` in the above example), and the (optional) second one being the nested list. The container element has to be set as the 'toleranceElement' in the options, and this, or one of its children, as the 'handle'. Also, the default list type is `

tabSize: How far right or left (in pixels) the item has to travel in order to be nested or to be sent outside its current list. Default: 20
disableNesting: The class name of the items that will not accept nested lists. Default: ui-nestedSortable-no-nesting
errorClass: The class given to the placeholder in case of error. Default: ui-nestedSortable-error
listType: The list type used (ordered or unordered). Default: ol
maxLevels: The maximum depth of nested items the list can accept. If set to '0' the levels are unlimited. Default: 0
protectRoot: Wether to protect the root level (i.e. root items can be sorted but not nested, sub-items cannot become root items). Default: false
rootID: The id given to the root element (set this to whatever suits your data structure). Default: null
rtl: Set this to true if you have a right-to-left page. Default: false
isAllowed (function): You can specify a custom function to verify if a drop location is allowed. Default: function(item, parent) { return true; }

serialize

Serializes the nested list into a string like setName[item1Id]=parentId&setName[item2Id]=parentId, reading from each item's id formatted as 'setName_itemId' (where itemId is a number). It accepts the same options as the original Sortable method (key, attribute and expression).

toArray

Builds an array where each element is in the form:

setName[n] =>
{
	'item_id': itemId,
	'parent_id': parentId,
	'depth': depth,
	'left': left,
	'right': right,
}

It accepts the same options as the original Sortable method (attribute and expression) plus the custom startDepthCount, that sets the starting depth number (default is 0).

toHierarchy

Builds a hierarchical object in the form:

'0' ...
	'id' => itemId
'1' ...
	'id' => itemId
	'children' ...
		'0' ...
			'id' => itemId
		'1' ...
			'id' => itemId
'2' ...
	'id' => itemId

Similarly to toArray, it accepts attribute and expression options.