Creating Sortable Plugins

Sortable plugins are plugins that can be directly mounted to the Sortable class. They are a powerful way of modifying the default behaviour of Sortable beyond what simply using events alone allows. To mount your plugin to Sortable, it must pass a constructor function to the Sortable.mount function. This constructor function will be called (with the new keyword in front of it) whenever a Sortable instance with your plugin enabled is initialized. The constructor function will be called with the parameters sortable and el, which is the HTMLElement that the Sortable is being initialized on. This means that there will be a new instance of your plugin each time it is enabled in a Sortable.

Constructor Parameters

sortable: Sortable — The sortable that the plugin is being initialized on

el: HTMLElement — The element that the sortable is being initialized on

Static Properties

The constructor function passed to Sortable.mount may contain several static properties and methods. The following static properties may be defined:

pluginName: String (Required) The name of the option that the user will use in their sortable's options to enable the plugin. Should start with a lower case and be camel-cased. For example: 'multiDrag'. This is also the property name that the plugin's instance will be under in a sortable instance (ex. sortableInstance.multiDrag).

utils: Object — Object containing functions that will be added to the Sortable.utils default object on the Sortable class.

eventOptions(eventName: String, sortable: Sortable): Function — A function that is called whenever Sortable fires an event. This function should return an object to be combined with the event object that Sortable will emit.

initializeByDefault: Boolean Determines whether or not the plugin will always be initialized on every new Sortable instance. If this option is enabled, it does not mean that by default the plugin will be enabled on the Sortable - this must still be done in the options via the plugin's pluginName, or it can be enabled by default if your plugin specifies it's pluginName as a default option that is truthy. Since the plugin will already be initialized on every Sortable instance, it can also be enabled dynamically via sortableInstance.option('pluginName', true). It is a good idea to have this option set to false if the plugin modifies the behaviour of Sortable in such a way that enabling or disabling the plugin dynamically could cause it to break. Likewise, this option should be disabled if the plugin should only be instantiated on Sortables in which that plugin is enabled. This option defaults to true.

Plugin Options

Plugins may have custom options or override the defaults of certain options. In order to do this, there must be an options object on the initialized plugin. This can be set in the plugin's prototype, or during the initialization of the plugin (when the el is available). For example:

function myPlugin(el) {
	this.options = {
		color: el.style.backgroundColor
	};
}

Sortable.mount(myPlugin);

Plugin Events

Context

The events will be fired in the context of their own parent object, however the plugin instance's Sortable instance is available under this.sortable.

Event List

The following table contains details on the events that a plugin may handle in the prototype of the plugin's constructor function.

Event Name	Description	Cancelable?	Cancel Behaviour	Event Type	Custom Event Object Properties
delayStart	If the sortable has the delay option set, fired when the delay starts	Yes	Cancels sorting	Normal	None
delayEnded	Fired when the delay ends, even if there is no delay	Yes	Cancels sorting	Normal	None
setupClone	Fired when Sortable clones the dragged element	Yes	Cancels normal clone setup	Normal	None
dragStart	Fired when the dragging is first started	Yes	Cancels sorting	Normal	None
clone	Fired when the clone is inserted into the DOM (if removeCloneOnHide: false). Tick after dragStart.	Yes	Cancels normal clone insertion & hiding	Normal	None
dragStarted	Fired tick after dragStart	No	-	Normal	None
dragOver	Fired when the user drags over a sortable	Yes	Cancels normal dragover behaviour	DragOver	None
dragOverValid	Fired when the user drags over a sortable that the dragged item can be inserted into	Yes	Cancels normal valid dragover behaviour	DragOver	None
revert	Fired when the dragged item is reverted to it's original position when entering it's sort:false root	Yes	Cancels normal reverting, but is still completed()	DragOver	None
dragOverCompleted	Fired when dragOver is completed (ie. bubbling is disabled). To check if inserted, use inserted even property.	No	-	DragOver	insertion: Boolean — Whether or not the dragged element was inserted
dragOverAnimationCapture	Fired right before the animation state is captured in dragOver	No	-	DragOver	None
dragOverAnimationComplete	Fired after the animation is completed after a dragOver insertion	No	-	DragOver	None
drop	Fired on drop	Yes	Cancels normal drop behavior	Normal	None
nulling	Fired when the plugin should preform cleanups, once all drop events have fired	No	-	Normal	None

Event Object

An object with the following properties is passed as an argument to each plugin event when it is fired.

Properties:

dragEl: HTMLElement — The element being dragged

parentEl: HTMLElement — The element that the dragged element is currently in

ghostEl: HTMLElement|undefined — If using fallback, the element dragged under the cursor (undefined until after dragStarted plugin event)

rootEl: HTMLElement — The element that the dragged element originated from

nextEl: HTMLElement — The original next sibling of dragEl before

cloneEl: HTMLElement|undefined — The clone element (undefined until after setupClone plugin event)

cloneHidden: Boolean — Whether or not the clone is hidden

dragStarted: Boolean — Boolean indicating whether or not the dragStart event has fired

putSortable: Sortable|undefined — The element that dragEl is dragged into from it's root, otherwise undefined

Methods:

cloneNowHidden() — Function to be called if the plugin has hidden the clone

cloneNowShown() — Function to be called if the plugin has shown the clone

dispatchSortableEvent(eventName: String) — Function that can be used to emit an event on the current sortable while sorting, with all usual event properties set

DragOverEvent Object

This event is passed to dragover events, and extends the normal event object.

Properties:

isOwner: Boolean — Whether or not the dragged over sortable currently contains the dragged element

axis: String — Direction of the dragged over sortable, 'vertical' or 'horizontal'

revert: Boolean — Whether or not the dragged element is being reverted to it's original position from another position

dragRect: DOMRect — DOMRect of the dragged element

targetRect: DOMRect — DOMRect of the target element

canSort: Boolean — Whether or not sorting is enabled in the dragged over sortable

fromSortable: Sortable — The sortable that the dragged element is coming from

activeSortable: Sortable — The active Sortable instance

target: HTMLElement — The sortable item that is being dragged over

Methods:

onMove(target: HTMLElement, after: Boolean): Boolean|Number — Calls the onMove function the user specified in the options

changed() — Fires the onChange event with event properties preconfigured

completed(insertion: Boolean) — Should be called when dragover has "completed", meaning bubbling should be stopped. If insertion is true, Sortable will treat it as if the dragged element was inserted into the sortable, and hide/show clone, set ghost class, animate, etc.