/Easy-DnD

A drag and drop implementation for Vue.js 2 https://codesandbox.io/s/easy-dnd-demo-9mbij https://codesandbox.io/s/easy-dnd-demo-2-xnqbz

Primary LanguageVueMIT LicenseMIT

Vue-Easy-DnD (A HTML5 Drag-and-Drop Replacement)

Easy-DnD is a drag and drop implementation for Vue.js 2 that uses only standard mouse events instead of the HTML5 drag and drop API, which is impossible to work with. Think of it as a way to transfer data from some components to others using the mouse or support for a mouse assisted copy/cut - paste. It also allows for lists to be reordered by drag and drop.

Installation

Install via npm or yarn

# Use npm
npm install vue-easy-dnd --save

# Use yarn
yarn add vue-easy-dnd

 
 
 
 

FAQ

Does it support IE 11 ?

Yes with a polyfill for custom events such as https://www.npmjs.com/package/custom-event-polyfill

Does it support touch devices ?

Yes, including tap vibration prop on Drag component.

Does it support SSR ?

Yes.

Does it support keyboard events?

Yes. ESC key can be pressed to cancel the drag.

Does it support Vue 3?

Not at the moment. (This is a community development, so feel free to chip in!)

 
 
 
 

Events

All emit events carry the current state of the drag operation by means of the following properties :

  • type : the type of the data being transferred
  • data : the data being transferred
  • position : the current position of the mouse cursor
  • top : the foremost Drop component currently under the mouse cursor if any
  • previousTop : for dragenter and dragleave, the previous value of top if any
  • source : the Drag component where the drag originated
  • success : whether the drag completed successfully or not
  • native : the associated mouse event (or touch event). Can be mousedown/touchstart, mousemove/touchmove or mouseup/touchend.

 
 
 
 

Mixins

DragAwareMixin

A mixin is available to make components sensitive to drag operations. It adds the following computed to components that incorporate it, reflecting the current state of the drag :

  • dragInProgress : true if a drag operation is in progress, false otherwise
  • dragType : the type of the current drag operation
  • dragData : the data of the current drag operation
  • dragPosition : the current position of the mouse relative to the document
  • dragSource : the Drag component from which the drag operation originated
  • dragTop : the foremost Drop component under the mouse if any

The following demo displays information about the current drag operation when it is in progress :

https://codesandbox.io/s/example-5-j8qo9

demo  
 
 
 

Components

Drag

The drag component is meant to define an area from which data can be exported.

Events

Event Name Description
@dragstart Triggered when a drag operation starts
@dragend Triggered when a drag operation terminates (whether successfully or not)
@cut / @copy Triggered when a drag operation completes successfully on a Drop component that requires the data to be removed / copied (event name is dependant on the selected drop mode prop)

Props

Prop Name Type / Default Description
tag Any This prop can be used to customize the root of the template, Can refer to a custom Vue component, including its props, slots, scoped slots and listeners.
type String (null) Refer to Types section below
data Any Any data associated with this drag which will be sent with the emit event
drag-image-opacity Number (0.7) 0-1 defining the opacity of the drag image
disabled Boolean (false) Whether to temporarily disable dragging this component
go-back Boolean (false) If a drag is not successful, the drag image will animate back to where the drag originated (demo below)
handle String (undefined) A handle / grabber for this Drag component
delta Number (3px) A pixel-distance which defines whether a drag has begun
delay Number (0ms) The number of milliseconds of which the user must hold down the Drag element until it is recognised as a drag (useful for allowing scrolling on Touch devices without it automatically trying to drag the element) (0 = no delay)
drag-class String (null) A class to bind to the image / ghost being dragged around
vibration Number (0ms) Vibration feedback on supported mobile devices when a Drag event has started (0 = no feedback)
scrolling-edge-size Number (100px) When dragging this element to the edge of its bounding container/list, the pixel amount defines how close to the edge of the container it will automatically scroll up/down/left/right (0 = no scrolling on its bounding container)

Slots

Slot Name Description
default Default content to add at the end of the DropList. Make sure to define a key prop for each element directly inside this slot.
drag-image Refer to Drag Image section below

Demo

An example of go-back prop

https://codesandbox.io/s/example-1-l6p54

demo

CSS classes

Depending on the mode of the Drop component currently under the mouse cursor, the source Drag component is assigned the classes drag-mode-copy, drag-mode-cut and drag-mode-reordering.

If a drag is in progress, dnd-ghost will be bound to the ghost. The Drag component can also optionally accept an additional class (drag-class prop) to bind to the ghost. When using a DropList, the dnd-ghost class and drag-class prop will both NOT be bound if the drag-image slot is defined.

