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Accessibility of HTML5 and Rich Internet Applications - CSUN 2012

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  • Demos:Bad treeGood Tree
  • Every widget should have one stopComposite widgets: menus, trees, grids, tabsEnsure all widgets are reachable by keyboardDepend on Tab order: default or custom?Support global keyboard shortcutsHow do you notify your users?Implement a custom focus managerMight be best solution for very complex UI'sLet go of the traditional tab order idea: "all focusable elements must be reachable by tab order"
  • Jquery Demo (collapsible sections)GXT Focus Manager
  • GXT Focus Manager demo (open window under "Window" tab)
  • Basic GridGridrow editor
  • Can point to multiple Ids, to ‘concatenate’ labels / decriptionsAT Support Summary: http://www.paciellogroup.com/blog/aria-tests/aria-labelledby-input.html When defining more than one of these, the order of precedence is:If these are defined: aria-label, aria-labelledBy, and Title: JAWS reads titleIf these are defined: aria-label, and aria-labelledBy: JAWS reads Label
  • Jquery dialog example
  • Example: stock updater To identify a live region, add the aria-live attribute.One of the most important concepts behind live regions is politeness. Politeness indicates how much priority a live region has. To create a live region, the developer adds the aria-live property to the element with a value of off, polite, assertive, or rude. The value, or politeness level (or alternatively the intrusiveness level), specifies what a screen reader should do when the element is updated.A value of off (aria-live="off") tells the screen reader to not announce the update. If/when the screen reader user encounters the updated content, it will be read at that time. This would be used for non-important or irrelevant content updates.A value of polite will notify the user of the content change as soon as he/she is done with the current task. This might take the form of a beep or an audio indication of the update. The user can then choose to directly jump to the updated content. This value would be the most common for content updates, especially for things like status notification, weather or stock updates, chat messages, etc.An aria-live value of assertive will result in the user being alerted to the content change immediately or as soon as possible. Assertive would be used for important updates, such as error messagesaria-live="rude" is reserved for the most critical of updates. It would immediately inform the user of the update and possibly set focus immediately to the updated content.
  • The following politeness values are available for aria-live: off, polite, and assertive.Aria-live="off"Default value, identical to not setting aria-live. Examples:A DHTML clockNumber of users currently onlineAria-live=“polite” Updates are announced but won’t interrupt the userShould be used in most situations involving live regions that present new information to users:Updates to news headlines, twitter alerts, monitored stocks, etc.Aria-live=“assertive”Updates are announced and interrupt what the user is doingOnly use for important updates that require immediate attention.Warnings & error notifications. Session timeout notificationsaria-atomic="true | false" Optional. Indicates if assistive technology should present all or part of the changed region to the user.aria-atomic=“true”: assistive technology should announce the entire region when part of it changes; aria-atomic=“false”: only the part of the region that changed should be announced on its own. aria-busy="true | false" Optional. Indicates whether region has finished updating, or whether certain parts are still expected to change. aria-busy=“true”: region not fully updated yet, AT should wait.aria-busy=“false”: region update is complete, AT can start announcing the update.Fall back solution for dialogs In IE, JAWS currently does not properly announce dialogs when moving focus into themIt's possible to provide a fallback