init_select = function($input, settings_element) {
			var i, n, tagName, $children, order = 0;
			var options = settings_element.options;
	
			var readData = function($el) {
				var data = attr_data && $el.attr(attr_data);
				if (typeof data === 'string' && data.length) {
					return JSON.parse(data);
				}
				return null;
			};
	
			var addOption = function($option, group) {
				$option = $($option);
	
				var value = hash_key($option.attr('value'));
				if (!value && !settings.allowEmptyOption) return;
	
				// if the option already exists, it's probably been
				// duplicated in another optgroup. in this case, push
				// the current group to the "optgroup" property on the
				// existing option so that it's rendered in both places.
				if (optionsMap.hasOwnProperty(value)) {
					if (group) {
						var arr = optionsMap[value][field_optgroup];
						if (!arr) {
							optionsMap[value][field_optgroup] = group;
						} else if (!$.isArray(arr)) {
							optionsMap[value][field_optgroup] = [arr, group];
						} else {
							arr.push(group);
						}
					}
					return;
				}
	
				var option             = readData($option) || {};
				option[field_label]    = option[field_label] || $option.text();
				option[field_value]    = option[field_value] || value;
				option[field_optgroup] = option[field_optgroup] || group;
	
				optionsMap[value] = option;
				options.push(option);
	
				if ($option.is(':selected')) {
					settings_element.items.push(value);
				}
			};
	
			var addGroup = function($optgroup) {
				var i, n, id, optgroup, $options;
	
				$optgroup = $($optgroup);
				id = $optgroup.attr('label');
	
				if (id) {
					optgroup = readData($optgroup) || {};
					optgroup[field_optgroup_label] = id;
					optgroup[field_optgroup_value] = id;
					settings_element.optgroups.push(optgroup);
				}
	
				$options = $('option', $optgroup);
				for (i = 0, n = $options.length; i < n; i++) {
					addOption($options[i], id);
				}
			};
	
			settings_element.maxItems = $input.attr('multiple') ? null : 1;
	
			$children = $input.children();
			for (i = 0, n = $children.length; i < n; i++) {
				tagName = $children[i].tagName.toLowerCase();
				if (tagName === 'optgroup') {
					addGroup($children[i]);
				} else if (tagName === 'option') {
					addOption($children[i]);
				}
			}
		}
Initializes selectize from a <select> element.

@param {object} $input
@param {object} settings_element