$('select').zelect()

It's just yet another <select>.

Small, ~ 300 LOC
Zero base CSS, roll your own
Customizable (well, at least workaroundable)
Handles asynchronous paged loading of large option lists (read: AJAX-ready-and-enabled)
Initializable in a detached or hidden DOM node
Programmatically selectable and changeable
Unit-tested

for opts in $.fn.zelect(opts)

option	default	type	usage
throttle	300	ms.	Delay for throttling keyups for filtering/loading option items based on a search term. 0 makes things synchronous.
loader	`undefined`	function(term, page, callback): Array[Item]	Function for loading a pageful of option items. See example
renderItem	`item.label \|\| item.toString()`	function(item, term): String, DOM, jQuery, etc.	Function to render a single option item. See example
initial	`undefined`	item	Initially selected item
placeholder	`undefined`	String, DOM, jQuery, etc	Placeholder text or HTML to show when no initial selection. The first option item is selected by default if this is left undefined.
noResults	"No results for '$query'"	function(query?): String, DOM, jQuery, etc.	Function to render a no-hits text.
regexpMatcher	`/(^\|\s)term/i`	function(term): RegExp	Function to create a RegExp to filter <select>-based options with.

An item is any javascript data structure: String, Object, Array, whatever.

Minimal Setup

If the option list is known on the client, finite and manageable, use HTML:

<select id="select-backed-zelect">
  <option value="first">First Option</option>
  <option value="second">Another Option</option>
  <option value="third" selected="selected">Third option</option>
</select>

$('#select-backed-zelect').zelect()

Asyncronous Paged Setup

If the option list is server-backed, infinite or close to it, use opts.loader:

<select id="async-backed-zelect"></select>

$('#async-backed-zelect').zelect({
  initial: 'Third',
  loader: function(term, page, callback) {
    callback(['First for page '+page, 'Second', 'Third'])
  }
})

Callback expects an array. Elements in the array can be anything that renderItem can handle.

zelect will load the next page of results from opts.loader whenever the option list is scrolled to the bottom. It will stop trying to load more once the callback is called with an empty array.

Subscribing to Changes

These events are triggered on the <select>-element:

event	args	triggered when
`ready`	-	zelect is ready: first results have loaded and the initial selection has been made
`change`	event, item	Selected item changed. 2nd parameter is the item itself.

In addition:

If the zelect is <select>-backed, $('select').val() will return the value of the currently selected option.

$('select').data('zelect-item') will always return the currently selected item.

Programmatically Changing The Selection

$('select').zelectItem(myNewItemThatIWantToSelectNow, fireChangeEvent) will do that.

Whether a change event fires can be controlled with the fireChangeEvent boolean. The default is true.

Programmatically Refreshing an Externally Updated Item

$('select').refreshZelectItem(myUpdatedItem, function(item) { return item._id }) will replace and rerender the item matching myUpdatedItem._id with the new version.

No change events are fired.

Programmatically Resetting the Zelect

$('select').resetZelect() will reset the query to an empty string, load the first results and select the first item.

A change event will fire.

Styling

zelect comes with no base css. Make your own.

For inspiration, see an example.

Initial Selection

When first rendered, zelect determines the initially selected item in this order:

opts.initial if defined
<option selected="selected"> if opts.loader not defined
Render placeholder text from opts.placeholder if defined
Select the first option from the list if there are items
Render noResults text without a term

Custom Option Item Rendering Example

$('select'.zelect({
  renderItem: function(item, term) {
    return $('<span>').addClass('my-item').text(item.label).highlight(term)
  }
})

Highlights matches of the search term in the option text, by using e.g. jquery.highlight.js.

Ajax Loader Example

$('select'.zelect({
  loader: function(term, page, callback) {
    $.get('/search', { query: term, page: page }, function(arrayOfItems) {
      callback(arrayOfItems)
    }
  }
})

Uses a GET to retrieve paged results from a server.

Convoluted Semi-Real-World Example

$('select').on('ready', function() { $('form').enable() })
$('select').on('change', function(evt, item) { $('form input.id-container').val(item.id) })
$('select').zelect({
  throttle: 150,
  placeholder: $('<i>').text('Which one...'),
  loader: loader,
  renderItem: renderer,
  noResults: noResultser
}

function loader(term, page, callback) {
  $.get('/q', { q:term, p:page }).then(function(items) {
    var result = _(items).map(function(item) {
      return { text:item.content, img:item.imageUrl || 'default.png', id:item.uniqueId }
    }
    callback(result)
  }
}

function renderer(item, term) {
  return $('<div>')
    .append($('<img>').attr('src', item.img))
    .append($('<span>').addClass('content').text(item.label))
}

function noResultser(term) {
  return $('<span>').addClass('no-results').text(term + "didn't hit anything.")
}

Enjoy

omahlama/zelect