--- title: Dropbox pagination_prev: demos/local/index pagination_next: demos/extensions/index --- 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 ``` 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. :::caution If the live demo shows a message ``` ReferenceError: Dropbox is not defined ``` please refresh the page. This is a known bug in the documentation generator. ::: ```jsx live function SheetJSChoisissez() { const [msg, setMsg] = React.useState("Press the button to show a Chooser"); const btn = useRef(), tbl = useRef(); React.useEffect(() => { if(typeof Dropbox == "undefined") return setMsg("Dropbox is not defined"); /* 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 ( <>{msg}
); } ``` ## 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. :::caution If the live demo shows a message ``` ReferenceError: Dropbox is not defined ``` please refresh the page. This is a known bug in the documentation generator. ::: ```jsx live function SheetJSEnregistrez() { const [msg, setMsg] = React.useState("Press the button to write XLS file"); const btn = useRef(), tbl = useRef(); React.useEffect(async() => { if(typeof Dropbox == "undefined") return setMsg("Dropbox is not defined"); /* 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 ( <>{msg}
); } ``` ## Dropbox App :::note This demo was last tested on 2023 February 28. ::: 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).