solution for IE to fix this, using hidden fieldsets to apply the ARIA dialog markup to Hide fieldset's padding, margin, and borderMove legend off-screen <fieldsetrole="dialog" aria-labelledby="dialogTitle" aria-describedby="dialogDescription"> <legend id="dialogTitle">Confirm</legend> <p id="dialogDescription"> Are you sure you want to do that? </p> <button>Yes</button> <button>No</button></fieldset>Fallback solutions for link buttons Developers often use links as (icon) buttonsSide effect: screen reader will announce them as a link, not a buttonThis can be made accessible by setting role="button"Screen reader announces link as button now, but also provides hint for using a button ("press" space to activate)You lie! Links work through the Enter key, Space will scroll down the page To make sure JAWS is not lying, you'll have to manually add a key event handler for the Space key. <a role="button"onkeypress="handleKeyPress(event);">refresh</a>Fixing Structure: Aria-ownsSometimes a widget structure is not explicit via the DOM and logical structure of a page.Aria-owns=“IDREFS”Indicates that the element(s) referenced by the IDs should be considered a child of the element that has this attribute.<h3 id="header">Vegetables</h3> <ul role="list" aria-labelledby="header" aria-owns="external_listitem"> <li role="listitem">Carrot</li> <li role="listitem">Tomato</li> <li role="listitem">Lettuce</li> </ul> … <div role="listitem" id="external_listitem">Asparagus</div> Fixing Incorrect Grid Structure (1) Some developers will use multiple HTML <table> elements to create one single grid. For example:One <table> for the header row, one <table> for the body rowsOne <table> for every single rowWhy? Because this is easier to manage, style, position, drag & drop, etc.Screen reader does not perceive one single table, but it sees two ore more separate tablesAssociation between column headers and cells is brokenScreen reader's table navigation is brokenFixing Incorrect Grid Structure (2) If using a single table is not feasible, use ARIA to fix the grid structure as perceived by the screen reader Use role="presentation" to hide the original table elements form the screen readersUse a combination of "grid", "row", "gridcell", "columnheader" roles to make the screen reader see one big grid.Fixing Incorrect Grid Structure (3) Using ARIA to create a correct grid structure <div role="grid"> <table role="presentation"> <trrole="row"> <throle="columnheader">Dog Names</th> <throle="columnheader">Cat Names</th> <throle="columnheader">Cow names</th> </tr> </table> <table role="presentation"> <trrole="row"> <td role="gridcell">Fido</td> <td role="gridcell">Whiskers</td> <td role="gridcell">Clarabella</td> </tr> </table> </div> 
  • Validation sample
  • Requirements Screen Reader UsersScreen reader normally runs in ‘virtual mode’For web apps, switch to ‘non virtual mode’Keyboard input will not be disrupted by screen readerARIA will be properly recognizedIn JAWS pre version 11, use INS + Z to switch to PC Cursor modeUse shortcut twice fast to permanently stay in this modeIn WindowEyes, use CTRL + SHIFT+ A to move out of browse modeUse ins + A to turn autoload on or off
  • ARIA grid fix example
  • Transcript

    • 1. Hans Hillen (TPG) Steve Faulkner (TPG)02 / 27 / 12 Accessibility of HTML5 and Rich Internet Applications - CSUN 2012 1
    • 2.  www.paciellogroup.com/training/CSUN2012 Examples: part 1 http://www.html5accessibility.com/CSUN12/
    • 3. If you can avoid using:— JavaScript— CSS— ARIA— HTML5DO IT!Now back to reality...
    • 4. I am not an expertI know some things about HTML5 and WAI-ARIAI know some people who know some other thingsabout HTML5 and WAI-ARIAI will hold up a virtual sign if you ask a question I cannotanswerConsider it held up when you ask a question and I lookvague
    • 5. Hans emailor tweet
    • 6. There’s a clue in the name:Accessible Rich Internet Applications
    • 7. “This specification introduces features toHTML and the DOM that ease theauthoring of Web-based applications.”
