as-table

A simple function that print objects and arrays as ASCII tables. Supports ANSI styling and weird 💩 Unicode emoji symbols (they won't break the layout), thanks to printable-characters.

npm install as-table

Printing objects

asTable = require ('as-table')
 
asTable ([ { foo: true,  string: 'abcde',      num: 42 },
           { foo: false, string: 'qwertyuiop', num: 43 },
           {             string:  null,        num: 44 } ])

foo    string      num
----------------------
true   abcde       42 
false  qwertyuiop  43 
       null        44 

Printing arrays

asTable ([['qwe',       '123456789', 'zxcvbnm'],
          ['qwerty',    '12',        'zxcvb'],
          ['qwertyiop', '1234567',   'z']])

qwe        123456789  zxcvbnm
qwerty     12         zxcvb
qwertyiop  1234567    z

Limiting total width by proportionally trimming cells + setting columns delimiter

asTable.configure ({ maxTotalWidth: 22, delimiter: ' | ' }) (data)

qwe   | 1234… | zxc…
qwer… | 12    | zxc…
qwer… | 1234… | z   

Right align

asTable.configure ({ right: true }) (data)

      foo        bar      baz
-----------------------------
      qwe  123456789  zxcvbnm
   qwerty         12    zxcvb
qwertyiop    1234567        z

Providing a custom object printer

asTable.configure ({ print: x => (typeof x === 'boolean') ? (x ? 'yes' : 'no') : String (x) }) (data)

foo  string      num
--------------------
yes  abcde       42 
no   qwertyuiop  43 
     null        44 

The callback also receives a field name (in case of objects) or a column index (in case of arrays):

asTable = require ('as-table').configure ({
    print (x, k) {
        if (k === 'timestamp') return new Date (x).toGMTString()
        return String (x)
    }
})
 
asTable ([ { name: 'A', timestamp: 1561202591572 },
           { name: 'B', timestamp: 1558524240034 } ])

Obtaining a pre-configured function

asTable = require ('as-table').configure ({ maxTotalWidth: 25, delimiter: ' | ' })
 
asTable (data)

Customizing the title rendering and the header separator

With string coloring by ansicolor (just for the demo purposes, any library will fit):

asTable = require ('as-table').configure ({ title: x => x.bright, delimiter: ' | '.dim.cyan, dash: '-'.bright.cyan })
 
console.log (
   asTable ([ { foo: true,  string: 'abcde',                             num: 42 },
              { foo: false, string: 'qwertyuiop'.bgMagenta.green.bright, num: 43 } ])