# Bootstrap Multiselect

Some option names may have changed during the last few commits!

Please consult the FAQ and the Issue Tracker before creating a new issue.

Please have a look at How to contribute? and the Issue Tracker.

## Getting Started

1. ### Link the Required Files

   First, the jQuery library needs to be included. Then Twitter Bootstrap - both the Javascript library and the CSS stylesheet - needs to be included.

       <!-- Include Twitter Bootstrap and jQuery: -->
       <link rel="stylesheet" href="css/bootstrap.min.css" type="text/css"/>
       <script type="text/javascript" src="js/jquery.min.js"></script>
       <script type="text/javascript" src="js/bootstrap.min.js"></script>

       <!-- Include the plugin's CSS and JS: -->
       <script type="text/javascript" src="js/bootstrap-multiselect.js"></script>
       <link rel="stylesheet" href="css/bootstrap-multiselect.css" type="text/css"/>

   The jQuery library can also be included using a CDN, for example the Google CDN:

       <script src="//ajax.googleapis.com/ajax/libs/jquery/2.0.3/jquery.min.js"></script>

   Note that the plugin will work both with version 2.x of the jQuery library as well as with version 1.10.x of the jQuery library. So for using the Google CDN you may have to adjust the version.

2. ### Create a Select

   Now simply use HTML to create your `select` input which you want to turn into a multiselect. Remember to set the `multiple` attribute as to get a real multiselect - but do not worry, the plugin can also be used as usual select without the `multiple` attribute being present.

       <!-- Build your select: -->
       <select id="example-getting-started" multiple="multiple">
           <option value="cheese">Cheese</option>
           <option value="tomatoes">Tomatoes</option>
           <option value="mozarella">Mozzarella</option>
           <option value="mushrooms">Mushrooms</option>
           <option value="pepperoni">Pepperoni</option>
           <option value="onions">Onions</option>
       </select>

3. ### Call the Plugin

   In the end, simply call the plugin on your `select`. You may also specify further options, see the Options tab for further information.

       <!-- Initialize the plugin: -->
       <script type="text/javascript">
           $(document).ready(function() {
               $('#example-getting-started').multiselect();
           });
       </script>

## Configuration Options

Use Firebug, Chrome Developer Tools to get the best out of the below examples.

`multiple`

`multiple` is not a real configuration option. It refers to the `multiple` attribute of the `select` the plugin is applied on. When the `multiple` attribute of the `select` is present, the plugin uses checkboxes to allow multiple selections. If it is not present, the plugin uses radio buttons to allow single selections. When using the plugin for single selections (without the `multiple` attribute present), the first option will automatically be selected if no other option is selected in advance. See #129 for how to avoid this behavior.

The following example shows the default behavior when the `multiple` attribute is omitted:

    <script type="text/javascript">
        $('#example-single').multiselect();
    </script>
    <!-- Note the missing multiple attribute! -->
    <select id="example-single">
        <option value="1">Option 1</option>
        <option value="2">Option 2</option>
        <option value="3">Option 3</option>
        <option value="4">Option 4</option>
        <option value="5">Option 5</option>
        <option value="6">Option 6</option>
    </select>

If multiple options are selected in advance and the `select` lacks the `multiple` attribute, the last option marked as `selected` will initially be selected by the plugin.

    <script type="text/javascript">
        $('#example-single-selected').multiselect();
    </script>
    <!-- Note the missing multiple attribute! -->
    <select id="example-single-selected">
        <option value="1">Option 1</option>
        <option value="2" selected="selected">Option 2</option>
        <!-- Option 3 will be selected in advance ... -->
        <option value="3" selected="selected">Option 3</option>
        <option value="4">Option 4</option>
        <option value="5">Option 5</option>
        <option value="6">Option 6</option>
    </select>

The following example shows the default behavior when the `multiple` attribute is present. Initially selected options will be adopted automatically:

    <script type="text/javascript">
        $('#example-multiple-selected').multiselect();
    </script>
    <!-- Note the missing multiple attribute! -->
    <select id="example-multiple-selected" multiple="multiple">
        <option value="1">Option 1</option>
        <option value="2" selected="selected">Option 2</option>
        <!-- Option 3 will be selected in advance ... -->
        <option value="3" selected="selected">Option 3</option>
        <option value="4">Option 4</option>
        <option value="5">Option 5</option>
        <option value="6">Option 6</option>
    </select>

The plugin naturally supports `optgroup`'s, however the group headers are not clickable by default. See the `enableClickableOptGroups` option for details.

    <script type="text/javascript">
        $('#example-multiple-optgroups').multiselect();
    </script>
    <select id="example-multiple-optgroups">
        <optgroup label="Group 1">
            <option value="1-1">Option 1.1</option>
            <option value="1-2" selected="selected">Option 1.2</option>
            <option value="1-3" selected="selected">Option 1.3</option>
        </optgroup>
        <optgroup label="Group 2">
            <option value="2-1">Option 2.1</option>
            <option value="2-2">Option 2.2</option>
            <option value="2-3">Option 2.3</option>
        </optgroup>
    </select>

`enableHTML`

XSS injection is a serious thread for all modern web applications. Setting `enableHTML` to `false` (default setting) will create a XSS save multiselect.

    <script type="text/javascript">
        $(document).ready(function() {
            $('#example-xss').multiselect();
        });
    </script>
    <select id="example-xss" multiple="multiple">
        <option value="1">&lt;script&gt;alert(1);&lt;/script&gt;</option>
    </select>

On the other hand, when setting `enableHTML` to `true`, the plugin will support HTML within `option`s:

    <script type="text/javascript">
        $(doclect>

ument).ready(function() { $('#example-xss-html').multiselect(); }); </script> <select id="example-xss-html" multiple="multiple"> <option value="1">&gt;span style="color:red"&lt;Option 1&gt;/span&gt;</option> </select>

`enableClickableOptGroups`

If set to `true`, `optgroup`'s will be clickable, allowing to easily select multiple options belonging to the same group.

    <script type="text/javascript">
        $(document).ready(function() {
            $('#example-enableClickableOptGroups').multiselect({
                enableClickableOptGroups: true
            });
        });
    </script>

Note that this option does also work with disabled options:

    <script type="text/javascript">
        $(document).ready(function() {
            $('#example-enableClickableOptGroups-disabled').multiselect({
                enableClickableOptGroups: true
            });
        });
    </script>

`enableCollapsibleOptGroups`

For this option to be available, `bootstrap-multiselect-collapsible-groups.js` needs to be included.

Make your groups collapsible.

    <script type="text/javascript">
    	$(document).ready(function() {
    		$('#example-enableCollapsibleOptGroups').multiselect({
    			enableCollapsibleOptGroups: true
    		});
    	});
    </script>

    <select id="example-enableCollapsibleOptGroups" multiple="multiple">
        <optgroup label="Group 1">
            <option value="1-1" disabled>Option 1.1</option>
            <option value="1-2" selected="selected">Option 1.2</option>
            <option value="1-3" selected="selected">Option 1.3</option>
        </optgroup>
        <optgroup label="Group 2">
            <option value="2-1" disabled>Option 2.1</option>
            <option value="2-2">Option 2.2</option>
            <option value="2-3">Option 2.3</option>
        </optgroup>
    </select>

`disableIfEmpty`

If set to `true`, the multiselect will be disabled if no options are given.