    • 8. ARIA is not so much about contentARIA is about interaction
    • 9. Much of ARIA only makes sense inconjunction with scripting.Much of ARIA is about making senseof scripted interaction
    • 10. ARIA Stuff that makes sense without scripting—Landmark roles—A few of the relationship attributes—A few of the document structure roles
    • 11. <div tabindex="0" role="button" act="20" class="T-I J-J5-Ji nu T-I-ax7 L3" style="-moz-user-select: none;" aria-label="Refresh" data- tooltip="Refresh"><div class="asa"><span class="J-J5-Ji ask">&nbsp;</span><div class="asf T-I-J3 J-J5-Ji"></div></div></div>
    • 12. ARIA can/could be used with any markup language.— HTML— XHTML— SVG— MATHML— MXML— XUL
    • 13. Firebug accessibility implemented by Hans Hillen using ARIA
    • 14. ARIA attributesrole aria-*
    • 15. abstract role Document Landmarkwidget structure ‘main’ ‘heading’
    • 16. command (abstract role) composite (abstract role) input (abstract role) landmark (abstract role) range (abstract role) roletype (abstract role) section (abstract role) sectionhead (abstract role) select (abstract role) structure (abstract role) widget (abstract role) window (abstract role)Don’t use
    • 17. widgetSimple Composite‘button’ ‘menubar’ typically act as containers that manage other, contained widgets.
    • 18. What do they do?How do they do it?What they don’t do (generally)
    • 19. Override native html roles If you want the native semantic to be used Do not add a role! BAD <h1 role=“button”>heading text</h1> GOOD <h1> <span role=“button”>heading text</span> </h1>
    • 20. Expose role information to accessibility APIsrole=“button”
    • 21. UIA MACWAI- IAccessible2 Control MSAA role ATK role AccessibiARIA role role Pattern lity Role Type ROLE_SYSTEM IA2_ROLE_TOG ATK_ROLE_PUSbutton _PUSHBUTTON GLE_BUTTON Button H_BUTTON AXButton .HTML to Platform Accessibility APIs Implementation Guide
    • 22. role=“button” “to activate press space bar” http://www.paciellogroup.com/blog/aria-tests/user-input-widgets.html demo
    • 23. They are not magic!They do not (generally) add ANY interaction behaviours.Adding a role does not:Make an element focusableProvide keyboard eventsAdd properties Button example
    • 24. The following roles are regions of the pageintended as navigational landmarks.application form html4banner maincomplementary html5 navigation html5contentinfo search demo
    • 25. aria-* Widget Live Region Drag & Drop Relationship‘aria-checked’ ‘aria-live’ ‘ aria-dragged’ ‘aria-labelledby’
    • 26. — Use of ARIA in HTML<5 is non conforming and probably always will be.— It doesn’t make any difference— Simple solution – use the HTML5 doctype<!DOCTYPE html>
    • 27. There are rules:HTML5 – WAI-ARIA 3.2.7
    • 28. You can use:—validator.w3.org/nu/But some of the rules are out of date
    • 29. • Browsers with ARIA support: rough guide – Firefox 3+ – Internet Explorer 8+ – Safari 5 (Mac/iOS) – Chrome 17• Assistive Technology: – JAWS 8 and up – WindowEyes 5.5 and up – Zoomtext – Free screen readers: NVDA, ORCA – VoiceOver – ChromeVox• Libraries (support) – ExtJs, Jquery, Dojo, GWT, YUI, Glow + others
    • 30. Chart Title 10 JAWS 13 NVDA 2012 9 VoiceOver 8Support score 7 Orca 6 5 Window eyes 4 7.5 3 2 1 0 1
    • 31.  Accessibility support: www.HTML5accessibility.com New interactive elements: html5 interactive controls Text alternatives: long descriptions Canvas: canvas example Structural elements: HTML5 structural elements Figure and figcaption: figures and figcaption
    • 32.  Aviewer (free desktop application for windows ) Dom Inspector (free Firefox extension) Inspect.exe (free desktop application for windows available as part of the Windows SDK) Accprobe (free open source cross platform app) Accessibility Inspector (free Mac app) Java ferret (free cross platform app) Accerciser (free gnome desktop app)
    • 33.  www.twitter.com/stevefaulkner www.twitter.com/hanshillen www.paciellogroup.com/blog www.html5accessibility.com sfaulkner@paciellogroup.com hhillen@paciellogroup.com
    • 34. Hans Hillen (TPG) Steve Faulkner (TPG)02 / 27 / 12 Accessibility of HTML5 and Rich Internet Applications - CSUN 2012 42
