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"New Visitor","(not set)","(not set)","0"
"New Visitor","(not set)","(not set)","mobile"
"New Visitor","(not set)","(not set)","mobile"
"New Visitor","(not set)","(not set)","mobile"
Please give me suggetions using Node.js.
// 1. One way - if you want the results to be in double quotes and you have comas inside
// choose another string to temporally replace commas if necessary
let stringToReplaceComas = '!!!!';
myObj.rows.map((singleRow) => {
singleRow.map((value, index) => {
singleRow[index] = value.replace(/,/g, stringToReplaceComas);
let csv = `"${myObj.rows.join('"\n"').replace(/,/g, '","')}"`;
// // or like this
// let csv = `"${myObj.rows.join('"\n"').split(',').join('","')}"`;
csv = csv.replace(new RegExp(`${stringToReplaceComas}`, 'g'), ',');
// // 2. Another way - if you don't need the double quotes in the generated csv and you don't have comas in rows' values
// let csv = myObj.rows.join('\n')
fs.writeFile('name.csv', csv, 'utf8', function(err) {
if (err) {
console.log('Some error occured - file either not saved or corrupted file saved.');
} else {
console.log('It\'s saved!');
Use libraries
ex. https://github.com/mrodrig/json-2-csv, https://github.com/wdavidw/node-csv, https://github.com/wdavidw/node-csv-stringify
an example using json-2-csv (https://github.com/mrodrig/json-2-csv)
'use strict';
const converter = require('json-2-csv');
let myObj = {
"rows": [
value1: "New Visitor",
value2: "(not set)",
value3: "(not set)",
value4: "0"
value1: "New Visitor",
value2: "(not set)",
value3: "(not set)",
value4: "mobile"
value1: "New Visitor",
value2: "(not set)",
value3: "(not set)",
value4: "mobile"
value1: "New Visitor",
value2: "(not set)",
value3: "(not set)",
value4: "mobile",
let json2csvCallback = function (err, csv) {
if (err) throw err;
fs.writeFile('name.csv', csv, 'utf8', function(err) {
if (err) {
console.log('Some error occured - file either not saved or corrupted file saved.');
} else {
console.log('It\'s saved!');
converter.json2csv(myObj.rows, json2csvCallback, {
prependHeader: false // removes the generated header of "value1,value2,value3,value4" (in case you don't want it)
an example using csv-stringify (https://github.com/wdavidw/node-csv-stringify)
'use strict';
var stringify = require('csv-stringify');
var fs = require('fs');
let myObj = {
"rows": [
"New Visitor",
"(not set)",
"(not set)",
"New Visitor",
"(not set)",
"(not set)",
"mobile"
"New Visitor",
"(not set)",
"(not set)",
"mobile"
"New Visitor",
"(not set)",
"(not set)",
"mobile",
stringify(myObj.rows, function(err, output) {
fs.writeFile('name.csv', output, 'utf8', function(err) {
if (err) {
console.log('Some error occured - file either not saved or corrupted file saved.');
} else {
console.log('It\'s saved!');
–
–
–
Step 1: Read.
If you need to read the JSON from a file (as indicated by your inclusion of the filename response.json in your post), you will require the Node.js FileSystem API:
const fs = require('fs'); // Require Node.js FileSystem API.
const JSONFile = fs.readFileSync('response.json'); // Read the file synchronously.
Note: If you prefer, you can read the file asynchronously with fs.readFile() and perform the conversion in a callback function.
Step 2: Convert.
Whether you read your JSON from a local file or GET it from a server, you will need to parse it into a Plain Old JavaScript Object first using the JSON.parse method:
const JSONasPOJO = JSON.parse(JSONFile); // Parse JSON into POJO.
Then perform a series of joins on the child arrays and parent array:
SEE EDIT BELOW
/* THIS IS UNNECESSARY FOR "COMMA" SEPARATED VALUES
const CSVString = JSONasPOJO
.rows // Get `rows`, which is an array.
