Offcanvas as component (#29017)

* Add a new offcanvas component

* offcanvas.js: switch to string constants and `event.key`

* Remove unneeded code

* Sass optimizations

* Fixes

Make sure the element is hidden and not offscreen when inactive
fix close icon negative margins
Add content in right & bottom examples
Re-fix bottom offcanvas height not to cover all viewport

* Wording tweaks

* update tests and offcanvas class

* separate scrollbar functionality and use it in offcanvas

* Update .bundlewatch.config.json

* fix focus

* update btn-close / fix focus on close

* add aria-modal and role
return focus on trigger when offcanvas is closed
change body scrolling timings

* move common code to reusable functions

* add aria-labelledby

* Replace lorem ipsum text

* fix focus when offcanvas is closed

* updates

* revert modal, add tests for scrollbar

* show backdrop by default

* Update offcanvas.md

* Update offcanvas CSS to better match modals

- Add background-clip for borders
- Move from outline to border (less clever, more consistent)
- Add scss-docs in vars

* Revamp offcanvas docs

- Add static example to show and explain the components
- Split live examples and rename them
- Simplify example content
- Expand docs notes elsewhere
- Add sass docs

* Add .offcanvas-title instead of .modal-title

* Rename offcanvas example to offcanvas-navbar to reflect it's purpose

* labelledby references title and not header

* Add default shadow to offcanvas

* enable offcanvas-body to fill all the remaining wrapper area

* Be more descriptive, on Accessibility area

* remove redundant classes

* ensure in case of an already open offcanvas, not to open another one

* bring back backdrop|scroll combinations

* bring back toggling class

* refactor scrollbar method, plus tests

* add check if element is not full-width, according to #30621

* revert all in modal

* use documentElement innerWidth

* Rename classes to -start and -end

Also copyedit some docs wording

* omit some things on scrollbar

* PASS BrowserStack tests

-- IOS devices, Android devices and Browsers on Mac, hide scrollbar by default and appear it, only while scrolling.

* Rename '_handleClosing' to '_addEventListeners'

* change pipe usage to comma

* change Data.getData to Data.get

Co-authored-by: XhmikosR <xhmikosr@gmail.com>
Co-authored-by: Martijn Cuppens <martijn.cuppens@gmail.com>
Co-authored-by: Mark Otto <markdotto@gmail.com>

