Bootstrap Multiselect

Bootstrap Multiselect is a JQuery based plugin to provide an intuitive user interface for using select inputs with the multiple attribute present. Instead of a select a bootstrap button will be shown as dropdown menu containing the single options as checkboxes.

Note: The option names may have changed due to the latest updates.

Examples

The best way learning from the examples is using firebug, chrome developer tools or similar tools for your browser. Examine the generated markup and used javascript code.

Normal select. The plugin will add the multiple="multiple" attribute automatically. The first option is selected automatically by the browser when ommitting the multiple attribute. But note: If the mutliple attribute is omitted and more than one option is selected by default, the browser will select the last selected option before the plugin has the chance to add the mutliple attribute.
Select with preselected options: <option value="cheese" selected>Cheese</option>
As link using buttonClass: 'btn btn-link'.
Small button using buttonClass: 'btn btn-small'.
Disabled using buttonClass: 'btn btn-primary disabled'.
Multiple select within a group with add-ons and default container for the plugin: buttonContainer: '<div class="btn-group" />'.
Multiple selects within a group using buttonContainer: '<span class="dropdown" />'.
Using the onChange option you can add an event handler to the change event. The event handler gets the selected option as first parameter and a variable saying whether the option is checked or not as second one.
For long option lists the maxheight option can be set.
The plugin supports disabled options, too: disabled="disabled"
Use the buttonWidth option to adjust the width of the button.
Using the onChange option to prevent user from deselecting selected options.
Option groups are detected automatically and for each option group an header element is added: <optgroup label="Mathematics">...</optgroup>

Code

Basic markup used in the above examples: 

<link rel="stylesheet" href="css/bootstrap.min.css" type="text/css">
<link rel="stylesheet" href="css/bootstrap-responsive.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>
<script type="text/javascript" src="js/bootstrap-multiselect.js"></script>

<script type="text/javascript">
  $(document).ready(function() {
    $('.multiselect').multiselect({
      buttonClass: 'btn',
      buttonWidth: 'auto',
      buttonContainer: '<div class="btn-group" />',
      maxHeight: false,
      buttonText: function(options) {
        if (options.length == 0) {
          return 'None selected <b class="caret"></b>';
        }
        else if (options.length > 3) {
          return options.length + ' selected  <b class="caret"></b>';
        }
        else {
          var selected = '';
          options.each(function() {
            selected += $(this).text() + ', ';
          });
          return selected.substr(0, selected.length -2) + ' <b class="caret"></b>';
        }
      }
    });
  });
</script>

<select class="multiselect" 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>

<div class="input-prepend input-append">
  <span class="add-on"><b class="icon-list-alt"></b></span>
  <select class="multiselect" 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>
  <button class="btn btn-danger">Cancel</button>
  <button class="btn btn-success">Save</button>
</div>

Methods

.multiselect('destroy')
This method is used to destroy the plugin on the given element - meaning unbinding the plugin.
.multiselect('refresh')
This method is used to refresh the checked checkboxes based on the currently selected options within the select. Click 'Select some options' so select some of the options (meaning added the selected attribute to some of the options). Then click refresh. The plugin will update the checkboxes accordingly.
.multiselect('rebuild')
Rebuilds the whole dropdown menu. All selected options will remain selected (if still existent!).
.multiselect('select', value)
Selects an option by its value.
.multiselect('select', value)
Deselect an option by its value.

Options

Option Explanation Usage
buttonText A function returning the string displayed if options are selected. All currently selected options and the select are passed as argument. In addition HTML can be added to the button, for example the caret icon seen in the examples. 
<script type="text/javascript">
  $(document).ready(function() {
    $('.multiselect').multiselect({
      buttonText: function(options, select) {
        if (options.length == 0) {
          return 'None selected <b class="caret"></b>';
        }
        else if (options.length > 3) {
          return options.length + ' selected  <b class="caret"></b>';
        }
        else {
          var selected = '';
          options.each(function() {
            selected += $(this).text() + ', ';
          });
          return selected.substr(0, selected.length -2) + ' <b class="caret"></b>';
        }
      }
    });
  });
</script>
buttonClass The width of the dropdown button. Default: btn. 
<script type="text/javascript">
  $(document).ready(function() {
    $('.multiselect').multiselect({
      buttonClass: 'btn-primary btn-large',
    });
  });
</script>
buttonWidth The width of the dropdown button. Default: auto. Allowed formats:
  • 100px
  • 50%
  • auto
If the width is defined using CSS the option should be set to false. 
<script type="text/javascript">
  $(document).ready(function() {
    $('.multiselect').multiselect({
      buttonWidth: '300px',
    });
  });
</script>
buttonContainer The used container holding both the dropdown button and the dropdown menu. Default: <div class="btn-group" />. 
<script type="text/javascript">
  $(document).ready(function() {
    $('.multiselect').multiselect({
      buttonContainer: '<span class="dropdown" />',
    });
  });
</script>
onChange This event handler is triggered when the selected options are changed. 
<script type="text/javascript">
  $(document).ready(function() {
    $('.multiselect').multiselect({
      onChange: function(element, checked) {
      	alert('Change event invoked!');
      },
    });
  });
</script>
maxHeight Used for a long list of options this option defines the maximum height of the dropdown menu. If the size is exceeded a scrollbar will appear. 
<script type="text/javascript">
  $(document).ready(function() {
    $('.multiselect').multiselect({
      maxHeight: 400,
    });
  });
</script>

Additional Styling

For additionaly styling of the multiselect button the CSS class multiselect can be used.

Text alignment combined with fixed width and bold, underlined text for option group headers. 
.multiselect {
	text-align: left;
}
.multiselect b.caret {
	float: right;
}
.multiselect-group {
	font-weight: bold;
	text-decoration: underline;
}

© 2012 David Stutz - Apache License v2.0