.map( // Map returns a new array.
row => row.join(',') // Each child array becomes a comma-separated string.
.join('\n'); // Parent array becomes a newline-separated string...
// ...of comma-separated strings.
// It is now a single CSV string!
EDIT:
While the previous code certainly works, it is unnecessary to use .map and .join on the child arrays. As @Relu demonstrates, a single .join on the parent array is sufficient because JavaScript will automatically convert the child arrays into comma-separated strings by default since .join must return a string and cannot contain any child arrays.
You could use the above pattern if you want to join the child arrays with something other than a comma.
Otherwise:
var CSVString = JSONasPOJO.rows.join('\n'); // Array becomes a newline-separated...
// ...string of comma-separated strings.
// It is now a single CSV string!
Here, we can see that conversion in action:
const JSONasPOJO = {
"rows": [
"New Visitor",
"(not set)",
"(not set)",
"New Visitor",
"(not set)",
"(not set)",
"mobile"
"New Visitor",
"(not set)",
"(not set)",
"mobile"
"New Visitor",
"(not set)",
"(not set)",
"mobile" // NOTE: Here I removed a trailing comma,
// ...which is invalid JSON!
const CSVString = JSONasPOJO.rows.join('\n');
console.log(CSVString);
Step 3: Write.
Using the FileSystem API again, write to a file, and log an error or a success message:
fs.writeFile('name.csv', CSVString, err => {
if (err) return console.log(err);
console.log('FILE SUCCESSFULLY WRITTEN!\n');
Note: Here, I demonstrate the asynchronous pattern using a callback to log my error and success messages. If you prefer, you can write the file synchronously with fs.writeFileSync().
Putting it all together
I like to add plenty of console.log() messages to my Node.js scripts.
const fs = require('fs');
const inFilename = 'response.json',
outFilename = 'name.csv';
console.log(`Preparing to read from ${inFilename} …`);
const JSONContents = fs.readFileSync(inFilename);
console.log(`READ:\n${JSONContents}`);
console.log('Preparing to parse as JSON …');
const JSONasPOJO = JSON.parse(JSONContents);
console.log(`PARSED:\n${JSONasPOJO}`);
console.log('Preparing to convert into CSV …');
const CSVString = JSONasPOJO.rows.join('\n');
console.log(`CONVERTED:\n${CSVString}`);
console.log(`Preparing to write to ${outFilename} …`);
fs.writeFile(outFilename, CSVString, err => {
if (err) return console.error(err);
console.log('FILE SUCCESSFULLY WRITTEN!');
I don't know about you guys, but i like small packages that just work as expected without a lot of extra configuration, try using jsonexport, i think its the best module for this, works really well with objects, arrays, .. and its fast!
Install
npm i --save jsonexport
Usage
const jsonexport = require('jsonexport');
const fs = require('fs');
jsonexport([{
value1: "New Visitor",
value2: "(not set)",
value3: "(not set)",
value4: "0"
value1: "New Visitor",
value2: "(not set)",
value3: "(not set)",
value4: "mobile"
value1: "New Visitor",
value2: "(not set)",
value3: "(not set)",
value4: "mobile"
value1: "New Visitor",
value2: "(not set)",
value3: "(not set)",
value4: "mobile",
}], function(err, csv) {
if (err) return console.error(err);
fs.writeFile('output.csv', csv, function(err) {
if (err) return console.error(err);
console.log('output.csv saved');
https://github.com/kauegimenes/jsonexport
–
After several hours trying to use the library and I ended up write my own.
https://github.com/KhanhPham2411/simple-node-csv
import { SimpleNodeCsv } from './simple-node-csv';
SimpleNodeCsv.obj2csv({a: 1, b:2}, ",");
// output
// "a","b"
// 1,2
const header = Object.keys(data[0]).map(_ => JSON.stringify(_)).join(';') + '\n'
const outData = data.reduce((acc, row) => {
return acc + Object.values(row).map(_ => JSON.stringify(_)).join(';') + '\n'
}, header)
console.log(outData)
–
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