Need help with react-vtree?
Click the “chat” button below for chat support from the developer who created it, or find similar developers for support.

About the developer

Lodin
249 Stars 26 Forks MIT License 201 Commits 10 Opened issues

Description

React component for efficiently rendering large tree structures

Services available

!
?

Need anything else?

Contributors list

# 82,044
HTML
Webpack
elm
tabular...
166 commits
# 375,483
TypeScr...
JavaScr...
google-...
Redux
5 commits
# 220,642
Redux
CSS
Electro...
node
2 commits
# 530,972
Python
text-ed...
content...
TypeScr...
1 commit

react-vtree

Latest Stable Version License CI Status Coverage Bugs Vulnerabilities

This package provides a lightweight and flexible solution for rendering large tree structures. It is built on top of the react-window library.

Attention! This library is entirely rewritten to work with the

react-window
. If you are looking for the tree view solution for the react-virtualized, take a look at react-virtualized-tree.

NOTE: This is the documentation for version

3.x.x
. For version
2.x.x
see this branch.

Installation

# npm
npm i react-window react-vtree

Yarn

yarn add react-window react-vtree

Usage

FixedSizeTree

Example

You can also take a look at the very similar example at the Storybook:

import {FixedSizeTree as Tree} from 'react-vtree';

// Tree component can work with any possible tree structure because it uses an // iterator function that the user provides. Structure, approach, and iterator // function below is just one of many possible variants. const treeNodes = [ { name: 'Root #1', id: 'root-1', children: [ { children: [ {id: 'child-2', name: 'Child #2'}, {id: 'child-3', name: 'Child #3'}, ], id: 'child-1', name: 'Child #1', }, { children: [{id: 'child-5', name: 'Child #5'}], id: 'child-4', name: 'Child #4', }, ], }, { name: 'Root #2', id: 'root-2', }, ];

// This helper function constructs the object that will be sent back at the step // [2] during the treeWalker function work. Except for the mandatory data // field you can put any additional data here. const getNodeData = (node, nestingLevel) => ({ data: { id: node.id.toString(), // mandatory isLeaf: node.children.length === 0, isOpenByDefault: true, // mandatory name: node.name, nestingLevel, }, nestingLevel, node, });

// The treeWalker function runs only on tree re-build which is performed // whenever the treeWalker prop is changed. function* treeWalker() { // Step [1]: Define the root node of our tree. There can be one or // multiple nodes. for (let i = 0; i < treeNodes.length; i++) { yield getNodeData(treeNodes[i], 0); }

while (true) { // Step [2]: Get the parent component back. It will be the object // the getNodeData function constructed, so you can read any data from it. const parent = yield;

for (let i = 0; i &lt; parent.node.children.length; i++) {
  // Step [3]: Yielding all the children of the provided component. Then we
  // will return for the step [2] with the first children.
  yield getNodeData(parent.node.children[i], parent.nestingLevel + 1);
}

} }

// Node component receives all the data we created in the treeWalker + // internal openness state (isOpen), function to change internal openness // state (setOpen) and style parameter that should be added to the root div. const Node = ({data: {isLeaf, name}, isOpen, style, setOpen}) => (

{!isLeaf && ( setOpen(!isOpen)}> {isOpen ? '-' : '+'} )}
{name}
);

ReactDOM.render( {Node} , document.querySelector('#root'), );

Props

Props inherited from
FixedSizeList

You can read more about these properties in the

FixedSizeList
documentation.

  • children: component
    . Uses own implementation, see below.
  • className: string = ""
  • direction: strig = "ltr"
  • height: strig | number
  • initialScrollOffset: number = 0
  • innerRef: function | createRef object
    . This property works as it described in the
    react-window
    . For getting a
    FixedSizeList
    reference use
    listRef
    .
  • innerElementType: React.ElementType = "div"
  • innerTagName: string
    . Deprecated by
    react-window
    .
  • itemData: any
  • itemKey: function
    . Handled internally.
  • itemSize: number
  • layout: string = "vertical"
  • onItemsRendered: function
  • onScroll: function
  • outerRef: function | createRef object
  • outerElementType: React.ElementType = "div"
  • outerTagName: string
    . Deprecated by
    react-window
    .
  • overscanCount: number = 1
  • style: object = null
  • useIsScrolling: boolean = false
  • width: number | string
async: boolean

This option allows making the tree asynchronous; e.g. you will be able to load the branch data on the node opening. All it does under the hood is preserving the tree state between tree buildings on

treeWalker
update, so the user does not see the tree resetting to the default state when the async action is performed.

