@atomictech/xlsx-write-stream

⏩ XLSX Write Stream ⏩

Stream huge amount of data into an XLSX generated file stream with minimum memory footprint.

XLSX Write Stream is a streaming writer for XLSX spreadsheets. Its purpose is to replace CSV for large exports, because using CSV in Excel is very buggy and error prone. It's very efficient and can quickly write hundreds of thousands of rows with low memory usage.

Table of content

• ⏩ XLSX Write Stream ⏩
  • Table of content
  • 📦 Install
  • 🦄 Usage
    • Basic pipe
    • Basic write
    • Custom styles
  • 🔧 API
    • XLSXWriteStream ⇐ Transform
    • new XLSXWriteStream([options])
    • StyleDefs
  • 🚧 Compatibility
  • 👥 Authors
  • 🤝 Contributing
  • ⭐️ Show your support
  • 📝 License

📦 Install

npm install @atomictech/xlsx-write-stream

🦄 Usage

For all usages keep in mind that you should feed your XLSXWriteStream instance one row at a time, where a row could be an array or an object.

const row = [1, '02', new Date('2015-10-21T16:29:00.000Z'), true, false, '🦄'];

or

const row = {
  'A Number Column': 1,
  'A Text Column': '02',
  'A Date Column': new Date('2015-10-21T16:29:00.000Z'),
  'A Boolean Column': true,
  'Another Boolean Column': false,
  'Another Text Column': '🦄'
};

Basic pipe

import XLSXWriteStream from '@atomictech/xlsx-write-stream';

// Initialize the writer
const xlsxWriter = new XLSXWriteStream();

// Pipe a Stream.Readable input stream into the writer
const inputStream = new MyCustomReadableStream();
inputStream.pipe(xlsxWriter);

// Pipe the writer into a Stream.Writable output stream in order to retrieve XLSX file data,
// write it into file or send it as HTTP response.
const writeStream = fs.createWriteStream('file.xlsx');
xlsxWriter.pipe(writeStream);

Basic write

import XLSXWriteStream from '@atomictech/xlsx-write-stream';

// [optional] Define some headers
const headers = ['A Number Column', 'A Text Column', 'A Date Column', 'A Boolean Column', 'Another Boolean Column', 'Another Text Column'];

// Initialize the writer
const xlsxWriter = new XLSXWriteStream({ headers });

// Pipe the writer into a Stream.Writable output stream in order to retrieve XLSX file data,
// write it into file or send it as HTTP response.
const writeStream = fs.createWriteStream('file.xlsx');
xlsxWriter.pipe(writeStream);

// Write rows one by one with
const row = [1, '02', new Date('2015-10-21T16:29:00.000Z'), true, false, '🦄'];
xlsxWriter.write(row);
xlsxWriter.end(); // Do not forget to end the stream!

⚠️ Caution ⚠️

If you are not familiar with streams, in order to take advantage of the smallest memory footprint possible with this form, you need to be aware of backpressure concept and use the boolean returned by the write function!

See explanations here: writable.write(chunk[, encoding][, callback])

Custom styles

An options.styleDefs parameter is available in order to redefine type style formats.

import { TypeStyleKey } from '@atomictech/xlsx-write-stream';

// Declare custom styles definitions
const styleDefs = {};
styleDefs[TypeStyleKey.DATE] = { formatCode: 'yy-mm-dd hh:mm' };
styleDefs[TypeStyleKey.INT] = { numFmtId: 49 }; // 49 is "enforced text format"

// Create the writer
const xlsxWriter = new XLSXWriterStream({ styleDefs });

// NB: if you set `format: false` your styleDefs will not be used

🔧 API

XLSXWriteStream ⇐ Transform

new XLSXWriteStream([options])

Create new stream transform that handles Array or Object as input chunks. Be aware that first row chunk is determinant in the transform configuration process for further row chunks.

Param	Type	Default	Description
[options]	Object
[options.headers]	`Array	Boolean`	false
[options.format]	Boolean	true	If set to false writer will not format cells with number, date, boolean and text.
[options.styleDefs]	StyleDefs		If set you can overwrite default standard type styles by other standard ones or even define custom formatCode.
[options.immediateInitialization]	Boolean	false	If set to true writer will initialize archive and start compressing xlsx common stuff immediately, adding subsequently a little memory and processor footprint. If not, initialization will be delayed to the first data processing.

StyleDefs

A little of TypeScript to explain StyleDefs interface:

enum TypeStyleKey = {
  NUMBER: 'default', //!\\ Unused in the actual type conversion
  INT: 'int', // Integer <1000
  FLOAT: 'float', // Float <1000
  BIG_INT: 'bigInt', // Integer >=1000
  BIG_FLOAT: 'bigFloat', // Float >=1000
  EXP_NUMBER: 'expNumber', // Number with more than 10 digits/characters (ex: 10000000000 or 12.45678901)
  TEXT: 'text', // String
  DATE: 'date', // Date
  DATETIME: 'datetime' //!\\ Unused in the actual type conversion
};

interface TypeFormatReference {
  numFmtId: number;
}

interface TypeFormatDefinition {
  formatCode: string;
}

interface StyleDefs {
    [typeKey: TypeStyleKey]: TypeFormatReference | TypeFormatDefinition;
}

Example:

{
  date: { formatCode: 'yy-mm-dd hh:mm' },
  int: { numFmt: 49 }
}

See here for other default numFmtId: https://docs.microsoft.com/en-us/dotnet/api/documentformat.openxml.spreadsheet.numberingformat?view=openxml-2.8.1

🚧 Compatibility

XLSX Write Stream - supported:

Cell type:

• string [starting with =] ➡ formula
• string [others] ➡ text
• date ➡ date
• number ➡ number
• boolean ➡ boolean

Cell type formatting:

• text (default: numFmtId: 49 - enforce text even if could be interpreted as number)
• date (default: formatCode: 'yyyy-mm-dd' - )
• number
  • int (default: numFmtId: 1)
  • float (default: numFmtId: 2)
  • bigInt (default: numFmtId: 3)
  • bigFloat (default: numFmtId: 4)
  • expNumber (default: numFmtId: 1)

XLSX Write Stream - NOT supported:

• charts
• comments
• ... and a myriad of other OOXML features. It's strictly a CSV replacement.

👥 Authors

👤 Apify

• Website: https://apify.com/
• Github: @apifytech

👤 AtomicTech

• Github: @atomictech

🤝 Contributing

Contributions, issues and feature requests are welcome!
Feel free to check issues page. You can also take a look at the contributing guide.

⭐️ Show your support

Give a ⭐️ if this project helped you!

📝 License

This project is Apache-2.0 licensed.