table-layout

Styleable plain-text table generator. Useful for formatting console output. Available as both a command-line tool and isomorphic Javascript library.

Install as a library

Add table-layout to your project:

$ npm install --save table-layout

Display an array of objects as a table

Trivial example. Read a JSON file from disk and output a table with a maximum width (in characters) of 60.

1import Table from 'table-layout'
2import { promises as fs } from 'fs'
3
4const issues = await fs.readFile('./issues.json', 'utf8')
5const table = new Table(JSON.parse(issues), { maxWidth: 60 })
6
7console.log(table.toString())
8

This is the example input file:

1[
2  {
3    "number": 15134,
4    "title": "Coveralls has no source available ",
5    "login": "ndelangen",
6    "comments": 0
7  },
8  {
9    "number": 15133,
10    "title": "Fixing --preserve-symlinks. Enhancing node to exploit.",
11    "login": "phestermcs",
12    "comments": 0
13  },
14  {
15    "number": 15131,
16    "title": "Question - Confused about NPM's local installation philosophy",
17    "login": "the1mills",
18    "comments": 0
19  },
20  {
21    "number": 15130,
22    "title": "Question - global npm cache directory if user is root?",
23    "login": "ORESoftware",
24    "comments": 0
25  }
26]

This is the output:

 15134  Coveralls has no source available   ndelangen     0
 15133  Fixing --preserve-symlinks.         phestermcs    0
        Enhancing node to exploit.
 15131  Question - Confused about NPM's     the1mills     0
        local installation philosophy
 15130  Question - global npm cache         ORESoftware   0
        directory if user is root?
 15127  how to installa gulp fontfacegen    aramgreat     0
        on Windows 10
 15097  Cannot install package from         mastertinner  3
        tarball out of package.json entry
        generated by npm
 15067  npm "SELF_SIGNED_CERT_IN_CHAIN"     LegendsLyfe   3
        error when installing discord.js
        with .log

Cherry-picked and computed values

Sometimes, your input data might contain a deeper structure or you want to transform or compute some values. Some example input data with structural depth and large numbers you'd like to reformat:

1[
2  {
3    "country": { "name": "USA" },
4    "GDP": 19485394000000,
5    "population": 325084756
6 },
7  {
8    "country": { "name": "China" },
9    "GDP": 12237700479375,
10    "population": 1421021791
11  },
12  {
13    "country": { "name": "Japan" },
14    "GDP": 4872415104315,
15    "population": 127502725
16 }
17]

Example usage of the column getter function:

1import Table from 'table-layout'
2import { promises as fs } from 'fs'
3
4const rows = JSON.parse(await fs.readFile('./example/deep-data/gdp.json', 'utf8'))
5const germanCurrency = new Intl.NumberFormat('de-DE', { style: 'currency', currency: 'EUR' })
6const germanNumber = new Intl.NumberFormat('de-DE', { notation: 'compact', maximumSignificantDigits: 3, maximumFractionDigits: 0 })
7
8const table = new Table(rows, {
9  maxWidth: 60,
10  columns: [
11    {
12      name: 'country',
13      get: (cellValue) => cellValue.name
14    },
15    {
16      name: 'GDP',
17      get: (cellValue) => germanCurrency.format(cellValue)
18    },
19    {
20      name: 'population',
21      get: (cellValue) => germanNumber.format(cellValue)
22    },
23  ]
24})
25
26console.log(table.toString())

Output.

$ node example/computed-values.js

 USA    19.485.394.000.000,00 €  325 Mio.
 China  12.237.700.479.375,00 €  1,42 Mrd.
 Japan  4.872.415.104.315,00 €   128 Mio.

Colour-scale conditional formatting

See this file for a example of colour-scale formatting (increasing intensity of red/green for more positive/negative values).

API Reference

For the full API documentation, see here.

Load anywhere

This library is compatible with Node.js, the Web and any style of module loader. It can be loaded anywhere, natively without transpilation.

Within a Node.js CommonJS Module:

1const Table = require('table-layout')

Within a Node.js ECMAScript Module:

1import Table from 'table-layout'

Within a modern browser ECMAScript Module:

1import Table from './node_modules/table-layout/dist/index.mjs'

See Also

• gfmt: A github-flavoured-markdown table generator.

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© 2015-24 Lloyd Brookes <75pound@gmail.com>.

Isomorphic test suite by test-runner. Documented by jsdoc-to-markdown.