4 files changed, 257 insertions, 1 deletions

diff --git a/site/content/docs/5.0/components/offcanvas.md b/site/content/docs/5.0/components/offcanvas.md
new file mode 100644
index 0000000000..9eacfd6b40
--- /dev/null
+++ b/site/content/docs/5.0/components/offcanvas.md
@@ -0,0 +1,256 @@
+---
+layout: docs
+title: Offcanvas
+description: Build hidden sidebars into your project for navigation, shopping carts, and more with a few classes and our JavaScript plugin.
+group: components
+toc: true
+---
+
+## How it works
+
+Offcanvas is a sidebar component that can be toggled via JavaScript to appear from the left, right, or bottom edge of the viewport. Buttons or anchors are used as triggers that are attached to specific elements you toggle, and `data` attributes are used to invoke our JavaScript.
+
+- Offcanvas shares some of the same JavaScript code as modals. Conceptually, they are quite similar, but they are separate plugins.
+- Similarly, some [source Sass](#sass) variables for offcanvas's styles and dimensions are inherited from the modal's variables.
+- When shown, offcanvas includes a default backdrop that can be clicked to hide the offcanvas.
+- Similar to modals, only one offcanvas can be shown at a time.
+
+**Heads up!** Given how CSS handles animations, you cannot use `margin` or `translate` on an `.offcanvas` element. Instead, use the class as an independent wrapping element.
+
+{{< callout info >}}
+{{< partial "callout-info-prefersreducedmotion.md" >}}
+{{< /callout >}}
+
+## Examples
+
+### Offcanvas components
+
+Below is a _static_ offcanvas example (meaning its `position`, `display`, and `visibility` have been overridden). Offcanvas includes support for a header with a close button and an optional body class for some initial `padding`. We suggest that you include offcanvas headers with dismiss actions whenever possible, or provide an explicit dismiss action.
+
+{{< example class="bd-example-offcanvas p-0 bg-light" >}}
+<div class="offcanvas offcanvas-start" tabindex="-1" id="offcanvas" aria-labelledby="offcanvasLabel">
+  <div class="offcanvas-header">
+    <h5 class="offcanvas-title" id="offcanvasLabel">Offcanvas</h5>
+    <button type="button" class="btn-close text-reset" data-bs-dismiss="offcanvas" aria-label="Close"></button>
+  </div>
+  <div class="offcanvas-body">
+    Content for the offcanvas goes here. You can place just about any Bootstrap component or custom elements here.
+  </div>
+</div>
+{{< /example >}}
+
+### Live demo
+
+Use the buttons below to show and hide an offcanvas element via JavaScript that toggles the `.show` class on an element with the `.offcanvas` class.
+
+- `.offcanvas` hides content (default)
+- `.offcanvas.show` shows content
+
+You can use a link with the `href` attribute, or a button with the `data-bs-target` attribute. In both cases, the `data-bs-toggle="offcanvas"` is required.
+
+{{< example >}}
+<a class="btn btn-primary" data-bs-toggle="offcanvas" href="#offcanvasExample" role="button" aria-controls="offcanvasExample">
+  Link with href
+</a>
+<button class="btn btn-primary" type="button" data-bs-toggle="offcanvas" data-bs-target="#offcanvasExample" aria-controls="offcanvasExample">
+  Button with data-bs-target
+</button>
+
+<div class="offcanvas offcanvas-start" tabindex="-1" id="offcanvasExample" aria-labelledby="offcanvasExampleLabel">
+  <div class="offcanvas-header">
+    <h5 class="offcanvas-title" id="offcanvasExampleLabel">Offcanvas</h5>
+    <button type="button" class="btn-close text-reset" data-bs-dismiss="offcanvas" aria-label="Close"></button>
+  </div>
+  <div class="offcanvas-body">
+    <div class="">
+      Some text as placeholder. In real life you can have the elements you have chosen. Like, text, images, lists, etc.
+    </div>
+    <div class="dropdown mt-3">
+      <button class="btn btn-secondary dropdown-toggle" type="button" id="dropdownMenuButton" data-bs-toggle="dropdown">
+        Dropdown button
+      </button>
+      <ul class="dropdown-menu" aria-labelledby="dropdownMenuButton">
+        <li><a class="dropdown-item" href="#">Action</a></li>
+        <li><a class="dropdown-item" href="#">Another action</a></li>
+        <li><a class="dropdown-item" href="#">Something else here</a></li>
+      </ul>
+    </div>
+  </div>
+</div>
+{{< /example >}}
+
+## Placement
+
+There's no default placement for offcanvas components, so you must add one of the modifier classes below;
+
+- `.offcanvas-start` places offcanvas on the left of the viewport (shown above)
