table

Table

• Table
  • Features
  • Usage
    • Cell Content Alignment
    • Column Width
    • Custom Border
    • Draw Horizontal Line
    • Padding Cell Content
    • Predefined Border Templates
    • Streaming
    • Text Truncation
    • Text Wrapping

Produces a string that represents array data in a text table.

Features

• Works with strings containing fullwidth characters.
• Works with strings containing ANSI escape codes.
• Configurable border characters.
• Configurable content alignment per column.
• Configurable content padding per column.
• Configurable column width.
• Text wrapping.

Usage

Table data is described using an array (rows) of array (cells).

import table from 'table';

let data,
    output;

data = [
    ['0A', '0B', '0C'],
    ['1A', '1B', '1C'],
    ['2A', '2B', '2C']
];

/**
 * @typedef {string} table~cell
 */

/**
 * @typedef {table~cell[]} table~row
 */

/**
 * @typedef {Object} table~columns
 * @property {string} alignment Cell content alignment (enum: left, center, right) (default: left).
 * @property {number} width Column width (default: auto).
 * @property {number} truncate Number of characters are which the content will be truncated (default: Infinity).
 * @property {number} paddingLeft Cell content padding width left (default: 1).
 * @property {number} paddingRight Cell content padding width right (default: 1).
 */

/**
 * @typedef {Object} table~border
 * @property {string} topBody
 * @property {string} topJoin
 * @property {string} topLeft
 * @property {string} topRight
 * @property {string} bottomBody
 * @property {string} bottomJoin
 * @property {string} bottomLeft
 * @property {string} bottomRight
 * @property {string} bodyLeft
 * @property {string} bodyRight
 * @property {string} bodyJoin
 * @property {string} joinBody
 * @property {string} joinLeft
 * @property {string} joinRight
 * @property {string} joinJoin
 */

/**
 * Used to dynamically tell table whether to draw a line separating rows or not.
 * The default behavior is to always return true.
 *
 * @typedef {function} drawJoin
 * @param {number} index
 * @param {number} size
 * @return {boolean}
 */

/**
 * @typedef {Object} table~config
 * @property {table~border} border
 * @property {table~columns[]} columns Column specific configuration.
 * @property {table~columns} columnDefault Default values for all columns. Column specific settings overwrite the default values.
 * @property {table~drawJoin} drawHorizontalLine
 */

/**
 * Generates a text table.
 *
 * @param {table~row[]} rows
 * @param {table~config} config
 * @return {String}
 */
output = table(data);

console.log(output);

╔════╤════╤════╗
║ 0A │ 0B │ 0C ║
╟────┼────┼────╢
║ 1A │ 1B │ 1C ║
╟────┼────┼────╢
║ 2A │ 2B │ 2C ║
╚════╧════╧════╝

Cell Content Alignment

{string} config.columns[{number}].alignment property controls content horizontal alignment within a cell.

Valid values are: "left", "right" and "center".

let config,
    data,
    output;

data = [
    ['0A', '0B', '0C'],
    ['1A', '1B', '1C'],
    ['2A', '2B', '2C']
];

config = {
    columns: {
        0: {
            alignment: 'left',
            minWidth: 10
        },
        1: {
            alignment: 'center',
            minWidth: 10
        },
        2: {
            alignment: 'right',
            minWidth: 10
        }
    }
};

output = table(data, config);

console.log(output);

╔════════════╤════════════╤════════════╗
║ 0A         │     0B     │         0C ║
╟────────────┼────────────┼────────────╢
║ 1A         │     1B     │         1C ║
╟────────────┼────────────┼────────────╢
║ 2A         │     2B     │         2C ║
╚════════════╧════════════╧════════════╝

Column Width

{number} config.columns[{number}].width property restricts column width to a fixed width.

let data,
    output,
    options;

data = [
    ['0A', '0B', '0C'],
    ['1A', '1B', '1C'],
    ['2A', '2B', '2C']
];

options = {
    columns: {
        1: {
            width: 10
        }
    }
};

output = table(data, options);

console.log(output);

╔════╤════════════╤════╗
║ 0A │ 0B         │ 0C ║
╟────┼────────────┼────╢
║ 1A │ 1B         │ 1C ║
╟────┼────────────┼────╢
║ 2A │ 2B         │ 2C ║
╚════╧════════════╧════╝

