Assistive technologies need semantic information about the structures and expected behaviors of a document in order to convey appropriate information to persons with disabilities. This specification defines a WAI-ARIA 1.1 [[WAI-ARIA-1.1]] module of core roles specific to web graphics. These semantics allow an author to express the logical structure of the graphic to assistive technologies in order improve accessibility of graphics. Assistive technologies could then enable semantic navigation and adapt styling and interactive features, to provide an optimal experience for the audience. These features complement the graphics and document structure elements defined by HTML [[HTML52]] and SVG [[SVG2]].
This document is part of the WAI-ARIA suite described in the WAI-ARIA Overview.
This is an Editor's Draft of WAI-ARIA Graphics Module 1.0 by the SVG Accessibility Taskforce, a joint task force of the Accessible Rich Internet Applications Working Group and the SVG Working Group.
Feedback on any aspect of the specification is accepted. For this publication, the SVG Accessibility Task Force particularly seeks feedback on the following questions:
To comment, file an issue in the W3C graphics-aria GitHub repository. If this is not feasible, send email to public-aria@w3.org (comment archive). In-progress updates to the document may be viewed in the publicly visible editors' draft.
WAI-ARIA is a technical specification that provides a framework to improve the accessibility and interoperability of web content and applications. It enables web browsers to map the accessibility semantics in web content to platform-specific accessibility APIs. This enables web content to be interoperable with platform assistive technologies, similar to native platform applications, without requiring authors to include platform dependencies.
This specification is a modular extension of WAI-ARIA [[WAI-ARIA-1.1]] designed to support graphics. The goals of this specification include:
This specification defines the core roles that would be used in all structured graphics or diagrams. It establishes the default roles that can be used to describe graphical markup elements such as shapes and canvases. In combination with WAI-ARIA attributes to provide alternative text and to indicate relationships between elements, this provides a framework for annotating many figures and diagrams. Future work will expand on this framework to enable more detailed annotation of data-rich graphics such as charts or maps.
For a more detailed explanation of WAI-ARIA please refer to the WAI-ARIA Introduction and how it applies to Rich Internet Application Accessibility.
This specification defines a module of WAI-ARIA for graphics, consisting of graphics-specific element roles. It impacts several audiences:
Each conformance requirement indicates the audience to which it applies.
This module follows the general User Agent support principles defined in WAI-ARIA [[WAI-ARIA-1.1]]. The roles defined here do not require any change in behavior by user agents other than in the information exposed to the accessibility API. However, the semantics defined here provide the ability for user agents to enhance the general user interface presented to readers. For example, a user agent may provide alternative keyboard navigation suitable to a graphical environment, or may allow users to extract a copy of a graphic from a larger document.
The WAI-ARIA Graphics module follows the model for co-evolution of WAI-ARIA and host languages defined in WAI-ARIA [[WAI-ARIA-1.1]]. It is intended to augment semantics in supporting languages like HTML [[HTML52]], SVG [[SVG2]] and EPUB, or to be used as an accessibility enhancement technology in other markup-based languages that do not explicitly include support for ARIA. WAI-ARIA roles clarify semantics to assistive technologies when authors create new types of objects, via style and script, or use markup languages which describe the visual appearance of a document rather than its meaning.
Although markup languages may provide some of these semantics natively, it is expected that there will be a persistent need for the semantics provided by the WAI-ARIA Graphics module. Some host languages exist to create semantics for features other than the user interface. For example, SVG expresses the semantics behind production of graphical objects, not of user interface components that those objects may represent. Host languages such as these might, by design, not provide native semantics that map to all of this specification's features. In these host languages, the WAI-ARIA Graphics module could be adopted as a long-term approach to add semantic information.
Programmatic access to accessibility semantics is essential for assistive technologies. For more information, refer to the Assistive Technologies section in WAI-ARIA [[WAI-ARIA-1.1]].
For the graphics roles in particular, two categories of assistive technology are particularly relevant, but have different needs:
The role descriptions suggest which features of an element with that role are considered semantically important and should be conveyed to the reader whenever possible.
The main content of this specification is normative and defines requirements that impact conformance claims. Introductory material, appendices, sections marked as "non-normative" and their subsections, diagrams, examples, and notes are informative (non-normative). Non-normative material provides advisory information to help interpret the guidelines but does not create requirements that impact a conformance claim.
Normative sections provide requirements that user agents must follow for an implementation to conform to this specification. The keywords MUST, MUST NOT, REQUIRED, SHALL, SHALL NOT, SHOULD, RECOMMENDED, MAY, and OPTIONAL in this document are to be interpreted as described in Keywords for use in RFCs to indicate requirement levels [[!RFC2119]]. RFC-2119 keywords are formatted in uppercase and contained in an element with class="rfc2119"
. When the keywords shown above are used, but do not share this format, they do not convey formal information in the RFC 2119 sense, and are merely explanatory, i.e., informative. As much as possible, such usages are avoided in this specification.
Normative sections provide requirements that authors, user agents and assistive technologies MUST follow for an implementation to conform to this specification.
Non-normative (informative) sections provide information useful to understanding the specification. Such sections may contain examples of recommended practice, but it is not required to follow such recommendations in order to conform to this specification.
This section defines additions to the WAI-ARIA role taxonomy and describes the characteristics and properties of all roles. See ARIA Roles for descriptions of the fields provided by this module.
Authors are given the ability to influence what is presented to assistive technologies and to influence navigation through the use of roles and properties. This includes the ability to mark elements as having no semantic importance. With graphics, there are many cases where presenting and navigating every element will make the graphic harder to understand and use.
