Beautiful, accessible drag and drop for lists with React.js
See how beautiful it is for yourself - have a play with the examples!
- beautiful, natural movement of items
- clean and powerful api which is simple to get started with
- unopinionated styling
- no creation of additional wrapper dom nodes - flexbox and focus management friendly!
- plays well with existing interactive nodes such as anchors
- state driven dragging - which allows for dragging from many input types, including programatic dragging. Currently only mouse and keyboard dragging are supported
There are a lot of libraries out there that allow for drag and drop interactions within React. Most notable of these is the amazing react-dnd
. It does an incredible job at providing a great set of drag and drop primitives which work especially well with the wildly inconsistent html5 drag and drop feature. react-beautiful-dnd
is a higher level abstraction specifically built for vertical and horizontal lists. Within that subset of functionality react-beautiful-dnd
offers a powerful, natural and beautiful drag and drop experience. However, it does not provide the breadth of functionality offered by react-dnd. So this library might not be for you depending on what your use case is.
This library is still fairly new and so there is a relatively small feature set. Be patient! Things will be moving rather quickly!
- dragging an item within a single vertical list
- multiple independent lists on the one page
- mouse 🐭 and keyboard 🎹 dragging
- flexible height items (the draggable items can have different heights)
- custom drag handle (you can drag a whole item by just a part of it)
- the vertical list can be a scroll container (without a scrollable parent) or be the child of a scroll container (that also does not have a scrollable parent)
- Dragging within a horizontal list
- Moving items between vertical lists (until this lands conditional dropping will not be available)
- Moving items between horizontal lists
- Moving a
Draggable
from a vertical list to a horizontal list - Dragging multiple items at once
- Touch support
- Automatically disabling animations when the frame rate drops below a threshold.
- A mechanism to programatically perform dragging without user input
- And lots more!
This is a simple reorderable list. You can play with it on webpackbin
import React, { Component } from 'react';
import ReactDOM from 'react-dom';
import { DragDropContext, Droppable, Draggable } from 'react-beautiful-dnd';
// fake data generator
const getItems = count =>
Array.from({ length: count }, (v, k) => k).map(k => ({
id: `item-${k}`,
content: `item ${k}`,
}));
// a little function to help us with reordering the result
const reorder = (list, startIndex, endIndex) => {
const result = Array.from(list);
const [removed] = result.splice(startIndex, 1);
result.splice(endIndex, 0, removed);
return result;
};
// using some little inline style helpers to make the app look okay
const grid = 8;
const getItemStyle = (draggableStyle, isDragging) => ({
// some basic styles to make the items look a bit nicer
userSelect: 'none',
padding: grid * 2,
marginBottom: grid,
// change background colour if dragging
background: isDragging ? 'lightgreen' : 'grey',
// styles we need to apply on draggables
...draggableStyle,
});
const getListStyle = isDraggingOver => ({
background: isDraggingOver ? 'lightblue' : 'lightgrey',
padding: grid,
width: 250,
});
class App extends Component {
constructor(props) {
super(props);
this.state = {
items: getItems(10),
};
this.onDragEnd = this.onDragEnd.bind(this);
}
onDragEnd(result) {
// dropped outside the list
if (!result.destination) {
return;
}
const items = reorder(
this.state.items,
result.source.index,
result.destination.index
);
this.setState({
items,
});
}
// Normally you would want to split things out into separate components.
// But in this example everything is just done in one place for simplicity
render() {
return (
<DragDropContext onDragEnd={this.onDragEnd}>
<Droppable droppableId="droppable">
{(provided, snapshot) => (
<div
ref={provided.innerRef}
style={getListStyle(snapshot.isDraggingOver)}
>
{this.state.items.map(item => (
<Draggable key={item.id} draggableId={item.id}>
{(provided, snapshot) => (
<div>
<div
ref={provided.innerRef}
style={getItemStyle(
provided.draggableStyle,
snapshot.isDragging
)}
{...provided.dragHandleProps}
>
{item.content}
</div>
{provided.placeholder}
</div>
)}
</Draggable>
))}
</div>
)}
</Droppable>
</DragDropContext>
);
}
}
// Put the thing into the DOM!