Custom Border

{object} config.border property describes characters used to draw the table border.

let config,
    data,
    output;

data = [
    ['0A', '0B', '0C'],
    ['1A', '1B', '1C'],
    ['2A', '2B', '2C']
];

config = {
    border: {
        topBody: `─`,
        topJoin: `┬`,
        topLeft: `┌`,
        topRight: `┐`,

        bottomBody: `─`,
        bottomJoin: `┴`,
        bottomLeft: `└`,
        bottomRight: `┘`,

        bodyLeft: `│`,
        bodyRight: `│`,
        bodyJoin: `│`,

        joinBody: `─`,
        joinLeft: `├`,
        joinRight: `┤`,
        joinJoin: `┼`
    }
};

output = table(data, config);

console.log(output);

┌────┬────┬────┐
│ 0A │ 0B │ 0C │
├────┼────┼────┤
│ 1A │ 1B │ 1C │
├────┼────┼────┤
│ 2A │ 2B │ 2C │
└────┴────┴────┘

Draw Horizontal Line

{function} config.drawHorizontalLine property is a function that is called for every non-content row in the table. The result of the function {boolean} determines whether a row is drawn.

let data,
    output,
    options;

data = [
    ['0A', '0B', '0C'],
    ['1A', '1B', '1C'],
    ['2A', '2B', '2C'],
    ['3A', '3B', '3C'],
    ['4A', '4B', '4C']
];

options = {
    /**
     * @typedef {function} drawJoin
     * @param {number} index
     * @param {number} size
     * @return {boolean}
     */
    drawHorizontalLine: (index, size) => {
        return index === 0 || index === 1 || index === size - 1 || index === size;
    }
};

output = table(data, options);

console.log(output);

╔════╤════╤════╗
║ 0A │ 0B │ 0C ║
╟────┼────┼────╢
║ 1A │ 1B │ 1C ║
║ 2A │ 2B │ 2C ║
║ 3A │ 3B │ 3C ║
╟────┼────┼────╢
║ 4A │ 4B │ 4C ║
╚════╧════╧════╝

Padding Cell Content

{number} config.columns[{number}].paddingLeft and {number} config.columns[{number}].paddingRight properties control content padding within a cell. Property value represents a number of whitespaces used to pad the content.

let config,
    data,
    output;

data = [
    ['0A', 'AABBCC', '0C'],
    ['1A', '1B', '1C'],
    ['2A', '2B', '2C']
];

config = {
    columns: {
        0: {
            paddingLeft: 3
        },
        1: {
            width: 2,
            paddingRight: 3
        }
    }
};

output = table(data, config);

console.log(output);

╔══════╤══════╤════╗
║   0A │ AA   │ 0C ║
║      │ BB   │    ║
║      │ CC   │    ║
╟──────┼──────┼────╢
║   1A │ 1B   │ 1C ║
╟──────┼──────┼────╢
║   2A │ 2B   │ 2C ║
╚══════╧══════╧════╝

Predefined Border Templates

You can load one of the predefined border templates using getBorderCharacters function.

import table, {
    getBorderCharacters
} from 'table';

let config,
    data;

data = [
    ['0A', '0B', '0C'],
    ['1A', '1B', '1C'],
    ['2A', '2B', '2C']
];

config = {
    border: getBorderCharacters(`name of the template`)
};

table(data, config);

# honeywell

╔════╤════╤════╗
║ 0A │ 0B │ 0C ║
╟────┼────┼────╢
║ 1A │ 1B │ 1C ║
╟────┼────┼────╢
║ 2A │ 2B │ 2C ║
╚════╧════╧════╝

# norc

┌────┬────┬────┐
│ 0A │ 0B │ 0C │
├────┼────┼────┤
│ 1A │ 1B │ 1C │
├────┼────┼────┤
│ 2A │ 2B │ 2C │
└────┴────┴────┘

# ramac (ASCII; for use in terminals that do not support Unicode characters)

+----+----+----+
| 0A | 0B | 0C |
|----|----|----|
| 1A | 1B | 1C |
|----|----|----|
| 2A | 2B | 2C |
+----+----+----+

# void (no borders; see "bordless table" section of the documentation)

 0A  0B  0C

 1A  1B  1C

 2A  2B  2C

Raise an issue if you'd like to contribute a new border template.