To see how it works you can check the

AsyncData
story. You can use the

disableAsync
to see what will happen on the async action if the
async
prop is
false
.

If it is combined with the

placeholder
option, the tree re-building won't be interrupted by showing the placeholder; it will be shown only at the first time the tree is building.

To see how two options interact with each other see the

AsyncDataIdle
story.

children: component

The

Node
component responsible for rendering each node.

It receives the following props:

  • Inherited from
    react-window
    's
    Row
    component:
    • style: object
    • isScrolling: boolean
      - if
      useIsScrolling
      is enabled.
  • Node
    -specific props:
    • All fields of the
      FixedSizeNodePublicState
      object.
    • treeData: any
      - any data provided via the
      itemData
      property of the
      FixedSizeTree
      component.
placeholder: ReactNode | null

This property receives any react node that will be displayed instead of a tree during the building process. This option should only be used if the tree building process requires too much time (which means you have a really giant amount of data, e.g. about a million nodes).

Setting this option enables the

requestIdleCallback
under the hood for browsers that support this feature. For other browsers the original scenario is applied; no placeholder will be shown.

Using this feature allows avoiding UI freezes; however, it may slightly increase the time spent for the building process.

To see how it works, you can check the BigData story. Use

placeholder
tool to add and remove placeholder.

If you have an asynchronous giant tree and want to use profits of

requestIdleCallback
but don't want placeholder to be shown on the first render (that is probably quite small because all other data will be loaded asynchronously), set
placeholder
to
null
. No placeholder will be shown on the first render but the
requestIdleCallback
building will be enabled and allow avoiding freezes on tree re-building when tree becomes bigger.

To see how it works you can check the AsyncDataIdle story. It uses the

null
placeholder, so no text is shown for the first build but async requests don't block the UI.
buildingTaskTimeout: number

This option works in tandem with the

placeholder
option. With it, you can set the task timeout for the
requestIdleCallback
. The
buildingTaskTimeout
will be sent directly as the
requestIdleCallback
's
timeout
option.
listRef: Ref

This option allows you to get the instance of the internal

react-window
list. It is usually unnecessary because all necessary methods are already provided but still can be useful for edge cases.
rowComponent: component

This property receives a custom

Row
component for the
FixedSizeList
that will override the default one. It can be used for adding new functionality.

Row
component receives the following props:
  • index: number
  • data: object
    - the data tree component provides to
    Row
    . It contains the following data:
    • component: component
      - a
      Node
      component to create a React element from.
    • getRecordData: function
      - a function that gets the record data by
      index
      . It returns a
      FixedSizeNodePublicState
      object.
    • treeData: any
      - any data provided via the
      itemData
      property of the
      FixedSizeTree
      component.
  • style: object
  • isScrolling: boolean
* treeWalker()

An iterator function that walks around the tree and yields node data to build an inner representation of the tree. For algorithm details, see TreeWalker section.

The

treeWalker
function should yield the object of the following shape:
  • data: FixedSizeNodeData
    - this field is mandatory. See
    FixedSizeNodeData
    type
    for the shape.
  • ...
    - you can add any other data to this object. It will be sent directly to the
    treeWalker
    at the step [2] of the execution.

Tree is re-computed on each

treeWalker
change. To avoid unnecessary tree re-computation keep the
treeWalker
memoized (e.g. with
useCallback
hook). If you want to update tree data, send the new version of
treeWalker
to the tree component.

Note that when

treeWalker
is updated no internal state will be shared with the new tree. Everything will be built from scratch.

Methods

The component provides the following methods.

scrollToItem(id: string | symbol, align?: Align): void

The

scrollToItem
method behaves the same as
scrollToItem
from
FixedSizeList
but receives node
id
instead of
index
.
async recomputeTree(state): void

This method starts the tree traversing to update the internal state of nodes.

It receives

state
object that contains nodes'
id
as keys and update rules as values. Each record traverses a subtree of the specified node (also "owner node") and does not affect other nodes (it also means that if you specify the root node the whole tree will be traversed).

