sheetjs/docbits/31_writestream.md

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 Readable Stream. They are only exposed in NodeJS.

• 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.

nodejs convert to CSV and write file (click to show)

var output_file_name = "out.csv";
var stream = XLSX.stream.to_csv(worksheet);
stream.pipe(fs.createWriteStream(output_file_name));

nodejs write JSON stream to screen (click to show)

/* to_json returns an object-mode stream */
var stream = XLSX.stream.to_json(worksheet, {raw:true});

/* the following stream converts JS objects to text via JSON.stringify */
var conv = new Transform({writableObjectMode:true});
conv._transform = function(obj, e, cb){ cb(null, JSON.stringify(obj) + "\n"); };

stream.pipe(conv); conv.pipe(process.stdout);

https://github.com/sheetjs/sheetaki pipes write streams to nodejs response.