ReactDOM.render(<App />, document.getElementById('app'));
The core design idea of react-beautiful-dnd
is physicality: we want users to feel like they are moving physical objects around
It is a fairly standard drag and drop pattern for things to disappear and reappear in response to the users drag. For a more natural drag we animate the movement of items as they need to move out of the way while dragging to more clearly show a drags effect. We also animate the drop of an item so that it animates into its new home position. At no point is an item instantly moved anywhere — regardless of whether it is dragging or not.
It is quite common for drag and drop interactions to be based on the position that user started the drag from.
In react-beautiful-dnd
a dragging items impact is based on its centre of gravity — regardless of where a user grabs an item from. A dragging items impact follows similar rules to a set of scales ⚖️. Here are some rules that are followed to allow for a natural drag experience even with items of flexible height:
- A list is dragged over when the centre position of a dragging item goes over one of the boundaries of the list
- A resting drag item will move out of the way of a dragging item when the centre position of the dragging item goes over the edge of the resting item. Put another way: once the centre position of an item (A) goes over the edge of another item (B), B moves out of the way.
Drop shadows are useful in an environment where items and their destinations snap around. However, with react-beautiful-dnd
it should be obvious where things will be dropping based on the movement of items. This might be changed in the future - but the experiment is to see how far we can get without any of these affordances.
react-beautiful-dnd
works really hard to avoid as many periods of non-interactivity as possible. The user should feel like they are in control of the interface and not waiting for an animation to finish before they can continue to interact with the interface. However, there is a balance that needs to be made between correctness and power in order to make everybody's lives more sane. Here are the only situations where some things are not interactive:
- From when a user cancels a drag to when the drop animation completes. On cancel there are lots of things moving back to where they should be. If you grab an item in a location that is not its true home then the following drag will be incorrect.
- Starting a drag on an item that is animating its own drop. For simplicity this is the case - it is actually quite hard to grab something while it is animating home. It could be coded around - but it seems like an edge case that would add a lot of complexity.
Keep in mind that these periods of inactivity may not always exist.
For now, the library does not support drag axis locking (aka drag rails). This is where the user is restricted to only dragging along one axis. The current thinking is this breaks the physical metaphore we are going for and sends a message to the user that they are interacting with a piece of software rather than moving physical objects around. It is possible to ensure that a user can only drop in a single list by using props type
and isDropEnabled
. You can also do some visual treatment to the list onDragStart
to show the user that this is the only place they can interact with.
When a user presses the mouse down on an element, we cannot determine if the user was clicking or dragging. Also, sometimes when a user clicks they can move the cursor slightly — a sloppy click. So we only start a drag once the user has moved beyond a certain distance with the mouse down (the drag threshold) — more than they would if they where just making a sloppy click. If the drag threshold is not exceeded then the user interaction behaves just like a regular click. If the drag threshold is exceeded then the interaction will be classified as a drag and the standard click action will not occur.
This allows consumers to wrap interactive elements such as an anchor and have it be both a standard anchor as well as a draggable item in a natural way.
(🐱🎁 is a schrodinger's cat joke)
react-beautiful-dnd
does not create any wrapper elements. This means that it will not impact the usual tab flow of a document. For example, if you are wrapping an anchor tag then the user will tab to the anchor directly and not an element surrounding the anchor. Whatever element you wrap will be given a tab-index
to ensure that users can tab to the element to perform keyboard dragging.
Traditionally drag and drop interactions have been exclusively a mouse or touch interaction. This library ships with support for drag and drop interactions using only a keyboard. This enables power users to drive their experience entirely from the keyboard. As well as opening up these experiences to users who would have been excluded previously.
In addition to supporting keyboard, we have also audited how the keyboard shortcuts interact with standard browser keyboard interactions. When the user is not dragging they can use their keyboard as they normally would. While dragging we override and disable certain browser shortcuts (such as tab
) to ensure a fluid experience for the user.