    <script type="text/javascript">
        $(document).ready(function() {
            $('#example-disableIfEmpty').multiselect({
                disableIfEmpty: true
            });
        });
    </script>

`dropRight`

The dropdown can also be dropped right.

    <script type="text/javascript">
        $(document).ready(function() {
            $('#example-dropRight').multiselect({
                buttonWidth: '400px',
                dropRight: true
            });
        });
    </script>

`maxHeight`

The maximum height of the dropdown. This is useful when using the plugin with plenty of options.

The multiselect on the left uses `maxHeight` set to `200`. On the other hand, the multiselect on the right does not use `maxHeight`.

    <script type="text/javascript">
        $(document).ready(function() {
            $('#example-with-maxHeight').multiselect({
                maxHeight: 200
            });
        });
    </script>

`checkboxName`

The name used for the generated checkboxes. See Server-Side Processing for details.

    <script type="text/javascript">
        $(document).ready(function() {
            $('#example-checkboxName').multiselect({
                checkboxName: 'multiselect[]'
            });
        });
    </script>

`onChange`

A function which is triggered on the change event of the options. Note that the event is not triggered when selecting or deselecting options using the `select` and `deselect` methods provided by the plugin.

    <script type="text/javascript">
        $(document).ready(function() {
            $('#example-onChange').multiselect({
                onChange: function(option, checked, select) {
                    alert('Changed option ' + $(option).val() + '.');
                }
            });
        });
    </script>

`onDropdownShow`

A callback called when the dropdown is shown.

The `onDropdownShow` option is not available when using Twitter Bootstrap 2.3.

    <script type="text/javascript">
        $(document).ready(function() {
            $('#example-onDropdownShow').multiselect({
                onDropdownShow: function(event) {
                    alert('Dropdown shown.');
                }
            });
        });
    </script>

`onDropdownHide`

A callback called when the dropdown is closed.

The `onDropdownHide` option is not available when using Twitter Bootstrap 2.3.

    <script type="text/javascript">
        $(document).ready(function() {
            $('#example-onDropdownHide').multiselect({
                onDropdownHide: function(event) {
                    alert('Dropdown closed.');
                }
            });
        });
    </script>

`onDropdownShown`

A callback called after the dropdown has been shown.

The `onDropdownShown` option is not available when using Twitter Bootstrap 2.3.

    <script type="text/javascript">
        $(document).ready(function() {
            $('#example-onDropdownShown').multiselect({
                onDropdownShown: function(event) {
                    alert('Dropdown closed.');
                }
            });
        });
    </script>

`onDropdownHidden`

A callback called after the dropdown has been closed.

The `onDropdownHidden` option is not available when using Twitter Bootstrap 2.3.

    <script type="text/javascript">
        $(document).ready(function() {
            $('#example-ondropdownHidden').multiselect({
                onDropdownHidden: function(event) {
                    alert('Dropdown closed.');
                }
            });
        });
    </script>

`buttonClass`

The class of the multiselect button.

    <script type="text/javascript">
        $(document).ready(function() {
            $('#example-buttonClass').multiselect({
                buttonClass: 'btn btn-link'
            });
        });
    </script>

`inheritClass`

Inherit the class of the button from the original select.

    <script type="text/javascript">
        $(document).ready(function() {
            $('#example-inheritButton').multiselect({
                inheritClass: true
            });
        });
    </script>

`buttonContainer`

The container holding both the button as well as the dropdown.

    <script type="text/javascript">
        $(document).ready(function() {
            $('#example-buttonContainer').multiselect({
                buttonContainer: '<div class="btn-group" />'
            });
        });
    </script>

`buttonWidth`

The width of the multiselect button may be fixed using this option.

    <script type="text/javascript">
        $(document).ready(function() {
            $('#example-buttonWidth').multiselect({
                buttonWidth: '400px'
            });
        });
    </script>

Note that if the text in the button title is too long, it will be truncated and use an ellipsis

    <script type="text/javascript">
        $(document).ready(function() {
            $('#example-buttonWidth-overflow').multiselect({
                buttonWidth: '150px'
            });
        });
    </script>

This does also work for long options:

    <script type="text/javascript">
        $(document).ready(function() {
            $('#example-buttonWidth-overflow').multiselect({
                buttonWidth: '150px'
            });
        });
    </script>

`buttonText`

A callback specifying the text shown on the button dependent on the currently selected options.

The callback gets the currently selected `options` and the `select` as argument and returns the string shown as button text. The default `buttonText` callback returns `nonSelectedText` in the case no option is selected, `nSelectedText` in the case more than `numberDisplayed` options are selected and the names of the selected options if less than `numberDisplayed` options are selected.

    <script type="text/javascript">
        $(document).ready(function() {
            $('#example-buttonText').multiselect({
                buttonText: function(options, select) {
                    if (options.length === 0) {
                        return 'No option selected ...';
                    }
                    else if (options.length > 3) {
                        return 'More than 3 options selected!';
                    }
                     else {
                         var labels = [];
                         options.each(function() {
                             if ($(this).attr('label') !== undefined) {
                                 labels.push($(this).attr('label'));
                             }
                             else {
                                 labels.push($(this).html());
                             }
                         });
                         return labels.join(', ') + '';
                     }
                }
            });
        });
    </script>

`buttonTitle`

A callback specifying the title of the button.

The callback gets the currently selected `options` and the `select` as argument and returns the title of the button as string. The default `buttonTitle` callback returns `nonSelectedText` in the case no option is selected and the names of the selected options of less than `numberDisplayed` options are selected. If more than `numberDisplayed` options are selected, `nSelectedText` is returned.

    <script type="text/javascript">
        $(document).ready(function() {
            $('#example-buttonTitle').multiselect({
                buttonText: function(options, select) {
                    return 'Check the title!';
                },
                buttonTitle: function(options, select) {
                    var labels = [];
                    options.each(function () {
                        labels.push($(this).text());
                    });
                    return labels.join(' - ');
                }
            });
        });
    </script>

`nonSelectedText`

The text displayed when no option is selected. This option is used in the default `buttonText` and `buttonTitle` functions.

    <script type="text/javascript">
        $(document).ready(function() {
            $('#example-nonSelectedText').multiselect({
                nonSelectedText: 'Check an option!'
            });
        });
    </script>

`nSelectedText`

The text displayed if more than `numberDisplayed` options are selected. This option is used by the default `buttonText` and `buttonTitle` callbacks.

    <script type="text/javascript">
        $(document).ready(function() {
            $('#example-nSelectedText').multiselect({
                nSelectedText: ' - Too many options selected!'
            });
        });
    </script>

`allSelectedText`

The text displayed if all options are selected.

