10.0.0

🎧🎶 Release notes designed to be listed to with Angus & Julia Stone - Chateau (ARTY Remix)

Release at a glance 🤩

🚀 30% faster 💥 smarter collision engine 🎹 more robust keyboard movement system 🎳 new: combine items 🐣 new: add and remove items during a drag 🌲 new: tree library @atlaskit/tree by @Confluence

I know right!? Pretty awesome!! Okay, lets get into the details

✌️ Low risk breaking change `9.x` → `10.x`

This release is a listed as a breaking change 💥. However, the risk of actual breakage is very low. Most consumers should be able to upgrade without any issues 👍. We will call out any breaking changes in these releases notes.

Features

Combining `Draggable`s #511

react-beautiful-dnd now supports the combining of Draggables 🤩

combining

👩‍🔬 Designed to work intuitively in conjunction with reordering
🕺 Works on both the vertical and horizontal axis
🎹 Full keyboard support
♿️ English screen reader messaging baked in. (You can override the defaults - see our screen reader guide)

We have created a combining guide which will show you how you can use the new feature and the thinking behind it.

I am biased, but the combining guide is really worth a read! The logic for doing combining in conjunction with reordering is very cool

Add and remove `Draggable`s while dragging #484

react-beautiful-dnd now supports the adding and removing of Draggables during a drag. This is a powerful feature that unlocks a lot of behaviors

Lazy loading	Trees! (Read more below)

We have created a guide to help you use this new feature.

New tree library: `@atlaskit/tree` 🌲🎉

In conjunction with this release, we have also released a new tree library: @atlaskit/tree!!! 🎉 It is a beautiful and accessible tree implementation built on top of react-beautiful-dnd

Display and interact with your own tree structure
Mouse 🐭, touch 📱 and keyboard support 🎹
Dropping on a closed group will add the dragging item to the group
Dragging over a collapsed group will expand the group after a small timer
Dragging an expanded group will collapse the group as the drag starts
Lazy loading of subtrees
Does not render any DOM ❤️

Hover to expand	Drop onto expanded parent	Drop onto collapsed parent	Drop on another item to create new group

Improvements

🚀 Speed

We have significantly improved the performance of react-beautiful-dnd.

🤘 30% more frames when dragging
🤩 66% more frames for drop animations in low resource environments

You can read about how we did this in our blog "Grabbing the flame 🔥"

💥 Smarter collision engine

Our collision engine has been rebuilt in order to take into account:

the direction a user is currently moving in, and
what items are currently displaced

This results in a much more consistent and natural movement experience.

collision

There was a flaw in the previous engine where edge detection did not consider what was already displaced.

The collision engine is now aware of displacement and so will now always shift items when the visible center goes over the visible edge of an item - even if the visible edge is displaced.

The collision engine is also now aware of the direction a user is currently moving in which is used to facilitate our new combining mode.

🎹 More robust keyboard movement system

The internal keyboard movement system has been completely rebuilt to provide more spacing flexibility and resilience. Improvements:

Drastically improved spacing flexibility. Can now use margin safely on any edge of a Draggable (as long as it does not lead to margin collapsing between items) #201
Moving from a patch based system, where each movement patches the previous one, to a system where every movement is computed from scratch based on the current displacement. This also means the algorithm is self healing. If a movement ever looks off (which it shouldn't), then the next move will correct the misalignment
The new placement system is now what we use to calculate drop placements for consistency

Example of old spacing issue	Now handled correctly

More drop animation control

We have moved to using only CSS for the drop animation for performance reasons (you can read more about that in "Grabbing the flame 🔥").

As a side benefit of this you are now able to tweak the drop animation, or opt out of it completely. We recommend not opting out the drop animation as it is important communication for the user.

Your own animation	No animation (not recommended)

We have created a drop animation guide to assist you

Cleaner development build messaging

We have made our development build warnings and error message prettier and more informative

We only long warnings if there are actual setup issues (not just for fun!). That said, if you want to, you are now able to disable all warnings:

// disable all development only warnings
window['__react-beautiful-dnd-disable-dev-warnings'] = true;

We have also added tests to ensure that these messages are correctly dropped from production builds.

Better ie11 support #320 #724

Previously we required consumers to polyfill Array.prototype.find in order for react-beautiful-dnd to work in ie11. We now bake in our own light ponyfills so that you are not required to polyfill anything to use react-beautiful-dnd in ie11

🔬 Smaller

react-beautiful-dnd 10.0.0 is actually a little bit smaller than 9.x. Which is amazing considering how many new capabilities the library has!

`Hooks` → `Responders`

~~DragDropContext > Responders~~ DragDropContext > Responders

Recently React announced a new alpha Hooks API. To avoid overloading the term Hook and confusing people, we have replaced our usage of the word Hook to Responder. The names of the actual ~~Hooks~~ Responders are unchanged:

onBeforeDragStart
onDragStart
onDragUpdate
onDragEnd

This is a type name change, as well as changing how we refer to them in the docs.