Currently the keyboard handling is hard coded. This might be changed in the future to become customisable. Here is the existing keyboard mapping:
- tab tab ↹ - standard browser tabbing will navigate through the
Droppable
's. The library does not do anything fancy withtab
while users are selecting. Once a drag has started,tab
is blocked for the duration of the drag. - spacebar space - lift a focused
Draggable
. Also, drop a draggingDraggable
where the drag was started with aspacebar
. - Up arrow ↑ - move a
Draggable
that is dragging up on a vertical list - Down arrow ↓ - move a
Draggable
that is dragging down on a vertical list - Escape esc - cancel an existing drag - regardless of whether the user is dragging with the keyboard or mouse.
There is current limitation of keyboard dragging: the drag will cancel if the user scrolls the window. This could be worked around but for now it is the simpliest initial approach.
With things moving a lot it would be easy for the user to become distracted by the animations or for them to get in the way. We have tweaked the various animations to ensure the right balance of guidance, performance and interactivity.
When you drop a dragging item its movement is based on physics (thanks react-motion
). This results in the drop feeling more weighted and physical.
Items that are moving out of the way of a dragging item do so with a CSS transition rather than physics. This is to maximise performance by allowing the GPU to handle the movement. The CSS animation curve has been designed to communicate getting out of the way.
How it is composed:
- A warm up period to mimic a natural response time
- A small phase to quickly move out of the way
- A long tail so that people can read any text that is being animated in the second half of the animation
animation curve used when moving out of the way
# yarn
yarn add react-beautiful-dnd
# npm
npm install react-beautiful-dnd --save
So how do you use the library?
In order to use drag and drop, you need to have the part of your React
tree that you want to be able to use drag and drop in wrapped in a DragDropContext
. It is advised to just wrap your entire application in a DragDropContext
. Having nested DragDropContext
's is not supported. You will be able to achieve your desired conditional dragging and dropping using the props of Droppable
and Draggable
. You can think of DragDropContext
as having a similar purpose to the react-redux Provider component
type Hooks = {|
onDragStart?: (id: DraggableId, location: DraggableLocation) => void,
onDragEnd: (result: DropResult) => void,
|}
type Props = Hooks & {|
children?: ReactElement,
|}
import { DragDropContext } from 'react-beautiful-dnd';
class App extends React.Component {
onDragStart = () => {
/*...*/
};
onDragEnd = () => {
/*...*/
};
render() {
return (
<DragDropContext
onDragStart={this.onDragStart}
onDragEnd={this.onDragEnd}
>
<div>Hello world</div>
</DragDropContext>
);
}
}
These are top level application events that you can use to perform your own state updates.
This function will get notified when a drag starts. You are provided with the following details:
id
: the id of theDraggable
that is now dragginglocation
: the location (droppableId
andindex
) of where the dragging item has started within aDroppable
.
This function is optional and therefore does not need to be provided. It is highly recommended that you use this function to block updates to all Draggable
and Droppable
components during a drag. (See Best hooks
practices)
Type information
onDragStart?: (id: DraggableId, location: DraggableLocation) => void
// supporting types
type Id = string;
type DroppableId: Id;
type DraggableId: Id;
type DraggableLocation = {|
droppableId: DroppableId,
// the position of the draggable within a droppable
index: number
|};
This function is extremely important and has an critical role to play in the application lifecycle. This function must result in the synchronous reordering of a list of Draggables
It is provided with all the information about a drag:
result.draggableId
: the id of theDraggable
was dragging.result.source
: the location that theDraggable
started in.result.destination
: the location that theDraggable
finished in. Thedestination
will benull
if the user dropped into no position (such as outside any list) or if they dropped theDraggable
back into the same position that it started in.
Because this library does not control your state, it is up to you to synchronously reorder your lists based on the result
.
Here is what you need to do:
- if the
destination
isnull
: all done! - if
source.droppableId
equalsdestination.droppableId
you need to remove the item from your list and insert it at the correct position. - if
source.droppableId
does not equaldestination.droppable
you need to theDraggable
from thesource.droppableId
list and add it into the correct position of thedestination.droppableId
list.
onDragEnd: (result: DropResult) => void
// supporting types
type DropResult = {|
draggableId: DraggableId,
source: DraggableLocation,
// may not have any destination (drag to nowhere)
destination: ?DraggableLocation
|}
type Id = string;
type DroppableId: Id;
type DraggableId: Id;
type DraggableLocation = {|
droppableId: DroppableId,
// the position of the droppable within a droppable
index: number
|};
Block updates during a drag
It is highly recommended that while a user is dragging that you block any state updates that might impact the amount of Draggable
s and Droppable
s, or their dimensions. Please listen to onDragStart
and block updates to the Draggable
s and Droppable
s until you receive at onDragEnd
.