    • 35.  Keyboard and Focus Management Labeling and Describing Live Regions Form Validation Mode Conflicts Fallback Solutions02 / 27 / 12 Accessibility of HTML5 and Rich Internet Applications - CSUN 2012 43
    • 36. 02 / 27 / 12 Accessibility of HTML5 and Rich Internet Applications - CSUN 2012 44
    • 37. Problem: Images, divs, spans etc. are not standard controls with defined behaviors o Not focusable with keyboard o Have a default tab order o Behavior is unknownSolution: Ideally: Use native focusable HTML controls o <a>, <input type=“image” />, <button>, etc. Or manually define keyboard focus and behavior needs02 / 27 / 12 Accessibility of HTML5 and Rich Internet Applications - CSUN 2012 45
    • 38.  Reachability: Moving keyboard focus to a widget o Through tab order • Native focusable controls or tabindex=“0” o Through globally defined shortcut o By activating another widget Operability: Interacting with a widget o All functionally should be performable through keyboard and mouse input02 / 27 / 12 Accessibility of HTML5 and Rich Internet Applications - CSUN 2012 46
    • 39.  To be accessible, ARIA input widgets need focus o Use natively focusable elements, such as <a>, <input />, etc o Add ‘tabindex’ attribute for non focusable elements, such as <span>, <div>, etc. • Tabindex=“0”: Element becomes part of the tab order • Tabindex=“-1” (Element is not in tab order, but focusable) o For composite widgets (menus, trees, grids, etc.): • Every widget should only have 1 stop in the tab order. • Keep track where your widget’s current tab stop is: o Alternative for tabindex: ‘aria-activedescendant=“<idref>” • Focus remains on outer container • AT perceives element with the specified ID as being focused. • You must manually highlight this active element, e.g. With CSS02 / 27 / 12 Accessibility of HTML5 and Rich Internet Applications - CSUN 2012 47
    • 40.  Every widget needs to be operable by keyboard. common keystrokes are: o Arrow keys o Home, end, page up, page down o Enter, space o ESC Mimic the navigate in the desktop environment o DHML Style Guide: http://dev.aol.com/dhtml_style_guide o ARIA Best Practices: http://www.w3.org/TR/wai-aria-practices/02 / 27 / 12 Accessibility of HTML5 and Rich Internet Applications - CSUN 2012 48
    • 41.  The ability to skip content is crucial for both screen reader and keyboard users Skip links are out of date, out of fashion and often misused o But keyboard users still need to be able to skip Other alternatives for skipping: o Collapsible sections o Consistent shortcuts (e.g. a shortcut that moves focus between panes and dialogs) o Custom focus manager that allows the user to move focus into a container to skip its contents02 / 27 / 12 Accessibility of HTML5 and Rich Internet Applications - CSUN 2012 49
    • 42.  More and more web apps use HTML based popup dialogs rather than actual browser windows/dialogs o Get a screen reader to perceive it properly using role="dialog" Dialogs should have their own tab order o Focus should "wrap" For modal dialogs, it should not be possible to interact with the main page o Prevent keyboard access o Virtual mode access cant be prevented For non modal dialogs, provide shortcut to switch between dialog and main page If dialog supports moving or resizing, these features must be keyboard accessible Support closing dialogs using Enter (OK) or Escape (Cancel) keys o Focus should be placed back on a logical element, e.g. the button that triggered the dialog.02 / 27 / 12 Accessibility of HTML5 and Rich Internet Applications - CSUN 2012 50
    • 43.  Trees, Lists, Grids can support single or multiple selection o Multiple selection must be keyboard accessible, for example: • Shift + arrow keys: contiguous selection • Ctrl + arrow keys: move focus without selection • Ctrl + space: Toggle focused item in selection (discontiguous selection) Editable grids need to support switching to edit mode by keyboard02 / 27 / 12 Accessibility of HTML5 and Rich Internet Applications - CSUN 2012 51
    • 44. 02 / 27 / 12 Accessibility of HTML5 and Rich Internet Applications - CSUN 2012 52
