Class: Sparkr::Sparkline

Inherits:
Object
  • Object
show all
Defined in:
lib/sparkr/sparkline.rb

Constant Summary collapse

TICKS = 
%w(▁ ▂ ▃ ▄ ▅ ▆ ▇ █)
DEFAULT_SEPARATOR = 
''

Instance Method Summary collapse

Constructor Details

#initialize(_numbers) ⇒ Sparkline

Returns a new instance of Sparkline.



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# File 'lib/sparkr/sparkline.rb', line 8

def initialize(_numbers)
  if _numbers.empty?
    @ticks = []
  else
    @original_numbers = _numbers

    numbers  = normalize_numbers(_numbers)
    one_step = step_height(numbers)

    @ticks = numbers.map do |n|
      index = (n / one_step).to_i
      TICKS[index]
    end
  end
end

Instance Method Details

#format ⇒ Sparkline

Formats all the ticks in the Sparkline with a given block, returns itself

Example:

Let’s say you have a list of open and closed issues and want to format it so the open ones are red and the closed ones are green, so you can quickly see how you are doing. Let’s further suppose you use a gem that adds a #color method to String for ANSI coloring.

list = [open_issue_count, closed_issue_count]
sparkline = Sparkr::Sparkline.new(list)
sparkline.format do |tick, count, index|
  if index == 0
    tick.color(:red)
  else
    tick.color(:green)
  end
end

sparkline.to_s
# => "▁█" (colored, which you can't see)

Returns:



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# File 'lib/sparkr/sparkline.rb', line 49

def format
  @ticks = @ticks.map.with_index do |tick, index|
    yield tick, @original_numbers[index], index
  end
  self
end

#normalize_numbers(_numbers) ⇒ Fixnum

Returns the normalized equivalent of a given list

normalize_numbers([3, 4, 7])
# => [0, 1, 4]

Returns:

  • (Fixnum) —

    the normalized equivalent of the given _numbers



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# File 'lib/sparkr/sparkline.rb', line 62

def normalize_numbers(_numbers)
  numbers = _numbers.map(&:to_i)
  min = numbers.min
  numbers.map do |n|
    n - min
  end
end

#step_height(_numbers) ⇒ Float

Returns the numerical “height” of a single bar “step”.

Returns:

  • (Float) —

    the numerical “height” of a single bar “step”



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# File 'lib/sparkr/sparkline.rb', line 71

def step_height(_numbers)
  min, max = _numbers.minmax
  actual_height = max - min
  step = actual_height / steps.to_f
  if step == 0
    1
  else
    step
  end
end

#steps ⇒ Fixnum

Returns the count of steps between the smallest and highest bar.

Returns:

  • (Fixnum) —

    the count of steps between the smallest and highest bar



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# File 'lib/sparkr/sparkline.rb', line 83

def steps
  TICKS.size - 1
end

#to_s(sep = nil) ⇒ String

Returns the sparkline, seperated by sep (defaults to ”).

Parameters:

  • sep (String, nil) (defaults to: nil) —

    separator used to join the bars of the sparkline

Returns:

  • (String) —

    the sparkline, seperated by sep (defaults to ”)



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# File 'lib/sparkr/sparkline.rb', line 89

def to_s(sep = nil)
  @ticks.join(sep || DEFAULT_SEPARATOR)
end