text-table

A feature-rich, easy-to-use plain text table formatter.

Introduction

Allows you to easily create and format plain text tables, useful when working with the terminal or when you want to quickly print formatted tables to a dot-matrix printer.

Text::Table is compatible with Ruby 1.8.6, 1.8.7 and 1.9.1 and includes a comprehensive test suite.

This project was heavily inspired by visionmedia’s terminal-table, and to a lesser-extent, by prawn, ruport and hirb. I initially wanted to add more features to terminal-table (footer, separators between rows, etc) and to fix a then alignment issue with spanned columns. Instead of forking terminal-table, I’ve decided to start a new project primarily as an exercise, and to be able to model-out the classes differently.

Install

If you haven’t yet,

gem install gemcutter
gem tumble

Then,

gem install text-table

Calling the `to_table` Method

Just call the to_table method (or to_text_table if the former is already defined) on Arrays (and other Enumerables).

require 'rubygems'
require 'text-table'

array = [
  ['Student', 'Mid-Terms', 'Finals'],
  ['Sam', 94, 93],
  ['Jane', 92, 99],
  ['Average', 93, 96]
]

puts array.to_table

#    +---------+-----------+--------+
#    | Student | Mid-Terms | Finals |
#    | Sam     | 94        | 93     |
#    | Jane    | 92        | 99     |
#    | Average | 93        | 96     |
#    +---------+-----------+--------+

You could specify that the first row is the table heading.

puts array.to_table(:first_row_is_head => true)

#    +---------+-----------+--------+
#    | Student | Mid-Terms | Finals |
#    +---------+-----------+--------+
#    | Sam     | 94        | 93     |
#    | Jane    | 92        | 99     |
#    | Average | 93        | 96     |
#    +---------+-----------+--------+

You could also specify that the last row is the table footer.

puts array.to_table(:first_row_is_head => true, :last_row_is_foot => true)

#    +---------+-----------+--------+
#    | Student | Mid-Terms | Finals |
#    +---------+-----------+--------+
#    | Sam     | 94        | 93     |
#    | Jane    | 92        | 99     |
#    +---------+-----------+--------+
#    | Average | 93        | 96     |
#    +---------+-----------+--------+

Creating a New Text::Table Object

You could create a Text::Table object by passing an options hash:

table = Text::Table.new(:head => ['A', 'B'], :rows => [['a1', 'b1'], ['a2', 'b2']])

Or by passing a block:

table = Text::Table.new do |t|
  t.head = ['A', 'B']
  t.rows = [['a1', 'b1']]
  t.rows << ['a2', 'b2']
end

table.to_s

#    +----+----+
#    | A  | B  |
#    +----+----+
#    | a1 | b1 |
#    | a2 | b2 |
#    +----+----+

Aligning Cells and Spanning Columns

Alignment and column span can be specified by passing a cell as a Hash object.

The acceptable aligments are :left, :center and :right.

Cells and footers are aligned to the left by default, while headers are centered by default.

table = Text::Table.new do |t|
  t.head = ['Heading A', 'Heading B']
  t.rows << ['a1', 'b1']
  t.rows << ['a2', {:value => 'b2', :align => :right}]
  t.rows << ['a3', 'b3']
  t.rows << [{:value => 'a4', :colspan => 2, :align => :center}]
end

puts table

#    +-----------+-----------+
#    | Heading A | Heading B |
#    +-----------+-----------+
#    | a1        | b1        |
#    | a2        |        b2 |
#    | a3        | b3        |
#    |          a4           |
#    +-----------+-----------+

There’s also an easy way to align columns:

table = Text::Table.new :rows => [%w(a bb), %w(aa bbb), %w(aaa b)]
puts table

#    +-----+-----+
#    | a   | bb  |
#    | aa  | bbb |
#    | aaa | b   |
#    +-----+-----+

table.align_column 2, :right

#    +-----+-----+
#    | a   |  bb |
#    | aa  | bbb |
#    | aaa |   b |
#    +-----+-----+

Note that headers, spanned cells and cells with explicit alignments are not affected by align_column.

Adding a Separator

You can add a separator by inserting :separator symbols between the rows.

Text::Table.new :rows => [
  ['a', 'b'],
  ['c', 'd'],
  :separator,
  ['e', 'f'],
  :separator,
  ['g', 'h']
]

#    +---+---+
#    | a | b |
#    | c | d |
#    +---+---+
#    | e | f |
#    +---+---+
#    | g | h |
#    +---+---+

Other Options

Cell padding and table boundaries can be modified.

Text::Table.new :rows => [['a', 'b'], ['c', 'd']],
                :horizontal_padding    => 3,
                :vertical_boundary     => '=',
                :horizontal_boundary   => ':',
                :boundary_intersection => 'O'

#    O=======O=======O
#    :   a   :   b   :
#    :   c   :   d   :
#    O=======O=======O