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# Data Export
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## Writing Workbooks
### API
_Generate spreadsheet bytes (file) from data_
```js
var data = XLSX.write(workbook, opts);
```
The `write` method attempts to package data from the workbook into a file in
memory. By default, XLSX files are generated, but that can be controlled with
the `bookType` property of the `opts` argument. Based on the `type` option,
the data can be stored as a "binary string", JS string, `Uint8Array` or Buffer.
The second `opts` argument is required. ["Writing Options"](/docs/api/write-options)
covers the supported properties and behaviors.
_Generate and attempt to save file_
```js
XLSX.writeFile(workbook, filename, opts);
```
The `writeFile` method packages the data and attempts to save the new file. The
export file format is determined by the extension of `filename` (`SheetJS.xlsx`
signals XLSX export, `SheetJS.xlsb` signals XLSB export, etc).
The second `opts` argument is optional. ["Writing Options"](/docs/api/write-options)
covers the supported properties and behaviors.
_Generate and attempt to save an XLSX file_
```js
XLSX.writeFileXLSX(workbook, filename, opts);
```
The `writeFile` method embeds a number of different export functions. This is
great for developer experience but not amenable to tree shaking using the
current developer tools. When only XLSX exports are needed, this method avoids
referencing the other export functions.
The second `opts` argument is optional. ["Writing Options"](/docs/api/write-options)
covers the supported properties and behaviors.
:::note
The `writeFile` and `writeFileXLSX` methods uses platform-specific APIs to save
files. The APIs do not generally provide feedback on whether files were created.
:::
#### Examples
Here are a few common scenarios (click on each subtitle to see the code).
The [demos](/docs/demos) cover special deployments in more detail.
### Example: Local File
`XLSX.writeFile` supports writing local files in platforms like NodeJS. In other
platforms like React Native, `XLSX.write` should be called with file data.
`XLSX.writeFile` wraps a few techniques for triggering a file save:
- `URL` browser API creates an object URL for the file, which the library uses
by creating a link and forcing a click. It is supported in modern browsers.
- `msSaveBlob` is an IE10+ API for triggering a file save.
- `IE_FileSave` uses VBScript and ActiveX to write a file in IE6+ for Windows
XP and Windows 7. The shim must be included in the containing HTML page.
There is no standard way to determine if the actual file has been downloaded.
```js
/* output format determined by filename */
XLSX.writeFile(workbook, "out.xlsb");
/* at this point, out.xlsb will have been downloaded */
```
:::caution Web Workers
None of the file writing APIs work from Web Workers. To generate a file:
1) use `XLSX.write` with type `array` to generate a `Uint8Array`:
```js
// in the web worker, generate the XLSX file as a Uint8Array
const u8 = XLSX.write(workbook, { type: "array", bookType: "xlsx" });
```
2) send the data back to the main thread:
```js
// in the web worker, send the generated data back to the main thread
postMessage({t: "export", v: u8 });
```
3) from the main thread, add an event listener to write to file:
```js
// in the main page
worker.addEventListener('message', function(e) {
if(e && e.data && e.data.t == "export") {
e.stopPropagation();
e.preventDefault();
// data will be the Uint8Array from the worker
const data = e.data.v;
var blob = new Blob([data], {type:"application/octet-stream"});
var url = URL.createObjectURL(blob);
var a = document.createElement("a");
a.download = "SheetJSXPort.xlsx";
a.href = url;
document.body.appendChild(a);
a.click();
}
});
```
:::
SWF workaround for Windows 95+ (click to show)
:::warning
Each moving part in this solution has been deprecated years ago:
- Adobe stopped supporting Flash Player at the end of 2020
- Microsoft stopped supporting IE8 in 2019 and stopped supporting IE9 in 2020
- `Downloadify` support ended in 2010 and `SWFObject` support ended in 2016
New projects should strongly consider requiring modern browsers. This info is
provided on an "as is" basis and there is no realistic way to provide support
given that every related vendor stopped providing support for their software.
:::
`XLSX.writeFile` techniques work for most modern browsers as well as older IE.
For much older browsers, there are workarounds implemented by wrapper libraries.
