feat(MultiSelect): add a global search option, improve keyboard support and accessibility

Author: mrholek

docs/content/forms/multi-select.md

@@ -16,7 +16,7 @@ other_frameworks: multi-select
 A straightforward demonstration of how to implement a basic Bootstrap Multi Select dropdown, highlighting essential attributes and configurations.
 
 {{< example >}}
-<select class="form-multi-select" id="ms1" multiple data-coreui-search="true">
+<select class="form-multi-select" id="ms1" multiple data-coreui-search="global">
   <option value="0">Angular</option>
   <option value="1">Bootstrap</option>
   <option value="2">React.js</option>
@@ -77,6 +77,63 @@ We use the following JavaScript to set up our multi-select:
 
 {{< js-docs name="multi-select-array-data" file="docs/assets/js/snippets.js" >}}
 
+## Search
+
+You can configure the search functionality within the component. The `data-coreui-search` option determines how the search input element is enabled and behaves. It accepts multiple types to provide flexibility in configuring search behavior. By default is set to `false`.
+
+{{< example >}}
+<select class="form-multi-select" multiple>
+  <option value="0">Angular</option>
+  <option value="1">Bootstrap</option>
+  <option value="2">React.js</option>
+  <option value="3">Vue.js</option>
+  <optgroup label="backend">
+    <option value="4">Django</option>
+    <option value="5">Laravel</option>
+    <option value="6">Node.js</option>
+  </optgroup>
+</select>
+{{< /example >}}
+
+### Standard search
+
+To enable the default search input element with standard behavior, please add `data-coreui-search="true"` like in the example below:
+
+{{< example >}}
+<select class="form-multi-select" multiple data-coreui-search="true">
+  <option value="0">Angular</option>
+  <option value="1">Bootstrap</option>
+  <option value="2">React.js</option>
+  <option value="3">Vue.js</option>
+  <optgroup label="backend">
+    <option value="4">Django</option>
+    <option value="5">Laravel</option>
+    <option value="6">Node.js</option>
+  </optgroup>
+</select>
+{{< /example >}}
+
+### Global search
+
+{{< added-in "5.6.0" >}}
+
+To enable the global search functionality within the Multi Select component, please add `data-coreui-search="global"`. When `data-coreui-search` is set to `'global'`, the user can perform searches across the entire component, regardless of where their focus is within the component. This allows for a more flexible and intuitive search experience, ensuring the search input is recognized from any point within the component.
+
+{{< example >}}
+<select class="form-multi-select" multiple data-coreui-search="global">
+  <option value="0">Angular</option>
+  <option value="1">Bootstrap</option>
+  <option value="2">React.js</option>
+  <option value="3">Vue.js</option>
+  <optgroup label="backend">
+    <option value="4">Django</option>
+    <option value="5">Laravel</option>
+    <option value="6">Node.js</option>
+  </optgroup>
+</select>
+{{< /example >}}
+
+
 ## Selection types
 
 Explore different selection modes, including single and multiple selections, allowing customization based on user requirements.
@@ -276,7 +333,8 @@ const mulitSelectList = mulitSelectElementList.map(mulitSelectEl => {
 {{< bs-table >}}
 | Name | Type | Default | Description |
 | --- | --- | --- | --- |
-| `cleaner`| boolean| `true` | Enables selection cleaner element. |
+| `ariaCleanerLabel`| string | `Clear all selections` | A string that provides an accessible label for the cleaner button. This label is read by screen readers to describe the action associated with the button. |
+| `cleaner`| boolean | `true` | Enables selection cleaner element. |
 | `container` | string, element, false | `false` | Appends the dropdown to a specific element. Example: `container: 'body'`. |
 | `disabled` | boolean | `false` | Toggle the disabled state for the component. |
 | `invalid` | boolean | `false` | Toggle the invalid state for the component. |
@@ -286,7 +344,7 @@ const mulitSelectList = mulitSelectElementList.map(mulitSelectEl => {
 | `optionsMaxHeight` | number, string | `'auto'` | Sets `max-height` of options list.	 |
 | `optionsStyle` | string | `'checkbox'` | Sets option style. |
 | `placeholder` | string | `'Select...'` | Specifies a short hint that is visible in the input. |
-| `search` | boolean | `false` | Enables search input element.	 |
+| `search` | boolean, string | `false` | Enables search input element. When set to `'global'`, the user can perform searches across the entire component, regardless of where their focus is within the component. |
 | `searchNoResultsLabel` | string | `'No results found'` | Sets the label for no results when filtering.	|
 | `selectAll` | boolean | `true` | Enables select all button.|
 | `selectAllLabel` | string | `'Select all options'` | Sets the select all button label.	 |

js/src/multi-select.js

@@ -29,10 +29,13 @@ const DATA_KEY = 'coreui.multi-select'
 const EVENT_KEY = `.${DATA_KEY}`
 const DATA_API_KEY = '.data-api'
 