+- `.offcanvas-end` places offcanvas on the right of the viewport
+- `.offcanvas-bottom` places offcanvas on the bottom of the viewport
+
+Try the right and bottom examples out below.
+
+{{< example >}}
+<button class="btn btn-primary" type="button" data-bs-toggle="offcanvas" data-bs-target="#offcanvasRight" aria-controls="offcanvasRight">Toggle right offcanvas</button>
+
+<div class="offcanvas offcanvas-end" tabindex="-1" id="offcanvasRight" aria-labelledby="offcanvasRightLabel">
+  <div class="offcanvas-header">
+    <h5 id="offcanvasRightLabel">Offcanvas right</h5>
+    <button type="button" class="btn-close text-reset" data-bs-dismiss="offcanvas" aria-label="Close"></button>
+  </div>
+  <div class="offcanvas-body">
+    ...
+  </div>
+</div>
+{{< /example >}}
+
+{{< example >}}
+<button class="btn btn-primary" type="button" data-bs-toggle="offcanvas" data-bs-target="#offcanvasBottom" aria-controls="offcanvasBottom">Toggle bottom offcanvas</button>
+
+<div class="offcanvas offcanvas-bottom" tabindex="-1" id="offcanvasBottom" aria-labelledby="offcanvasBottomLabel">
+  <div class="offcanvas-header">
+    <h5 class="offcanvas-title" id="offcanvasBottomLabel">Offcanvas bottom</h5>
+    <button type="button" class="btn-close text-reset" data-bs-dismiss="offcanvas" aria-label="Close"></button>
+  </div>
+  <div class="offcanvas-body small">
+    ...
+  </div>
+</div>
+{{< /example >}}
+
+## Options
+
+By default, we disable scrolling on the `<body>` when an offcanvas is visible and use a gray backdrop. Use the `data-bs-body` attribute to enable `<body>` scrolling, or a combination of both options
+
+{{< example >}}
+<button class="btn btn-primary" type="button" data-bs-toggle="offcanvas" data-bs-target="#offcanvasScrolling" aria-controls="offcanvasScrolling">Enable body scrolling</button>
+<button class="btn btn-primary" type="button" data-bs-toggle="offcanvas" data-bs-target="#offcanvasWithBackdrop" aria-controls="offcanvasWithBackdrop">Enable backdrop (default)</button>
+<button class="btn btn-primary" type="button" data-bs-toggle="offcanvas" data-bs-target="#offcanvasWithBothOptions" aria-controls="offcanvasWithBothOptions">Enable both scrolling & backdrop</button>
+
+<div class="offcanvas offcanvas-start" data-bs-body="scroll" tabindex="-1" id="offcanvasScrolling" aria-labelledby="offcanvasScrollingLabel">
+  <div class="offcanvas-header">
+    <h5 class="offcanvas-title" id="offcanvasScrollingLabel">Colored with scrolling</h5>
+    <button type="button" class="btn-close text-reset" data-bs-dismiss="offcanvas" aria-label="Close"></button>
+  </div>
+  <div class="offcanvas-body">
+    <p>Try scrolling the rest of the page to see this option in action.</p>
+  </div>
+</div>
+<div class="offcanvas offcanvas-start" data-bs-body="backdrop" tabindex="-1" id="offcanvasWithBackdrop" aria-labelledby="offcanvasWithBackdropLabel">
+  <div class="offcanvas-header">
+    <h5 class="offcanvas-title" id="offcanvasWithBackdropLabel">Offcanvas with backdrop</h5>
+    <button type="button" class="btn-close text-reset" data-bs-dismiss="offcanvas" aria-label="Close"></button>
+  </div>
+  <div class="offcanvas-body">
+    <p>.....</p>
+  </div>
+</div>
+<div class="offcanvas offcanvas-start" data-bs-body="scroll,backdrop" tabindex="-1" id="offcanvasWithBothOptions" aria-labelledby="offcanvasWithBothOptionsLabel">
+  <div class="offcanvas-header">
+    <h5 class="offcanvas-title" id="offcanvasWithBothOptionsLabel">Backdroped with scrolling</h5>
+    <button type="button" class="btn-close text-reset" data-bs-dismiss="offcanvas" aria-label="Close"></button>
+  </div>
+  <div class="offcanvas-body">
+    <p>Try scrolling the rest of the page to see this option in action.</p>
+  </div>
+</div>
+{{< /example >}}
+
+## Accessibility
+
+Since the offcanvas panel is conceptually a modal dialog, be sure to add `aria-labelledby="..."`—referencing the offcanvas title—to `.offcanvas`. Note that you don’t need to add `role="dialog"` since we already add it via JavaScript.
+
+## Sass
+
+### Variables
+
+{{< scss-docs name="offcanvas-variables" file="scss/_variables.scss" >}}
+
+## Usage
+
+The offcanvas plugin utilizes a few classes and attributes to handle the heavy lifting:
+
+- `.offcanvas` hides the content
+- `.offcanvas.show` shows the content
+- `.offcanvas-start` hides the offcanvas on the left
+- `.offcanvas-end` hides the offcanvas on the right
+- `.offcanvas-bottom` hides the offcanvas on the bottom