    • 45.  All of these must have an accessible name: o Every interactive widget o Composite widgets (menu(bar), toolbar, tablist, tree, grid) o Groups, regions and landmarks Browsers determines an element’s accessible name by checking the following : 1. aria-labelledby 2. aria-label 3. Associated label (<label for=“myControl”>) or alt attribute 4. Text contents 5. Title attributeOptionally, add an accessible description for additional info02 / 27 / 12 Accessibility of HTML5 and Rich Internet Applications - CSUN 2012 53
    • 46.  Aria-labelledby=“elemID” o Points to element ID that identifies the widget. o Can also use regular label element / title attribute Aria-describedby=“elemID” o Optional, provides additional info besides identity o Useful for additional info, instructions, hints Aria-label=“text” o Only use when no on-screen text Title attribute will also work<h2 id=“treeLbl”>My Folders</h2><p id=“treeDesc” class=“hidden”>Each tree item has a context menu with more options</p><div role=“tree” aria-labelledby=“treeLbl” aria-describedby=“treeDesc”> 02 / 27 / 12 Accessibility of HTML5 and Rich Internet Applications - CSUN 2012 54
    • 47.  Aria-labelledby=“IDREFS” o Value is one or more IDs of elements that identifiy the widget. o The elements ‘aria-labelledby’ targets can be any kind of text based element, anywhere in the document. o Add multiple Ids to concatinate label text: • Multiple elements can label one widget, and one element can label multiple widgets. (example) Aria-describedby=“IDREFS” o Similar to labelledby, except used for additional description, e.g. Form hints, instructions, etc. Aria-label o Simply takes a string to be used as label. o Quick and dirty way of making the screen reader say what you want. o Very easy to use, but only supported in Firefox at the moment.<h2 id=“treeLbl”>My Folders</h2><p class=“hidden”>Each tree item has a context menu with more options</p><div role=“tree” aria-labelledby=“treeLbl” aria-describedby=“treeDesc”>...02 / 27 / 12 Accessibility of HTML5 and Rich Internet Applications - CSUN 2012 55
    • 48.  Containers such as toolbars, dialogs, and regions provide context for their contents When the user moves focus into the container, the screen reader should first announce the container before announcing the focused control<div role="dialog" aria-labelledby="dialogTitle" aria-describedby="dialogDescription"> <h2 id="dialogTitle">Confirm</h2> <p id="dialogDescription"> Are you sure you want to do that? </p> <button>Yes</button> <button>No</button></div>02 / 27 / 12 Accessibility of HTML5 and Rich Internet Applications - CSUN 2012 56
    • 49. 02 / 27 / 12 Accessibility of HTML5 and Rich Internet Applications - CSUN 2012 57
    • 50.  Problem: content is updated dynamically on screen may not be apparent to screen reader users o No page refresh, no screen reader announcement o Change is only announced by stealing focus o Users miss relevant information o Users have to ‘search’ for updated page content Solution: live regions indicate page updates without losing focus o Screen readers announce change based on type of live region Challenge: When should users be informed of the change? o Ignore trivial changes: changing seconds in a clock o Announce important changes immediately / as convenient02 / 27 / 12 Accessibility of HTML5 and Rich Internet Applications - CSUN 2012 58
    • 51.  Role=“alert” for one-time, high-priority notifications o Shown for a period of time, or until the cause of the alert is solved o Basic message, no complex content o The element with the alert role does not need to be focused to be announced Role=“alertdialog” is similar to alert, but for actual (DHTML) dialogs. o May contain other widgets, such as buttons or other form fields o Does require a sub-element (such as a ‘confirm’ button) to receive focus Live regions ‘built into ‘ roles’ • role="timer", "log", "marquee" or "status“ get default live behavior • Role=“alert” implicitly sets live to assertive02 / 27 / 12 Accessibility of HTML5 and Rich Internet Applications - CSUN 2012 59