    <script type="text/javascript">
        $(document).ready(function() {
            $('#example-allSelectedText').multiselect({
                allSelectedText: 'No option left ...'
            });
        });
    </script>

This option may be useful in combination with the `includeSelectAllOption`:

    <script type="text/javascript">
        $(document).ready(function() {
            $('#example-allSelectedText-includeSelectAllOption').multiselect({
                includeSelectAllOption: true,
                allSelectedText: 'No option left ...'
            });
        });
    </script>

`numberDisplayed`

This option is used by the `buttonText` and `buttonTitle` functions to determine of too much options would be displayed.

    <script type="text/javascript">
        $(document).ready(function() {
            $('#example-numberDisplayed').multiselect({
                numberDisplayed: 1
            });
        });
    </script>

`delimiterText`

Sets the separator for the list of selected items for mouse-over. Defaults to ', '. Set to '\n' for a neater display.

    <script type="text/javascript">
        $(document).ready(function() {
            $('#example-delimiterText').multiselect({
                delimiterText '; '
            });
        });
    </script>

`optionLabel`

A callback used to define the labels of the options.

    <script type="text/javascript">
        $(document).ready(function() {
            $('#example-optionLabel').multiselect({
                optionLabel: function(element) {
                    return $(element).html() + '(' + $(element).val() + ')';
                }
            });
        });
    </script>
    <select id="example-label" multiple="multiple">
        <option value="option-1">Option 1</option>
        <option value="option-2">Option 2</option>
        <option value="option-3">Option 3</option>
        <option value="option-4">Option 4</option>
        <option value="option-5">Option 5</option>
        <option value="option-6">Option 6</option>
    </select>

`selectedClass`

The class(es) applied on selected options.

    <style type="text/css">
        #example-selectedClass-container li.multiselect-selected a label {
            color: red;
        }
    </style>
    <script type="text/javascript">
        $(document).ready(function() {
            $('#example-selectedClass').multiselect({
                buttonContainer: '<div class="btn-group" id="example-selectedClass-container"></div>',
                selectedClass: 'multiselect-selected'
            });
        });
    </script>

`includeSelectAllOption`

Set to `true` or `false` to enable or disable the select all option.

To see an example using both the select all option and the filter, see the documentation of the `enableFiltering` option.

    <script type="text/javascript">
        $(document).ready(function() {
            $('#example-includeSelectAllOption').multiselect({
                includeSelectAllOption: true
            });
        });
    </script>

The `includeSelectAllOption` option can also be used in combination with `optgroup`'s.

    <script type="text/javascript">
        $(document).ready(function() {
            $('#example-includeSelectAllOption-optgroups').multiselect({
                includeSelectAllOption: true
            });
        });
    </script>

`selectAllText`

The text displayed for the select all option.

    <script type="text/javascript">
        $(document).ready(function() {
            $('#example-selectAllText').multiselect({
                includeSelectAllOption: true,
                selectAllText: 'Check all!'
            });
        });
    </script>

`selectAllValue`

The select all option is added as additional `option` within the `select`. To distinguish this option from the original options the value used for the select all option can be configured using the `selectAllValue` option.

    <script type="text/javascript">
        $(document).ready(function() {
            $('#example-selectAllValue').multiselect({
                includeSelectAllOption: true,
                selectAllValue: 'select-all-value'
            });
        });
    </script>

The `selectAllValue` option should usually be a string, however, numeric values work as well:

    <script type="text/javascript">
        $(document).ready(function() {
            $('#example-selectAllValue-numeric').multiselect({
                includeSelectAllOption: true,
                selectAllValue: 0
            });
        });
    </script>

`selectAllName`

This option allows to control the name given to the select all option. See Server-Side Processing for more details.

    <script type="text/javascript">
        $(document).ready(function() {
            $('#example-selectAllName').multiselect({
                includeSelectAllOption: true,
                selectAllName: 'select-all-name'
            });
        });
    </script>

`selectAllNumber`

If set to `true` (default), the number of selected options will be shown in parantheses when all options are seleted. The below example shows the behavior of the selectalloption with `selectAllNumber` set to `false`:

    <script type="text/javascript">
        $(document).ready(function() {
            $('#example-selectAllNumber').multiselect({
                includeSelectAllOption: true,
                selectAllNumber: false
            });
        });
    </script>

`onSelectAll`

This function is triggered when the select all option is used to select all options. Note that this can also be triggered manually using the `.multiselect('selectAll')` method.

    <script type="text/javascript">
        $('#example-onSelectAll').multiselect({
            includeSelectAllOption: true,
            onSelectAll: function() {
                alert('onSelectAll triggered.');
            }
        });
    </script>

`enableFiltering`

Set to `true` or `false` to enable or disable the filter. A filter `input` will be added to dynamically filter all options.

    <script type="text/javascript">
        $(document).ready(function() {
            $('#example-enableFiltering').multiselect({
                enableFiltering: true
            });
        });
    </script>

The `enableFiltering` option can easily be used in combination with the `includeSelectAllOption` option:

    <script type="text/javascript">
        $(document).ready(function() {
            $('#example-enableFiltering-includeSelectAllOption').multiselect({
                includeSelectAllOption: true,
                enableFiltering: true
            });
        });
    </script>

The `enableFiltering` option can also be used in combination with `optgroup`'s.

    <script type="text/javascript">
        $(document).ready(function() {
            $('#example-example-enableFiltering-optgroups').multiselect({
                enableFiltering: true
            });
        });
    </script>

Clickable `optgroup`'s are also supported:

    <script type="text/javascript">
        $(document).ready(function() {
            $('#example-example-enableFiltering-enableClickableOptgroups').multiselect({
                enableFiltering: true,
                enableClickableOptGroups: true
            });
        });
    </script>

Finally, the option can also be used together with `onChange` or similar events:

    <script type="text/javascript">
        $(document).ready(function() {
            $('#example-enableFiltering-onChange-onDropdownHide').multiselect({
                enableFiltering: true,
                onChange: function(option, checked) {
                    alert('onChange!');
                },
                onDropdownHide: function(event) {
                    alert('onDropdownHide!');
                }
            });
        });
    </script>

`enableCaseInsensitiveFiltering`

The filter as configured above will use case sensitive filtering, by setting `enableCaseInsensitiveFiltering` to `true` this behavior can be changed to use case insensitive filtering.

    <script type="text/javascript">
        $(document).ready(function() {
            $('#example-enableCaseInsensitiveFiltering').multiselect({
                enableCaseInsensitiveFiltering: true
            });
        });
    </script>

`filterBehavior`

The options are filtered based on their `text`. This behavior can be changed to use the `value` of the options or `both` the text and the value.

In this example, the options have values from `a` to `n`. Instead of searching the text of the options, the value of the options is searched.

    <script type="text/javascript">
        $(document).ready(function() {
            $('#example-filterBehavior').multiselect({
                enableFiltering: true,
                filterBehavior: 'value'
            });
        });
    </script>
    <select id="example-filterBehavior" multiple="multiple">
        <option value="a">Option 1</option>
        <option value="b">Option 2</option>
        <option value="c">Option 3</option>
        <option value="d">Option 4</option>
        <option value="e">Option 5</option>
        <option value="f">Option 6</option>
        <option value="g">Option 7</option>
        <option value="h">Option 8</option>
        <option value="i">Option 9</option>
        <option value="j">Option 10</option>
        <option value="k">Option 11</option>
        <option value="l">Option 12</option>
        <option value="m">Option 13</option>
        <option value="n">Option 14</option>
    </select>

`filterPlaceholder`

The placeholder used for the filter input.