+- `data-bs-body="scroll"` enables `<body>` scrolling when offcanvas is open
+- `data-bs-body="backdrop"` disables scrolling and creates a backdrop over the `<body>` when offcanvas is open `(default)`
+- `data-bs-body="backdrop,scroll"` combines both options to enable `<body>` scrolling and create a backdrop over the `<body>` when offcanvas is open
+
+Add a dismiss button with the `data-bs-dismiss="offcanvas"` attribute, which triggers the JavaScript functionality. Be sure to use the `<button>` element with it for proper behavior across all devices.
+
+### Via data attributes
+
+Add `data-bs-toggle="offcanvas"` and a `data-bs-target` or `href` to the element to automatically assign control of one offcanvas element. The `data-bs-target` attribute accepts a CSS selector to apply the offcanvas to. Be sure to add the class `offcanvas` to the offcanvas element. If you'd like it to default open, add the additional class `show`.
+
+### Via JavaScript
+
+Enable manually with:
+
+```js
+var offcanvasElementList = [].slice.call(document.querySelectorAll('.offcanvas'))
+var offcanvasList = offcanvasElementList.map(function (offcanvasEl) {
+  return new bootstrap.Offcanvas(offcanvasEl)
+})
+```
+
+### Methods
+
+{{< callout danger >}}
+{{< partial "callout-danger-async-methods.md" >}}
+{{< /callout >}}
+
+Activates your content as an offcanvas element. Accepts an optional options `object`.
+
+You can create an offcanvas instance with the constructor, for example:
+
+```js
+var myOffcanvas = document.getElementById('myOffcanvas')
+var bsOffcanvas = new bootstrap.Offcanvas(myOffcanvas)
+```
+
+| Method | Description |
+| --- | --- |
+| `toggle` | Toggles an offcanvas element to shown or hidden. **Returns to the caller before the offcanvas element has actually been shown or hidden** (i.e. before the `shown.bs.offcanvas` or `hidden.bs.offcanvas` event occurs). |
+| `show` | Shows an offcanvas element. **Returns to the caller before the offcanvas element has actually been shown** (i.e. before the `shown.bs.offcanvas` event occurs).|
+| `hide` | Hides an offcanvas element. **Returns to the caller before the offcanvas element has actually been hidden** (i.e. before the `hidden.bs.offcanvas` event occurs).|
+| `_getInstance` | *Static* method which allows you to get the offcanvas instance associated with a DOM element |
+
+### Events
+
+Bootstrap's offcanvas class exposes a few events for hooking into offcanvas functionality.
+
+<table class="table table-bordered table-striped">
+  <thead>
+    <tr>
+      <th style="width: 150px;">Event Type</th>
+      <th>Description</th>
+    </tr>
+  </thead>
+  <tbody>
+    <tr>
+      <td>show.bs.offcanvas</td>
+      <td>This event fires immediately when the <code>show</code> instance method is called.</td>
+    </tr>
+    <tr>
+      <td>shown.bs.offcanvas</td>
+      <td>This event is fired when an offcanvas element has been made visible to the user (will wait for CSS transitions to complete).</td>
+    </tr>
+    <tr>
+      <td>hide.bs.offcanvas</td>
+      <td>This event is fired immediately when the <code>hide</code> method has been called.</td>
+    </tr>
+    <tr>
+      <td>hidden.bs.offcanvas</td>
+      <td>This event is fired when an offcanvas element has been hidden from the user (will wait for CSS transitions to complete).</td>
+    </tr>
+  </tbody>
+</table>
+
+```js
+var myOffcanvas = document.getElementById('myOffcanvas')
+myOffcanvas.addEventListener('hidden.bs.offcanvas', function () {
+  // do something...
+})
+```
diff --git a/site/content/docs/5.0/examples/offcanvas/index.html b/site/content/docs/5.0/examples/offcanvas-navbar/index.html
index 9aed0aed7d..12bb91e079 100644
--- a/site/content/docs/5.0/examples/offcanvas/index.html
+++ b/site/content/docs/5.0/examples/offcanvas-navbar/index.html
@@ -1,6 +1,6 @@
 ---
 layout: examples
-title: Offcanvas template
+title: Offcanvas navbar template
 extra_css:
   - "offcanvas.css"
 extra_js:
diff --git a/site/content/docs/5.0/examples/offcanvas/offcanvas.css b/site/content/docs/5.0/examples/offcanvas-navbar/offcanvas.css
index 29e26b11bd..29e26b11bd 100644
--- a/site/content/docs/5.0/examples/offcanvas/offcanvas.css
+++ b/site/content/docs/5.0/examples/offcanvas-navbar/offcanvas.css
diff --git a/site/content/docs/5.0/examples/offcanvas/offcanvas.js b/site/content/docs/5.0/examples/offcanvas-navbar/offcanvas.js
index 793ea86cd3..793ea86cd3 100644
--- a/site/content/docs/5.0/examples/offcanvas/offcanvas.js
+++ b/site/content/docs/5.0/examples/offcanvas-navbar/offcanvas.js