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<!DOCTYPE html>
<html>
<head>
<title>
Accessibility API
</title>
<meta charset='utf-8'>
<script src='https://www.w3.org/Tools/respec/respec-w3c-common' async
class='remove'>
</script>
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shortName: "a11y-api",
// if your specification has a subtitle that goes below the main
// formal title, define it here
// subtitle : "an excellent document",
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name: "Alexander Surkov"
, url: "http://mozilla.org/"
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, company: "Mozilla"
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name: "Marcos Caceres"
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</head>
<body>
<section id='abstract'>
<p>
There's number of objectives on the web to improve accessibility and
usability support. Web applications want to provide special support for
their users, helping them navigate and perceive the content. The
browser has a number of add-ons serving to improve accessibility
support, for example, the app letting to navigate landmarks on the web
page. These tasks require accessibility API similar to what desktop
assistive technologies have.
</p>
<p>
Web accessibility API also allows for in-browser automated
accessibility testing of web content, i.e. helpful for checking that
HTML and other standards in the browser are accessible to all users.
</p>
<p>
On the other hand there's a growing need for making graphical content
accessible. These are charts, graphs and other various visual forms
that are drawn using HTML canvas or SVG. There's also a tendency to use
HTML canvas element in place of DOM because of performance matter,
here's an example. All markup in the example is defined in JavaScript
and there is a need for a non-DOM accessibility solution to make the
content accessible.
</p>
</section>
<section id='sotd'>
<p>
This is a work in progress.
</p>
<section>
<h3>
Things we want feedback on!
</h3>
<ul>
<li>Should we specify hasAnyOf() and hasAllOf() for Set interface? Or
should we just rely on JS's Array interface to do the same thing?
Pros:... Cons:....
</li>
</ul>
</section>
</section>
<section>
<h2>
Accessibility API
</h2>
<p>
The API provides bunch of interfaces that are used to express the
semantics of web content in a way that assistive technologies (AT)
knows how to deal with. Also it provides the ability to search and
traverse the content and interact with it. It has a way to extend
existing semantics of the markup, and add new semantics for
inaccessible content like drawings made using the <code>canvas</code>
element. Each piece of semantic content has an associated accessible
element the AT operates on.
</p>
<section>
<h3>
Terms
</h3>
<p>
An <dfn>assistive technology</dfn> or <dfn>AT</dfn> is software that
provides an improved user experience for different types of users
including people with disabilities. It can be in the form of a native
application, or web application (e.g., zoom tool), or service (e.g.,
speech-to-text).
</p>
<p>
A <dfn>content entity</dfn> is semantically isolated piece of
content. For example, <a>interactive content</a> in [[!HTML]].
</p>
<p>
An <dfn data-lt="accessible elements">accessible element</dfn> is an
object expressing the semantics of a <a>content entity</a>. Such
objects are represented by the <code>AccessibleElement</code>
interface.
</p>
<p>
A <dfn>role</dfn> of an <a>accessible element</a> identifies the
function of the accessible element to assistive technology (e.g.,
"button", "textbox", etc. See also [[!WAI-ARIA]] roles).
</p>
<p>
A <dfn>name</dfn> of an <a>accessible element</a> is a primary human
readable property of an accessible element. For example, <a>assistive
technology</a> could present the name of the <a>accessible
element</a> to the user.
</p>
<p>
A <dfn>description</dfn> of an <a>accessible element</a> is a
secondary human readable property of an <a>accessible element</a>.
It's used to provide more detailed information than <a>name</a> to
the user about a <a>content entity</a> the <a>accessible element</a>
was created for (e.g., a tool tip).
</p>
<p>
A <dfn>text</dfn> of an <a>accessible element</a> is text associated
with the <a>accessible element</a>.
</p>
<p>
An <a>accessible element</a> has a set of <dfn>states</dfn>, which is
represented by a <code>Set</code>-like object. Conceptually, each one
of these <dfn>states</dfn> is a boolean that represents the state the
content entity is currently in. For example, if a [[!HTML]]
<code>button</code> element is in the focused state (e.g., the user
has focused the button by tabbing to it), then its <a>accessible
element</a> will have "<code>focused</code>" state in its
<a>accessible states</a>.