When the user starts dragging we take a snapshot of all of the dimensions of the applicable Draggable
and Droppable
nodes. If these change during a drag we will not know about it.
Here are a few poor user experiences that can occur if you change things during a drag:
- If you increase the amount of nodes the library will not know about them and they will not be moved when the user would expect them to be.
- If you decrease the amount of nodes then there might be gaps and unexpected movements in your lists.
- If you change the dimensions of any node, it can cause the changed node as well as others to move at incorrect times.
- If you remove the node that the user is dragging the drag will instantly end
- If you change the dimension of the dragging node then other things will not move out of the way at the correct time.
onDragStart
and onDragEnd
pairing
We try very hard to ensure that each onDragStart
event is paired with a single onDragEnd
event. However, there maybe a rouge situation where this is not the case. If that occurs - it is a bug. Currently there is no mechanism to tell the library to cancel a current drag externally.
Style
During a drag it is recommended that you add two styles to the body:
user-select: none;
andcursor: grab;
(or whatever cursor you want to use while dragging)
user-select: none;
prevents the user drag from selecting text on the page as they drag.
cursor: [your desired cursor];
is needed because we apply pointer-events: none;
to the dragging item. This prevents you setting your own cursor style on the Draggable directly based on snapshot.isDragging
(see Draggable
).
Dynamic hooks
Your hook functions will only be captured once at start up. Please do not change the function after that. If there is a valid use case for this then dynamic hooks could be supported. However, at this time it is not.
Droppable
components can be dropped on by a Draggable
. They also contain Draggable
s. A Draggable
must be contained within a Droppable
.
import { Droppable } from 'react-beautiful-dnd';
<Droppable droppableId="droppable-1" type="PERSON">
{(provided, snapshot) => (
<div
ref={provided.innerRef}
style={{ backgroundColor: snapshot.isDraggingOver ? 'blue' : 'grey' }}
>
I am a droppable!
</div>
)}
</Droppable>;
droppableId
: A requiredDroppableId(string)
that uniquely identifies the droppable for the application. Please do not change this prop - especially during a drag.type
: An optionalTypeId(string)
that can be used to simply accept a class ofDraggable
. For example, if you use the typePERSON
then it will only allowDraggable
s of typePERSON
to be dropped on itself.Draggable
s of typeTASK
would not be able to be dropped on aDroppable
with typePERSON
. If notype
is provided, it will be set to'DEFAULT'
. Currently thetype
of theDraggable
s within aDroppable
must be the same. This restriction might be loosened in the future if there is a valid use case.isDropDisabled
: An optional flag to control whether or not dropping is currently allowed on theDroppable
. You can use this to implement your own conditional dropping logic. It will default tofalse
.
The React
children of a Droppable
must be a function that returns a ReactElement
.
<Droppable droppableId="droppable-1">
{(provided, snapshot) => ({
/*...*/
})}
</Droppable>;
The function is provided with two arguments:
1. provided: (Provided)
type Provided = {|
innerRef: (HTMLElement) => void,
|}
In order for the droppable to function correctly, you must bind the provided.innerRef
to the highest possible DOM node in the ReactElement
. We do this in order to avoid needing to use ReactDOM
to look up your DOM node.
<Droppable droppableId="droppable-1">
{(provided, snapshot) => <div ref={provided.innerRef}>Good to go</div>}
</Droppable>;
2. snapshot: (StateSnapshot)
type StateSnapshot = {|
isDraggingOver: boolean,
|};
The children
function is also provided with a small amount of state relating to the current drag state. This can be optionally used to enhance your component. A common use case is changing the appearance of a Droppable
while it is being dragged over.