[`Downloadify`](/docs/demos/frontend/legacy#download-strategies) uses a Flash SWF button
to generate local files, suitable for environments where ActiveX is unavailable:
```js
Downloadify.create(id,{
/* other options are required! read the downloadify docs for more info */
filename: "test.xlsx",
data: function() { return XLSX.write(wb, {bookType:"xlsx", type:"base64"}); },
append: false,
dataType: "base64"
});
```
The [`oldie` demo](/docs/demos/frontend/legacy#internet-explorer) shows an IE-compatible fallback scenario.
`writeFile` uses `fs.writeFileSync` under the hood:
```js
var XLSX = require("xlsx");
/* output format determined by filename */
XLSX.writeFile(workbook, "out.xlsb");
```
For Node ESM, `fs` must be loaded manually:
```js
import * as fs from "fs";
import { writeFile, set_fs } from "xlsx";
set_fs(fs);
/* output format determined by filename */
writeFile(workbook, "out.xlsb");
```
As with Node ESM, `fs` must be loaded manually:
```js
import * as fs from "fs";
import { writeFile, set_fs } from "xlsx";
set_fs(fs);
/* output format determined by filename */
writeFile(workbook, "out.xlsb");
```
`writeFile` uses `Deno.writeFileSync` under the hood:
{`\
// @deno-types="https://cdn.sheetjs.com/xlsx-${current}/package/types/index.d.ts"
import * as XLSX from 'https://cdn.sheetjs.com/xlsx-${current}/package/xlsx.mjs';
XLSX.writeFile(workbook, "test.xlsx");`}
:::note
Applications writing files must be invoked with the `--allow-write` flag.
:::
`writeFile` can be used in the renderer process:
```js
/* From the renderer process */
var XLSX = require("xlsx");
XLSX.writeFile(workbook, "out.xlsb");
```
Electron APIs have changed over time. The [`electron` demo](/docs/demos/desktop#electron)
shows a complete example and details the required version-specific settings.
[The React Native Demo](/docs/demos/mobile#rn-file-plugins) covers tested plugins.
`writeFile` wraps the `File` logic in Photoshop and other ExtendScript targets.
The specified path should be an absolute path:
```js
#include "xlsx.extendscript.js"
/* Ask user to select path */
var thisFile = File.saveDialog("Select an output file", "*.xlsx;*.xls");
/* output format determined by filename */
XLSX.writeFile(workbook, thisFile.absoluteURI);
```
The [`extendscript` demo](/docs/demos/extendscript) includes a more complex example.
The [`headless` demo](/docs/demos/headless) includes complete
examples of converting HTML TABLE elements to XLSB workbooks using Puppeteer
and other headless automation tools.
Headless browsers may not have access to the filesystem, so `XLSX.writeFile`
may fail. It is strongly recommended to generate the file bytes in the browser
context, send the bytes to the automation context, and write from automation.
Puppeteer and Playwright are NodeJS modules that support binary strings:
```js
/* from the browser context */
var bin = XLSX.write(workbook, { type:"binary", bookType: "xlsb" });
/* from the automation context */
fs.writeFileSync("SheetJSansHead.xlsb", bin, { encoding: "binary" });
```
PhantomJS `fs.write` supports writing files from the main process. The mode
`wb` supports binary strings:
```js
/* from the browser context */
var bin = XLSX.write(workbook, { type:"binary", bookType: "xlsb" });
/* from the automation context */
fs.write("SheetJSansHead.xlsb", bin, "wb");
```
### Example: Server Responses
This example focuses on responses to network requests in a server-side platform
like NodeJS. While files can be generated in the web browser, server-side file
generation allows for exact audit trails and has better mobile user support.
:::caution
Production deployments should use a server framework like ExpressJS. These
snippets use low-level APIs for illustration purposes.
:::
The `Content-Type` header should be set to `application/vnd.ms-excel` for Excel
exports including XLSX. The default `application/octet-stream` can be used, but
iOS will not automatically suggest to open files in Numbers or Excel for iOS
The `Content-Disposition` header instructs browsers to download the response
into a file. The header can also include the desired file name.
