<p>The select menus are driven off native <code>select</code> elements, but the native selects are hidden from view and replaced with a custom-styled select button that matches the look and feel of the jQuery Mobile framework. The replacement selects are ARIA-enabled and are keyboard accessible on the desktop as well.</p>
<p>When the select button is clicked, the native select menu picker for the OS will open. When a value is selected in the menu, the custom select button is updated to match the new selection. </p>
<p>To add a select widget to your page, start with a standard <code>select</code> element populated with a set of <code>option</code> elements. Set the <code>for</code> attribute of the <code>label</code> to match the ID of the <code>select</code> so they are semantically associated. Wrap them in a <code>div</code> with the <code>data-role="fieldcontain"</code> attribute to help visually group it in a longer form. </p>
<p>When clicked, if the menu has room it will appear as an overlay listbox, but if there are too many options to fit in the window without scrolling, the page content is wrapped in a div and hidden, and the menu is appended as a whole new page. This lets us take advantage of native scrolling while the menu is in use. </p>
<p>You can optionally use custom-styled select menus instead of the native versions. This adds the ability to theme the menu to better match the look and feel of your site and provides visual consistency across platforms. In addition, it restores missing functionality on certain platforms such as <code>optgroup</code> support on Android, and adds an elegant way to handle placeholder values (explained below). Lastly, the custom menus will look better on desktop browsers because native menus on the desktop tend to be fairly small compared their mobile counterparts and this can look a bit odd if desktop if a priority for your project.</p>
<p>Keep in mind that there is overhead involved in parsing the native select to build a custom menu. If there are a lot of selects on a page, or a select has a long list of options, this can impact the performance of the page so we recommend using custom menus sparingly. </p>
<p>To use custom menus on a specific <code>select</code>, just add the <code>data-native-menu="false"</code> attribute. Alternately, this can also programmatically set the select menu's <code>nativeMenu</code> configuration option to <code>false</code> in a callback bound to the <code>mobileinit</code> event to achieve the same effect. This will globally make all selects use the custom menu by default. The following must be included in the page after jQuery is loaded but before jQuery Mobile is loaded.</p>
<p>If there is a select menu with too many options to show on the device's screen, the framework will automatically create a new "page" populated with a standard list view that contains all the options. This allows us to use the native scrolling included on the device for moving through a long list. The text inside the <code>label</code> is used as the title for this page.</p>
<p>When clicked, the native select picker menu will open. When a value is selected in the menu, the custom select button will be updated to match the new selection. if the menu has room it will appear as an overlay listbox, but if there are too many options to fit in the window without scrolling, the page content is wrapped in a div and hidden, and the menu is appended as a whole new page. This lets us take advantage of native scrolling while the menu is in use. </p>
<p>It's common for developers to include a "null" option in their select element to force a user to choose an option. If a placeholder option is present in your markup, jQuery Mobile will hide them in the overlay menu, showing only valid choices to the user, and display the placeholder text inside the menu as a header. A placeholder option is added when the framework finds:</p>
<li>An option with no value attribute (or an empty value attribute)</li>
<li>An option with no text node</li>
<li>An option with a <code>data-placeholder="true"</code> attribute. (This allows you to use an option that has a value and a textnode as a placeholder option).</li>
<p>jQuery Mobile will automatically disable and style option tags with the <code>disabled</code> attribute. In the demo below, the second option "Rush: 3 days" has been set to disabled.</p>
<p>If a select menu contains <code>optgroup</code> elements, jQuery Mobile will create a divider & group items based on the <code>label</code> attribute's text:</p>
<li>A header element will be created inside the menu and display the placeholder text and a close button.</li>
<li>Clicking on an item inside the overlay menu will not close the widget.</li>
<li>A ghosted, unchecked icon will appear adjacent to each unselected item. When the item is selected the icon will change to a checkbox. Neither icon will appear inside a single select box.</li>
<li>Once 2+ items are selected, a counter element with the total number of selected items will appear inside the button.</li>
<li>The text of each selected item will appear inside the button as a list. If the button is not wide enough to display the entire list, it is truncated with an ellipses.</li>
<li>If no items are selected, the button's text will default to the placeholder text.</li>
<li>If no placeholder element exists, the default button text will be blank and the header will appear with just a close button. Because this isn't a friendly user experience, we recommended that you always specify a placeholder element when using multiple select boxes.</li>
<p>When a select is large enough to where the menu will open in a new page, the placeholder text is displayed in the button when no items are selected, and the <code>label</code> text is displayed in the menu's header. This differs from smaller overlay menus where the placeholder text is displayed in both the button and the header, and from full-page single selects where the placeholder text is not used at all.</p>
<p>You can specify any jQuery Mobile button data- attribute on a select element too. In this example, we're setting the theme, icon and inline properties though data- attributes.</p>
