npm package discovery and stats viewer.

Discover Tips

  • General search

    [free text search, go nuts!]

  • Package details

    pkg:[package-name]

  • User packages

    @[username]

Sponsor

Optimize Toolset

I’ve always been into building performant and accessible sites, but lately I’ve been taking it extremely seriously. So much so that I’ve been building a tool to help me optimize and monitor the sites that I build to make sure that I’m making an attempt to offer the best experience to those who visit them. If you’re into performant, accessible and SEO friendly sites, you might like it too! You can check it out at Optimize Toolset.

About

Hi, 👋, I’m Ryan Hefner  and I built this site for me, and you! The goal of this site was to provide an easy way for me to check the stats on my npm packages, both for prioritizing issues and updates, and to give me a little kick in the pants to keep up on stuff.

As I was building it, I realized that I was actually using the tool to build the tool, and figured I might as well put this out there and hopefully others will find it to be a fast and useful way to search and browse npm packages as I have.

If you’re interested in other things I’m working on, follow me on Twitter or check out the open source projects I’ve been publishing on GitHub.

I am also working on a Twitter bot for this site to tweet the most popular, newest, random packages from npm. Please follow that account now and it will start sending out packages soon–ish.

Open Software & Tools

This site wouldn’t be possible without the immense generosity and tireless efforts from the people who make contributions to the world and share their work via open source initiatives. Thank you 🙏

© 2024 – Pkg Stats / Ryan Hefner

@iwsio/json-csv-node

v6.1.7

Published

ESM/CJS module that easily converts JSON to CSV. This package supports streaming and buffered conversion to CSV.

Downloads

4,451

Readme

@iwsio/json-csv-node

Push to main - @iwsio/json-csv-node

This package extends @iwsio/json-csv-core specifically targeting Node.JS to support streaming. This package now supports both ESM and CommonJS and includes the same API as json-csv. You can read more about it on my blog.

Usage

Buffered (Converts to CSV with an in-memory data source)

const { toCsv, toCsvSync } = require('@iwsio/json-csv-node') // CJS
import { toCsv, toCsvSync } from '@iwsio/json-csv-node' // ESM

// as a promise
const csv = await toCsv(data, options) // toCsv returns Promise<string>

// optionally, you can use a classic callback instead
toCsv(data, options, function(err, csv) {...}))

// synchronous
const csv = toCsvSync(data, options) // toCsvSync returns string

Streaming (Converts a "row at a time" from a stream source)

When using the streaming API, you can pipe data to it in object mode.

const { toCsvStream } = require('@iwsio/json-csv-node') // CJS
import { toCsvStream } from '@iwsio/json-csv-node' // ESM

const things = [
  {name: 'thing1', age: 20},
  {name: 'thing2', age: 30},
  {name: 'thing3', age: 45}
]
Readable.from(things) // <readable source in object mode>
  .pipe(toCsvStream(options)) // transforms to string and emits lines
  .pipe(process.stdout) // anything Writable


// toCsvStream(options) supports classic callback (for backwards compatibility)
toCsvStream(options, (err, transform) => {
  Readable.from(things)
    .pipe(toCsvStream(options))
})

NOTE: All the aliases from previous versions remain intact.

I renamed this API mostly for cosmetics and to cleanup named exports for ES Modules. It made more sense to me to import { toCSV } from 'json-csv' rather than importing the default and calling its prop. (I've been doing a lot of Typescript lately). But all the original versions are kept intact and tests are in place to assert they work.

const jsonCsv = require('@iwsio/json-csv-node') // CJS
import jsonCsv, { toCSV, toCsvStream, buffered, stream } from '@iwsio/json-csv-node' // ESM

jsonCsv.buffered // buffered (promise or callback)
jsonCsv.bufferedSync // buffered synchronous (passthrough from core)
jsonCsv.stream // stream (or callback w/ stream)

jsonCsv.toCsv // buffered, returns promise, callback optional
jsonCsv.toCsvSync // buffered synchronous (passthrough from core)
jsonCsv.toCsvStream // stream, returns stream, callback optional

// These are deprecated
jsonCsv.csv // alias to toCsvStream (streamed)
jsonCsv.csvBuffered // alias to toCsv (buffered)

Options

{
  // field definitions for CSV export
  fields :
  [
    {
      // required: field name for source value
      name: 'string',

      // optional: column label for CSV header
      label: 'string',

      // optional: transform value before exporting
      transform: function(value) { return value; }
    }
  ],

  // Other default options:
  fieldSeparator: ",",
  ignoreHeader: false
}

Advanced Example

Here, you can see we're using a deeper set of objects for our source data, and we're using dot notation in the field definitions like: contact.name for the contact name.

const items = [
  {
    downloaded: false,
    contact: {
      company: 'Widgets, LLC',
      name: 'John Doe',
      email: '[email protected]',
    },
    registration: {
      year: 2013,
      level: 3,
    },
  },
  {
    downloaded: true,
    contact: {
      company: 'Sprockets, LLC',
      name: 'Jane Doe',
      email: '[email protected]',
    },
    registration: {
      year: 2013,
      level: 2,
    },
  },
]
const options = {
  fields: [
    {
      name: 'contact.company', // uses dot notation
      label: 'Company',
    },
    {
      name: 'contact.name',
      label: 'Name',
    },
    {
      name: 'contact.email',
      label: 'Email',
    },
    {
      name: 'downloaded',
      label: "Downloaded",
      transform: (v) => v ? 'downloaded' : 'pending',
    },
    {
      name: 'registration.year',
      label: 'Year',
    },
    {
      name: 'registration.level',
      label: 'Level',
      transform: (v) => {
        switch (v) {
          case 1: return 'Test 1'
          case 2: return 'Test 2'
          default: return 'Unknown'
        }
      },
    },
  ],
}

(async () => {
  let result = await toCsv(items, options)
  console.log(result)
})()

// OR synchronous

(() => {
  let result = toCsvSync(items, options)
  console.log(result)
})()

Output

Company,Name,Email,Downloaded,Year,Level
"Widgets, LLC",John Doe,[email protected],pending,2013,Unknown
"Sprockets, LLC",Jane Doe,[email protected],downloaded,2013,Test 2