Rule: ARIA required context role (ff89c9)

_rules/SC1-3-1-aria-required-context-role.md

@@ -0,0 +1,191 @@
+---
+name: ARIA required context role
+description: | 
+  This rule checks that a role does not exist outside of its required context roles
+
+success_criterion:
+- 1.3.1 # Info and Relationships
+
+test_aspects: 
+- DOM Tree
+- CSS Styling
+
+authors:
+- Anne Thyme Nørregaard
+---
+
+## Test procedure
+
+### Applicability
+
+The rule applies to any HTML or SVG element that is [included in the accessibility tree](#included-in-the-accessibility-tree) and has an explicit [semantic role](#semantic-role) with a [WAI-ARIA required context role](https://www.w3.org/TR/wai-aria-1.1/#scope), except if the element has an implicit semantic role that is identical to its explicit semantic role.
+
+### Expectation
+
+The [owner element](owner-element) for each target element has a [semantic role](#semantic-role) matching one of the [WAI-ARIA required context roles](https://www.w3.org/TR/wai-aria-1.1/#scope) for the target element.
+
+## Assumptions
+
+_There are currently no assumptions_
+
+## Accessibility Support
+
+This rule relies on assistive technologies to recognize [owner elements](#owner-element). This includes when the owner elements are ancestors that are not parents of the target element. However, some assistive technologies do not recognize owner elements that are not parents, unless workarounds are used.
+Furthermore, `aria-owns` has limited support in user agents.
+
+## Background
+
+- [Required Context Role](https://www.w3.org/TR/wai-aria-1.1/#scope)
+
+## Test Cases
+
+### Passed
+
+#### Passed example 1
+
+Element with role `listitem` is contained within its required context role `list`, expressed as an explicit role.
+
+```html
+<div role="list">
+    <div role="listitem"></div>
+</div>
+```
+
+#### Passed example 2
+
+Element with role `listitem` is contained within its required context role `list`, through the implicit role of `ul`.
+
+```html
+<ul>
+    <div role="listitem"></div>
+</ul>
+```
+
+#### Passed example 3
+
+Element contained within its required context role even though it is not a direct child of the context role.
+
+```html
+<div role="list">
+    <div>
+         <div>
+             <div>
+                <div role="listitem"></div>
+             </div>
+         <div>
+    <div>
+</div>
+```
+
+#### Passed example 4
+
+`aria-owns` used to give the target element the right context role.
+
+```html
+<div role="list" aria-owns="id1">
+  <div role="tabpanel">
+    <div id="id1" role="listitem"></div>
+   </div>
+</div>
+```
+
+### Failed
+
+#### Failed example 1
+
+No context role.
+
+```html
+<div role="listitem"></div>
+```
+
+#### Failed example 2
+
+Wrong context role
+
+```html
+<div role="tablist">
+    <div role="listitem"></div>
+</div>
+```
+
+#### Failed example 3
+
+Element not contained within its required context role.
+
+```html
+<div role="list"></div>
+    <div role="listitem"></div>
+```
+
+#### Failed example 4
+
+Element with role `listitem` has a closer ancestor, that is included in the accessibility tree, than the role `list` that should have been its context role
+
+```html
+<div role="list">
+    <div aria-label="menu">
+         <div role="listitem"></div>
+    <div>
+</div>
+```
+
+#### Failed example 5
+
+Element with role `listitem` has a closer ancestor, that is included in the accessibility tree, than the role `list` that should have been its context role
+
+```html
+<div role="list">
+  <div role="tabpanel">
+    <div role="listitem"></div>
+   </div>
+</div>
+```
+
+#### Failed example 6
+
+The owner element is the first element that references the target element through `aria-owns`, which results in the wrong context role.
+
+```html
+<div role="tabpanel" aria-owns="id1">
+  <div role="list" aria-owns="id1">
+    <div id="id1" role="listitem"></div>
+   </div>
+</div>
+```
+
+### Inapplicable
+
+#### Inapplicable example 1
+
+Element does not have an explicit semantic role
+
+```html
+<ul></ul>
+```
+
+#### Inapplicable example 2
+
+Element is not exposed to assistive technologies.
+
+```html
+<div role="tab" aria-hidden="true"></div>
+```
+
+#### Inapplicable example 3
+
+Role does not have any required context roles listed in WAI-ARIA spec.
+
+```html
+<div role="radio"></div>
+```
+
+#### Failed example 4
+
+Element is not exposed to assistive technologies, since decendant has `aria-hidden` attribute with value set to `true`.
+
+```html
+<div role="list" aria-hidden="true">
+    <div role="listitem"></div>
+</div>
+```