</p>
<p>
An <dfn>attribute</dfn> of an <a>accessible element</a> is a property
that provides extra information about its <a>content entity</a>. For
example, autocomplete feature on an <code>input</code> element would
map to <code>autocomplete</code> attribute with possible values
<code>inline</code>, <code>list</code>, or <code>both</code>.
</p>
<p>
A <dfn>pattern</dfn> of an <a>accessible element</a> expresses the
associated semantics of the <a>content entity</a> that is not
expressed by means of the <code>AccessibleElement</code> interface.
</p>
<p>
A <a>accessible element</a> can have one or more <dfn>relations</dfn>
to other <a>accessible elements</a>. Each relation has a
<dfn>relation type</dfn> that expresses its semantics. Relations of
an accessible objects are represented by objects that implement the
<code>Set</code> interface.
</p>
<p>
An <dfn>user action</dfn> of an <a>accessible element</a> is an
action supported by the <a>content entity</a>. An user action can be
performed on a content entity by the user or the user agent via
script (e.g., a button click). In the API, user actions are
represented by objects that implement the <code>Set</code> interface.
</p>
<p>
A <dfn>device-dependent interaction</dfn> includes things like
keyboard shortcut or mouse gesture used to invoke the <a>action</a>.
In the API, a device-dependent interaction is represented by the
<a>Interaction</a> interface. All supported <a>device-dependent
interactions</a> on an <a>accessible element</a> are represented by
objects that implement the <code>InteractionMap</code> interface.
</p>
<p>
An <dfn data-lt="accessible trees">accessible tree</dfn> is a tree of
<a>accessible elements</a> associated to each other by a parent-child
relationship.
</p>
<p>
An <dfn>accessible parent</dfn> of the referred <a>accessible
element</a> is its parent in the <a>accessible tree</a>.
</p>
<p>
An <dfn>accessible child</dfn> of the referred <a>accessible
element</a> are its child accessible elements in the <a>accessible
tree</a>. It is represented by the <code>AccessibleChildren</code>
interface.
</p>
<p>
An <dfn>accessible DOM node</dfn> or <dfn>accessible DOM
element</dfn> is a [[!DOM]] <code>Node</code> or <code>Element</code>
that has an associated <a>accessible element</a>.
</p>
<p>
An <dfn>accessible position</dfn> is a point in the content when it's
presented in one-dimensional way, that can be semantically traversed.
For example, paragraph text can be traversed by words, or traversing
the document using HTML's outlining algorithm. User focus can also be
described by an <a>accessible position</a>; for example tabbing from
one HTML input element to another within a form.
</p>
<p>
An <dfn>accessible pin</dfn> is an object representing an
<a>accessible position</a> and implementing
<code>AccessiblePin</code> interface.
</p>
</section>
<section class="informative">
<h3>
Understanding the terms
</h3>
<p>
Each <a>content entity</a> has an associated <a>accessible
element</a>. Each <a>accessible element</a> is described by
accessible properties like <a>role</a>, <a>name</a>, <a>relations</a>
etc.
</p>
<figure>
<img src="images/props.png" alt="accessible properties diagram">
<figcaption>
Accessible properties.
</figcaption>
</figure>
<p>
<a>Accessible elements</a> can be related to each other by number of
different types.
</p>
<figure>
<img src="images/rels.png" alt="accessible relations diagram">
<figcaption>
Relations. A color of arrows connecting accessible element
represent own relation type.
</figcaption>
</figure>
<p>
All <a>accessible elements</a> are organized into <a>accessible
trees</a>. In other words, all <a>accessible elements</a> are
supposed to stay in parent-child relationship. The <a>assistive
technology</a> can traverse the document by traversing its
<a>accessible tree</a>.
</p>
<figure>
<img src="images/tree.png" alt="accessible tree">
<figcaption>
Accessible tree.
</figcaption>
</figure>
<p>
The browser exposes semantics of the content to the <a>assistive
technology</a> like screen readers or screen magnifiers softwares via
platform APIs like ATK, IAccessible2, UIA, NSAccessibility or this
API. The <a>assistive technology</a> communicates back to the content
by the browser via platform APIs.
</p>
<figure>
<img src="images/overview.png" alt="overview diagram">
<figcaption>
Overview of the communication between the content and the
<a>assistive technology</a>.
</figcaption>
</figure>
</section>
</section>
<section>
<h2>
Extensions to the <code>Node</code> interface
</h2>
<p>
Assistive technology, or the developer, can request an <a>accessible
element</a> from a [[!DOM]] <code>Node</code> if the <code>Node</code>
is accessible, i.e. it expresses semantics to the assistive technology.