    <script type="text/javascript">
        $(document).ready(function() {
            $('#example-filter-placeholder').multiselect({
                enableFiltering: true,
                filterPlaceholder: 'Search for something...'
            });
        });
    </script>
    <select id="example-filterBehavior" multiple="multiple">
        <option value="a">Option 1</option>
        <option value="b">Option 2</option>
        <option value="c">Option 3</option>
        <option value="d">Option 4</option>
        <option value="e">Option 5</option>
        <option value="f">Option 6</option>
        <option value="g">Option 7</option>
        <option value="h">Option 8</option>
        <option value="i">Option 9</option>
        <option value="j">Option 10</option>
        <option value="k">Option 11</option>
        <option value="l">Option 12</option>
        <option value="m">Option 13</option>
        <option value="n">Option 14</option>
    </select>

## Templates

The generated HTML markup can be controlled using templates. Basically, templates are simple configuration options. The default templates are shown below:

However, note that messing with the template's classes may cause unexpected behavior. For example the button should always have the class `.multiselect`,

In addition, note that other options may also have influence on the templates, for example the `buttonClass` option.

    <script type="text/javascript">
        $(document).ready(function() {
            $('#example').multiselect({
                templates: {
                    button: '<button type="button" class="multiselect dropdown-toggle" data-toggle="dropdown"></button>',
                    ul: '<ul class="multiselect-container dropdown-menu"></ul>',
                    filter: '<li class="multiselect-item filter"><div class="input-group"><span class="input-group-addon"><i class="glyphicon glyphicon-search"></i></span><input class="form-control multiselect-search" type="text"></div></li>',
                    filterClearBtn: '<span class="input-group-btn"><button class="btn btn-default multiselect-clear-filter" type="button"><i class="glyphicon glyphicon-remove-circle"></i></button></span>',
                    li: '<li><a href="javascript:void(0);"><label></label></a></li>',
                    divider: '<li class="multiselect-item divider"></li>',
                    liGroup: '<li class="multiselect-item group"><label class="multiselect-group"></label></li>'
                }
            });
        });
    </script>

For example other elements instead of buttons may be used by adaptign the template:

    <script type="text/javascript">
        $(document).ready(function() {
            $('#example-filter-placeholder').multiselect({
                buttonContainer: '<div></div>',
                buttonContainer: '',
                buttonClass: '',
                templates: {
                    button: '<span class="multiselect dropdown-toggle" data-toggle="dropdown">Click me!</span>'
                }
            });
        });
    </script>
    <style type="text/css">
        span.multiselect {
            padding: 2px 6px;
            font-weight: bold;
            cursor: pointer;
        }
    </style>

## Methods

`.multiselect('destroy')`

This method is used to destroy the plugin on the given element - meaning unbinding the plugin.

    <script type="text/javascript">
        $(document).ready(function() {
            $('#example-destroy').multiselect();
            $('#example-destroy-button').on('click', function() {
                $('#example-destroy').multiselect('destroy');
            });
        });
    </script>

`.multiselect('refresh')`

This method is used to refresh the checked checkboxes based on the currently selected options within the `select`. Click 'Select some options' to select some of the options. Then click refresh. The plugin will update the checkboxes accordingly.

    <script type="text/javascript">
        $(document).ready(function() {
            $('#example-refresh').multiselect();

            $('#example-refresh-select').on('click', function() {
                $('option[value="1"]', $('#example-refresh')).prop('selected', true);
                $('option[value="3"]', $('#example-refresh')).prop('selected', true);
                $('option[value="4"]', $('#example-refresh')).prop('selected', true);

                alert('Option 1, 2 and 4.');
            });

            $('#example-refresh-deselect').on('click', function() {
                $('option', $('#example-refresh')).each(function(element) {
                    $(this).removeAttr('selected').prop('selected', false);
                });
            });

            $('#example-refresh-button').on('click', function() {
                $('#example-refresh').multiselect('refresh');
            });
        });
    </script>

`.multiselect('rebuild')`

Rebuilds the whole dropdown menu. All selected options will remain selected (if still existent!).

    <script type="text/javascript">
        $(document).ready(function() {
            $('#example-rebuild').multiselect();

            $('#example-rebuild-button').on('click', function() {
                $('#example-rebuild').multiselect('rebuild');
            });

            $('#example-rebuild-add').on('click', function() {
                $('#example-rebuild').append('<option value="add1">Addition 1</option>
    <option value="add2">Addition 2</option><option value="add3">Addition 3</option>');
            });

            $('#example-rebuild-delete').on('click', function() {
                $('option[value="add1"]', $('#example-rebuild')).remove();
                $('option[value="add2"]', $('#example-rebuild')).remove();
                $('option[value="add3"]', $('#example-rebuild')).remove();
            });
        });
    </script>

`.multiselect('select', value)`

Selects an option by its value. Works also using an array of values.

    <script type="text/javascript">
        $(document).ready(function() {
            $('#example-select').multiselect();

            $('#example-select-button').on('click', function() {
                $('#example-select').multiselect('select', ['1', '2', '4']);

                alert('Selected 1, 2 and 4.');
            });
        });
    </script>

The method provides an additional parameter: `.multiselect('select', value, triggerOnChange)`. If the second parameter is set to true, the method will manually trigger the `onChange` option.

    <script type="text/javascript">
        $(document).ready(function() {
            $('#example-select-onChange').multiselect({
                onChange: function(option, checked, select) {
                    alert('onChange triggered ...');
                }
            });

            $('#example-select-onChange-button').on('click', function() {
                $('#example-select-onChange').multiselect('select', '1', true);
            });
        });
    </script>

The above parameter does also work when selecting multipe values. Note that `onChange` is called for each selected option individually!

    <script type="text/javascript">
        $(document).ready(function() {
            $('#example-select-onChange-array').multiselect({
                onChange: function(option, checked, select) {
                    alert('onChange triggered ...');
                }
            });

            $('#example-select-onChange-button').on('click', function() {
                $('#example-select-onChange').multiselect('select', '1', true);
            });
        });
    </script>

`.multiselect('deselect', value)`

Deselect an option by its value. Works also using an array of values.

    <script type="text/javascript">
        $(document).ready(function() {
            $('#example-deselect').multiselect();

            $('#example-deselect-button').on('click', function() {
                $('#example-deselect').multiselect('deselect', ['1', '2', '4']);

                alert('Deselected 1, 2 and 4.');
            });
        });
    </script>

The method provides an additional parameter: `.multiselect('deselect', value, triggerOnChange)`. If the second parameter is set to true, the method will manually trigger the `onChange` option.

    <script type="text/javascript">
        $(document).ready(function() {
            $('#example-deselect-onChange').multiselect({
                onChange: function(option, checked, select) {
                    alert('onChange triggered ...');
                }
            });

            $('#example-deselect-onChange-button').on('click', function() {
                $('#example-deselect-onChange').multiselect('deselect', '1', true);
            });
        });
    </script>

The above parameter does also work when deselecting multiple options. Note that `onChange` is called for each deselected option individually.