pages/glossary/included-in-the-accessibility-tree.md

@@ -3,8 +3,21 @@ title: Included in the accessibility tree
 key: included-in-the-accessibility-tree
 ---
 
-Elements included in the accessibility tree of platform specific accessibility APIs. Elements in the accessibility tree are exposed to assistive technologies, allowing users to interact with the elements in a way that meet the requirements of the individual user.
+Elements included in the accessibility tree of platform specific accessibility APIs. 
 
-The general rules for when elements are included in the accessibility tree are defined in the [core accessibility API mappings](https://www.w3.org/TR/core-aam/). For native markup languages, such as HTML and SVG, additional rules for when elements are [included in the accessibility tree][] can be found in the [HTML accessibility API mappings](https://www.w3.org/TR/html-aam/) and the [SVG accessibility API mappings](https://www.w3.org/TR/svg-aam/).
+Elements in the accessibility tree are exposed to assistive technologies, allowing users to interact with the elements in a way that meet the requirements of the individual user.
+
+An element is included in the accessibility tree if it is a DOM node in the flattened DOM tree that meets the following criteria:
+
+1. It isn't hidden through WAI-ARIA or CSS, and
+2. it has one or more of the following:
+   * It has a [semantic role](#semantic-role), or
+   * It has an accessible name that, when trimmed of whitespace, is not an empty string, or
+   * it owns another element though an `aria-owns` attribute, or
+   * It is owned by another element that references it with `aria-owns`
+
+ > **Note:** Text nodes and pseudo elements can also be part of the accessibility tree, since they have their text content as the accessible name.
+
+The general rules for when elements are included in the accessibility tree are defined in the [core accessibility API mappings](https://www.w3.org/TR/core-aam/). For native markup languages, such as HTML and SVG, additional rules for when elements are [included in the accessibility tree](#included-in-the-accessibility-tree) can be found in the [HTML accessibility API mappings](https://www.w3.org/TR/html-aam/) and the [SVG accessibility API mappings](https://www.w3.org/TR/svg-aam/).
 
  > **Note:** Users of assistive technologies might still be able to interact with elements that are not included in the accessibility tree. An example of this is a [focusable](#focusable) element with an `aria-hidden` attribute with a value of `true`. Such an element could still be interacted with using sequential keyboard navigation regardless of the assistive technologies used, even though the element would not be included in the accessibility tree.

pages/glossary/owner-element.md

@@ -0,0 +1,12 @@
+---
+title: Owner element
+key: owner-element
+---
+
+
+If the node is referenced by an element through the `aria-owns` attribute, then the owner element is the first node in the DOM tree that references it through `aria-owns`.
+Otherwise, the owner element is the closest ancestor that is [included in the accessibility tree](#included-in-the-accessibility-tree).
+
+Nodes that are not included in the accessibility tree do not have an owner element.
+
+ > **Note:** This definition is diverging from the definition of ["owned element" in WAI-ARIA](https://www.w3.org/TR/wai-aria-1.1/#dfn-owned-element). The reason is that the WAI-ARIA definition was found to provide too little guidance on how to handle specific edge cases where several elements compete about the ownership, and it seem that browser implementations of this are diverging a lot. This definition seeks to find a reasonable middle ground, but will have to be updated if the WAI-ARIA definition changes.