The rules object has the following shape:

  • open: boolean
    - this rule changes the openness state for the owner node only (subtree nodes are not affected).
  • subtreeCallback(node: object, ownerNode: object): void
    - this callback runs against each node in the subtree of the owner node (including the owner node as well). It receives the subtree node and the owner node. Changing any property of the subtree node will affect the node state and how it will be displayed (e.g. if you change the node openness state it will be displayed according to the changed state).

The order of rules matters. If you specify the child node rules before the parent node rules, and that rules affect the same property, the parent node

subtreeCallback
will override that property. So if you want to override parent's rules, place children rules after the parent's.

The type of the node objects received by

subtreeCallback
is
FixedSizeNodePublicState
. See the types description below.
recomputeTree
example
// The tree
const tree = {
  name: 'Root #1',
  id: 'root-1',
  children: [
    {
      children: [
        {id: 'child-2', name: 'Child #2'},
        {id: 'child-3', name: 'Child #3'},
      ],
      id: 'child-1',
      name: 'Child #1',
    },
    {
      children: [{id: 'child-5', name: 'Child #5'}],
      id: 'child-4',
      name: 'Child #4',
    },
  ],
};

// recomputeTree

tree.recomputeTree({ 'root-1': { open: false, subtreeCallback(node, ownerNode) { // Since subtreeCallback affects the ownerNode as well, we can check if the // nodes are the same, and run the action only if they aren't if (node !== ownerNode) { // All nodes of the tree will be closed node.isOpen = false; } }, }, // But we want child-4 to be open 'child-4': true, });

Types

  • FixedSizeNodeData
    - value of the
    data
    field of the object yielded by the
    treeWalker
    function. The shape is the following:
    • id
      - a unique identifier of the node.
    • isOpenByDefault
      - a default openness state of the node.
    • ...
      - you can add any number of additional fields to this object. This object without any change will be sent directly to the
      Node
      component. You can also use
      getRecordData
      function to get this object along with the other record data by the index. To describe that data, you have to create a new type that extends the
      FixedSizeNodeData
      type.
  • FixedSizeNodePublicState
    - the node state available for the
    Node
    component and
    recomputeTree
    's
    subtreeCallback
    function. It has the following shape:
    • data: FixedSizeNodeData
      .
    • isOpen: boolean
      - a current openness status of the node.
    • setOpen(state: boolean): function
      - a function to change the openness state of the node. It receives the new openness state as a
      boolean
      and opens/closes the node accordingly.
  • FixedSizeTreeProps
    - props that
    FixedSizeTree
    component receives. Described in the Props section.
  • FixedSizeTreeState
    - state that
    FixedSizeTree
    component has.

VariableSizeTree

Example

You can also take a look at the very similar example at the Storybook:

import {VariableSizeTree as Tree} from 'react-vtree';

// Tree component can work with any possible tree structure because it uses an // iterator function that the user provides. Structure, approach, and iterator // function below is just one of many possible variants. const tree = { name: 'Root #1', id: 'root-1', children: [ { children: [ {id: 'child-2', name: 'Child #2'}, {id: 'child-3', name: 'Child #3'}, ], id: 'child-1', name: 'Child #1', }, { children: [{id: 'child-5', name: 'Child #5'}], id: 'child-4', name: 'Child #4', }, ], };

// This helper function constructs the object that will be sent back at the step // [2] during the treeWalker function work. Except for the mandatory data // field you can put any additional data here. const getNodeData = (node, nestingLevel) => ({ data: { defaultHeight: itemSize, // mandatory id: node.id.toString(), // mandatory isLeaf: node.children.length === 0, isOpenByDefault: true, // mandatory name: node.name, nestingLevel, }, nestingLevel, node, });

// The treeWalker function runs only on tree re-build which is performed // whenever the treeWalker prop is changed. function* treeWalker() { // Step [1]: Define the root node of our tree. There can be yielded one or // multiple nodes. yield getNodeData(tree, 0);

while (true) { // Step [2]: Get the parent component back. It will be the object // the getNodeData function constructed, so you can read any data from it. const parent = yield;

for (let i = 0; i &lt; parent.node.children.length; i++) {
  // Step [3]: Yielding all the children of the provided component. Then we
  // will return for the step [2] with the first children.
  yield getNodeData(parent.node.children[i], parent.nestingLevel + 1);
}

} }

// Node component receives current node height as a prop const Node = ({data: {isLeaf, name}, height, isOpen, style, setOpen}) => (

{!isLeaf && ( setOpen(!isOpen)}> {isOpen ? '-' : '+'} )}
{name}
);

const Example = () => ( {Node} );

Props

Props inherited from
VariableSizeList

You can read more about these properties in the

VariableSizeList
documentation.

