# @react-md/tree

Create accessible tree widgets following the tree view specifications using the material design styles and fairly customizable renderers and styles and reasonable defaults.

# Installation

npm install --save @react-md/tree

It is also recommended to install these other packages as they work hand-in-hand with this package:

npm install --save @react-md/theme \
  @react-md/typography \
  @react-md/icon \
  @react-md/material-icons \
  @react-md/list

# Usage

The main export from this package is the Tree component which allows you to render a tree from TreeData which is really a lookup of Record<TreeItemId, TreeItem>. The Tree component is fully controlled and requires you to provide the selection and logic expansion with a few props. You can use the useTreeItemExpansion and useTreeItemSelection hooks to get pretty reasonable support out of the box including multi-select behavior.

If you are a Typescript user, this package also exports a decent amount of types to help out such as the TreeData, BaseTreeItem, and TreeItemSorter.

Here's a quick example:

12345678910111213141516171819202122232425262728293031323334353637383940414243444546import React, { ReactElement, ReactNode } from "react";
import { render } from "react-dom";
import {
  Tree,
  TreeData,
  BaseTreeItem,
  useTreeItemExpansion,
  useTreeItemSelection,
} from "@react-md/tree";

interface MyTreeItem extends BaseTreeItem {
  name: string;
}

const data: TreeData<MyTreeItem> = {
  "item-1-id": {
    name: "Root Node",
    itemId: " item-1-id",
    parentId: null,
  },
  "item-2-id": {
    name: "Child 1",
    itemId: "item-2-id",
    parentId: "item-1-id",
  },
  "item-3-id": {
    name: "Child 2",
    itemId: "item-3-id",
    parentId: "item-1-id",
  },
};

export default function Example(): ReactElement {
  const selection = useTreeItemSelection([], false);
  const expansion = useTreeItemExpansion([]);

  return (
    <Tree
      id="example-tree"
      aria-label="Tree"
      data={data}
      {...selection}
      {...expansion}
    />
  );
}