    <script type="text/javascript">
        $(document).ready(function() {
            $('#example-deselect-onChange-array').multiselect({
                onChange: function(option, checked, select) {
                    alert('onChange triggered ...');
                }
            });

            $('#example-deselect-onChange-array-button').on('click', function() {
                $('#example-deselect-onChange-array').multiselect('deselect', '1', true);
            });
        });
    </script>

`.multiselect('selectAll', justVisible)`

Selects all options. If `justVisible` is set to `true` or not provided, all visible options are selected (when using the filter), otherweise (`justVisible` set to `false`) all options are selected.

Note that setting `justVisible` to `true`, or providing no parameter will select all visible options, that is the dropdown needs to be opened.

Currently, it is required to call `.multiselect('updateButtonText')` manually after calling `.multiselect('selectAll', justVisible)`.

    <script type="text/javascript">
        $(document).ready(function() {
            $('#example-selectAll').multiselect();

            $('#example-selectAll-visible').on('click', function() {
                $('#example-selectAll').multiselect('selectAll', true);
                $('#example-selectAll').multiselect('updateButtonText');
            });
            $('#example-selectAll-all').on('click', function() {
                $('#example-selectAll').multiselect('selectAll', false);
                $('#example-selectAll').multiselect('updateButtonText');
            });
        });
    </script>

`.multiselect('deselectAll', justVisible)`

Deselects all options. If `justVisible` is set to `true` or not provided, all visible options are deselected, otherweise (`justVisible` set to `false`) all options are deselected.

Note that setting `justVisible` to `true`, or providing no parameter will select all visible options, that is the dropdown needs to be opened.

Currently, it is required to call `.multiselect('updateButtonText')` manually after calling `.multiselect('selectAll', justVisible)`.

    <script type="text/javascript">
        $(document).ready(function() {
            $('#example-deselectAll').multiselect();

            $('#example-deselectAll-visible').on('click', function() {
                $('#example-deselectAll').multiselect('deselectAll', true);
                $('#example-deselectAll').multiselect('updateButtonText');
            });
            $('#example-deselectAll-all').on('click', function() {
                $('#example-deselectAll').multiselect('deselectAll', false);
                $('#example-deselectAll').multiselect('updateButtonText');
            });
        });
    </script>

`.multiselect('updateButtonText')`

When manually selecting/deselecting options and the corresponding checkboxes, this function updates the text and title of the button.

Note that usually this method is only needed when using `.multiselect('selectAll', justVisible)` or `.multiselect('deselectAll', justVisible)`. In all other cases, `.multiselect('refresh')` should be used.

    <script type="text/javascript">
        $(document).ready(function() {
            $('#example-deselectAll').multiselect();

            $('#example-deselectAll-visible').on('click', function() {

                $('#example-deselectAll').multiselect('updateButtonText', true);
            });
        });
    </script>

`.multiselect('setOptions', options)`

Used to change configuration after initializing the multiselect. This may be useful in combination with `.multiselect('rebuild')`.

    <script type="text/javascript">
        $(document).ready(function() {

            var firstConfigurationSet = {
                includeSelectAllOption: false,
                enableFiltering: false
            };
            var secondConfigurationSet = {
                includeSelectAllOption: false,
                enableFiltering: true
            };

            var set = 1;
            $('#example-setOptions').multiselect(firstConfigurationSet);

            function rebuildMultiselect(options) {
                $('#example-setOptions').multiselect('setOptions', options);
                $('#example-setOptions').multiselect('rebuild');
            }

            $('#example-setOptions-button').on('click', function(event) {
                switch (set) {
                    case 2:
                        rebuildMultiselect(firstConfigurationSet);

                        $(this).text('Configuration Set 2');
                        set = 1;
                        break;
                    case 1:
                    default:
                        rebuildMultiselect(secondConfigurationSet);

                        $(this).text('Configuration Set 1');
                        set = 2;
                        break;

                }
            });
        });
    </script>

`.multiselect('disable')`

Disable both the underlying select and the dropdown button.

    <script type="text/javascript">
        $(document).ready(function() {
            $('#example-disable').multiselect();

            $('#example-disable-button').on('click', function() {
                $('#example-disable').multiselect('disable');
            });
        });
    </script>

`.multiselect('enable')`

Enable both the underlying select and the dropdown button.

    <script type="text/javascript">
        $(document).ready(function() {
            $('#example-enable').multiselect();

            $('#example-enable-button').on('click', function() {
                $('#example-enable').multiselect('enable');
            });
        });
    </script>

`.multiselect('dataprovider', data)`

This method is used to provide options programmatically. See the example below.

    <script type="text/javascript">
        $('#example-dataprovider').multiselect();

        var options = [
            {label: 'Option 1', title: 'Option 1', value: '1', selected: true},
            {label: 'Option 2', title: 'Option 2', value: '2'},
            {label: 'Option 3', title: 'Option 3', value: '3', selected: true},
            {label: 'Option 4', title: 'Option 4', value: '4'},
            {label: 'Option 5', title: 'Option 5', value: '5'},
            {label: 'Option 6', title: 'Option 6', value: '6', disabled: true}
        ];
        $('#example-dataprovider').multiselect('dataprovider', options);
    </script>
    <select id="example-dataprovider" multiple="multiple"></select>

The method is also able to handle `optgroup`'s:

    <script type="text/javascript">
        $('#example-dataprovider-optgroups').multiselect();

        var optgroups = [
            {
                label: 'Group 1', children: [
                    {label: 'Option 1.1', value: '1-1', selected: true},
                    {label: 'Option 1.2', value: '1-2'},
                    {label: 'Option 1.3', value: '1-3'}
                ]
            },
            {
                label: 'Group 2', children: [
                    {label: 'Option 2.1', value: '1'},
                    {label: 'Option 2.2', value: '2'},
                    {label: 'Option 2.3', value: '3', disabled: true}
                ]
            }
        ];
        $('#example-dataprovider-optgroups').multiselect('dataprovider', optgroups);
    </script>
    <select id="example-dataprovider-optgroups" multiple="multiple"></select>

`.multiselect('setAllSelectedText', value)`

This method is used to programmatically provide a new text to display in the button when all options are selected, at runtime.

    <script type="text/javascript">
        $('#example-set-all-selected-text').multiselect({allSelectedText: "Initial All Selected"});

        $('#new-all-selected-text-btn').click(function(){
            $('#example-set-all-selected-text').multiselect('setAllSelectedText', $('#new-all-selected-text-box').val());
        });
    </script>

## Further Examples

Using the `onChange` configuration option, the following example asks for confirmation if deselecting an option.

    <script type="text/javascript">
        $(document).ready(function() {
            $('#example-confirmation').multiselect({
                onChange: function(element, checked) {
                    if(checked === true) {
                        //action taken here if true
                    }
                    else if(checked === false) {
                        if(confirm('Do you wish to deselect the element?')) {
                            //action taken here
                        }
                        else {
                            $("#example-confirmation").multiselect('select', element.val());
                        }
                    }
                }
            });
        });
    </script>

Limit the number of selected options using the `onChange` option. The user may only select a maximum of 4 options. Then all other options are disabled.