Since

VariableSizeList
in general inherits properties from the
FixedSizeList
, everything described in the same section for
FixedSizeTree
affects this section. For the rest, there are the following changes:
  • estimatedItemSize: number = 50
  • itemSize: (index: number) => number
    . This property is optional. If it is not provided, the
    defaultHeight
    of the specific node will be used. Advanced property; prefer using node state for it.
children

The

Node
component. It is the same as the
FixedSizeTree
's one but receives properties from the
VariableSizeNodePublicState
object.
listRef: Ref

Same as

listRef
of

FixedSizeTree
.
rowComponent: component

See

rowComponent
in the

FixedSizeTree
section; the
getRecordData
returns the
VirtualSizeNodePublicState
object.
* treeWalker(refresh: boolean)

An iterator function that walks over the tree. It behaves the same as

FixedSizeTree
's
treeWalker
. The
data
object should be in the
VariableSizeNodeData
shape.

Methods

The component provides the following methods:

scrollToItem(id: string | symbol, align?: Align): void

The

scrollToItem
method behaves the same as
scrollToItem
from
VariableSizeList
but receives node
id
instead of
index
.
resetAfterId(id: string | symbol, shouldForceUpdate: boolean = false): void

This method replaces the

resetAfterIndex
method of
VariableSizeList
but works exactly the same. It receives node
id
as a first argument.
async recomputeTree(state): void

See

FixedSizeTree
's
recomputeTree
description. There are no differences.

Types

All types in this section are the extended variants of

FixedSizeTree
types.

  • VariableSizeNodeData
    - this object extends
    FixedSizeNodeData
    and contains the following additional fields:
    • defaultHeight: number
      - the default height the node will have.
  • VariableSizeNodePublicState
    . The node state object. Extends the
    FixedSizeNodePublicState
    and contains the following additional fields:
    • height: number
      - the current height of the node. The node will be displayed with this height.
    • resize(newHeight: number, shouldForceUpdate?: boolean): function
      - a function to change the height of the node. It receives two parameters:
    • newHeight: number
      - a new height of the node.
    • shouldForceUpdate: boolean
      - an optional argument that will be sent directly to the
      resetAfterIndex
      method.
  • VariableSizeTreeProps
    .
  • VariableSizeTreeState
    .

TreeWalker algorithm

The

treeWalker
algorithm works in the following way. During the execution, the
treeWalker
function sends a bunch of objects to the tree component which builds an internal representation of the tree. However, for it, the specific order of yieldings should be performed.
  1. The first yielding is always root nodes. They will be the foundation of the whole tree.
  2. Now start a loop where you will receive the parent node and yield all the children of it.
  3. The first yielding of loop iteration should yield an
    undefined
    . In exchange, you will receive a node for which you should yield all the children in the same way you've done with the root ones.
  4. When all the children are yielded, and the new iteration of loop is started, you yield
    undefined
    again and in exchange receive the next node. It may be:
    • a child node if the previous node has children;
    • a sibling node if it has siblings;
    • a sibling of the elder node.
  5. When the whole tree is finished and algorithm reaches the end, the loop stops. You don't have to finish
    treeWalker
    's loop manually.

The example of this algorithm is the following

treeWalker
function:
function* treeWalker() {
  // Here we start our tree by yielding the data for the root node.
  yield getNodeData(rootNode, 0);

while (true) { // Here in the loop we receive the next node whose children should be // yielded next. const parent = yield;

for (let i = 0; i &lt; parent.node.children.length; i++) {
  // Here we go through the parent's children and yield them to the tree
  // component
  yield getNodeData(parent.node.children[i], parent.nestingLevel + 1);
  // Then the loop iteration is over, and we are going to our next parent
  // node.
}

} }

Migrating
2.x.x
->
3.x.x

If you use

react-vtree
of version 2, it is preferable migrate to the version 3. The third version is quite different under the hood and provides way more optimized approach to the initial tree building and tree openness state change. The most obvious it becomes if you have a giant tree (with about 1 million of nodes).