</p>
<pre class="idl">
partial interface Node {
readonly attribute AccessibleElement? a11ement;
};
</pre>
<section>
<h3>
<code>AccessibleElement</code> attribute
</h3>
<p>
The <code>AccessibleElement</code> attribute return the <a>accessible
element</a> associated with this <code>Node</code> (if any).
Otherwise, it returns <code>null</code>.
</p>
</section>
</section>
<section>
<h2>
AccessibleElement interface
</h2>
<pre class="idl">
interface AccessibleElement {
attribute DOMString role;
attribute DOMString name;
attribute DOMString description;
attribute DOMString text;
readonly attribute AccessibleIterable states;
readonly attribute AccessibleIterable attributes;
readonly attribute AccessibleIterable patterns;
readonly attribute AccessibleIterable relations;
boolean is(DOMString ... something);
any get(DOMString attribute);
boolean has(DOMString attribute);
object to(DOMString pattern);
AccessibleElement? relativeOf(DOMString type);
sequence<AccessibleElement> relativeOfAll(DOMString type);
readonly attribute Actions actions;
void activate(DOMString action);
Interactions interactionsOf(optional DOMString action, optional DOMString device);
readonly attribute AccessibleElement? parent;
readonly attribute AccessibleChildren children;
readonly attribute Node? DOMNode;
attribute AccessibleSource? source;
};
</pre>
<section>
<h3>
<code>role</code> attribute
</h3>
<p>
The <dfn><code>role</code></dfn> attribute represents the accessible
role that is either developer defined or a role as per [[!WAI-ARIA]]
(e.g., "button", "menu", "textfield").
</p>
<div class="note">
For the author convenience the attribute value may be a space
separated list of <a>roles</a>. This is useful when an <a>accessible
element</a> should express semantics of both roles but the taxonomy
misses a separate role for that. For example, a check menu item
<a>accessible element</a> may have <code>menuitem checkbox</code>
role if the role taxonomy doesn't have <code>checkmenuitem</code>
<a>role</a>. In this case <code>is</code> method is supposed to
return true for both <code>checkbox</code> and <code>menuitem</code>
values.
</div>
</section>
<section>
<h3>
<code>name</code> attribute
</h3>
<p>
The <dfn><code>name</code></dfn> attribute represents <a>name</a>.
</p>
<p>
When setting, ...
</p>
</section>
<section>
<h3>
<code>description</code> attribute
</h3>
<p>
The <dfn><code>description</code></dfn> attribute <a>description</a>
</p>
<p>
When setting, ...
</p>
</section>
<section>
<h3>
<code>text</code> attribute
</h3>
<p>
The <dfn><code>text</code></dfn> attribute represents <a>text</a>.
</p>
<p>
When setting, ...
</p>
</section>
<section>
<h3>
<code>states</code> attribute
</h3>
<p>
The <dfn><code>states</code></dfn> attribute represents the
<a>states</a>.
</p>
<p>
Returns an <code>iterable</code> for all states exposed on the
accessible element. The implementation is not required to pre-compute
any of the states.
</p>
</section>
<section>
<h3>
<code>attributes</code> attribute
</h3>
<p>
The <dfn><code>attributes</code></dfn> attribute represents
<a>attributes</a>.
</p>
<p>
The accessible element can support a number of attributes to express
the semantics that cannot be described by base properties of an
accessible element.
</p>
<p>
Returns an <code>iterable</code> for all object attributes exposed on
the accessible element. The implementation is not required to
pre-compute any of the attributes.
</p>
<div class="note">
<p>
Set of exposed attributes depends on semantics of the [[!DOM]]
element. As an example, typical attributes are:
</p>
<dl>
<dt>
DOMString autocomplete:
</dt>
<dd>
Exposed on text fields. Values are list, none, inline, both.
</dd>
<dt>
DOMString live:
</dt>
<dd>
Points that the accessible is live region. Values are assertive
and polite.
</dd>
<dt>
DOMString relevant:
</dt>
<dd>
Lists all notifications that qualifies for live region.
</dd>
</dl>
</div>
</section>
<section>
<h3>
<code>patterns</code> attribute
</h3>
<p>
The <dfn><code>patterns</code></dfn> attribute represents the
<a>patterns</a>.