NodeJS `http.ServerResponse#end` can accept `Buffer` objects. `XLSX.write` with
`buffer` type returns `Buffer` objects.
```js
/* generate Buffer */
const buf = XLSX.write(wb, { type:"buffer", bookType:"xlsx" });
/* prepare response headers */
res.statusCode = 200;
res.setHeader('Content-Disposition', 'attachment; filename="SheetJSNode.xlsx"');
res.setHeader('Content-Type', 'application/vnd.ms-excel');
res.end(buf);
```
Complete Example (click to show)
Install the library with
```bash
npm i https://cdn.sheetjs.com/xlsx-latest/xlsx-latest.tgz
```
Save the following script to `node.js` and run with `node node.js`:
```js title="node.js"
const http = require('http');
const XLSX = require('xlsx');
const hostname = '127.0.0.1';
const port = 7262;
/* fixed sample worksheet */
const wb = XLSX.utils.book_new();
XLSX.utils.book_append_sheet(wb, XLSX.utils.aoa_to_sheet([
["a","b","c"], [1,2,3]
]), "Sheet1");
const server = http.createServer((req, res) => {
const buf = XLSX.write(wb, { type:"buffer", bookType:"xlsx" });
res.statusCode = 200;
res.setHeader('Content-Disposition', 'attachment; filename="SheetJSNode.xlsx"');
res.setHeader('Content-Type', 'application/vnd.ms-excel');
res.end(buf);
});
server.listen(port, hostname, () => {
console.log(`Server running at http://${hostname}:${port}/`);
});
```
Complete Example (click to show)
Save the following script to `deno.ts` and run with `deno run -A deno.ts`. Open
a web browser and access `http://localhost:7262/` to download the workbook.
```ts title="deno.ts"
// @deno-types="https://cdn.sheetjs.com/xlsx-latest/package/types/index.d.ts"
import * as XLSX from 'https://cdn.sheetjs.com/xlsx-latest/package/xlsx.mjs';
const wb = XLSX.utils.book_new();
XLSX.utils.book_append_sheet(wb, XLSX.utils.aoa_to_sheet([
["a","b","c"], [1,2,3]
]), "Sheet1");
async function doNotAwaitThis(conn: Deno.Conn) {
for await (const e of Deno.serveHttp(conn)) e.respondWith(new Response(
XLSX.write(wb, {type:"buffer", bookType:"xlsx"}),
{
status: 200,
headers: {
"Content-Type": "application/vnd.ms-excel",
"Content-Disposition": 'attachment; filename="SheetJSDeno.xlsx"'
}
}
));
}
/* standard Deno web server */
const server = Deno.listen({ port: 7262 });
console.log(`HTTP webserver running. Access it at: http://localhost:7262/`);
for await (const conn of server) doNotAwaitThis(conn);
```
Complete Example (click to show)
Download [`xlsx.mjs`](https://cdn.sheetjs.com/xlsx-latest/package/xlsx.mjs).
Save the following script to `bun.js` and run with `bun bun.js`. Open a web
browser and access `http://localhost:7262/` to download the exported workbook.
```js title="bun.js"
import * as XLSX from "./xlsx.mjs";
/* fixed sample worksheet */
const wb = XLSX.utils.book_new();
XLSX.utils.book_append_sheet(wb, XLSX.utils.aoa_to_sheet([
["a","b","c"], [1,2,3]
]), "Sheet1");
export default {
port: 7262,
fetch(request) {
/* generate Buffer */
const buf = XLSX.write(wb, {type:"buffer", bookType:"xlsx"});
/* return Response */
return new Response(buf, {
headers: {
"Content-Type": "application/vnd.ms-excel",
"Content-Disposition": 'attachment; filename="SheetJSBun.xlsx"'
}
});
},
};
```
Populating a database (SQL or no-SQL) (click to show)
The [`data` demo](/docs/demos/data/) includes examples of working with databases and query results.
