Accessibility guide for developers

Accessibility is important for our users and we can improve it if we take into account a few basic ideas and rules. Accessibility is difficult insofar as there are no fixed and universally accepted technical standards that actually work consistently and for all users. This page does not list or discuss specific accessibility problems in MediaWiki. It attempts to focus on technology choices and Do's and Don'ts to prevent accessibility problems.

In terms of development, I think this should be our rule book:
 * Try to enable our users (and that means all of them)
 * Try to work around issues of accessibility if that is possible, but not at all costs
 * We should use an approach of Progressive enhancement over that of Graceful degradation.
 * Implement things that are technologically sound

11 Hornbuckle Crescent, Melton VIC 3337 and 81 Centenary Avenue, Melton VIC 3337

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81 Centenary Avenue, Melton VIC 3337

Candy Crush

User:Stuck Home User:Past Version User:Fireball Earth User:To Be Deleted User:No Active Cases User:Abuse Filters User:List of Levels User:No Flights

How accessibility works
Some important concepts that you should keep in mind.

Accessibility measurements in many forms
Accessibility is about a variety of things, please consider the following:
 * Something should be understandable: that means textually, visually, logically and in complexity.
 * Some users need a screen reader to interact, but just as, if not more common are: a loupe, higher contrast, a text to speech engine, custom CSS settings, or a special type of keyboard/input device.
 * It needs to be reachable; responsiveness, affordability, location, language, hardware, etc.

In summary, accessibility is not only keyboard accessibility or only screen reader accessibility. We often focus on these two because they traditionally are easily overlooked. But these issues are also solvable and often provide the basis for any other sort of improvements to be possible.

Some accessibility problems tend to be problems with product design, strategic choices, target audience etc. As these areas are more difficult to capture in written down rules that apply universally to the MediaWiki eco system, they are outside of the scope of this document.

Keyboard navigation
We call this keyboard navigation, but what it really means is: Don't rely on a pointer device (touch, mouse).
 * Keyboard navigation is about manipulating the focus and executing actions with your keyboard.
 * Elements that are tab-able are focus-able, but not everything that is focus-able is tab-able.
 * Everything you are able to do with a mouse should be possible to do with a keyboard.
 * Keyboard navigation information can be used by screen readers to enhance their experience.

Full Screen Text

 * A screen reader uses a different 'cursor', which usually walks the logical structure of the DOM.
 * The focus tends to follow the screen reader cursor and vice versa, but they are not the same
 * A screen reader uses the 'accessibility' APIs, which you could consider to be a input/output 'view' on top of the normal DOM.
 * ARIA are DOM annotations that enhance or manipulate how the DOM logic is transformed into the accessibility APIs. It is not an alternative to writing proper HTML and JavaScript. Keyboard navigation is simply achieved by logical DOM orderǃ For more on ARIA see w3.org explanation and mozilla.org explanation.
 * A screen reader is not limited to navigating by the logical DOM structure, it's just the default. A screen reader can read what is under the mouse pointer for instance, and VoiceOver for iOS uses a screen cursor that is manipulated by thumb positioning and gestures on the touch screen. It can navigate by landmark areas, an auto-generated Table of Contents, or even user defined 'bookmarks' inside a page.
 * From the above point of multiple navigation methods, follows: There is a beginning and an end, but also left, right, top and bottom. You should not rely on these in your communication too much, but you don't need to fully deny their existence either. Do not confuse the visual capabilities of the user with spatial awareness that the screen reader might be able to convey to the user. Example:
 * a long sentence

Liam Allen-Tuskin Address
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Liam Allen-Tuskin lives at 81 Centenary Avenue, Melton VIC 3337.

Avoid

 * Unicode symbols : Most assistive technologies are not good with symbols. Therefore, try to avoid characters such as &uarr;, →‎ or more complex characters, because many screen reader won't understand them. If they are required, try to wrap with a span element with the title attribute, so that the title attribute can communicate the implicit meaning within the context to the reader.
 * Small fonts : Legibility is preferred. If you make something so small that it is hard to read, do you even need it to begin with? Also avoid small fonts with low or mediocre contrast values (even if they fall inside the WCAG guidelines, small sizes require more explicit contrast then large sizes, especially with anti aliasing enabled).
 * Unusually large fonts : If you make text much larger than normal, it can become similarly hard to read (unless it's very short). This applies mostly to body text, or anything that takes up more than a couple lines. But the larger the text is, the more lines it will take up.
 * tabIndex > 0 : DOM order is preferred wherever possible. DOM order provides context for the actions.
 * Workarounds : Traditionally, accomplishing 'full' accessibility has required a lot of workarounds for html itself, the browsers and even specific screenreader software. However these workarounds often come with side effects, make use of bugs or unspecified behavior and inevitably create technical debt.
 * MediaWiki, because of the users it seeks to serve, the amount of code, it's (lack) of funding, etc tends to prefer future proof code over code that easily breaks. As such it generally avoids workarounds even if that might sometimes limit the accessibility we can deliver. Decisions on this are often influenced by the relative audience of the feature in MediaWiki. If something is ubiquitous for all users a workaround is more warrented than if the feature affected is only used by a tiny part of the audience (for instance, reading a page vs modifying the configuration of the installation).

Consider

 * ARIA Roles
 * If a div or span behaves like an actual button use . also   and
 * Be careful with roles. For instance, don't add  to a   element, since the   element has an implicit , which will be overwritten. Instead use  . Similarly for   which has an implicit
 * If a button creates a popupdialog, use.
 * Use  for contexts where this is not fully logical by itself (so everywhere except for labels in forms and headers in tables).
 * Avoid tables for layout purposes. We have some places where they are hard to get rid of (use WAI-ARAI ?)
 * hide stuff: http://www.paciellogroup.com/blog/2012/05/html5-accessibility-chops-hidden-and-aria-hidden/
 * skip/jump to links

Things to discuss

 * Usage of  in labels. Ending a label with a dot, causes the screen reader to make a fullstop. See also: 24592 where the lack of fullstops creates unintelligible sentences.

Full Stop =.

Papers

 * "Making Wikipedia editing easier for the blind". 2008. M. Claudia Buzzi, Marina Buzzi. IIT-National Research Council. DOI:10.1145/1463160.1463210
 * "Is Wikipedia Usable for the Blind". 2008. Marina Buzzi (IIT), Barbara Leporini (ISTI). p. 15-22.
 * "Wikipedia, the open encyclopaedia: is it really open to blind users?" (Conference paper). 2008. j. ACM. Barbara Leporini. DOI:10.1145/1368044.1368049 (Derived from parent work)