<Droppable droppableId="droppable-1">
{(provided, snapshot) => (
<div
ref={provided.innerRef}
style={{ backgroundColor: snapshot.isDraggingOver ? 'blue' : 'grey' }}
>
I am a droppable!
</div>
)}
</Droppable>;
Keep in mind that this is not supported at this time. In this current initial version we only support reordering within a single list.
Droppable
s can only be dropped on byDraggable
s who share the sametype
. This is a simple way of allowing conditional dropping. If you do not provide atype
for theDroppable
then it will only acceptDraggable
s which also have the default type.Draggable
s andDroppable
s both will have theirtypes
set to'DEFAULT'
when none is provided. There is currently no way to set multipletypes
, or atype
wildcard that will acceptDraggable
s of multiple any types. This could be added if there is a valid use case.- Using the
isDropDisabled
prop you can conditionally allow dropping. This allows you to do arbitrarily complex conditional transitions. This will only be considered if thetype
of theDroppable
matches thetype
of the currently draggingDraggable
. - You can disable dropping on a
Droppable
altogether by always settingisDropDisabled
to false. You can do this to create a list that is never able to be dropped on, but containsDraggable
s. - Technically you do not need to use
type
and do all of your conditional drop logic with theisDropDisabled
function. Thetype
parameter is a convenient shortcut for a common use case.
This library supports dragging within scroll containers (DOM elements that have overflow: auto;
or overflow: scroll;
). The only supported use cases are:
- The
Droppable
can itself be a scroll container with no scrollable parents - The
Droppable
has one scrollable parent
Auto scrolling is not provided
Currently auto scrolling of scroll containers is not part of this library. Auto scrolling is where the container automatically scrolls to make room for the dragging item as you drag near the edge of a scroll container. You are welcome to build your own auto scrolling list, or if you would you really like it as part of this library we could provide a auto scrolling Droppable
.
Users will be able to scroll a scroll container while dragging by using their trackpad or mouse wheel.
Keyboard dragging limitation
Getting keyboard dragging to work with scroll containers is quite difficult. Currently there is a limitation: you cannot drag with a keyboard beyond the visible edge of a scroll container. This limitation could be removed if we introduced auto scrolling.
Draggable
components can be dragged around and dropped onto Droppable
s. A Draggable
must always be contained within a Droppable
. It is possible to reorder a Draggable
within its home Droppable
or move to another Droppable
. It is possible because a Droppable
is free to control what it allows to be dropped on it.
Note: moving between
Droppable
s is currently not supported in the initial version.
import { Draggable } from 'react-beautiful-dnd';
<Draggable draggableId="draggable-1" type="PERSON">
{(provided, snapshot) => (
<div>
<div
ref={provided.innerRef}
style={provided.draggableStyle}
{...provided.dragHandleProps}
>
<h4>My draggable</h4>
</div>
{provided.placeholder}
</div>
)}
</Draggable>;
Note: when the library moves to React 16 this will be cleaned up a little bit as we will be able to return the placeholder as a sibling to your child function without you needing to create a wrapping element
draggableId
: A requiredDraggableId(string)
that uniquely identifies theDraggable
for the application. Please do not change this prop - especially during a drag.type
: An optional type (TypeId(string)
) of theDraggable
. This is used to control whatDroppable
s theDraggable
is permitted to drop on.Draggable
s can only drop onDroppable
s that share the sametype
. If notype
is provided, it will be set to'DEFAULT'
. Currently thetype
of aDraggable
must be the same as its containerDroppable
. This restriction might be loosened in the future if there is a valid use case.isDragDisabled
: An optional flag to control whether or not theDraggable
is permitted to drag. You can use this to implement your own conditional drag logic. It will default tofalse
.
The React
children of a Draggable
must be a function that returns a ReactElement
.
<Draggable draggableId="draggable-1">
{(provided, snapshot) => (
<div>
<div
ref={provided.innerRef}
style={provided.draggableStyle}
{...provided.dragHandleProps}
>
Drag me!