To prevent dragging your Draggable component from a child element, you may attach the class dnd-no-drag to the child. That way the entire element remains draggable, whereas specific sub-children can have dragging from themselves disabled.

Types

A drag operation may have a type. The type is a data structure (can be a simple string) that defines the kind of data being transfered. The type of a drag operation is defined by the Drag component that initiates it using the type prop.

A Drop component is said to participate in a drag operation if it accepts its type (the default is to accept any type). The type(s) a Drop component accepts can be defined by mean of the accepts-type prop (can be a string, an array of strings or a function that takes the type as parameter and returns a boolean).

The following demo illustrates the use of types. There are two types in use : 'string' and 'number'. The Drag components that contain '1' and '2' are of type 'number', the ones containing 'a' and 'b' are of type 'string'. The two Drop components on the left accept numbers, the ones on the right accept strings. When you drag a number/string (respectively), only Drop components that accept numbers/strings (respectively) react (i.e. drag images, CSS classes, cursors are applied). The other ones are left alone.

https://codesandbox.io/s/example-3-g7io8

demo

Drag image

During the drag, an image may move along the mouse cursor. Easy-DnD makes it so that this image is always on top of everything else.

Drag components provide the drag-image slot that can be used to set the default image displayed during the drag operation :

  • if the slot isn't defined, the image is a clone of the Drag component.
  • if the slot is defined and empty, there is no image.
  • if the slot is not empty, a clone of its content is used.

Drop and DropList components provide the drag-image slot (props : data and type) that can be used to set the image to be displayed when the mouse is over them, if they participates in the current drag operation (i.e. accept its type) :

  • if the slot isn't defined, the default image set by the Drag component is used.
  • if the slot is defined and empty, there is no image.
  • if the slot is not empty, a clone of its content is used.

DropList components additionaly provide the reordering-drag-image slot (prop : item subject to reordering) that behaves the same way as drag-image but controls the drag image to be displayed during list reordering.

The position of the drag image relative to the mouse cursor can be controlled by CSS using the transform property.

The following demo illustrate the use of custom drag images, nested Drop components and a mask :

https://codesandbox.io/s/example-4-6h8zy

demo

 
 
 
 

Drop

The drop component is meant to define an area into which data can be imported. Drop components can be nested forming hierarchies of arbitrary depth.

Events

Event Name Description
@dragenter Triggered when the mouse enters a Drop component
@dragleave Triggered when the mouse leaves a Drop component
@dragover Triggered when the mouse moves over a Drop component
@dragend Triggered when a drag event is finished while a Drag element is hovered over this Drop component. (Including if ESC is pressed while a Drag element was over the top of this Drop component)
@drop Triggered when a drop operation completes on a Drop component

Props

Prop Name Type / Default Description
tag Any This prop can be used to customize the root of the template, Can refer to a custom Vue component, including its props, slots, scoped slots and listeners.
accepts-type String / Array Refer to Types section above
accepts-data Any Refer to Restricting droppable data section below
drag-image-opacity Number (0.7) 0-1 defining the opacity of the drag image when dragging over this drop component
mode String (copy) Refer to Modes section below

CSS classes

During a drag operation, the Drop components on the page are assigned several CSS classes :

  • for all Drop components : type-allowed if the Drop component accepts the type of the drag operation, type-forbidden otherwise
  • for the Drop components that participate in the drag operation (i.e. accepts its type) :
    • drop-in when the mouse is over one that is foremost at the current mouse position (remember Drop components can be nested), drop-out otherwise
    • drop-allowed when the Drop component accepts the data and the source of the drag accepts its mode, drop-forbidden otherwise

Modes

A drag and drop can occur in several possible modes, depending on its effect on the origin of the drag :

  • copy (the default) : if the source of the drag is unaffected by the drag operation,
  • cut : if the source of the drag is to be removed when the drag operation completes.

Drop components must declare what mode must be triggered when data is dropped into them using the mode property.

When a drag operation completes on a Drop component that declares the cut (respectively copy) mode, a cut (respectively copy) event is emitted on the Drag component from which the drag operation originated. This gives the opportunity to the surroundings of the Drag component to react to the drop that just happened, for example by removing the data that has been dropped in case of the cut event.

If a drag operation originates from a Drag components that doesn't declare a listener for the cut event, then dropping is forbidden on a Drop component that declares the cut mode.

The following demo illustrates modes in action :

https://codesandbox.io/s/example-2-r8n1k

demo

Restricting droppable data

Drop components can restrict the data they accept by mean of the accepts-data prop (a function that takes the data and type as parameter and returns a boolean).