</p>
<p>
Returns an <code>iterable</code> for all patterns exposed on the
accessible element. The implementation is not required to pre-compute
any of the values.
</p>
<div class="note">
Each markup can come with own set of supported patterns. A single
<a>accessible element</a> may support several <a>patterns</a>. A
typical example of a pattern is <code>table cell</code> pattern which
has extra properties like <code>row index</code> and <code>column
index</code>.
</div>
</section>
<section>
<h3>
<code>relations</code> attribute
</h3>
<p>
The <dfn><code>relations</code></dfn> attribute represents the
<a>relation types</a> on the <a>accessible element</a>.
</p>
<p>
Returns an <code>iterable</code> for all <a>relation types</a> that
the <a>accessible element</a> has. The implementation is not required
to pre-compute any of the relations.
</p>
</section>
<section>
<h3>
<code>is</code> method
</h3>
<p>
Return true if the <a>accessible element</a> complies with the given
values. A <a>state</a>, <a>role</a> or <a>pattern</a> can be used as
a value. In case of <a>states</a> the method returns true if the
<a>accessible element</a> has the given <a>state</a>. In case of
<a>role</a> the method returns true if the <a>accessible element</a>
<a>role</a> belongs to a role taxonomy of the given <a>role</a>
value. In case of <a>pattern</a> value the method returns true if the
<a>accessible element</a> supports the given pattern.
</p>
<div class="note">
The taxonomy provider must make sure that <a>role</a> and
<a>states</a> taxonomies don't overlap in names. If a markup have a
<a>pattern</a> and a <a>role</a> of same name then each <a>accessible
element</a> having the <a>role</a> in its role taxonomy must
implement a <a>pattern</a> of same naming. For example, HTML table
cell has <code>cell</code> <a>role</a> and exposes <code>cell</code>
pattern.
</div>
<p>
In the example <code>is</code> method calls on a HTML button return
true.
</p>
<pre class="example highlight">
let al = document.getElementById("button").a11ement;
console.assert(al.is("widget", "focusable"), "should a focusable widget");
</pre>
</section>
<section>
<h3>
<code>get</code> method
</h3>
<p>
Return a value of the request <a>attribute</a> on this <a>accessible
element</a>.
</p>
</section>
<section>
<h3>
<code>has</code> method
</h3>
<p>
Return true if the given <a>attribute</a> is present on the
<a>accessible element</a>.
</p>
<div class="note">
<p>
The method can be used to check whether the <a>accessible
element</a> has non empty text properties like <a>name</a>,
<a>description</a> or <a>text</a>.
</p>
</div>
</section>
<section>
<h3>
<code>to</code> method
</h3>
<p>
Return an object representing the requested <a>pattern</a> if exposed
by the <a>accessible element</a>. Otherwise returns null.
</p>
<div class="note">
<p>
The implementation is allowed to return same object or a new one.
</p>
</div>
<div class="note">
<p>
The implementation is allowed to expose predefined set of patterns
right on an <a>accessible element</a> object by default.
</p>
</div>
<p>
The example of queries <code>cell</code> pattern on a HTML td element
and logs its row and column indexes.
</p>
<pre class="example highlight">
var al = document.getElementById("td").a11ement;
if (al.is("cell")) {
let cell = al.to("cell");
console.log(cell.rowindex);
console.log(cell.colindex);
}
</pre>
</section>
<section>
<h3>
<code>relativeOf</code> method
</h3>
<p>
Returns a relative <a>accessible element</a> of the given <a>relation
type</a> for this <a>accessible element</a> if any. If the
<a>accessible element</a> has multiple relatives then the first one
is returned.
</p>
</section>
<section>
<h3>
<code>relativeOfAll</code> method
</h3>
<p>
Returns all relative <a>accessible elements</a> of the given relation
type for this <a>accessible element</a>. If there are no relatives
then empty sequence is returned.
</p>
</section>
<section>
<h3>
<code>actions</code> attribute
</h3>
<p>
Returns a set of all actions exposed by the <a>accessible
element</a>. Returned object implements <code>Actions</code>
interface.
</p>
<div class="note">
An <a>accessible element</a> may expose number of actions, for
example, a tree item accessible typically has two <a>actions</a>:
<code>activate</code>, which makes the tree item focused, and
<code>expand</code> / <code>collapse</code> action, which expands or
collapses its subtree.