## Generating HTML Tables
#### API
_Generate HTML Table from Worksheet_
```js
var html = XLSX.utils.sheet_to_html(worksheet);
```
The `sheet_to_html` utility function generates HTML code based on the worksheet
data. Each cell in the worksheet is mapped to a `` element. Merged cells
in the worksheet are serialized by setting `colspan` and `rowspan` attributes.
#### Examples
The `sheet_to_html` utility function generates HTML code that can be added to
any DOM element by setting the `innerHTML`:
```js
var container = document.getElementById("tavolo");
container.innerHTML = XLSX.utils.sheet_to_html(worksheet);
```
Combining with `fetch`, constructing a site from a workbook is straightforward:
This example assigns the `innerHTML` of a DIV element:
```html
```
It is generally recommended to use a React-friendly workflow, but it is possible
to generate HTML and use it in React with `dangerouslySetInnerHTML`:
```jsx
import * as XLSX from 'xlsx';
function Tabeller(props) {
/* the workbook object is the state */
const [workbook, setWorkbook] = React.useState(XLSX.utils.book_new());
/* fetch and update the workbook with an effect */
React.useEffect(() => { (async() => {
/* fetch and parse workbook -- see the fetch example for details */
const wb = XLSX.read(await (await fetch("sheetjs.xlsx")).arrayBuffer());
setWorkbook(wb);
})(); });
return workbook.SheetNames.map(name => (<>
name
));
}
```
The [`react` demo](/docs/demos/frontend/react) includes more React examples.
It is generally recommended to use a VueJS-friendly workflow, but it is possible
to generate HTML and use it in VueJS with the `v-html` directive:
```jsx
import { read, utils } from 'xlsx';
import { reactive } from 'vue';
const S5SComponent = {
mounted() { (async() => {
/* fetch and parse workbook -- see the fetch example for details */
const workbook = read(await (await fetch("sheetjs.xlsx")).arrayBuffer());
/* loop through the worksheet names in order */
workbook.SheetNames.forEach(name => {
/* generate HTML from the corresponding worksheets */
const html = utils.sheet_to_html(workbook.Sheets[name]);
/* add to state */
this.wb.wb.push({ name, html });
});
})(); },
/* this state mantra is required for array updates to work */
setup() { return { wb: reactive({ wb: [] }) }; },
template: `
`
};
```
The [`vuejs` demo](/docs/demos/frontend/vue) includes more React examples.
## Generating Single-Worksheet Snapshots
The `sheet_to_*` functions accept a worksheet object.
#### API
_Generate a CSV from a single worksheet_
```js
var csv = XLSX.utils.sheet_to_csv(worksheet, opts);
```
This snapshot is designed to replicate the "CSV UTF-8 (`.csv`)" output type.
["Delimiter-Separated Output"](/docs/api/utilities#delimiter-separated-output) describes the
function and the optional `opts` argument in more detail.
_Generate "Text" from a single worksheet_
```js
var txt = XLSX.utils.sheet_to_txt(worksheet, opts);
```
This snapshot is designed to replicate the "UTF-16 Text (`.txt`)" output type.
["Delimiter-Separated Output"](/docs/api/utilities#delimiter-separated-output) describes the
function and the optional `opts` argument in more detail.
_Generate a list of formulae from a single worksheet_
```js
var fmla = XLSX.utils.sheet_to_formulae(worksheet);
```
This snapshot generates an array of entries representing the embedded formulae.
Array formulae are rendered in the form `range=formula` while plain cells are
rendered in the form `cell=formula or value`. String literals are prefixed with
an apostrophe `'`, consistent with Excel's formula bar display.
["Formulae Output"](/docs/api/utilities#formulae-output) describes the function in more detail.
## Streaming Write
The streaming write functions are available in the `XLSX.stream` object. They
take the same arguments as the normal write functions but return a NodeJS
Readable Stream.
- `XLSX.stream.to_csv` is the streaming version of `XLSX.utils.sheet_to_csv`.
- `XLSX.stream.to_html` is the streaming version of `XLSX.utils.sheet_to_html`.
- `XLSX.stream.to_json` is the streaming version of `XLSX.utils.sheet_to_json`.
Examples are included in ["Large Datasets"](/docs/demos/stream#streaming-write)
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