React DnD TreeView

A draggable and droppable React treeview component.
You can use render props to create each node freely.

Demo and Examples

Some of the examples below use MUI(Material-UI) components, but TreeView does not depend on MUI, so you can use other libraries or your own custom components.

https://minop1205.github.io/react-dnd-treeview/

Breaking changes and migration

See Migration Guide for information on breaking changes and migrations between major versions.

Getting Started

Installation

$ npm i react-dnd @minoru/react-dnd-treeview

Usage

import { useState } from "react";
import {
  Tree,
  getBackendOptions,
  MultiBackend,
} from "@minoru/react-dnd-treeview";
import { DndProvider } from "react-dnd";
import initialData from "./sample-default.json";

function App() {
  const [treeData, setTreeData] = useState(initialData);
  const handleDrop = (newTreeData) => setTreeData(newTreeData);

  return (
    <DndProvider backend={MultiBackend} options={getBackendOptions()}>
      <Tree
        tree={treeData}
        rootId={0}
        onDrop={handleDrop}
        render={(node, { depth, isOpen, onToggle }) => (
          <div style={{ marginLeft: depth * 10 }}>
            {node.droppable && (
              <span onClick={onToggle}>{isOpen ? "[-]" : "[+]"}</span>
            )}
            {node.text}
          </div>
        )}
      />
    </DndProvider>
  );
}

Backends

MultiBackend is a backend to support both touch and pointer devices. If you only need support for one or the other, you can also use the backend provided by react-dnd-html5-backend or react-dnd-touch-backend.

import { DndProvider } from "react-dnd";
import { HTML5Backend } from "react-dnd-html5-backend";

function App() {
  return (
    <DndProvider backend={HTML5Backend}>
      <Tree {...someProps}> />
    </DndProvider>
  );
}

import { DndProvider } from "react-dnd";
import { TouchBackend } from "react-dnd-touch-backend";

function App() {
  return (
    <DndProvider backend={TouchBackend}>
      <Tree {...someProps}> />
    </DndProvider>
  );
}

Backend options

HTML5Backend, TouchBackend and MultiBackend allow setting the BackendOptions defined in react-dnd.

For more information on TouchBackend, please see here. (For the HTML5Backend option, only the rootElement option is available.)

import { DndProvider } from "react-dnd";
import { HTML5Backend, HTML5BackendOptions } from "react-dnd-html5-backend";
import {TouchBackend, TouchBackendOptions} from "react-dnd-touch-backend"
import {Tree, MultiBackend, getBackendOptions} from "@minoru/react-dnd-treeview"

const touchOptions: Partial<TouchBackendOptions> = {
  // some options
};

const html5Options: Partial<HTML5BackendOptions> = {
  rootElement: document.body,
  // some options
};

const multiOptions = {
  touch: touchOptions,
  html5: html5Options,
}

function App() {
  return (
    <DndProvider
      backend={MultiBackend}
      options={getBackendOptions(multiOptions)}

      // or
      // backend={HTML5Backend}
      // options={html5Options}

      // or
      // backend={TouchBackend}
      // options={touchOptions}
    >
      <Tree {...someProps}> />
    </DndProvider>
  );
}

Data Structure

To display the treeview, pass data with the following structure to the tree property of the Tree component.

Basic example

The minimal data structure for representing the tree is shown in the following example

[
  {
    "id": 1,
    "parent": 0,
    "droppable": true,
    "text": "Folder 1"
  },
  {
    "id": 2,
    "parent": 1,
    "text": "File 1-1"
  },
  {
    "id": 3,
    "parent": 1,
    "text": "File 1-2"
  },
  {
    "id": 4,
    "parent": 0,
    "droppable": true,
    "text": "Folder 2"
  },
  {
    "id": 5,
    "parent": 4,
    "droppable": true,
    "text": "Folder 2-1"
  },
  {
    "id": 6,
    "parent": 5,
    "text": "File 2-1-1"
  }
]

Optional data

If you want to pass custom properties to each node's rendering,
you can use the data property.

[
  {
    "id": 1,
    "parent": 0,
    "droppable": true,
    "text": "Folder 1"
  },
  {
    "id": 2,
    "parent": 1,
    "text": "File 1-1",
    "data": {
      "fileType": "csv",
      "fileSize": "0.5MB"
    }
  },
  {
    "id": 3,
    "parent": 1,
    "text": "File 1-2",
    "data": {
      "fileType": "pdf",
      "fileSize": "4.8MB"
    }
  },
  {
    "id": 4,
    "parent": 0,
    "droppable": true,
    "text": "Folder 2"
  },
  {
    "id": 5,
    "parent": 4,
    "droppable": true,
    "text": "Folder 2-1"
  },
  {
    "id": 6,
    "parent": 5,
    "text": "File 2-1-1",
    "data": {
      "fileType": "image",
      "fileSize": "2.1MB"
    }
  }
]

Node properties

Component API

Render prop

To render each tree node, please pass a render function to the render property.

<Tree
  {...props}
  render={(node, { depth, isOpen, draggable, onToggle }) => (
    <div style={{ marginLeft: depth * 10 }}>
      {node.droppable && (
        <span onClick={onToggle}>{isOpen ? "[-]" : "[+]"}</span>
      )}
      {node.text}
    </div>
  )}
/>

The arguments passed to the render function are as follows

Drag handle

By default, the entire node is draggable, but the handleRef render option allows the node to be dragged only by the specified handle, as in the following example.

<Tree
  {...props}
  render={(node, { handleRef }) => (
    <div>
      <span ref={handleRef}>[Drag me]</span>
      {node.text}
    </div>
  )}
/>

Dragging preview

By default, the drag preview is a screenshot of a DOM node.
The dragPreviewRender property allows you to display a custom React component instead of a screenshot.

