# Bootstrap version

---

Because there are some changes in class names and layout between Bootstrap 3 and Bootstrap 4, bootstrap-select needs to know the version of Bootstrap you are using. By default, bootstrap-select automatically detects the version of Bootstrap. However, there are some instances where the version detection does not work properly (e.g. Bootstrap is being loaded asynchronously or there is a namespace collision). For now, bootstrap-select defaults to using Bootstrap 3 formatting if version detection fails. This will be changed in the next major release.

You can manually specify Bootstrap's version via bootstrap-select's `Constructor.BootstrapVersion` object:

```js
$.fn.selectpicker.Constructor.BootstrapVersion = '4';
```

# Core options

---

Options can be passed via data attributes or JavaScript. For data attributes, append the option name to `data-`, as in 
`data-style=""` or `data-selected-text-format="count"`.

<table class="table table-bordered table-striped">
  <thead>
  <tr>
    <th style="width: 15%;">Name</th>
    <th style="width: 22%;">Type</th>
    <th style="width: 20%;">Default</th>
    <th style="width: 43%;">Description</th>
  </tr>
  </thead>
  <tbody>
  <tr>
    <td>actionsBox</td>
    <td>boolean</td>
    <td><code>false</code></td>
    <td>
      <p>When set to <code>true</code>, adds two buttons to the top of the dropdown menu (<strong>Select All</strong> &amp; <strong>Deselect All</strong>).</p>
    </td>
  </tr>
  <tr>
    <td>container</td>
    <td>string | false</td>
    <td><code>false</code></td>
    <td>
        <p>When set to a string, appends the select to a specific element or selector, e.g., <code>container: 'body' | '.main-body'</code></p>
    </td>
  </tr>
  <tr>
    <td>countSelectedText</td>
    <td>string | function</td>
    <td><code>function</code></td>
    <td>
      <p>Sets the format for the text displayed when selectedTextFormat is <code>count</code> or <code>count > #</code>. {0} is the selected amount. {1} is total available for selection.</p>
      <p>When set to a function, the first parameter is the number of selected options, and the second is the total number of 
      options. The function must return a string.</p>
    </td>
  </tr>
  <tr>
    <td>deselectAllText</td>
    <td>string</td>
    <td><code>'Deselect All'</code></td>
    <td>
      <p>The text on the button that deselects all options when <code>actionsBox</code> is enabled.</p>
    </td>
  </tr>
  <tr>
    <td>dropdownAlignRight</td>
    <td>boolean | <code>'auto'</code></td>
    <td><code>false</code></td>
    <td>
      <p>Align the menu to the right instead of the left. If set to <code>'auto'</code>, the menu will automatically align right if there isn't room for the menu's full width when aligned to the left.</p>
    </td>
  </tr>
  <tr>
    <td>dropupAuto</td>
    <td>boolean</td>
    <td><code>true</code></td>
    <td>
      <p>checks to see which has more room, above or below. If the dropup has enough room to fully open normally, but
      there is more room above, the dropup still opens normally. Otherwise, it becomes a dropup. If dropupAuto is
      set to false, dropups must be called manually.</p>
    </td>
  </tr>
  <tr>
    <td>header</td>
    <td>string</td>
    <td><code>false</code></td>
    <td>
      <p>adds a header to the top of the menu; includes a close button by default</p>
    </td>
  </tr>
  <tr>
    <td>hideDisabled</td>
    <td>boolean</td>
    <td><code>false</code></td>
    <td>
      <p>removes disabled options and optgroups from the menu <code>data-hide-disabled: true</code></p>
    </td>
  </tr>
  <tr>
    <td>iconBase</td>
    <td>string</td>
    <td><code>'glyphicon'</code></td>
    <td>
      <p>Set the base to use a different icon font instead of Glyphicons. If changing iconBase, you might also want to change <code>tickIcon</code>, in case the new icon font uses a different naming scheme.</p>
    </td>
  </tr>
  <tr>
    <td>liveSearch</td>
    <td>boolean</td>
    <td><code>false</code></td>
    <td>
      <p>When set to <code>true</code>, adds a search box to the top of the selectpicker dropdown.</p>
    </td>
  </tr>
  <tr>
    <td>liveSearchNormalize</td>
    <td>boolean</td>
    <td><code>false</code></td>
    <td>
      <p>Setting liveSearchNormalize to <code>true</code> allows for accent-insensitive searching.</p>
    </td>
  </tr>
  <tr>
    <td>liveSearchPlaceholder</td>
    <td>string</td>
    <td><code>null</code></td>
    <td>
      <p>When set to a string, a placeholder attribute equal to the string will be added to the liveSearch input.</p>
    </td>
  </tr>
  <tr>
    <td>liveSearchStyle</td>
    <td>string</td>
    <td><code>'contains'</code></td>
    <td>
      <p>When set to <code>'contains'</code>, searching will reveal options that contain the searched text. For example, searching for pl with return both Ap<b>pl</b>e, <b>Pl</b>um, and <b>Pl</b>antain. When set to <code>'startsWith'</code>, searching for pl will return only <b>Pl</b>um and <b>Pl</b>antain.</p>
    </td>
  </tr>
  <tr>
    <td>maxOptions</td>
    <td>integer | false</td>
    <td><code>false</code></td>
    <td>
      <p>When set to an integer and in a multi-select, the number of selected options cannot exceed the given value.</p>
      <p>This option can also exist as a data-attribute for an <code>&lt;optgroup&gt;</code>, in which case it only applies to that <code>&lt;optgroup&gt;</code>.</p>
    </td>
  </tr>
  <tr>
    <td>maxOptionsText</td>
    <td>string | array | function</td>
    <td><code>function</code></td>
    <td>
      <p>The text that is displayed when maxOptions is enabled and the maximum number of options for the given scenario have been selected.</p>
      <p>If a function is used, it must return an array. array[0] is the text used when maxOptions is applied to the entire select element. array[1] is the text used when maxOptions is used on an optgroup. If a string is used, the same text is used for both the element and the optgroup.</p>
