layout | tags |
---|---|
doc-api.html |
shadow-dom, service, argument-options |
Disables any type of user interaction - including the ability to focus elements - essentially rendering elements inert.
This allows an application to make sure no element other than the exempted can be focused. This is method is superior to the idea of trapping focus by intercepting Tab, because it allows cycling through the browser UI and is not as prone to break for spatial focus navigation (i.e. any sort of focus navigation that does not use the Tab key). The major benefit of disabling focus of elements is that in turn we do not have to meddle with the user's interaction to actually change focus - we can leave that to the browser.
Elements are disabled by ally.element.disabled
and can be identified in the DOM by the attribute [data-ally-disabled="true"]
to align with styling of other :disabled
elements.
The proposed inert
attribute was removed from HTML5, because people thought inert subtrees by way of the <dialog>
element would suffice. While we believe it doesn't, the inert
attribute would only have solved half of the problem, because there's no way to avoid inheriting the inert state onto children. This behavior can be observed in the Google Chrome Inert Attribute Polyfill.
ally.maintain.disabled
observes DOM manipulations and automatically disables newly added elements when necessary.
var handle = ally.maintain.disabled({
context: '.within-filter-selector',
filter: '.except-filter-selector',
});
handle.disengage();
Name | Type | Default | Description |
---|---|---|---|
context | <selector> |
documentElement |
The scope of the DOM in which to search. The first element of a collection is used. |
filter | <selector> |
null |
The significant elements to exclude from being disabled. |
A <service>
interface, providing the handle.disengage()
method to stop the service.
- EXAMPLE:
ally.maintain.disabled
Example
- Since
v1.1.0
changingtabindex
attribute values are properly handled. - Since
v1.1.0
thedisengage()
method reverts elements within ShadowHosts to their previous state. - Since
v1.1.0
DOM mutations withinShadowRoot
s are properly observed. - Since
v1.1.0
initially disabled elements are not accidentally enabled when disengaging the service. - Since
v#master
ancestors of exempted sub-trees (defined byfilter
option) are not disabled anymore.
- NOTE:
ShadowHost
s are pierced andShadowRoot
content is made inert as well (except for closed shadow trees). - NOTE: Internet Explorer 10 will not update changes made to elements within the inert sub-trees, because it does not support MutationObserver and Mutation Events are too much of a burden.
- WARNING: Any element not identified as focus relevant by
ally.is.focusRelevant
and not identified as only tabbable byally.is.onlyTabbable
is not made inert either. See the identified elements usingstrategy: "strict"
compatibility table.
ally.maintain.hidden
is a service hiding insignificant branches from the Accessibility Treeally.query.focusable
is used to identify the elements to disableally.element.disabled
is used to disable the elements