accessible dynamic forms

Accessible Dynamic Forms and Form

Validation with jQuery

Dylan Barrell (@dylanbarrell)Vice President of Product DevelopmentOctober, 2013

Examples and Code

• GitHub Repository with Examples– https://github.com/dylanb/a11yvalid

• Uses a11yfy code– https://github.com/dylanb/a11yfy

Overview• Commonly Violated WCAG 2.0 (A, AA) SC

• Form Accessibility Fundamentals

– Labels

– Instructions

– Layout

– Dynamism

– Controls

• Validation Fundamentals

– Fundamentals

– Layout and navigation

– Error messages and summaries

Common Success Criteria

Perceivable• All labels must be programmatically associated with the input

field [WCAG 1.3.1 A]

• Labels must be closely and visually associated with the input field [Best Practice]

• Error Messages must be associated with the input field [WCAG 1.3.1 A]

• Do not use color alone to indicate differences between fields [WCAG 1.4.1 A]– Required/Optional Fields, Error Fields

• Color Contrast between controls, labels, instructions, errors and the background must be sufficient [WCAG 1.4.3 AA]

Operable• Error messages that apply to the whole form must be

announced automatically [WCAG 2.4.3 A]

• Instructions that update/change dynamically must be announced automatically [WCAG 2.4.3 A]

• If you take action that allows the sighted mouse user to quickly identify and deal with fields that are in error, then an equivalent mechanism should be provided for keyboard users [WCAG 2.1.1 A]

• No Keyboard trap [WCAG 2.1.2 A]

Common Success Criteria

Operable• Focus order [WCAG 2.4.3 A]

• Focus Visible [WCAG 2.4.7 AA]

• Everything must be operable with the keyboard [WCAG 2.1.1 A]

Common Success Criteria

Understandable• On focus [WCAG 3.2.1 A]

• On input [WCAG 3.2.2 A]

• Error Suggestion [WCAG 3.3.3 AA]

• Error prevention (Legal, Financial, Test data) [WCAG 3.3.4 AA]

Common Success Criteria

Robust• Name, Role, Value and State [WCAG 4.1.2 A]

Common Success Criteria

Simple Labels • Use for-id association

<label for=“myinputid”>Label Text</label><input id=“myinputid” type=“text” />

• Use aria-labelledby

<label id=“mylabelid”>Label Text</label><input aria-labelledby=“mylabelid” type=“text” />

• Use label wrapping

<label for=“myinputid”>Label Text<input id=“myinputid” type=“text” />

</label>

• Example

Labels

Simple Labels • Use aria-label and/or title (beware)

<input id=“search” type=“text” aria-label=“Search”placeholder=“Search”/><button>Search</button>

– or<input id=“search” type=“text” title=“Search”placeholder=“Search”/><button>Search</button>

• Example

Labels

Multiple Labels

• Groups - fieldset<fieldset> <legend>Social Security Number</legend> <input type="text" name="ssn1" id="ssn1” title="first three digits"/> - <input type="text" name="ssn2" id="ssn2” title="middle two digits"/> - <input type="text" name="ssn3" id="ssn3” title="last four digits"/></fieldset>

• Example

Labels

Multiple Labels

• Groups – aria-labelledby<span id=“gender-group”>Gender</span><input aria-labelledby=“gender-group male-

gender” name=“gender” value=“male” type=“radio” />

<label id=“male-gender”>Male</label><input aria-labelledby=“gender-group female-

gender” name=“gender” value=“female” type=“radio” />

<label id=“female-gender”>Female</label>

• Example

Labels

Advisory Text, Additional Text…• aria-describedby

<p>

<label for=“mybirthdateid”>Date of Birth</label><input id=“mybirthdateid” type=“text” aria-

describedby=“datefmt”/><span id=“datefmt”>format: dd/mm/yyyy</span>

</p>

• Example

Instructions

Locate related items close to one another• Labels to input fields

• Error messages to input fields

• Instructional text/help icons to input fields

Layout

Layout

Layout

Layout

Layout

Layout

Maintain natural DOM order

• Do not use tabindex

• Do not use unnecessary JavaScript focus management in forms

Example

Layout

On Focus/Blur• Often used to show additional instructions

– Use aria-live and related attributes to announce changes

• Often used to do form validation– Use blur to recapture focus into field if it fails to validate (do not create a

keyboard trap)

– Use aria-live to announce errors

• Sometimes used to add fields– Use interim “busy” modal to trap and manage focus

Dynamism

On Change/Input• Do not auto advance multi-part fields (e.g. SSN, Date, Phone

number)*

• Use the modal focus trapping technique if modifying the form

• Be aware that updates to labels and aria-describedby fields do not auto announce– Use aria-live

Example – Good and Bad

Dynamism

jQuery Animations• Error Messages must be in the DOM and visible when the

appropriate field receives focus

• Form fields must be in the DOM, visible and enabled in order to receive focus programmatically

• iOS focus management requires waiting a full second after show before an element can receive focus

Dynamism

Use native controls where available• <button> or <input type=“submit|image” > and not <a>

• Use standard radio buttons if possible

• Conditional use of HTML5 new input types (iOS)– Date, Slider etc.

• Avoid use of “retrofit roles”– role=“button”

– role=“checkbox”

– role=“textbox”

– role=“radio”

Example

Controls

Be consistent• Choose either automatic validation or validation on

submission

• Choose one of:– Telling users which fields are required

– Telling users which fields are optional

• Consistent layout and visual design

• Consistent markup!!

Validation Fundamentals

Structure• Ensure error messages are visually distinct

• Ensure error messages are visually associated with the input field(s)– Cognitive disabilities

– Zoom users

• Ensure that attention is drawn to the items that are in error– Submission: Either focus on first field or focus on error summary

– Auto: revert focus to the field that is in error (do not create a keyboard trap)

• In large forms, make navigation between fields that are in-error easy– Keyboard navigation and mouse navigation

Error Layout and Navigation

Layout

Layout

Structure• Ensure that error messages are programmatically associated

with the input field– Use techniques previously mentioned

• Ensure that form-wide error information either receives focus on validation failure (submission only) or is announced automatically

• Ensure that error messages are easy to understand

• If validation occurs on submission, validate all form fields at once and provide a summary of all the errors in a summary

Final Example

Error Messages

Questions

dylan.barrell@deque.com

http://www.deque.com/

@dylanbarrell

@unobfuscator

http://unobfuscated.blogspot.com/