    • 52. 1. Identify which part (containing HTML element) is expected to be updated2. To make it live, add ‘aria-live’ attribute with a politeness value: o Off (default): Do not speak this region o Polite: Speak this region when the user is idle o Assertive: Speak this region as soon as possible3. Choose whether entire region should be announced or just the part that changed: o ‘aria-atomic: true (all) or false (part)4. Add other attributes as necessary: o aria-relevant: choose what to announce: • Combination of ‘Additions’, ‘removals’, ‘text’, ‘all’ o aria-busy: indicate content is still updating o aria-labelledby, aria-describedby: label and describe regions02 / 27 / 12 Accessibility of HTML5 and Rich Internet Applications - CSUN 2012 60
    • 53. 02 / 27 / 12 Accessibility of HTML5 and Rich Internet Applications - CSUN 2012 61
    • 54.  You can used ARIA to make your form validation easier to manage. o aria-required & aria-invalid states o Role="alert" to flag validation errors immediately Use validation summaries invalid entries easier to find o Use role=“group” or Role="alertdialog" to mark up the summary o Link to corresponding invalid controls from summary items o Use different scope levels if necessary Visual tooltips: Useful for validation messages and formatting instructions o Tooltips must be keyboard accessible o Tooltip text must be associated with the form control using aria-describedby Live Regions: Use for concise feedback messages02 / 27 / 12 Accessibility of HTML5 and Rich Internet Applications - CSUN 2012 62
    • 55. 02 / 27 / 12 Accessibility of HTML5 and Rich Internet Applications - CSUN 2012 63
    • 56.  Screen readers normally browse in ‘virtual mode’ o Navigates a virtual copy of the web page o Intercepts all keystrokes for its own navigation (e.g. ‘H’ for heading navigation) For dynamic Web apps, virtual mode may need to be turned off o Interactive widgets need to define the keystrokes themselves o Content needs to be live, not a virtual copy o Automatically switches between virtual and non-virtual mode role=“application” o Screen reader switches to non-virtual for these elements o Must provide all keyboard navigation when in role=“application” mode o Screen readers don’t intercept keystrokes then, so typical functions will not work02 / 27 / 12 Accessibility of HTML5 and Rich Internet Applications - CSUN 2012 64
    • 57.  For apps with ‘reading’ or ‘editing’ sections o A reading pane in an email client o Screen reader switches back to virtual mode, standard ‘web page reading’ shortcuts work again o Read / edit documents in a web application Banner, complementary, contentinfo, main, navigation, search & form When applied to a container inside an application role, the screen reader switches to virtual mode.02 / 27 / 12 Accessibility of HTML5 and Rich Internet Applications - CSUN 2012 65
    • 58. 02 / 27 / 12 Accessibility of HTML5 and Rich Internet Applications - CSUN 2012 66
    • 59.  Role=“presentation” overrides existing role o Useful to ‘hide’ default HTML roles from AT For example: o Hide layout tables by adding the role to the <table> element o Textual content read by the screen reader but table is ignored02 / 27 / 12 Accessibility of HTML5 and Rich Internet Applications - CSUN 2012 67
    • 60.  In IE, JAWS currently does not properly announce dialogs when moving focus into them Its possible to provide a fallback solution for IE to fix this, using hidden fieldsets to apply the ARIA dialog markup to o Hide fieldsets padding, margin, and border o Move legend off-screen<fieldset role="dialog" aria-labelledby="dialogTitle" aria-describedby="dialogDescription"> <legend id="dialogTitle">Confirm</legend> <p id="dialogDescription"> Are you sure you want to do that? </p> <button>Yes</button> <button>No</button></fieldset>02 / 27 / 12 Accessibility of HTML5 and Rich Internet Applications - CSUN 2012 68