To migrate to the new version, you have to do the following steps.

1. Migrate
treeWalker

The

treeWalker
was and is the heart of the
react-vtree
. However, now it looks a bit different.

Old

treeWalker
worked for both initial tree building and changing node openness state:
function* treeWalker(refresh) {
  const stack = [];

stack.push({ nestingLevel: 0, node: rootNode, });

// Go through all the nodes adding children to the stack and removing them // when they are processed. while (stack.length !== 0) { const {node, nestingLevel} = stack.pop(); const id = node.id.toString();

// Receive the openness state of the node we are working with
const isOpened = yield refresh
  ? {
      id,
      isLeaf: node.children.length === 0,
      isOpenByDefault: true,
      name: node.name,
      nestingLevel,
    }
  : id;

if (node.children.length !== 0 &amp;&amp; isOpened) {
  for (let i = node.children.length - 1; i &gt;= 0; i--) {
    stack.push({
      nestingLevel: nestingLevel + 1,
      node: node.children[i],
    });
  }
}

} }

The new

treeWalker
is only for the tree building. The
Tree
component builds and preserves the tree structure internally. See the full description above.
// This function prepares an object for yielding. We can yield an object
// that has `data` object with `id` and `isOpenByDefault` fields.
// We can also add any other data here.
const getNodeData = (node, nestingLevel) => ({
  data: {
    id: node.id.toString(),
    isLeaf: node.children.length === 0,
    isOpenByDefault: true,
    name: node.name,
    nestingLevel,
  },
  nestingLevel,
  node,
});

function* treeWalker() { // Here we send root nodes to the component. for (let i = 0; i < rootNodes.length; i++) { yield getNodeData(rootNodes[i], 0); }

while (true) { // Here we receive an object we created via getNodeData function // and yielded before. All we need here is to describe its children // in the same way we described the root nodes. const parentMeta = yield;

for (let i = 0; i &lt; parentMeta.node.children.length; i++) {
  yield getNodeData(
    parentMeta.node.children[i],
    parentMeta.nestingLevel + 1,
  );
}

} }

2. Migrate tree components

Components haven't been changed a lot but you may want to add new features like:

3. Migrate
recomputeTree
method

The

recomputeTree
method now receives a list of nodes to change (previously, it was an
opennessState
object). See the full description above.

The most important change is the introduction of the

subtreeCallback
. It is a function that will be applied to each node in the subtree of the specified node. Among other useful things it also allows imitating the behavior of old
useDefaultOpenness
and
useDefaultHeight
options.

Old

recomputeTree
:
treeInstance.recomputeTree({
  opennessState: {
    'node-1': true,
    'node-2': true,
    'node-3': false,
  },
  refreshNodes: true,
  useDefaultOpenness: false,
});

New

recomputeTree
:
treeInstance.recomputeTree({
  'node-1': true,
  'node-2': {
    open: true,
    subtreeCallback(node, ownerNode) {
      if (node !== ownerNode) {
        node.isOpen = false;
      }
    },
  },
  'node-3': false,
});

4. Migrate all your
toggle()
calls to
setOpen(boolean)

In the

3.x.x
version node provides a
setOpen
function instead of
toggle
that allows more fine-grained control over the openness state.

Old

toggle
:
const Node = ({data: {isLeaf, name}, isOpen, style, toggle}) => (
  
{!isLeaf && (
{isOpen ? '-' : '+'}
)}
{name}
);

New

setOpen
:
javascript
const Node = ({data: {isLeaf, name}, isOpen, style, setOpen}) => (
  
{!isLeaf && (
// Imitating the old `toggle` function behavior setOpen(!isOpen)}>{isOpen ? '-' : '+'}
)}
{name}
);

5. Migrate all your IDs to string

Using node IDs as keys should improve React rendering performance. However, it means that you won't be able to use

Symbol
as IDs anymore. You should move all your IDs to be strings instead of symbols.

We use cookies. If you continue to browse the site, you agree to the use of cookies. For more information on our use of cookies please see our Privacy Policy.