objects-to-csv

What is objects-to-csv?

The objects-to-csv npm package is a simple and efficient tool for converting JavaScript objects into CSV (Comma-Separated Values) format. It is particularly useful for exporting data to CSV files, which can then be used for data analysis, reporting, or sharing with other systems.

What are objects-to-csv's main functionalities?

Convert Objects to CSV String

This feature allows you to convert an array of JavaScript objects into a CSV string. The code sample demonstrates how to create a CSV string from an array of objects.

const ObjectsToCsv = require('objects-to-csv');

const data = [
  { name: 'John', age: 30, city: 'New York' },
  { name: 'Jane', age: 25, city: 'San Francisco' }
];

const csv = new ObjectsToCsv(data);
const csvString = await csv.toString();
console.log(csvString);

Save CSV to File

This feature allows you to save the CSV string to a file on disk. The code sample demonstrates how to write the CSV data to a file named 'data.csv'.

const ObjectsToCsv = require('objects-to-csv');

const data = [
  { name: 'John', age: 30, city: 'New York' },
  { name: 'Jane', age: 25, city: 'San Francisco' }
];

const csv = new ObjectsToCsv(data);
await csv.toDisk('./data.csv');
console.log('CSV file saved.');

Append Data to Existing CSV File

This feature allows you to append new data to an existing CSV file. The code sample demonstrates how to append a new object to the existing 'data.csv' file.

const ObjectsToCsv = require('objects-to-csv');

const newData = [
  { name: 'Alice', age: 28, city: 'Los Angeles' }
];

const csv = new ObjectsToCsv(newData);
await csv.toDisk('./data.csv', { append: true });
console.log('Data appended to CSV file.');

Other packages similar to objects-to-csv

json2csv

The json2csv package is another popular tool for converting JSON data to CSV format. It offers a variety of options for customizing the output, such as specifying fields, field names, and delimiters. Compared to objects-to-csv, json2csv provides more flexibility and customization options but may require more configuration.

csv-writer

The csv-writer package is designed for writing CSV files in a simple and efficient manner. It supports writing both objects and arrays to CSV files and offers features like custom headers and field ordering. Compared to objects-to-csv, csv-writer is more focused on writing CSV files and provides a straightforward API for this purpose.

fast-csv

The fast-csv package is a comprehensive library for working with CSV files, including reading, writing, and parsing CSV data. It is known for its performance and flexibility, making it suitable for handling large datasets. Compared to objects-to-csv, fast-csv offers a broader range of functionalities beyond just converting objects to CSV.

README

Convert array of objects into a CSV file

Converts an array of JavaScript objects into the CSV format. You can save the CSV to file or return it as a string.

The keys in the first object of the array will be used as column names.

Any special characters in the values (such as commas) will be properly escaped.

Usage

const ObjectsToCsv = require('objects-to-csv');

// Sample data - two columns, three rows:
const data = [
  {code: 'CA', name: 'California'},
  {code: 'TX', name: 'Texas'},
  {code: 'NY', name: 'New York'},
];

// If you use "await", code must be inside an asynchronous function:
(async () => {
  const csv = new ObjectsToCsv(data);

  // Save to file:
  await csv.toDisk('./test.csv');

  // Return the CSV file as string:
  console.log(await csv.toString());
})();

Methods

There are two methods, toDisk(filename) and toString().

async toDisk(filename, options)

Converts the data and saves the CSV file to disk. The filename must include the path as well.

The options is an optional parameter which is an object that contains the settings. Supported options:

• append - whether to append to the file. Default is false (overwrite the file). Set to true to append. Column names will be added only once at the beginning of the file. If the file does not exist, it will be created.
• bom - whether to add the Unicode Byte Order Mark at the beginning of the file. Default is false; set to true to be able to view Unicode in Excel properly. Otherwise Excel will display Unicode incorrectly.
• allColumns - whether to check all array items for keys to convert to columns rather than only the first. This will sort the columns alphabetically. Default is false; set to true to check all items for potential column names.

const ObjectsToCsv = require('objects-to-csv');
const sampleData = [{ id: 1, text: 'this is a test' }];

// Run asynchronously, without awaiting:
new ObjectsToCsv(sampleData).toDisk('./test.csv');

// Alternatively, you can append to the existing file:
new ObjectsToCsv(sampleData).toDisk('./test.csv', { append: true });

// `allColumns: true` collects column names from all objects in the array,
// instead of only using the first one. In this case the CSV file will
// contain three columns:
const mixedData = [
  { id: 1, name: 'California' },
  { id: 2, description: 'A long description.' },
];
new ObjectsToCsv(mixedData).toDisk('./test.csv', { allColumns: true });

async toString(header = true, allColumns = false)

Returns the CSV file as a string.

Two optional parameters are available:

• header controls whether the column names will be returned as the first row of the file. Default is true. Set it to false to get only the data rows, without the column names.
• allColumns controls whether to check every item for potential keys to process, rather than only the first item; this will sort the columns alphabetically by key name. Default is false. Set it to true to process keys that may not be present in the first object of the array.

const ObjectsToCsv = require('objects-to-csv');
const sampleData = [{ id: 1, text: 'this is a test' }];

async function printCsv(data) {
  console.log(
    await new ObjectsToCsv(data).toString()
  );
}

printCsv(sampleData);

Requirements

Use Node.js version 8 or above.

Changelog

1.3.6

• Fix vulnerable package (handlebars) in dependency