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Diffstat (limited to 'docs/components/dropdowns.md')
| -rw-r--r-- | docs/components/dropdowns.md | 16 |
1 files changed, 14 insertions, 2 deletions
diff --git a/docs/components/dropdowns.md b/docs/components/dropdowns.md index 3c68f9453..4da232b7d 100644 --- a/docs/components/dropdowns.md +++ b/docs/components/dropdowns.md @@ -16,6 +16,16 @@ Dropdowns are toggleable, contextual overlays for displaying lists of links and Wrap the dropdown's toggle (your button or link) and the dropdown menu within `.dropdown`, or another element that declares `position: relative;`. Dropdowns can be triggered from `<a>` or `<button>` elements to better fit your potential needs. +{% callout info %} +### Dropdown menu accessibility + +The [<abbr title="Web Accessibility Initiative">WAI</abbr> <abbr title="Accessible Rich Internet Applications">ARIA</abbr>](https://www.w3.org/TR/wai-aria/) standard defines an actual [`role="menu"` widget](https://www.w3.org/TR/wai-aria/roles#menu), but this is specific to application-like menus which trigger actions or functions. <abbr title="Accessible Rich Internet Applications">ARIA</abbr> menus can only contain menu items, checkbox menu items, radio button menu items, radio button groups, and sub-menus. + +Bootstrap's dropdowns, on the other hand, are designed to be generic and applicable to a variety of situations and markup structures. For instance, it is possible to create dropdowns that contain additional inputs and form controls, such as search fields or login forms. For this reason, Bootstrap does not expect (nor automatically add) any of the `role` and `aria-` attributes required for true <abbr title="Accessible Rich Internet Applications">ARIA</abbr> menus. Authors will have to include these more specific attributes themselves. + +However, Bootstrap does add built-in support for most standard keyboard menu interactions, such as the ability to move through individual `.dropdown-item` elements using the cursor keys and close the menu with the <kbd>ESC</kbd> key. +{% endcallout %} + ### Single button dropdowns Any single `.btn` can be turned into a dropdown toggle with some markup changes. Here's how you can put them to work with either `<button>` elements: @@ -37,7 +47,7 @@ And with `<a>` elements: {% example html %} <div class="dropdown show"> - <a class="btn btn-secondary dropdown-toggle" href="https://example.com" id="dropdownMenuLink" data-toggle="dropdown" aria-haspopup="true" aria-expanded="false"> + <a class="btn btn-secondary dropdown-toggle" href="#" role="button" id="dropdownMenuLink" data-toggle="dropdown" aria-haspopup="true" aria-expanded="false"> Dropdown link </a> @@ -480,7 +490,9 @@ Add `.disabled` to items in the dropdown to **style them as disabled**. Via data attributes or JavaScript, the dropdown plugin toggles hidden content (dropdown menus) by toggling the `.show` class on the parent list item. -On mobile devices, opening a dropdown adds a `.dropdown-backdrop` as a tap area for closing dropdown menus when tapping outside the menu, a requirement for proper iOS support. **This means that switching from an open dropdown menu to a different dropdown menu requires an extra tap on mobile.** +{% callout info %} +On touch-enabled devices, opening a dropdown adds empty (`$.noop`) `mouseover` handlers to the immediate children of the `<body>` element. This admittedly ugly hack is necessary to work around a [quirk in iOS' event delegation](https://www.quirksmode.org/blog/archives/2014/02/mouse_event_bub.html), which would otherwise prevent a tap anywhere outside of the dropdown from triggering the code that closes the dropdown. Once the dropdown is closed, these additional empty `mouseover` handlers are removed. +{% endcallout %} Note: The `data-toggle="dropdown"` attribute is relied on for closing dropdown menus at an application level, so it's a good idea to always use it. |