</div>
{provided.placeholder}
</div>
)}
</Draggable>;
The function is provided with two arguments:
1. provided: (Provided)
type Provided = {|
innerRef: (HTMLElement) => void,
draggableStyle: ?DraggableStyle,
dragHandleProps: ?DragHandleProvided,
placeholder: ?ReactElement,
|}
Everything within the provided object must be applied for the Draggable
to function correctly.
provided.innerRef (innerRef: (HTMLElement) => void)
: In order for theDroppable
to function correctly, you must bind theinnerRef
function to theReactElement
that you want to be considered theDraggable
node. We do this in order to avoid needing to useReactDOM
to look up your DOM node.
<Draggable draggableId="draggable-1">
{(provided, snapshot) => <div ref={provided.innerRef}>Drag me!</div>}
</Draggable>;
Type information
innerRef: (HTMLElement) => void
provided.draggableStyle (?DraggableStyle)
: This is anObject
ornull
that contains an a number of styles that needs to be applied to theDraggable
. This needs to be applied to the same node that you applyprovided.innerRef
to. This controls the movement of the draggable when it is dragging and not dragging. You are welcome to add your own styles to this object – but please do not remove or replace any of the properties.
Ownership
It is a contract of this library that it owns the positioning logic of the dragging element. This includes properties such as top
, right
, bottom
, left
and transform
. The library may change how it positions things and what properties it uses without performing a major version bump. It is also recommended that you do not apply your own transition
property to the dragging element.
Warning: position: fixed
react-beautiful-dnd
uses position: fixed
to position the dragging element. This is quite robust and allows for you to have position: relative | absolute | fixed
parents. However, unfortunately position:fixed
is impacted by transform
(such as transform: rotate(10deg);
). This means that if you have a transform: *
on one of the parents of a Draggable
then the positioning logic will be incorrect while dragging. Lame! For most consumers this will not be an issue. We may look into creating a portal solution where we attach the dragging element to the body rather than leave it in place. However, leaving it in place is a really nice experience for everyone. For now we will leave it as is, but feel free to raise an issue if you this is important to you.
Usage of draggableStyle
<Draggable draggableId="draggable-1">
{(provided, snapshot) => (
<div>
<div ref={provided.innerRef} style={provided.draggableStyle}>
Drag me!
</div>
</div>
)}
</Draggable>;
Extending with your own styles
<Draggable draggable="draggable-1">
{(provided, snapshot) => {
const style = {
...provided.draggableStyle,
backgroundColor: snapshot.isDragging ? 'blue' : 'white',
fontSize: 18,
};
return (
<div>
<div ref={provided.innerRef} style={style}>
Drag me!
</div>
</div>
);
}}
</Draggable>;
Type information
type DraggableStyle = DraggingStyle | NotDraggingStyle;
type DraggingStyle = {|
pointerEvents: 'none',
position: 'fixed',
width: number,
height: number,
boxSizing: 'border-box',
top: number,
left: number,
margin: 0,
transform: ?string,
zIndex: ZIndex,
|}
type NotDraggingStyle = {|
transition: ?string,
transform: ?string,
pointerEvents: 'none' | 'auto',
|};
provided.placeholder (?ReactElement)
TheDraggable
element hasposition: fixed
applied to it while it is dragging. The role of theplaceholder
is to sit in the place that theDraggable
was during a drag. It is needed to stop theDroppable
list from collapsing when you drag. It is advised to render it as a sibling to theDraggable
node. When the library moves toReact
16 theplaceholder
will be removed from api.
<Draggable draggableId="draggable-1">
{(provided, snapshot) => (
<div>
<div ref={provided.innerRef} style={provided.draggableStyle}>
Drag me!
</div>
{/* Always render me - I will be null if not required */}
{provided.placeholder}
</div>
)}
</Draggable>;
provided.dragHandleProps (?DragHandleProps)
everyDraggable
has a drag handle. This is what is used to drag the wholeDraggable
. Often this will be the same node as theDraggable
, but sometimes it can be a child of theDraggable
.DragHandleProps
need to be applied to the node that you want to be the drag handle. This is a number of props that need to be applied to theDraggable
node. The simpliest approach is to spread the props onto the draggable node ({...provided.dragHandleProps}
). However, you are also welcome to monkey patch these props if you also need to respond to them. DragHandleProps will benull
whenisDragDisabled
is set totrue
.
