Bootstrap - Dropdowns

This chapter will highlight about Bootstrap dropdown menus. Dropdown menus are toggleable, contextual menus for displaying links in a list format. This can be made interactive with the dropdown JavaScript plugin.
To use dropdown, just wrap the dropdown menu within the class .dropdown.
The following example demonstrates a basic dropdown menu −

<div class = "dropdown">
   
   <button type = "button" class = "btn dropdown-toggle" id = "dropdownMenu1" data-toggle = "dropdown">
      Topics
      <span class = "caret"></span>
   </button>
   
   <ul class = "dropdown-menu" role = "menu" aria-labelledby = "dropdownMenu1">
      <li role = "presentation">
         <a role = "menuitem" tabindex = "-1" href = "#">Java</a>
      </li>
      
      <li role = "presentation">
         <a role = "menuitem" tabindex = "-1" href = "#">Data Mining</a>
      </li>
      
      <li role = "presentation">
         <a role = "menuitem" tabindex = "-1" href = "#">
            Data Communication/Networking
         </a>
      </li>
      
      <li role = "presentation" class = "divider"></li>
      
      <li role = "presentation">
         <a role = "menuitem" tabindex = "-1" href = "#">Separated link</a>
      </li>
   </ul>
   
</div>

Options

Alignment

Align the dropdown menu to right by adding the class .pull-right to .dropdown-menu. The following example demonstrates this −

<div class = "dropdown">
   
   <button type = "button" class = "btn dropdown-toggle" id = "dropdownMenu1" data-toggle = "dropdown">
      Topics
      <span class = "caret"></span>
   </button>
   
   <ul class = "dropdown-menu pull-right" role = "menu" aria-labelledby = "dropdownMenu1">
      <li role = "presentation">
         <a role = "menuitem" tabindex = "-1" href = "#">Java</a>
      </li>
      
      <li role = "presentation">
         <a role = "menuitem" tabindex = "-1" href = "#">Data Mining</a>
      </li>
      
      <li role = "presentation">
         <a role = "menuitem" tabindex = "-1" href = "#">
            Data Communication/Networking
         </a>
      </li>
      
      <li role = "presentation" class = "divider"></li>
      
      <li role = "presentation">
         <a role = "menuitem" tabindex = "-1" href = "#">Separated link</a>
      </li>
   </ul>
   
</div>

Headers

You can add a header to label sections of actions in any dropdown menu by using the class dropdown-header. The following example demonstrates this −

<div class = "dropdown">
   
   <button type = "button" class = "btn dropdown-toggle" id = "dropdownMenu1" data-toggle = "dropdown">
      Topics
      <span class = "caret"></span>
   </button>
   
   <ul class = "dropdown-menu" role = "menu" aria-labelledby = "dropdownMenu1">
      <li role = "presentation" class = "dropdown-header">Dropdown header</li>
      
      <li role = "presentation" >
         <a role = "menuitem" tabindex = "-1" href = "#">Java</a>
      </li>
      
      <li role = "presentation">
         <a role = "menuitem" tabindex = "-1" href = "#">Data Mining</a>
      </li>
      
      <li role = "presentation">
         <a role = "menuitem" tabindex = "-1" href = "#">
            Data Communication/Networking
         </a>
      </li>
      
      <li role = "presentation" class = "divider"></li>
      <li role = "presentation" class = "dropdown-header">Dropdown header</li>
      
      <li role = "presentation">
         <a role = "menuitem" tabindex = "-1" href = "#">Separated link</a>
      </li>
   </ul>
   
</div>