    </td>
  </tr>
  <tr>
    <td>mobile</td>
    <td>boolean</td>
    <td><code>false</code></td>
    <td>
      <p>When set to <code>true</code>, enables the device's native menu for select menus.</p>
    </td>
  </tr>
  <tr>
    <td>multipleSeparator</td>
    <td>string</td>
    <td><code>', '</code></td>
    <td>
      <p>Set the character displayed in the button that separates selected options.</p>
    </td>
  </tr>
  <tr>
    <td>noneSelectedText</td>
    <td>string</td>
    <td><code>'Nothing selected'</code></td>
    <td>
      <p>The text that is displayed when a multiple select has no selected options.</p>
    </td>
  </tr>
  <tr>
    <td>noneResultsText</td>
    <td>string</td>
    <td><code>'No results matched {0}'</code></td>
    <td>
      <p>The text displayed when a search doesn't return any results.</p>
    </td>
  </tr>
  <tr>
    <td>selectAllText</td>
    <td>string</td>
    <td><code>'Select All'</code></td>
    <td>
      <p>The text on the button that selects all options when <code>actionsBox</code> is enabled.</p>
    </td>
  </tr>
  <tr>
    <td>selectedTextFormat</td>
    <td><code>'values'</code> | <code>'static'</code> | <code>'count'</code> | <code>'count > x'</code> (where x is an integer)</td>
    <td><code>'values'</code></td>
    <td>
      <p>Specifies how the selection is displayed with a multiple select.</p>
      <p><code>'values'</code> displays a list of the selected options (separated by <code>multipleSeparator</code>. <code>'static'</code> simply displays the select element's title. <code>'count'</code> displays the total number of selected options. <code>'count > x'</code> behaves like <code>'values'</code> until the number of selected options is greater than x; after that, it behaves like <code>'count'</code>.
    </td>
  </tr>
  <tr>
    <td>selectOnTab</td>
    <td>boolean</td>
    <td><code>false</code></td>
    <td>
      <p>When set to <code>true</code>, treats the tab character like the enter or space characters within the selectpicker dropdown.</p>
    </td>
  </tr>
  <tr>
    <td>showContent</td>
    <td>boolean</td>
    <td><code>true</code></td>
    <td>
      <p>When set to <code>true</code>, display custom HTML associated with selected option(s) in the button. When set to <code>false</code>, the option value will be displayed instead.</p>
    </td>
  </tr>
  <tr>
    <td>showIcon</td>
    <td>boolean</td>
    <td><code>true</code></td>
    <td>
      <p>When set to <code>true</code>, display icon(s) associated with selected option(s) in the button.</p>
    </td>
  </tr>
  <tr>
    <td>showSubtext</td>
    <td>boolean</td>
    <td><code>false</code></td>
    <td>
      <p>When set to <code>true</code>, display subtext associated with a selected option in the button.</p>
    </td>
  </tr>
  <tr>
    <td>showTick</td>
    <td>boolean</td>
    <td><code>false</code></td>
    <td>
      <p>Show checkmark on selected option (for items without <code>multiple</code> attribute).</p>
    </td>
  </tr>
  <tr>
    <td>size</td>
    <td><code>'auto'</code> | integer | false</td>
    <td><code>'auto'</code></td>
    <td>
      <p>When set to <code>'auto'</code>, the menu always opens up to show as many items as the window will allow
      without being cut off.</p>
      <p>When set to an integer, the menu will show the given number of items, even if the dropdown is cut off.</p>
      <p>When set to <code>false</code>, the menu will always show all items.</p>
    </td>
  </tr>
  <tr>
    <td>style</td>
    <td>string | null</td>
    <td>
      <code>Bootstrap 4: 'btn-light'</code>
      <code>Bootstrap 3: 'btn-default'</code>
    </td>
    <td>
      <p>When set to a string, add the value to the button's style.</p>
    </td>
  </tr>
  <tr>
    <td>styleBase</td>
    <td>string | null</td>
    <td><code>'btn'</code></td>
    <td>
      <p>The default class applied to the button. When using the <code>setStyle</code> method, this class will always remain.</p>
      <p>Hint: If you want to style the element as a form control, set style to <code>''</code> and styleBase to <code>'form-control'</code>.</p>
    </td>
  </tr>
  <tr>
    <td>tickIcon</td>
    <td>string</td>
    <td><code>'glyphicon-ok'</code></td>
    <td>
      <p>Set which icon to use to display as the "tick" next to selected options.</p>
    </td>
  </tr>
  <tr>
    <td>title</td>
    <td>string | null</td>
    <td><code>null</code></td>
    <td>
      <p>The default title for the selectpicker.</p>
    </td>
  </tr>
  <tr>
    <td>virtualScroll</td>
    <td>boolean | integer</td>
    <td><code>600</code></td>
    <td>
      <p>If enabled, the items in the dropdown will be rendered using virtualization (i.e. only the items that are within the viewport will be rendered). This drastically improves performance for selects with a large number of options. Set to an integer to only use virtualization if the select has at least that number of options.</p>
    </td>
  </tr>
  <tr>
    <td>width</td>
    <td><code>'auto'</code> | <code>'fit'</code> | css-width | false (where <code>css-width</code> is a CSS width with units, e.g. <code>100px</code>)</td>
    <td><code>false</code></td>
    <td>
      <p>When set to <code>auto</code>, the width of the selectpicker is automatically adjusted to accommodate the widest option.</p>
      <p>When set to a css-width, the width of the selectpicker is forced inline to the given value.</p>
      <p>When set to <code>false</code>, all width information is removed.</p>
    </td>
  </tr>
  <tr>
    <td>windowPadding</td>
    <td>integer | array</td>
    <td><code>0</code></td>
    <td>
      <p>This is useful in cases where the window has areas that the dropdown menu should not cover - for instance a fixed header. When set to an integer, the same padding will be added to all sides. Alternatively, an array of integers can be used in the format <code>[top, right, bottom, left]</code>.</p>
    </td>
  </tr>
  </tbody>
</table>