</div>
<div class="note">
Here's a demo list of possible <a>actions</a>:
<dl>
<dt>
<code>activate</code>
</dt>
<dd>
Exposed on accessible elements that may be activated. Accessible
elements may use other names for this action to emphasize the
semantics they expose. For example, <code>jump</code> on links,
<code>press</code> on buttons, <code>check</code> and
<code>uncheck</code> on checkboxes. Accessible element may
provide more than one action. For example, tree item can provide
<code>select</code> / <code>unselect</code> as its primary action
and <code>expand</code> / <code>collapse</code> as secondary.
Tree column may implement <code>sort</code> action.
</dd>
<dt>
<code>focus</code>
</dt>
<dd>
Focus on an accessible element. May be different from "activate"
action, for example, in case of buttons where "activate" means
press.
</dd>
<dt>
<code>scroll</code>
</dt>
<dd>
Scrolls an accessible element into view, optionally takes
coordinates relative the element to scroll the view to. Extra
parameter: delta of <code>ScrollDelta</code>.
</dd>
<dt>
<code>drag</code> and <code>drop</code>
</dt>
<dd>
Used to start dragging and dropping the content related to the
accessible element the action is invoked on.
</dd>
<dt>
<code>zoom</code>
</dt>
<dd>
Zooms the content corresponding the accessible the action
is invoked on. Extra parameters: ratio of double. Values great than
1 zooms in the area, values lesser than zooms out it. 1 brings the area
to its normal size.
</dd>
<dt>
<code>undo</code> and <code>redo</code>
</dt>
<dd>
Performs clipboard operations on the accessible element of the
editable content.
</dd>
</dl>
</div>
</section>
<section>
<h3>
<code>activate</code> method
</h3>
<p>
Invokes the given <a>action</a> on the <a>accessible element</a>.
</p>
<div class="note">
The method may take extra information to invoke an <a>action</a>. For
example, <code>zoom</code> action may take a zoom ratio as a
parameter to change the zoom.
</div>
<p>
The example below zooms the document by ratio of 2 and then back to
normal.
</p>
<pre class="example highlight">
var al = document.a11ement;
al.activate("zoom", 2);
al.activate("zoom", 1);
</pre>
<p>
The second example scrolls the page to (400, 100) point and then
scrolls it 2 pages down.
</p>
<pre class="example highlight">
al.activate("scroll", { x: 400, y: 100 });
al.activate("scroll", { mode: "page", count: 2 });
</pre>
</section>
<section>
<h3>
<code>interactionsOf</code> method
</h3>
<p>
Returns a list of all interactions for given <a>action</a> and device
if provided. Returned object implements <code>Interactions</code>
interface.
</p>
</section>
<section>
<h3>
<code>parent</code> attribute
</h3>
<p>
The <dfn><code>parent</code></dfn> attribute represents <a>accessible
parent</a> of this <a>accessible element</a>.
</p>
</section>
<section>
<h3>
<code>children</code> attribute
</h3>
<p>
The <dfn><code>children</code></dfn> attribute represents the child
accessible elements of this <a>accessible element</a>.
</p>
<p>
Returns <code>AccessibleChildren</code> object containing all child
<a>accessible elements</a>.
</p>
</section>
<section>
<h3>
<code>DOMNode</code> attribute
</h3>
<p>
Returns a DOM node associated with this <a>accessible element</a> if
any.
</p>
</section>
</section>
<section>
<h2>
AccessiblePin interface
</h2>
<p>
<code>AccessiblePin</code> serves to traverse the content, for example,
if you need to navigate a document by headings or navigate a paragraph
by words. It describes an <a>accessible position</a> in the content.
The <a>accessible pin</a> can be moved into the given direction within
the document to the content complying with the given criteria. A
movement can be illustrated by verbal descriptions like "move the pin
forward to a next heading" or "move the pin one word back".
</p>
<pre class="idl">
[Constructor(AccessibleElement anchor, optional AccessibleElement root)]
interface AccessiblePin {
AccessiblePin? set(AccessibleElement anchor, Offset offset);
AccessiblePin? move(Where where, optional Criteria criteria);
readonly attribute AccessibleElement root;
readonly attribute AccessibleElement? anchor;
readonly attribute Offset;
};
enum Where {
"forward",
"backward"
};
enum Offset {
"before",
"at",
"after"
};
callback Criteria = boolean (AccessibleElement);
</pre>
<section>
<h3>
<code>set</code> method
</h3>
<p>
Sets the <a>accessible pin</a> to the given accessible and offset.