The following demo defines five Drag components that can be dragged into three Drop components, one that accepts even numbers, one that accepts odd numbers and one that accepts any number but removes them once the drag is complete.

https://codesandbox.io/s/easy-dnd-demo-fo078

demo

 
 
 
 

DropMask

The drop-mask component is meant to create an island insensitive to drag and rop on top of a Drop component.

Props

Prop Name Type / Default Description
tag Any This prop can be used to customize the root of the template, Can refer to a custom Vue component, including its props, slots, scoped slots and listeners.

Demo

https://codesandbox.io/s/example-1-gvwsw

demo

 
 
 
 

DropList

The drop-list component is a special kind of drop component that displays a list of items that support dragging into and reordering.

Events

Event Name Description
(Refer to Drop component) DropList components also emit all events by Drop components
@insert Triggered when data is to be inserted into the list (properties : type, data and index). If no listener is provided for this event, the list cannot be inserted into.
@reorder Triggers when data needs to be reordered (properties : from, to and apply - apply is a function that applies the required reordering to the given array). If no listener is provided for this event, the list cannot be reordered.

Props

Prop Name Type / Default Description
(Refer to Drop component) DropList components also inherit all props from Drop components
tag Any This prop can be used to customize the root of the template, just like it can be with drop components, but it can only refer to an HTML element, not a Vue component (this is a restriction of Vue transition-groups - there is nothing I can do about it). However, when the no-animations prop is set to true, this restriction is lifted, and you can use any Vue component.
items Any (Array) Array of data to use on this DropList
row Boolean (null) Defining the direction of the DropList as horizontally-flowing. (Necessary for Nested DropLists) (Refer to Nested Droplists section below)
column Boolean (null) Defining the direction of the DropList as vertically-flowing. (Necessary for Nested DropLists) (Refer to Nested Droplists section below)
no-animations Boolean (false) Disable animations on the DropList (necessary if the tag is a custom Vue component)
scrolling-edge-size Number (undefinedpx) When dragging a Drag component to the edge of this DropList, the pixel amount defines how close to the edge of the DropList a scroll will be triggered up/down/left/right (0 = no scrolling on this DropList). Undefined default value means that this DropList will use whatever scrolling-edge-size is defined on the Drag component.

Slots

Slot Name Description
default Default content to add at the end of the DropList. Make sure to define a key prop for each element directly inside this slot.
item Used to render each list item. It has three properties, item , index and reorder. Reorder is true when the item is the one subject to reordering. Don't forget to provide a key for the content of this slot !!
feedback Used to render a placeholder to show the position where the new item would be inserted if the drag operation ended at the current mouse position. It has two properties : type and data. Don't forget to provide a key for the content of this slot !!
reordering-drag-image Defines the drag image to be used when reordering the list (Refer to Drag Image section above).
reordering-feedback Used to control the feedback used during reordering
* If this slot isn't defined, then the items switch positions during reordering to display in real time the order that will be achieved if the drag terminates at the current position
* If this slot is defined, then its content is inserted into the list to display the new location of the item being dragged (for an example of this, see nested drop lists)
empty Defined content to display if the list is empty and not being dragged into. Make sure to define a key prop for each element directly inside this slot.

Demo

https://codesandbox.io/s/droplist-ozs8b

demo

Nested DropLists

Drop lists can be nested providing the following conditions are satisfied :

  • the row or column props must be defined to inform the drop list components of the direction the items are lining up (mandatory)
  • for lists that support reordering, the reordering-feedback slot must be defined (advisable)
  • both the feedback and reordering-feedback slots must take no space in the layout (for example, flex: 0 0 0; align-self: strech; outline: 1px solid blue;) (advisable)

Example :

https://codesandbox.io/s/nested-drop-lists-nw605

demo

 
 
 
 

Advanced Demos

These demos are meant to be pretty and reflect real life examples.

The following demo features list reordering, drag and drop between two lists, custom drag images and custom feedback when inserting new items. It uses Vuetify components.

https://codesandbox.io/s/easy-dnd-demo-9mbij

demo

The following demo features drag and drop between a table and a list, custom drag images and a custom style for drop areas when the drop is allowed. It uses Vuetify components.

https://codesandbox.io/s/easy-dnd-demo-2-xnqbz

demo

The following demo features nested drop lists and a custom drag image. It is a tool to design dashboards by WYSIWYG. New widgets can be dragged into the dashboard from the palette on the left and widgets can be moved around by drag and drop.

demo