    <script type="text/javascript">
        $(document).ready(function() {
            $('#example-limit').multiselect({
                onChange: function(option, checked) {
                    // Get selected options.
                    var selectedOptions = $('#example-limit option:selected');

                    if (selectedOptions.length >= 4) {
                        // Disable all other checkboxes.
                        var nonSelectedOptions = $('#example-limit option').filter(function() {
                            return !$(this).is(':selected');
                        });

                        var dropdown = $('#example-limit').siblings('.multiselect-container');
                        nonSelectedOptions.each(function() {
                            var input = $('input[value="' + $(this).val() + '"]');
                            input.prop('disabled', true);
                            input.parent('li').addClass('disabled');
                        });
                    }
                    else {
                        // Enable all checkboxes.
                        var dropdown = $('#example-limit').siblings('.multiselect-container');
                        $('#example-limit option').each(function() {
                            var input = $('input[value="' + $(this).val() + '"]');
                            input.prop('disabled', false);
                            input.parent('li').addClass('disabled');
                        });
                    }
                }
            });
        });
    </script>

Record the order the options are selected. When selecting an item an ordering number will be incremented and saved within the option.

    <script type="text/javascript">
        $(document).ready(function() {
            var orderCount = 0;
            $('#example-order').multiselect({
                onChange: function(option, checked) {
                    if (checked) {
                        orderCount++;
                        $(option).data('order', orderCount);
                    }
                    else {
                        $(option).data('order', '');
                    }
                },
                buttonText: function(options) {
                    if (options.length === 0) {
                        return 'None selected';
                    }
                    else if (options.length > 3) {
                        return options.length + ' selected';
                    }
                    else {
                        var selected = [];
                        options.each(function() {
                            selected.push([$(this).text(), $(this).data('order')]);
                        });

                        selected.sort(function(a, b) {
                            return a[1] - b[1];
                        });

                        var text = '';
                        for (var i = 0; i < selected.length; i++) {
                            text += selected[i][0] + ', ';
                        }

                        return text.substr(0, text.length -2);
                    }
                },
            });

            $('#example-order-button').on('click', function() {
                var selected = [];
                $('#example-order option:selected').each(function() {
                    selected.push([$(this).val(), $(this).data('order')]);
                });

                selected.sort(function(a, b) {
                    return a[1] - b[1];
                });

                var text = '';
                for (var i = 0; i < selected.length; i++) {
                    text += selected[i][0] + ', ';
                }
                text = text.substring(0, text.length - 2);

                alert(text);
            });
        });
    </script>

Simulate single selections using checkboxes. The behavior will be similar to a multiselect with radio buttons except that the selected option can be deselected again.

    <script type="text/javascript">
        $(document).ready(function() {
            $('#example-simulate-single').multiselect({
                on: {
                    change: function(option, checked) {
                        var values = [];
                        $('#example-simulate-single option').each(function() {
                            if ($(this).val() !== option.val()) {
                                values.push($(this).val());
                            }
                        });

                        $('#example-simulate-single').multiselect('deselect', values);
                    }
                }
            });
        });
    </script>

Using a reset button together with a multiselect.

    <script type="text/javascript">
        $(document).ready(function() {
            $('#example-reset').multiselect();
            $('#example-reset-form').on('reset', function() {
                $('#example-reset option:selected').each(function() {
                    $(this).prop('selected', false);
                })

                $('#example-reset').multiselect('refresh');
            });
        });
    </script>
    <form class="btn-group" id="example-reset-form">
        <div class="btn-group">
            <select id="example-reset" multiple="multiple">
                <option value="1">Option 1</option>
                <option value="2">Option 2</option>
                <option value="3">Option 3</option>
                <option value="4">Option 4</option>
                <option value="5">Option 5</option>
                <option value="6">Option 6</option>
            </select>
            <button type="reset" id="example-reset-button" class="btn btn-default">Reset</button>
        </div>
    </form>

Multiselect can also be used in modals:

#### Bootstrap Multiselect

    <script type="text/javascript">
        $(document).ready(function() {
            $('#example-modal').multiselect();
        });
    </script>
    <button class="btn btn-default" data-toggle="modal" data-target="#example-modal-modal">Launch modal</button>
    <div class="modal fade" id="example-modal-modal">
        <div class="modal-dialog">
            <div class="modal-content">
                <div class="modal-header">
                    <button type="button" class="close" data-dismiss="modal"><span aria-hidden="true">×</span><span class="sr-only">Close</span></button>
                    <h4 class="modal-title">Bootstrap Multiselect</h4>
                </div>
                <div class="modal-body">
                    <select id="example-modal" multiple="multiple">
                        <option value="1">Option 1</option>
                        <option value="2">Option 2</option>
                        <option value="3">Option 3</option>
                        <option value="4">Option 4</option>
                        <option value="5">Option 5</option>
                        <option value="6">Option 6</option>
                    </select>
                </div>
            </div>
        </div>
    </div>

An example of using multiselect in an accordion/collapse:

Note that the overflow of the `.panel` needs to be visible: `style="overflow:visible;"`. See the example below.

#### Bootstrap Multiselect

    <script type="text/javascript">
        $(document).ready(function() {
            $('#example-collapse').multiselect();
        });
    </script>
    <div class="panel-group" id="example-collapse-accordion">
        <div class="panel panel-default" style="overflow:visible;">
            <div class="panel-heading">
                <h4 class="panel-title">
                    <a data-toggle="collapse" data-parent="#example-collapse-accordion" href="#example-collapse-accordion-one">
                        Bootstrap Multiselect
                    </a>
                </h4>
            </div>
            <div id="example-collapse-accordion-one" class="panel-collapse collapse in">
                <div class="panel-body">
                    <select id="example-collapse" multiple="multiple">
                        <option value="1">Option 1</option>
                        <option value="2">Option 2</option>
                        <option value="3">Option 3</option>
                        <option value="4">Option 4</option>
                        <option value="5">Option 5</option>
                        <option value="6">Option 6</option>
                    </select>
                </div>
            </div>
        </div>
    </div>

The examples below are aimed to demonstrate the performance of several features when using a large number of options:

- Using the select all option, `includeSelectAllOption` set to `true`.
- Additionally using a filter, `enableFiltering` set to `true`.
- Additionally using `enableClickableOptGroups`.
- Resetting the multiselect.

The below examples need to be activated. Note that this may take some time!