</p>
<p>
Returns a reference to itself if succeeded. Otherwise returns null.
</p>
</section>
<section>
<h3>
<code>move</code> method
</h3>
<p>
Moves the <a>accessible pin</a> to a next/previous position in the
<a>accessible tree</a> according to the criteria. If the criteria is
omitted then it moves the pin to a next/previous accessible element
in the <a>accessible tree</a>.
</p>
<p>
Returns a reference to itself if succeeded. Otherwise returns null.
</p>
</section>
<section>
<h3>
<code>root</code> attribute
</h3>
<p>
Returns the <a>accessible pin</a>'s anchor <a>accessible element</a>.
</p>
</section>
<section>
<h3>
<code>anchor</code> attribute
</h3>
<p>
Returns the <a>accessible pin</a>'s anchor <a>accessible element</a>.
</p>
</section>
<section>
<h3>
<code>offset</code> attribute
</h3>
<p>
Returns the <a>accessible pin</a>'s offset relative its anchor
<a>accessible element</a>.
</p>
</section>
<section>
<h3>
<code>Where</code> constants
</h3>
<p>
<code><dfn>forward</dfn></code> is used to move an <a>accessible
pin</a> forward in an <a>accessible tree</a> it resides in.
</p>
<p>
<code><dfn>backward</dfn></code> is used to move an <a>accessible
pin</a> backward in an <a>accessible tree</a> it resides in.
</p>
</section>
<section>
<h3>
<code>Offset</code> constants
</h3>
<p>
<code><dfn>before</dfn></code> is used to set an <a>accessible
pin</a> right before its anchor.
</p>
<p>
<code><dfn>at</dfn></code> is used to set an <a>accessible pin</a> at
the anchor. For example, if the pin follows the focus, and a button
is focused then the pin is <code>at</code> the button.
</p>
<p>
<code><dfn>after</dfn></code> is used to set an <a>accessible pin</a>
right after its anchor.
</p>
</section>
<section>
<h3>
<code>Criteria</code> function
</h3>
<p>
<code><dfn>criteria</dfn></code> is a function defines rules that
describe how <a>accessible pin</a> should be moved within an
<a>accessible tree</a>.
</p>
</section>
</section>
<section>
<h2>
<code>Set</code> interface
</h2>
<p>
an object to list values of a given accessible property of an
accessible element, for example, <a>states</a>, <a>attributes</a> or
<a>patterns</a>. Implementation is not required to compute any value
until requested.
</p>
<pre class="idl">
[NoInterfaceObject]
interface AccessibleIterable {
readonly iterable<DOMString>;
};
</pre>
<section class="informative">
<h3>
Example of usage
</h3>
<p>
Example of a script that logs to console all accessible element
states.
</p>
<pre class="example highlight">
let al = document.getElementById("foo").a11ement;
for (let state of al.states) {
console.log(state);
}
</pre>
</section>
</section>
<section>
<h2>
<code>Actions</code> interface
</h2>
<p>
a set-like object listing all <a>actions</a> exposed by the
<a>accessible element</a>. Implementation is not required to compute
any value until requested.
</p>
<pre class="idl">
interface Actions {
readonly setlike<Action>;
};
</pre>
</section>
<section>
<h2>
<code>Action</code> interface
</h2>
<p>
an object representing an <a>action</a> on an <a>accessible
element</a>.
</p>
<section>
<h3>
<code>name</code> attribute
</h3>
<p>
The <a>action</a> name.
</p>
</section>
<section>
<h3>
<code>description</code> attribute
</h3>
<p>
A localized description of the <a>action</a>.
</p>
</section>
<pre class="idl">
interface Action {
stringifier readonly attribute DOMString name;
readonly attribute DOMString description;
};
</pre>
<section class="informative">
<h3>
Example of usage
</h3>
<p>
An example of a script logging all available actions on the
accessible element.
</p>
<pre class="example highlight">
var set = accElm.actions;
if (set.size() == 0) {
console.log("no actions on accessible element");
} else {
console.log("accessible element has " + set.size() + " actions");
set.forEach(action => say(action.description));
}
</pre>
</section>