# Default settings

---

You can change the default settings for bootstrap-select by modifying its `Constructor.DEFAULTS` object:

```js
$.fn.selectpicker.Constructor.DEFAULTS.multipleSeparator = ' | ';
```

# Events

---

Bootstrap-select exposes a few events for hooking into select functionality.

hide.bs.select, hidden.bs.select, show.bs.select, and shown.bs.select all have a `relatedTarget` property, whose value is the toggling anchor element.

<table class="table table-bordered table-striped">
  <thead>
    <tr>
      <th>Event Type</th>
      <th>Description</th>
    </tr>
  </thead>
  <tbody>
    <tr>
      <td>show.bs.select</td>
      <td>This event fires immediately when the show instance method is called.</td>
    </tr>
    <tr>
      <td>shown.bs.select</td>
      <td>This event is fired when the dropdown has been made visible to the user (will wait for CSS transitions, to complete).</td>
    </tr>
    <tr>
      <td>hide.bs.select</td>
      <td>This event is fired immediately when the hide instance method has been called.</td>
    </tr>
    <tr>
      <td>hidden.bs.select</td>
      <td>This event is fired when the dropdown has finished being hidden from the user (will wait for CSS transitions, to complete).</td>
    </tr>
    <tr>
      <td>loaded.bs.select</td>
      <td>This event fires after the select has been initialized.</td>
    </tr>
    <tr>
      <td>rendered.bs.select</td>
      <td>This event fires after the render instance has been called.</td>
    </tr>
    <tr>
      <td>refreshed.bs.select</td>
      <td>This event fires after the refresh instance has been called.</td>
    </tr>
    <tr>
      <td>changed.bs.select</td>
      <td>This event fires after the select's value has been changed. It passes through event, clickedIndex, isSelected, previousValue. previousValue is the value of the select prior to being changed.</td>
    </tr>
  </tbody>
</table>

```js
$('#mySelect').on('changed.bs.select', function (e, clickedIndex, isSelected, previousValue) {
  // do something...
});
```