-const ESCAPE_KEY = 'Escape'
-const TAB_KEY = 'Tab'
 const ARROW_UP_KEY = 'ArrowUp'
 const ARROW_DOWN_KEY = 'ArrowDown'
+const BACKSPACE_KEY = 'Backspace'
+const DELETE_KEY = 'Delete'
+const ENTER_KEY = 'Enter'
+const ESCAPE_KEY = 'Escape'
+const TAB_KEY = 'Tab'
 const RIGHT_MOUSE_BUTTON = 2 // MouseEvent.button value for the secondary button, usually the right button
 
 const SELECTOR_CLEANER = '.form-multi-select-cleaner'
@@ -80,6 +83,7 @@ const CLASS_NAME_TAG = 'form-multi-select-tag'
 const CLASS_NAME_TAG_DELETE = 'form-multi-select-tag-delete'
 
 const Default = {
+  ariaCleanerLabel: 'Clear all selections',
   cleaner: true,
   container: false,
   disabled: false,
@@ -101,6 +105,7 @@ const Default = {
 }
 
 const DefaultType = {
+  ariaCleanerLabel: 'string',
   cleaner: 'boolean',
   container: '(string|element|boolean)',
   disabled: 'boolean',
@@ -112,7 +117,7 @@ const DefaultType = {
   optionsStyle: 'string',
   placeholder: 'string',
   required: 'boolean',
-  search: 'boolean',
+  search: '(boolean|string)',
   searchNoResultsLabel: 'string',
   selectAll: 'boolean',
   selectAllLabel: 'string',
@@ -204,7 +209,10 @@ class MultiSelect extends BaseComponent {
       this._popper.destroy()
     }
 
-    this._searchElement.value = ''
+    if (this._config.search) {
+      this._searchElement.value = ''
+    }
+
     this._onSearchChange(this._searchElement)
     this._clone.classList.remove(CLASS_NAME_SHOW)
     this._clone.setAttribute('aria-expanded', 'false')
@@ -288,6 +296,30 @@ class MultiSelect extends BaseComponent {
     EventHandler.on(this._clone, EVENT_KEYDOWN, event => {
       if (event.key === ESCAPE_KEY) {
         this.hide()
+        return
+      }
+
+      if (this._config.search === 'global' && (event.key.length === 1 || event.key === BACKSPACE_KEY || event.key === DELETE_KEY)) {
+        this._searchElement.focus()
+      }
+    })
+
+    EventHandler.on(this._menu, EVENT_KEYDOWN, event => {
+      if (this._config.search === 'global' && (event.key.length === 1 || event.key === BACKSPACE_KEY || event.key === DELETE_KEY)) {
+        this._searchElement.focus()
+      }
+    })
+
+    EventHandler.on(this._togglerElement, EVENT_KEYDOWN, event => {
+      if (!this._isShown() && (event.key === ENTER_KEY || event.key === ARROW_DOWN_KEY)) {
+        event.preventDefault()
+        this.show()
+        return
+      }
+
+      if (this._isShown() && event.key === ARROW_DOWN_KEY) {
+        event.preventDefault()
+        this._selectMenuItem(event)
       }
     })
 
@@ -302,9 +334,16 @@ class MultiSelect extends BaseComponent {
     })
 
     EventHandler.on(this._searchElement, EVENT_KEYDOWN, event => {
-      const key = event.keyCode || event.charCode
+      if (!this._isShown()) {
+        this.show()
+      }
+
+      if (event.key === ARROW_DOWN_KEY && this._searchElement.value.length === this._searchElement.selectionStart) {
+        this._selectMenuItem(event)
+        return
+      }
 
-      if ((key === 8 || key === 46) && event.target.value.length === 0) {
+      if ((event.key === BACKSPACE_KEY || event.key === DELETE_KEY) && event.target.value.length === 0) {
         this._deselectLastOption()
       }
 
@@ -332,9 +371,7 @@ class MultiSelect extends BaseComponent {
     })
 
     EventHandler.on(this._optionsElement, EVENT_KEYDOWN, event => {
-      const key = event.keyCode || event.charCode
-
-      if (key === 13) {
+      if (event.key === ENTER_KEY) {
         this._onOptionsClick(event.target)
       }
 
@@ -486,6 +523,10 @@ class MultiSelect extends BaseComponent {
     togglerEl.classList.add(CLASS_NAME_INPUT_GROUP)
     this._togglerElement = togglerEl
 
+    if (!this._config.search && !this._config.disabled) {
+      togglerEl.tabIndex = 0
+    }
+
     const selectionEl = document.createElement('div')
     selectionEl.classList.add(CLASS_NAME_SELECTION)
 
@@ -509,6 +550,7 @@ class MultiSelect extends BaseComponent {
       cleaner.type = 'button'
       cleaner.classList.add(CLASS_NAME_CLEANER)
       cleaner.style.display = 'none'
+      cleaner.setAttribute('aria-label', this._config.ariaCleanerLabel)
 
       buttons.append(cleaner)
       this._selectionCleanerElement = cleaner

scss/forms/_form-multi-select.scss

@@ -143,7 +143,9 @@ select.form-multi-select {
     border-color: $input-disabled-border-color;
   }
 
-  .form-multi-select.show & {
+  .form-multi-select.show &,
+  &:has(*:focus),
+  &:focus {
     color: var(--#{$prefix}form-multi-select-focus-color);
     background-color: var(--#{$prefix}form-multi-select-focus-bg);
     border-color: var(--#{$prefix}form-multi-select-focus-border-color);
@@ -173,8 +175,8 @@ select.form-multi-select {
 }
 
 .form-multi-select-search {
-  display: none;
-  flex: 1 1 auto;
+  display: flex;
+  flex: 0 1 0px;
   max-width: 100%;
   padding: 0;
   background: transparent;
@@ -191,7 +193,8 @@ select.form-multi-select {
 
   .form-multi-select.show &,
   &:placeholder-shown {
-    display: flex;
+    flex: 1 1 auto;
+    // display: flex;
   }
 
   .form-multi-select-selection-tags & {