-type HookProvided = {|
+type ResponderProvided = {|
  announce: Announce,
|};

-type OnBeforeDragStartHook = (start: DragStart) => mixed;
+type OnBeforeDragStartResponder = (start: DragStart) => mixed;

-type OnDragStartHook = (
+type OnDragStartResponder = (
  start: DragStart,
  provided: ResponderProvided,
) => mixed;

-type OnDragUpdateHook = (
+type OnDragUpdateResponder = (
  update: DragUpdate,
  provided: ResponderProvided,
) => mixed;

-type OnDragEndHook = (
+type OnDragEndResponder = (
  result: DropResult,
  provided: ResponderProvided,
) => mixed;


-type Hooks = {|
-  onBeforeDragStart?: OnBeforeDragStartHook,
-  onDragStart?: OnDragStartHook,
-  onDragUpdate?: OnDragUpdateHook,
-  // always required
-  onDragEnd: OnDragEndHook,
-|};
+type Responders = {|
+  onBeforeDragStart?: OnBeforeDragStartResponder,
+  onDragStart?: OnDragStartResponder,
+  onDragUpdate?: OnDragUpdateResponder,
+  // always required
+  onDragEnd: OnDragEndResponder,
+|};

This is a breaking change 💥. But it should be a fairly trivial type rename if you are using flow or TypeScript. This would only impact you if you are directly importing the types:

- // this would now break:
-import type { OnDragStartHook } from 'react-beautiful-dnd`

+// need to use the new type name:
+import type { OnDragStartResponder } from 'react-beautiful-dnd`

`Responder` timings

In order to improve consistency we now force onDragStart and onDragUpdate to be in the tick after the snapshot values are updated. Previously there were in the same tick. We do this to ensure there is a full React render before calling the hooks. This was generally the case anyway so consumers should not be impacted. I found some very edge case scenarios where onDragStart could be batched into the same render pass by React as a snapshot update.

You can read all the timing details in our Responder guide.

This could be classified as a breaking change 💥, although the risk of breakage is almost nothing. In fact, it fixed a bug we found in one case 🤷‍

More information in `Responder`s 🕵️‍♀️

The values provided to the Responders now has some new information!

`DragStart` now contains `mode`

DragStart is supplied to onDragStart

type DragStart = {|
  draggableId: DraggableId,
  type: TypeId,
  source: DraggableLocation,
+ mode: MovementMode,
|};

+ type MovementMode = 'FLUID' | 'SNAP';

There are two seperate modes that a drag can be in

'FLUID': everything is done in response to highly granular input (eg mouse)
'SNAP': items move in response to commands (eg keyboard)

SNAP may also include our new programmatic dragging mode we have planned #162

`DragUpdate` (and `DragResult`) now contain `combine`

DragUpdate is supplied to onDragUpdate DropResult is supplied to onDragEnd

In order to facilitate the new combining mode a DragUpdate and DragResult now contain combine information

type DragUpdate = {|
  ...DragStart,
  // may not have any destination (drag to nowhere)
  destination: ?DraggableLocation,
+  // populated when a draggable is dragging over another in combine mode
+  combine: ?Combine,
|};

+ // details of the item that is being combined with
+ type Combine = {|
+   draggableId: DraggableId,
+   droppableId: DroppableId,
+ |};

// DropResult gets these too it it extends DragUpdate

type DropResult = {|
  ...DragUpdate,
  reason: DropReason,
|};

New data for a `Draggable` 👨‍🎨

We now provide your Draggable with more information for you to use!

type DraggableStateSnapshot = {|
  isDragging: boolean,
  isDropAnimating: boolean,
  draggingOver: ?DroppableId,
+  // Information about a drop animation
+  dropAnimation: ?DropAnimation
+  // the id of a draggable that you are combining with
+  combineWith: ?DraggableId,
+  // a combine target is being dragged over by
+  combineTargetFor: ?DraggableId,
+  // What type of movement is being done: 'FLUID' or 'SNAP'
+  mode: ?MovementMode,
|};

+ // information about a drop animation that you can patch if you like
+ type DropAnimation = {|
+   duration: number,
+   curve: string,
+   moveTo: Position,
+   opacity: ?number,
+   scale: ?number,
+ |};

Moved to CSS for the drop animation

As mentioned previously, we have moved to using a CSS animation for our drop animation. We where able to maintain the exact same visual animation using CSS as we where with a spring based animation. You can read more about this in "Grabbing the flame 🔥".

Breaking change 💥. We previously rendered a Draggable at 60fps to get it to its home location. Now we let CSS do it. If you were patching the drop animation then this change will break you. Good news, it will now be much easier for you! Check out our drop animation guide.

Other improvements

Throw an error when consumer forgets to pass a Draggable an index prop (a common setup error)
No longer throwing an error if trying to announce screen reader messages after a DragDropContext is unmounted. It will now print a dev only warning explaining any problems and how you could avoid dropping screen reader messages #556
Added a development only warning to let consumers know if they are not meeting the required React peer dependency version. npm will warn you about this, but we are getting a lot of issues about this. So we decided to bake our own warning into the library
Now has partial support for lists in a position:fixed container
Mentioning in the docs that indexes need to be dense and start from 0 #892
Given the docs a lot of love 📖❤️

Fixes

Drag Handle unmount performance #543
Aborting and drag due to an error when using ReactDOM.createPortal could cause the drag to lock
Preventing cross axis movement to invisible locations
Cross axis movement will now align correctly when entering the last position of a list #785
Auto scrolling shudder when near the end of a scrollable list #764
A cross axis move that results in a shift in window scroll is now accounted for

Engineering health

Added test to ensure consistent file naming within repo
Added test to ensure all developer warnings and any other console.* statements are removed in production builds
Added test to ensure styles applied to selectors are valid and pass stylelint
Upgrade to flow 0.86 #851

👋❤️ Community documentation

We have a new Community section and Addons section in our docs. If you have something that you would like to submit please pull request.

Thanks to these people who have already added content:

@LukeHendrick (Glitch app) #688
@rokborf: natural-drag-animation-rbdnd
@ng-hai: simple trello project #878

We would like your input

We have a few request for discussion (RFD) issues that would benefit from more input:

RFD: What would a React 16.7 hooks api look like? #871
RFD: Placement of Responders and flow of data #498

Thanks

This release has been months of hard work in the making. Thank you to everybody who has contributed to, and supported this release. A special thanks to:

.css-1dftfkb{color:rgb(10,95,217);}10.0.0