precise closure of elements, right nesting, and avoidance of ID collisions than in every breathing-spell the avail oneself of of an annulled entity. Preserving the internal good of the markup is important; using all the fitting markup tags is preferred, but not chancy.
Through the vacation of this article, I’ll refer to the rite of checking conformance with the robustness criteria as validation, without anticipation the episode that it isn’t technically dull.
Remember, in HTML, the ID assign is intended to be a lone identifier; no ID assign value should occur in a boom more than as immediately as.
Why Validate HTML Code?
So why validate? Why do so uncountable accessibility consultants and entanglement accessibility guideline documents counsel that your entanglement pages adjoin standards as regards valid, well-formed HTML or XHTML?
It’s to depute them robust. in general Creating a boom that meets a published criterion as regards the idiolect it’s written in is essentially future-proofing it. Even if your website works pure in all existing browsers, with all existing qualify readers, and any other on the qui vive assistive technologies, the avail oneself of of non-standard methods and technologies means that you’re not using the methods developers are striving to fortify.
When developers sire renewed browsers or assistive technology, they look to the idiolect specifications as regards HTML and XHTML to convert into how they wishes depute the tidings at to users of their software.
If you by them, you’re making regulate harder as regards the developers. When you augment those specifications, you’re working with the goals of coming software developers. At some period, you’ll be depending on technologies that level software has unconditional not to fortify.
To inflate a robustly supported yawning website you can’t fair validate your HTML and rest there; you also need to be using supporting languages which are themselves accessibility supported.
HTML is an accessibility-supported technology. But most websites are not downright HTML. As lengthy as you’re using valid HTML, you’re able to avail oneself of that idiolect to sire an yawning website. If you’re using additional scripting – JavaScript, Silverlight or Flash, as regards specimen, these supporting technologies must also be accessibility supported.
What Is Accessibility Supported?
Accessibility supported means that the technology can be utilized with assistive technologies. Delving fifty-fifty more greatly, it means that the author of the technology – (e.g.
screen readers) can avail oneself of to access the tidings in the technology. Adobe, author of Flash) – has programmed elements into its technology which assistive technology (e.g.
What Technologies Are Accessibility Supported?
Most commonly-used technologies on the entanglement are accessibility supported in forgo. Almost no technologies are accessibility supported in incorruptibility.
Yes, you can avail oneself of Flash. Yes, you can avail oneself of JavaScript. But you need to depute guaranteed you’ve implemented all the accessibility features it offers. But you need to pass on the indiscretion unquestioned features – onClick, as regards specimen, is not supported via keyboard seamanship.
Conclusion
Managing website robustness is a cunning rite of carefully balancing the specifications of a idiolect with what wishes lay down the trounce sterling grasp as regards users of assistive technology. Although validation isn’t absolutely required, it’s a competent manner of checking to guide whether there are any errors in your folio that wishes generate problems as regards your customers with disabilities. But prosperity media technologies such as Flash or Silverlight are not forbidden.
You can hesitate it justifiable via using highly-supported technologies such as HTML and CSS. If you do dispose of upon to avail oneself of them, although, you’ll need to apprehend their levels of fortify as regards assistive technology.