Use options:

    <script type="text/javascript">
        $(document).ready(function() {
            $('#example-large-enable').on('click', function() {
                var options = $('#example-large-options').val();

                if (options < 1 || options > 5000) {
                    $('#example-large-error').html('<p class="alert alert-error">Choose between 1 and 5000 options!</p>');
                }
                else {
                    $('#example-large-includeSelectAllOption').html('');
                    $('#example-large-includeSelectAllOption-enableFiltering').html('');
                    $('#example-large-includeSelectAllOption-enableFiltering-enableClickableOptGroups').html('');
                    $('#example-large-reset').html('');

                    for (var j = 0; j < options; j++) {
                        i = j + 1;
                        $('#example-large-includeSelectAllOption').append('<option value="' + i.toString() + '">Option ' + i.toString() + '</option>');
                        $('#example-large-includeSelectAllOption-enableFiltering').append('<option value="' + i.toString() + '">Option ' + i.toString() + '</option>');

                        var group = Math.floor(j/10) + 1;
                        var number = j % 10 + 1;
                        if (number === 1) {
                            $('#example-large-includeSelectAllOption-enableFiltering-enableClickableOptGroups').append('<optgroup label="Group ' + group.toString() + '"></optgroup>');
                        }
                        $('#example-large-includeSelectAllOption-enableFiltering-enableClickableOptGroups').append('<option value="' + group.toString() + '-' + number.toString() + '">Option ' + group.toString() + '.' + number.toString() + '</option>');

                        $('#example-large-reset').append('<option value="' + i.toString() + '">Option ' + i.toString() + '</option>');
                    }

                    $('#example-large-includeSelectAllOption').multiselect({
                        maxHeight: 200,
                        includeSelectAllOption: true
                    });

                    $('#example-large-includeSelectAllOption-enableFiltering').multiselect({
                        maxHeight: 200,
                        includeSelectAllOption: true,
                        enableFiltering: true
                    });

                    $('#example-large-includeSelectAllOption-enableFiltering-enableClickableOptGroups').multiselect({
                        maxHeight: 200,
                        includeSelectAllOption: true,
                        enableFiltering: true,
                        enableClickableOptGroups: true
                    });

                    $('#example-large-reset').multiselect({
                        maxHeight: 200,
                        includeSelectAllOption: true
                    });

                    $('#example-large-reset-form').on('reset', function() {
                        $('#example-large-reset').multiselect('deselectAll', false);
                        $('#example-large-reset').multiselect('updateButtonText');
                    });
                }
            });
        });
    </script>
    <div class="btn-toolbar" style="margin-bottom:12px;">
        <div class="btn-group">
            <select id="example-large-includeSelectAllOption" multiple="multiple">
                <option value="1">Option 1</option>
            </select>
        </div>
    </div>
    <div class="btn-toolbar" style="margin-bottom:12px;">
        <div class="btn-group">
            <select id="example-large-includeSelectAllOption-enableFiltering" multiple="multiple">
                <option value="1">Option 1</option>
            </select>
        </div>
    </div>
    <div class="btn-toolbar" style="margin-bottom:12px;">
        <div class="btn-group">
            <select id="example-large-includeSelectAllOption-enableFiltering-enableClickableOptGroups" multiple="multiple">
                <option value="1">Option 1</option>
            </select>
        </div>
    </div>
    <form id="example-large-reset-form" style="margin-bottom:12px;">
        <div class="btn-group">
            <select id="example-large-reset" multiple="multiple">
                <option value="1">Option 1</option>
            </select>
            <button type="reset" class="btn btn-default">Reset</button>
        </div>
    </form>

The following examples is aimed to demonstrate the performance of the `.multiselect('dataprovider', data)` for a large number of options.

The below examples need to be activated. Note that this may take some time!

    $(document).ready(function() {
        var data = [];
        for (var i = 0; i < 100; i++) {
            var group = {label: 'Group ' + (i + 1), children: []};
            for (var j = 0; j < 10; j++) {
                group['children'].push({
                    label: 'Option ' + (i + 1) + '.' + (j + 1),
                    value: i + '-' + j
                });
            }

            data.push(group);
        }

        $('#example-large-dataprovider-button').on('click', function() {
            $('#example-large-dataprovider').multiselect({
                maxHeight: 200
            });
            $('#example-large-dataprovider').multiselect('dataprovider', data);
        });
    });
    <p class="alert alert-info"><button id="example-large-dataprovider-button" class="btn btn-primary">Activate</button></p>
    <select id="example-large-dataprovider" multiple="multiple"></select>

The following example illsutrates how to disable options using JavaScript.

    $(document).ready(function() {
        $('#example-disable-javascript').multiselect();
    });
    <select id="example-disable-javascript" multiple="multiple"></select>

## Server-Side Processing

The below example uses a PHP script to demonstrate Server-Side Processing. Therefore, the below example will not run online - download the repository and try it on a local server.

In order to receive the correct data after submitting the form, the used `select` has to have an appropriate name. Note that an `[]` needs to be appended to the name when using the `multiple` option/attribute. Per default, the checkboxes used within the multiselect will not be submitted, however, this can be changed by adapting `checkboxName`. The select all option as well as the text input used for the filter will not be submitted. As this may be useful, the name of the select all checkbox may be adapted using the `selectAllName` option. The value of the select all checkbox can be controlled by the `selectAllValue` option while the values of the remaining checkboxes correspond to the values used by the `option`'s of the original `select`.

Multiselect
Text Input
Checkbox
Radio 1
Radio 2

    <script type="text/javascript">
        $(document).ready(function() {
            $('#example-post').multiselect({
                includeSelectAllOption: true,
                enableFiltering: true
            });
        });
    </script>
    <form class="form-horizontal" method="POST" action="post.php">
        <div class="form-group">
            <label class="col-sm-2 control-label">Multiselect</label>
            <div class="col-sm-10">
                <select id="example-post" name="multiselect[]" multiple="multiple">
                    <option value="1">Option 1</option>
                    <option value="2">Option 2</option>
                    <option value="3">Option 3</option>
                    <option value="4">Option 4</option>
                    <option value="5">Option 5</option>
                    <option value="6">Option 6</option>
                </select>
            </div>
        </div>
        <div class="form-group">
            <label class="col-sm-2 control-label">Text Input</label>
            <div class="col-sm-10">
                <input type="text" name="text" class="form-control" placeholder="Text Input" />
            </div>
        </div>
        <div class="form-group">
            <div class="col-sm-offset-2 col-sm-10">
                <div class="checkbox">
                    <label>
                        <input type="checkbox" name="checkbox"> Checkbox
                    </label>
                </div>
            </div>
        </div>
        <div class="form-group">
            <div class="col-sm-offset-2 col-sm-10">
                <div class="radio">
                    <label>
                        <input type="radio" name="radio"> Radio 1
                    </label>
                </div>
                <div class="radio">
                    <label>
                        <input type="radio" name="radio"> Radio 2
                    </label>
                </div>
            </div>
        </div>
        <div class="form-group">
            <div class="col-sm-offset-2 col-sm-10">
                <button type="submit" class="btn btn-default">Submit</button>
            </div>
        </div>
    </form>

## Keyboard Support

`Tab` | As with other form elements, `Tab` is used to switch to the next form elements. `Tab` can be used when the dropdown is opened as well as when it is closed.
`Space/Enter` | `Space` or `Enter` is used to open the dropdown and select options. After a multiselect is in focus, pressing `Space` or `Enter` will open the dropdown. Then, the options can be traversed using arrow up and down.
`Arrow Up/Arrow Down` | Used to traverse the options after opening the dropdown. An option can be selected using `Space` or `Enter`.