Authors may mark elements for exclusion
from the semantic representation of the document
(the accessibility tree) by assigning
the role
In all cases, to be considered presentational, an element must not be interactive
and must not be assigned any accessible properties or alternative text.
A role of none
or presentation
will be ignored
for interactive elements or those with WAI-ARIA states and properties.
Below is an alphabetical list of the WAI-ARIA roles defined in this specification. They would normally be used in combination with other roles defined in WAI-ARIA to annotate graphics within documents and rich internet applications [[WAI-ARIA-1.1]].
Placeholder for compact list of roles
A type of
Similar to other graphics-document
role applies to the root element of
a region of the page containing related information,
where the user's primary interaction mode is expected to be
browsing the document rather than controlling an application.
The element with this role
may be the root element of the document file,
or of a nested structure within it.
The graphics-document
may be distinguished
from similar roles as follows:
Relative to other documents, a graphics-document
is distinguished by the semantic importance of its
visual (usually two-dimensional) representation.
User agents and assistive technologies
SHOULD take this into consideration
when supporting navigation of the graphic.
Accessibility technologies that re-format or re-style a document
SHOULD NOT alter the layout of a graphics-document
except in ways that are consistent
with the semantic roles and relationships of its content.
Relative to an graphics-document
is distinguished by the structured nature of its content.
Its child elements may have semantic meaning,
and may include links or other interactive widgets.
Relative to a graphics-document
is self-contained.
Its meaning persists when separated from surrounding content.
The element with the graphics-document
role defines
the scope and context for interpretation of the child content.
In general, authors SHOULD use the graphics-document
role
for structured graphics such as
charts, maps, diagrams, technical drawing, blue prints and instructional graphics.
However, if a single large graphic has discrete regions
that may be safely re-arranged without sacrificing meaning,
each of those regions SHOULD be a distinct graphics-document
.
An alternative role (such as graphics-document
may also be nested inside another,
for example a bar chart that is embedded in a map
or a matrix of chart panels
should have a role of graphics-document
.
The nested document provides encapsulation;
navigation between components of
the inner and outer graphics should be explicit.
To support user agents and assistive technologies
based on the ARIA 1.0 specification,
authors may wish to include the role="graphics-document document"
.
Future specifications may define more specific roles
for particular types of graphical documents with
special semantic structures. Those more specific roles
would be subclasses of graphics-document
.
Characteristic | Value |
---|---|
Is Abstract: | |
Superclass Role: | |
Subclass Roles: | |
Base Concept: | |
Related Concepts: |
|
Required Context Role: | |
Required Owned Elements: | |
Required States and Properties: | |
Supported States and Properties: | |
Inherited States and Properties: | |
Name From: | author |
Accessible Name Required: | True |
Inherits Name Required: | |
Children Presentational: | False |
Inherits Presentational: | |
Implicit Value for Role: |
A section of a
Container elements that represent a collection
of disconnected objects should be given the
div
or SVG g
that is only used for styling or layout)
SHOULD NOT be given a role.
The lack of role may be explicitly indicated
with the role
Unlike a graphics-object
need not be self-contained,
and it does not establish a new context for navigation.
However, user agents and assistive technologies
SHOULD provide a way for users, particularly non-visual users,
to navigate the nested structure of objects
in a hierarchical manner, similar to nested lists.
To support user agents and assistive technologies
based on the ARIA 1.0 specification,
authors may wish to include the role="graphics-object group"
.
Characteristic | Value |
---|---|
Is Abstract: | |
Superclass Role: | |
Subclass Roles: | |
Base Concept: | |
Related Concepts: |
|
Required Context Role: | |
Required Owned Elements: | |
Required States and Properties: | |
Supported States and Properties: | |
Inherited States and Properties: | |
Name From: |
|
Accessible Name Required: | False |
Inherits Name Required: | |
Children Presentational: | False |
Inherits Presentational: | |
Implicit Value for Role: |
A graphical object used to convey a simple meaning or category, where the meaning is more important than the particular visual appearance. It may be a component of a larger structured graphic such as a chart or map. The symbol itself is an atomic object; children are presentational.
When used as part of a structured symbolic language,
the
To support user agents and assistive technologies
based on the ARIA 1.0 specification,
authors may wish to include the role="graphics-symbol img"
,
if that is not already the default semantic role for the element.
Characteristic | Value |
---|---|
Is Abstract: | |
Superclass Role: | |
Subclass Roles: | |
Base Concept: | |
Related Concepts: | symbol |
Required Context Role: | |
Required Owned Elements: | |
Required States and Properties: | |
Supported States and Properties: | |
Inherited States and Properties: | |
Name From: | author |
Accessible Name Required: | True |
Inherits Name Required: | |
Children Presentational: | True |
Inherits Presentational: | |
Implicit Value for Role: |
The following core ARIA roles, defined in ARIA 1.1 [[WAI-ARIA-1.1]], are also relevant for annotating graphics:
The following examples demonstrate appropriate use of
WAI-ARIA provides a collection of accessibility state and properties which are used to support platform accessibility APIs on various operating system platforms. Assistive technologies may access this information through an exposed user agent DOM or through a mapping to the platform accessibility API. When combined with roles, the user agent can supply the assistive technologies with user interface information to convey to the user at any time. Changes in states or properties will result in a notification to assistive technologies, which could alert the user that a change has occurred.
The full commit history to WAI-ARIA Graphics Module 1.0 is available.
The following people contributed to the development of this document.