How to download excel file from nodejs terminal - node.js

Question

I am new to nodejs. Need your help. From the nodejs terminal, i want to download an excel file and convert it to csv (say, mocha online.js). Note: i don't want to do this via a browser.
Below is a script i am working on to download and convert to csv. There is no error nor the expected result:
online.js
if (typeof require !== 'undefined') XLSX = require('xlsx');
var XMLHttpRequest = require("xmlhttprequest").XMLHttpRequest;
/* set up XMLHttpRequest */
var url = "http://oss.sheetjs.com/js-xlsx/test_files/formula_stress_test_ajax.xlsx";
var xhr = new XMLHttpRequest();
xhr.open("GET", url, true);
xhr.responseType = "arraybuffer";
describe('suite', function () {
it('case', function () {
var arraybuffer = xhr.response;
/* convert data to binary string */
var data = new Uint8Array(arraybuffer);
var arr = new Array();
for (var i = 0; i != data.length; ++i) arr[i] = String.fromCharCode(data[i]);
var bstr = arr.join("");
/* Call XLSX */
var sheetName = 'Database';
var workbook = XLSX.read(bstr, { type: "binary" });
var worksheet = workbook.Sheets[sheetName];
var csv = XLSX.utils.sheet_to_csv(worksheet);
console.log(csv);
xhr.send();
//.... perform validations here using the csv data
});
})}

Answer 1

I tried myself with this code, and it seems it is working, the only thing is that I spent 15 minutes trying to understand why my open office would not open the file, I eventually understood that they were sending a zip file ... here is the full code, the doc of the http get function is here http.get
You could have used the request module, but it isn't native, request is easier though.
enjoy!
const url = 'http://oss.sheetjs.com/js-xlsx/test_files/formula_stress_test_ajax.xlsx'
const http = require('http')
const fs = require('fs')
http.get(url, (res) => {
debugger
const {
statusCode
} = res;
const contentType = res.headers['content-type'];
console.log(`The type of the file is : ${contentType}`)
let error;
if (statusCode !== 200) {
error = new Error(`Request Failed.\n` +
`Status Code: ${statusCode}`);
}
if (error) {
console.error(error.message);
// consume response data to free up memory
res.resume();
return;
}
res.setEncoding('binary');
let rawData = '';
res.on('data', (chunk) => {
rawData += chunk;
});
res.on('end', () => {
try {
const parsedData = xlsxToCSVFunction(rawData);
// And / Or just put it in a file
fs.writeFileSync('fileName.zip', rawData, 'binary')
// console.log(parsedData);
} catch (e) {
console.error(e.message);
}
});
}).on('error', (e) => {
console.error(`Got error: ${e.message}`);
});
function xlsxToCSVFunction(rawData) {
return rawData //you should return the csv file here whatever your tools are
}

Answer 2

I actually encountered the same problem 3 months ago : here is what I did!
I did not find any nodeJS module that was exactly as I wanted, so I used in2csv (a python shell program) to transform the data; the t option is to use tabulation as the delimiter
1) Step 1: transforming the xlsx file into csv using in2csv
This code takes all the xlsx files in the current directory, transform them into csv files and put them in another directory
var shelljs = require('shelljs/global')
var dir = pwd().stdout.split('/')
dir = dir[dir.length - 1].replace(/\s/g, '\\ ')
mkdir('../'+ dir + 'CSV')
ls('*.xlsx').forEach(function(file) {
// below are the two lines you need
let string = 'in2csv -t ' + file.replace(/\s/g, '\\ ') + ' > ../'+ dir + 'CSV/' + file.replace('xlsx','csv').replace(/\s/g, '\\ ')
exec(string, {silent:true}, function(code, stdout, stderr){
console.log('new file : ' + file.replace('xlsx','csv'))
if(stderr){
console.log(string)
console.log('Program stderr:', stderr)
}
})
});
Step 2: loading the data in a nodejs program:
my script is very long but the main two lines are :
const args = fileContent.split('\n')[0].split(',')
const content = fileContent.split('\n').slice(1).map(e => e.split(','))

Answer 3

And for the benefit of seekers like me...here is a solution using mocha, request and xlsx
var request = require('request');
var XLSX = require('xlsx');
describe('suite', function () {
it('case', function (done) {
var url = "http://oss.sheetjs.com/js-xlsx/test_files/formula_stress_test_ajax.xlsx";
var options = {
url: url,
headers: {
'Content-Type': 'application/vnd.openxmlformats-officedocument.spreadsheetml.sheet'
},
encoding: null
};
request.get(options, function (err, res, body){
var arraybuffer = body;
/* convert data to binary string */
var data = arraybuffer;
//var data = new Uint8Array(arraybuffer);
var arr = new Array();
for (var i = 0; i != data.length; ++i) arr[i] = String.fromCharCode(data[i]);
var bstr = arr.join("");
/* Call XLSX */
var sheetName = 'Database';
var workbook = XLSX.read(bstr, { type: "binary" });
var worksheet = workbook.Sheets[sheetName];
var csv = XLSX.utils.sheet_to_csv(worksheet);
console.log(csv);
done();
});
});
});