This project is an addition to the excellent Chosen jQuery plugin that makes HTML input forms more friendly. Chosen adds search boxes to select HTML elements, so I felt it could use the addition of ajax autocomplete for awesomely dynamic forms.

This script bootstraps the existing Chosen plugin without making any modifications to the original code. Eventually, I would love to see this functionality built-in to the library, but until then, this seems to work pretty well.

This plugin exposes a new jQuery function named ajaxChosen that we call on a select element. The first argument consists of the options passed to the jQuery $.ajax function. The data parameter is optional, and the success callback is also optional.

The second argument is a callback that tells the plugin what HTML option elements to make. It is passed the data returned from the ajax call, and you have to return an array of objects for which each item has a value property corresponding to the HTML option elements' value attribute, and a text property corresponding to the text to display for each option. In other words:

[{"value": 3, "text": "Ohio"}]

becomes:

<option value="3">Ohio</option>

or for grouping:

[{
	group: true,
	text: "Europe",
	items: [
		{ "value": "10", "text": "Stockholm" },
		{ "value": "23", "text": "London" }
	]
},
{
	group: true,
	text: "Asia",
	items: [
		{ "value": "36", "text": "Beijing" },
		{ "value": "20", "text": "Tokyo" }
	]
}]

becomes:

    <optgroup label="Europe">
        <option value="10">Stockholm</option>
        <option value="23">London</option>
    </optgroup>
    <optgroup label="Asia">
        <option value="36">Beijing</option>
        <option value="20">Tokyo</option>
    </optgroup>

Note:

Due to a bug in Chosen, it is necessary to change choosen.css.

Add

display: list-item;

to

.chzn-container .chzn-results .group-result {

class

There are some additional ajax-chosen specific options you can pass into the first argument to control its behavior.

• minTermLength: minimum number of characters that must be typed before an ajax call is fired
• afterTypeDelay: how many milliseconds to wait after typing stops to fire the ajax call
• jsonTermKey: the ajax request key to use for the search query (defaults to term)

$("#example-input").ajaxChosen({
	type: 'GET',
	url: '/ajax-chosen/data.php',
	dataType: 'json'
}, function (data) {
	var results = [];
	
	$.each(data, function (i, val) {
		results.push({ value: val.value, text: val.text });
	});
	
	return results;
});

To have the results grouped in optgroup elements, have the function return a list of group objects instead:

$("#example-input").ajaxChosen({
	type: 'GET',
	url: '/ajax-chosen/grouped.php',
	dataType: 'json'
}, function (data) {
	var results = [];

	$.each(data, function (i, val) {
		var group = { // here's a group object:
			group: true,
			text: val.name, // label for the group
			items: [] // individual options within the group
		};

		$.each(val.items, function (i1, val1) {
			group.items.push({value: val1.value, text: val1.text});
		});

		results.push(group);
	});

	return results;
});

In order to install development dependencies, you can run in the ajax-chosen directory:

npm install -d

ajax-chosen is written in Coffeescript, so there is a Cakefile provided that will perform all necessary tasks for you. Simply run cake to see all available commands.