## Frequently Asked Questions

How to contribute?
  Pull requests to add additional feature or fix known bugs are always welcome! However, to make it easy for me to review and merge your pull request, the following guidelines should be considered:
  - Add one pull request per feature/fix. Otherwise, I cannot guarantee that I will merge the pull request.
  - Always document your changes. If new features are added, new options or methods should be added to the documentation (`index.html`) and appropriate examples should be added.
  - Add a throrough description to your pull request - yes, I am able to read your code, however, reading your description may speed up things!
  - Add comments to your code.
  A full list of contributors can be found here.
How about older browsers as for example Internet Explorer 6, 7 and 8?
  With version 2.0, jQuery no longer supports the older IE versions. Nevertheless, the plugin should run as expected using the 1.x branch of jQuery. See here for details.
May I use the plugin in a commercial project (e.g. a commercial Wordpress/Joomla theme)?
  The plugin is dual licensed under the Apache License v2.0 and the BSD 3-Clause License. The BSD 3-Clause License allows to use the plugin in commercial projects as long as all source files associated with this plugin retain the copyright notice.
Using `return false;` within the `onChange` option does not prevent the option from being selected/deselected ...
  The `return` statement within the `onChange` method has no influence on the result. For preventing an option from being deselected or selected have a look at the examples in the Further Examples section.
How to change the button class depending on the number of selected options?
  This issue is addressed in 332.
Why does the plugin crash when using `.multiselect('select', value);` or `.multiselect('deselect', value);`?
  This may be caused when the class used for the `select` occurs for other elements, as well. In addition this may be caused if the multiselect has the class `.multiselect`. See #330.
How to check whether filtering all options resulted no options being displayed (except the select all option)?
  This issue is discussed in #317.
How to use multiple plugin instances running single selections on one page?
  There is a minor bug when using multiple plugin instances with single selection on one page. The bug is described here: #331. A possible fix is suggested here: #336.
How to use the plugin within a `form.form-inline`?
  This issue is addressed in #322
Using jQuery, how to get the selected options dynamically?

      //  get all option elements
      $('#example option:selected');

      //  get all option element values
      $('#example option:selected').map(function(a, item){return item.value;});

How to get the selected options using PHP?
  This issue is addressed here: https://github.com/davidstutz/bootstrap-multiselect/issues/323. Mainly there are two ways, either add a name to the `select`:

      <select id="example2" multiple="multiple" name="select[]"></select>

  Or add an appropriate name to the checkboxes:

      $('#example2').multiselect({
          checkboxName: 'multiselect[]'
      });

Why does the plugin not work in Chrome for Mobile?
  This may be caused by several reasons one of which is described and resolved here: #223.
How to underline the searched text when using the filter?
  This issue is discussed in #309.
How to hide the checkboxes?
  A related issue is discussed in #205 and includes a possible solution when using CSS to hide the checkboxes:

      .multiselect-container input {
          display: none
      }

How to use Bootstrap Multiselect using `$.validate`?
  This topic is discussed in issue #347. The fix suggested is as follows:

      var $form = $("#myForm");
      var validator = $form.data('validator');
      validator.settings.ignore = ':hidden:not(".multiselect")';

How to prevent the plugin from selecting the first option in single select mode?
  This issue is mainly due to the default behavior of most browsers. A workaround can be found here: #129.
Which are the minimum required components of Twitter Botostrap to get the plugin working?
  The plugin needs at least the styles for forms and dropdowns. In addition the JavaScript dropdown plugin from Twitter Bootstrap is required. Details can be found here: #344.
How to use the `.multiselect('dataprovider', data)` method?
  Have a look at the Methods section. In the past, there has been some confusion about how the method handles option groups. If the documentation does not help you, have a look at the issue tracker, as for example issue #356.
A `type="reset"` button does not refresh the multiselect, what to do?
  Have a look at the Further Examples section (in addition, issue 360 discussed this).
Using multiple `select`'s in single selection mode with `option`'s sharing values across the different `select`'s.
  This issue is discussed in detail here: #362. A simple solution is to use different option values for the option `checkboxName`:

      $('.multiselect').multiselect({
          checkboxName: _.uniqueId('multiselect_')
      });

  where `_.uniqueId('multiselect_')` should be replaced with a random generator. Alternatively, a unique value for `checkboxName` can be used for each multiselect.
How to avoid `TypeError: Cannot read property "toString" of ...`?
  This error may be thrown if `null` or `undefined` is provided as argument of `.multiselect('select', value)` or `.multiselect('deselect', value)`, see #386.
Why is there no "uncheck all" option?
  This issue is discussed in #271.
Esc does not close the dropdown?!
  This issue is discussed in #368. Currently, pressing `Esc` will not close the dropdown as there were some bugs with this.
How to keep the dropdown open?
  This issue is discussed here: #426.
Why is the dropdown not showing (or only partly shown) within modals?
  This is a general issue not directly related to Bootstrap Multiselect: #455.
How do add icons to the options (#475)?
  Adapt the `optionLabel` option as follows:

      optionLabel: function(element){
          return $(element).attr('label') || $(element).html();
      },

How to add a deselect all functionality (the inverse to the select all option)?
  This issue was discussed in the following pull request: #487.
How to bind object values using Knockout JS?
  This issue was discussed in #532.
Options do net get updated when using Angular JS?
  This issues was discussed in #519.

## Known Issues

Slow dropdown on Chrome 35.
  As discussed in #268, certain versions seem to have some performance problems, especially Chrome 35.0.1916.114m.
Using `maxHeight` results in the filter being not fixed at the top.
  See issue . Pull requests are welcome.

## License

Apache License, Version 2.0

  Copyright 2012 - 2014 David Stutz

  Licensed under the Apache License, Version 2.0 (the "License"); you may not use this file except in compliance with the License. You may obtain a copy of the License at http://www.apache.org/licenses/LICENSE-2.0.

  Unless required by applicable law or agreed to in writing, software distributed under the License is distributed on an "AS IS" BASIS, WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied. See the License for the specific language governing permissions and limitations under the License.

BSD 3-Clause License

  Copyright (c) 2012 - 2014 David Stutz

  All rights reserved.

  Redistribution and use in source and binary forms, with or without modification, are permitted provided that the following conditions are met:

  - Redistributions of source code must retain the above copyright notice, this list of conditions and the following disclaimer.
  - Redistributions in binary form must reproduce the above copyright notice, this list of conditions and the following disclaimer in the documentation and/or other materials provided with the distribution.
  - Neither the name of David Stutz nor the names of its contributors may be used to endorse or promote products derived from this software without specific prior written permission.

  THIS SOFTWARE IS PROVIDED BY THE COPYRIGHT HOLDERS AND CONTRIBUTORS "AS IS" AND ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE ARE DISCLAIMED. IN NO EVENT SHALL THE COPYRIGHT HOLDER OR CONTRIBUTORS BE LIABLE FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION) HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF SUCH DAMAGE.

© 2012 - 2014 David Stutz - dual licensed: Apache License v2.0, BSD 3-Clause License