Type information
type DragHandleProps = {|
onMouseDown: (event: MouseEvent) => void,
onKeyDown: (event: KeyboardEvent) => void,
onClick: (event: MouseEvent) => void,
tabIndex: number,
'aria-grabbed': boolean,
draggable: boolean,
onDragStart: () => void,
onDrop: () => void,
|};
Standard example
<Draggable draggableId="draggable-1">
{(provided, snapshot) => (
<div>
<div
ref={provided.innerRef}
style={provided.draggableStyle}
{...provided.dragHandleProps}
>
Drag me!
</div>
{provided.placeholder}
</div>
)}
</Draggable>;
Custom drag handle
<Draggable draggableId="draggable-1">
{(provided, snapshot) => (
<div>
<div ref={provided.innerRef} style={provided.draggableStyle}>
<h2>Hello there</h2>
<div {...provided.dragHandleProps}>Drag handle</div>
</div>
{provided.placeholder}
</div>
)}
</Draggable>;
Monkey patching
If you want to also use one of the props in
DragHandleProps
const myOnClick = event => console.log('clicked on', event.target);
<Draggable draggableId="draggable-1">
{(provided, snapshot) => {
const onClick = (() => {
// dragHandleProps might be null
if (!provided.dragHandleProps) {
return myOnClick;
}
// creating a new onClick function that calls my onClick
// event as well as the provided one.
return event => {
provided.dragHandleProps.onClick(event);
// You may want to check if event.defaultPrevented
// is true and optionally fire your handler
myOnClick(event);
};
})();
return (
<div>
<div
ref={provided.innerRef}
style={provided.draggableStyle}
{...provided.dragHandleProps}
onClick={onClick}
>
Drag me!
</div>
{provided.placeholder}
</div>
);
}}
</Draggable>;
2. snapshot: (StateSnapshot)
type StateSnapshot = {|
isDragging: boolean,
|};
The children
function is also provided with a small amount of state relating to the current drag state. This can be optionally used to enhance your component. A common use case is changing the appearance of a Draggable
while it is being dragged. Note: if you want to change the cursor to something like grab
you will need to add the style to the body. (See DragDropContext
> style above)
<Draggable draggableId="draggable-1">
{(provided, snapshot) => {
const style = {
...provided.draggableStyle,
backgroundColor: snapshot.isDragging ? 'blue' : 'grey',
};
return (
<div>
<div
ref={provided.innerRef}
style={style}
{...provided.dragHandleProps}
>
Drag me!
</div>
{provided.placeholder}
</div>
);
}}
</Draggable>;
This codebase is typed with flowtype to promote greater internal consistency and more resilient code.
This code base employs a number of different testing strategies including unit, performance and integration tests. Testing various aspects of the system helps to promote its quality and stability.
While code coverage is not a guarantee of code health, it is a good indicator. This code base currently sits at ~95% coverage.
This codebase is designed to be extremely performant - it is part of its DNA. It builds on prior investigations into React
performance that you can read about here and here. It is designed to perform the minimum number of renders required for each task.
Highlights
- using connected-components with memoization to ensure the only components that render are the ones that need to - thanks
react-redux
,reselect
andmemoize-one
- all movements are throttled with a
requestAnimationFrame
- thanksraf-schd
- memoization is used all over the place - thanks
memoize-one
- conditionally disabling
pointer-events
onDraggable
s while dragging to prevent the browser needing to do redundant work - you can read more about the technique here - Non primary animations are done on the GPU
Minimal browser paints | Minimal React updates |
---|---|
This library supports the standard Atlassian supported browsers for desktop:
Desktop | Version |
---|---|
Microsoft Internet Explorer(Windows) | Version 11 |
Microsoft Edge | Latest stable version supported |
Mozilla Firefox (all platforms) | Latest stable version supported |
Google Chrome (Windows and Mac) | Latest stable version supported |
Safari (Mac) | Latest stable version on latest OS release supported |
Currently mobile is not supported. However, there are plans to add touch support in the future
Alex Reardon - @alexandereardon - [email protected]