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.

Install

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 editing it after the fact:

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

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
table.head = ['Heading A', 'Heading B']
table.rows << ['a1', 'b1']
table.rows << ['a2', {:value => 'b2', :align => :right}]
table.rows << ['a3', 'b3']
table.rows << [{:value => 'a4', :colspan => 2, :align => :center}]

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

Formatting the cells

If you want to add color into the cells you can edit them after the calculations for width have already been made

data = [
  [*1..4],
  [*5..8],
  [*9..12],
  [*13..16]
]

table = Text::Table.new :rows => data, :head => %w{one two three four}
table.formatter = Proc.new do |val,column_index,row_index|
  fg = (column_index+row_index)%2 == 0 ? :green : :white
  bg = column_index%2 == 1 ? :red : :blue
  CLIColorize.colorize(val, :foreground => fg, :background => bg)
end

puts table

This will make every other column red or blue, and every other cell green or white.

Special Thanks

This project was inspired by visionmedia’s terminal-table, and to a lesser-extent, by prawn, ruport and hirb. I’ve decided to start a new project, primarily as an exercise, and to be able to model-out the classes differently. Thanks to the authors and contributors of these projects.

Contributors

• Claudio Bustos (clbustos)

  • Fix Ruby 1.9 warnings on shadowed outer local variables

• Tal Atlas (talby)

  • Added formatter support

Copyright

Copyright © 2009 Aaron Tinio. See LICENSE for details.