---
title: Dropbox
pagination_prev: demos/ml
pagination_next: solutions/input
---

<head>
  <script type="text/javascript" src="https://www.dropbox.com/static/api/2/dropins.js" id="dropboxjs" data-app-key="4ysmnhy8wtm6k3w"></script>
</head>

Dropbox is a file hosting service that offers APIs for programmatic file access.

"Dropbox Apps" are the standard way to interact with the service.  The
["Dropbox App"](#dropbox-app) section describes how this demo was configured.

:::note

The Dropbox API script is loaded in this page with

```html
<script type="text/javascript" src="https://www.dropbox.com/static/api/2/dropins.js" id="dropboxjs" data-app-key="4ysmnhy8wtm6k3w"></script>
```

The `data-app-key` used in this demo is a "Development" key associated with the
`localhost` and `docs.sheetjs.com` domains.  Dropbox API does not require
"Production" approval for the Chooser or Saver.

:::

The live demos require a Dropbox account.

## Reading Files

"Chooser" is a small library that lets users select a file from their account.

### Live Demo

The button must have the following options:

- `multiselect: false` ensures only one file can be selected
- `folderselect: false` limits selection to real files
- `linkType: "direct"` ensures the link points to a raw file

When a file is selected, the `success` callback will receive an array of files
(even if `multiselect` is disabled).  Each file object has a `link` file which
corresponds to a temporary URL that can be fetched.

If the live demo shows a message about `Dropbox` being undefined, please reload
this demo page.

```jsx live
function SheetJSChoisissez() {
  const [msg, setMsg] = React.useState("Press the button to show a Chooser");
  const btn = useRef(), tbl = useRef();
  React.useEffect(() => {
    /* create button */
    var button = Dropbox.createChooseButton({
      /* required settings */
      multiselect: false,
      folderselect: false,
      linkType: "direct",
      /* optional settings */
      extensions: ['.xlsx', '.xls', '.numbers'], // list of extensions

      /* event handlers */
      cancel: () => setMsg("User Canceled Selection!"),
      success: async(files) => {
        /* get file entry -- note that dropbox API always passes an array */
        var file = files[0];
        setMsg(`Selected ${file.name} ID=${file.id}`);

        /* fetch file and parse */
        var wb = XLSX.read(await (await fetch(file.link)).arrayBuffer());

        /* convert first sheet to HTML table and add to page */
        tbl.current.innerHTML = XLSX.utils.sheet_to_html(wb.Sheets[wb.SheetNames[0]]);
      }
    });
    /* add button to page */
    btn.current.appendChild(button);
  }, []);
  return ( <><b>{msg}</b><br/><div ref={btn}/><div ref={tbl}/></> );
}
```

## Writing Files

:::caution

The Dropbox API was not designed for writing files that are created in the web
browser.  The Data URI approach is a neat workaround but should not be used in
production for larger files.  It is better to create the files in the server
using NodeJS and generate a proper URL for Dropbox to fetch.

:::

"Saver" is a small library that lets users save files to their account.

### Live Demo

The file must be written before the Save button is created. Unfortunately the
API does not accept data in the POST body, so the workaround is to create a data
URI by writing with the `base64` type and prepending the URI metadata.

This demo seeds data by fetching a file and writing to HTML table. The generated
table is scraped to create a new workbook that is written to XLS.

If the live demo shows a message about `Dropbox` being undefined, please reload
this demo page.

```jsx live
function SheetJSEnregistrez() {
  const [msg, setMsg] = React.useState("Press the button to write XLS file");
  const btn = useRef(), tbl = useRef();
  React.useEffect(async() => {
    /* fetch data and write table (sample data) */
    const f = await(await fetch("https://sheetjs.com/pres.xlsx")).arrayBuffer();
    const wb = XLSX.read(f);
    tbl.current.innerHTML = XLSX.utils.sheet_to_html(wb.Sheets[wb.SheetNames[0]]);

    /* create workbook from table */
    const table = tbl.current.getElementsByTagName("TABLE")[0];
    const new_wb = XLSX.utils.table_to_book(table);

    /* write XLS workbook (Base64 string) */
    const b64 = XLSX.write(new_wb, { type: "base64", bookType: "xls" });

    /* create data URI */
    const url = "data:application/vnd.ms-excel;base64," + b64;

    /* create save button using the concise function call */
    var button = Dropbox.createSaveButton( url, "SheetJSDropbox.xls", {
      success: () => setMsg("File saved successfully!"),
      cancel: () => setMsg("User Canceled Selection!"),
    });
    /* add button to page */
    btn.current.appendChild(button);
  }, []);
  return ( <><b>{msg}</b><br/><div ref={btn}/><div ref={tbl}/></> );
}
```

## Dropbox App

This demo requires a "Dropbox app":

0) Create a Dropbox app through the Developer tools.  For this demo:

- "Choose an APU": "Scoped access"
- "Choose the type of access you need": "Full Dropbox"
- "Name": (enter any name) "SheetJS Docs"

:::caution

The Dropbox API Terms and Conditions should be reviewed before acceptance.

:::

1) Configure the Dropbox app in the Developer tools.

The following permissions should be selected in the "Permissions" tab

- `files.metadata.write` (View and edit information about your Dropbox files and folders)
- `files.metadata.read` (View information about your Dropbox files and folders)
- `files.content.write` (Edit content of your Dropbox files and folders)
- `files.content.read` (View content of your Dropbox files and folders)

In the settings tab, under "Chooser / Saver / Embedder domains", the desired
public domains should be added. `localhost` must also be added for development
use (it is not automatically enabled).