Borderless Table

Simply using "void" border character template creates a table with a lot of unnecessary spacing.

To create a more plesant to the eye table, reset the padding and remove the joining rows, e.g.

let output;

output = table(data, {
    border: getBorderCharacters(`void`),
    columnDefault: {
        paddingLeft: 0,
        paddingRight: 1
    },
    drawJoin: () => {
        return false
    }
});

console.log(output);

0A 0B 0C
1A 1B 1C
2A 2B 2C

Streaming

table package exports createStream function used to draw a table and append rows.

createStream requires {number} columnDefault.width and {number} columnCount configuration properties.

import {
    createStream
} from 'table';

let config,
    stream;

config = {
    columnDefault: {
        width: 50
    },
    columnCount: 1
};

stream = createStream(config);

setInterval(() => {
    stream.write([new Date()]);
}, 500);

table package uses ANSI escape codes to overwrite the output of the last line when a new row is printed.

The underlying implementation is explained in this Stack Overflow answer.

Streaming supports all of the configuration properties and functionality of a static table (such as auto text wrapping, alignment and padding), e.g.

import {
    createStream
} from 'table';

import _ from 'lodash';

let config,
    stream,
    i;

config = {
    columnDefault: {
        width: 50
    },
    columnCount: 3,
    columns: {
        0: {
            width: 10,
            alignment: 'right'
        },
        1: {
            alignment: 'center',
        },
        2: {
            width: 10
        }
    }
};

stream = createStream(config);

i = 0;

setInterval(() => {
    let random;

    random = _.sample('abcdefghijklmnopqrstuvwxyz', _.random(1, 30)).join('');

    stream.write([i++, new Date(), random]);
}, 500);

Text Truncation

To handle a content that overflows the container width, table package implements text wrapping. However, sometimes you may want to truncate content that is too long to be displayed in the table.

{number} config.columns[{number}].truncate property (default: Infinity) truncates the text at the specified length.

let config,
    data,
    output;

data = [
    ['Lorem ipsum dolor sit amet, consectetur adipiscing elit. Phasellus pulvinar nibh sed mauris convallis dapibus. Nunc venenatis tempus nulla sit amet viverra.']
];

config = {
    columns: {
        0: {
            width: 20,
            truncate: 100
        }
    }
};

output = table(data, config);

console.log(output);

╔══════════════════════╗
║ Lorem ipsum dolor si ║
║ t amet, consectetur  ║
║ adipiscing elit. Pha ║
║ sellus pulvinar nibh ║
║ sed mauris conva...  ║
╚══════════════════════╝

Text Wrapping

table package implements auto text wrapping, i.e. text that has width greater than the container width will be separated into multiple lines, e.g.

let config,
    data,
    output;

data = [
    ['Lorem ipsum dolor sit amet, consectetur adipiscing elit. Phasellus pulvinar nibh sed mauris convallis dapibus. Nunc venenatis tempus nulla sit amet viverra.']
];

config = {
    columns: {
        0: {
            width: 20
        }
    }
};

output = table(data, config);

console.log(output);

╔══════════════════════╗
║ Lorem ipsum dolor si ║
║ t amet, consectetur  ║
║ adipiscing elit. Pha ║
║ sellus pulvinar nibh ║
║ sed mauris convallis ║
║ dapibus. Nunc venena ║
║ tis tempus nulla sit ║
║ amet viverra.        ║
╚══════════════════════╝

When wrapWord is true the text is broken at the nearest space or one of the special characters ("-", "_", "", "/", ".", ",", ";"), e.g.

let config,
    data,
    output;

data = [
    ['Lorem ipsum dolor sit amet, consectetur adipiscing elit. Phasellus pulvinar nibh sed mauris convallis dapibus. Nunc venenatis tempus nulla sit amet viverra.']
];

config = {
    columns: {
        0: {
            width: 20,
            wrapWord: true
        }
    }
};

output = table(data, config);

console.log(output);

╔══════════════════════╗
║ Lorem ipsum dolor    ║
║ sit amet,            ║
║ consectetur          ║
║ adipiscing elit.     ║
║ Phasellus pulvinar   ║
║ nibh sed mauris      ║
║ convallis dapibus.   ║
║ Nunc venenatis       ║
║ tempus nulla sit     ║
║ amet viverra.        ║
╚══════════════════════╝