    • 61.  Developers often use links as (icon) buttons o Side effect: screen reader will announce them as a link, not a button This can be made accessible by setting role="button" o Screen reader announces link as button now, but also provides hint for using a button ("press" space to activate) • You lie! Links work through the Enter key, Space will scroll down the page o To make sure JAWS is not lying, youll have to manually add a key event handler for the Space key.<a role="button" onkeypress="handleKeyPress(event);">refresh</a>02 / 27 / 12 Accessibility of HTML5 and Rich Internet Applications - CSUN 2012 69
    • 62.  Three types of hiding: 1. Hiding content visually and from AT: 2. Hiding content visually, but not from AT 3. Hiding content from AT, but not visually02 / 27 / 12 Accessibility of HTML5 and Rich Internet Applications - CSUN 2012 70
    • 63.  Display: none; o Hides content both visually and from AT products o Only works when CSS is supported (by user agent, user, or AT product) o Only use to hide content that still ‘makes sense’ • E.g. contents of a collapsible section o Do not use for content that provides incorrect information • E.g. preloaded error messages that are not applicable at the moment, or stale content • Instead, this content should be removed from the DOM completely02 / 27 / 12 Accessibility of HTML5 and Rich Internet Applications - CSUN 2012 71
    • 64.  Hiding content off-screen will still make it available for screen readers, without it being visible Useful to provide extra information to screen reader users or users that do not support CSS o E.g. add hidden headings, screen reader instructions, role & state info for older technology/* Old */.offscreen { position: absolute; left: -999em;}/* New */.ui-helper-hidden-accessible { position: absolute !important; clip: rect(1px 1px 1px 1px); clip: rect(1px,1px,1px,1px);}02 / 27 / 12 Accessibility of HTML5 and Rich Internet Applications - CSUN 2012 72
    • 65.  Sometimes developers want to hide content from screen readers, e.g.: o Duplicate controls o Redundant information that was already provided through semantic markup. Difficult to achieve: o Role=“presentation” will remove native role, but content is still visible for AT products o Aria-hidden=“true” would be ideal, but: • The spec did not intend for aria-hidden to be used this way • Browsers handle aria-hidden differently • IE does nothing • FF exposes content but marks it as hidden • Chrome does not expose content (i.e. truly hides it)02 / 27 / 12 Accessibility of HTML5 and Rich Internet Applications - CSUN 2012 73
    • 66. 02 / 27 / 12 Accessibility of HTML5 and Rich Internet Applications - CSUN 2012 74
    • 67.  Some developers will use multiple HTML <table> elements to create one single grid. For example: o One <table> for the header row, one <table> for the body rows o One <table> for every single row Why? Because this is easier to manage, style, position, drag & drop, etc. Screen reader does not perceive one single table, but it sees two ore more separate tables o Association between column headers and cells is broken o Screen readers table navigation is broken02 / 27 / 12 Accessibility of HTML5 and Rich Internet Applications - CSUN 2012 75
    • 68.  If using a single table is not feasible, use ARIA to fix the grid structure as perceived by the screen reader o Use role="presentation" to hide the original table elements form the screen readers o Use a combination of "grid", "row", "gridcell", "columnheader" roles to make the screen reader see one big grid.02 / 27 / 12 Accessibility of HTML5 and Rich Internet Applications - CSUN 2012 76
    • 69.  Using ARIA to create a correct grid structure <div role="grid"> <table role="presentation"> <tr role="row"> <th role="columnheader">Dog Names</th> <th role="columnheader">Cat Names</th> <th role="columnheader">Cow names</th> </tr> </table> <table role="presentation"> <tr role="row"> <td role="gridcell">Fido</td> <td role="gridcell">Whiskers</td> <td role="gridcell">Clarabella</td> </tr> </table> </div>02 / 27 / 12 Accessibility of HTML5 and Rich Internet Applications - CSUN 2012 77
    • 70.  Questions? Additional Topics? Course Material: http://www.paciellogroup.com/training/CSUN201202 / 27 / 12 Accessibility of HTML5 and Rich Internet Applications - CSUN 2012 78

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