NOTE:
The default preview is not displayed on touch devices.
Therefore, if you want to support touch devices, please define a custom preview in dragPreviewRender.

<Tree
  {...props}
  dragPreviewRender={(monitorProps) => {
    const item = monitorProps.item;

    return (
      <div>
        <p>{item.text}</p>
      </div>
    );
  }}
/>

The data passed to dragPreviewRender contains the following properties

onDrop callback

If the tree is modified by drag-and-drop, the changes can be retrieved by the onDrop callback.

const [treeData, setTreeData] = useState(initialTreeData);
const handleDrop = (
  newTree,
  { dragSourceId, dropTargetId, dragSource, dropTarget }
) => {
  // Do something

  setTreeData(newTree);
};

return <Tree {...props} tree={treeData} onDrop={handleDrop} />;

The arguments passed to the onDrop callback function are as follows

canDrop callback

By default, it allows dropping to any droppable node (or root node) except its own descendants. This callback can override the default rules.

If it returns nothing or returns undefined, the default rules will be applied. If it returns a boolean value, it will override the default rules and the droppable property of each node will no longer be referenced.

If it returns false and the user drops the dragged node, no action will be taken and the onDrop callback will not be fired.

This callback takes the same parameters as the onDrop callback, but the first parameter specifies the current tree.

const canDrop = (
  currentTree,
  { dragSourceId, dropTargetId, dragSource, dropTarget }
) => {
  return true;

  // or

  return false;

  // or

  return;

  // or

  return undefined;
};

return <Tree {...props} tree={treeData} canDrop={canDrop} />;

NOTE:
When overriding the default rules by returning true or false, be careful of inconsistencies in the tree structure.
For example, if you allow dropping from a parent node to a child node as shown in the figure below, inconsistency will occur and the tree will collapse.

Manual sort with placeholder

By default, nodes are automatically sorted and cannot be sorted manually, but by combining some APIs, you can sort them manually and display placeholders as follows.

The following is an example (excerpt) of the implementation of manual sort of nodes and placeholder display.

import { CustomPlaceholder } from "./CustomPlaceholder";
import styles from "./App.module.css";

function App() {
  const [treeData, setTreeData] = useState(SampleData);
  const handleDrop = (newTree) => setTreeData(newTree);

  return (
    <Tree
      {...props}
      tree={treData}
      onDrop={handleDrop}
      classes={{
        placeholder: styles.placeholder,
      }}
      sort={false}
      insertDroppableFirst={false}
      canDrop={(tree, { dragSource, dropTargetId }) => {
        if (dragSource?.parent === dropTargetId) {
          return true;
        }
      }}
      dropTargetOffset={5}
      placeholderRender={(node, { depth }) => (
        <CustomPlaceholder node={node} depth={depth} />
      )}
    />;
  );
}

External drag source

To drop elements outside the tree into the tree, extraAcceptTypes must be set.

If the external drag source is under a DndProvider, set the type and item using useDrag in react-dnd for that element. add the external drag source type to extraAcceptTypes so it can be dropped in the tree.

If the external drag source is an element or file external to DndProvider, adding the type defined in react-dnd-html5-backend to extraAcceptTypes will allow dropping into the tree.

In this case, the onDrop callback will access the dropped element via options.monitor and add the new node to the data array of tree, as in the following example.

import { NativeTypes } from "react-dnd-html5-backend";

function App() {
  const [treeData, setTreeData] = useState(SampleData);
  const [lastId, setLastId] = useState(100);

  const handleDrop = (tree, options) => {
    const { dropTargetId, monitor } = options;
    const itemType = monitor.getItemType();

    if (itemType === NativeTypes.FILE) {
      const files = monitor.getItem().files;
      const nodes = files.map((file, index) => ({
        id: lastId + index,
        parent: dropTargetId,
        text: file.name,
      }));

      const mergedTree = [...tree, ...nodes];
      setTree(mergedTree);
      setLastId(lastId + files.length);
    } else {
      setTree(tree);
    }
  };

  return (
    <Tree
      {...someProps}
      tree={treeData}
      extraAcceptTypes={[NativeTypes.FILE]}

      {/*
        extraAcceptTypes={[NativeTypes.URL]}
        extraAcceptTypes={[NativeTypes.TEXT]}
        extraAcceptTypes={[NativeTypes.HTML]}
      */}

      onDrop={handleDrop}
    />;
  );
}

Component styling

You are free to define the styling of individual nodes in the tree in your Render props, but the rest of the tree can be styled by specifying the CSS class name for the classes property.

<Tree
  {...props}
  classes={{
    root: "my-root-classname",
    dragOver: "my-dragover-classname",
    // listItem: "my-listitem-classname",
    // You can use callback function for listItem class name.
    listItem: (node, options) => {
      return options.depth === 0
        ? "my-listitem-root-classname"
        : "my-listitem-classname";
    },
  }}
/>

You can use the following keys for the objects you pass to the classes property. Neither key is required.

Usage to open / close methods

The open/close status of a node is managed within the Tree component, but the methods for opening and closing nodes are public, so they can be controlled from outside the Tree component.

const ref = useRef(null);

const handleOpenAll = () => ref.current.openAll();
const handleCloseAll = () => ref.current.closeAll();

// open /close method can be passed a node ID or an array of node IDs
const handleOpen = (nodeId) => ref.current.open(nodeId);
const handleClose = (nodeId) => ref.current.close(nodeId);

<Tree
  ref={ref}
  {...props}
>

<button onClick={handleOpenAll}>Open All Folders</button>
<button onClick={handleCloseAll}>Close All Folders</button>
<button onClick={handleOpen}>Open specific folder(s)</button>
<button onClick={handleClose}>Close specific folder(s)</button>

License

MIT.