Class: Array

Inherits:
Object
  • Object
show all
Defined in:
lib/railsbox/core_ext/array.rb

Instance Method Summary collapse

Instance Method Details

#natural_sort(&block) ⇒ Object

Returns the natural order of the array

The problem is that the sort method from the Array class cannot "see" the embedded numbers.
  %w( foobar a2 a30 a3 a20 a13bb20 ).sort # => %w( a13bb20 a2 a20 a3 a30 foobar)
with natural_sort
  %w( foobar a2 a30 a3 a20 a13bb20 ).natural_sort # => %w( a2 a3 a13bb20 a20 a30 foobar )
with block
  obj = Obj.find(:all) 
  obj.natural_sort { |o| o.name }



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# File 'lib/railsbox/core_ext/array.rb', line 12

def natural_sort(&block)
  reg_number = /\d+/

  self.sort do |str1, str2|

    # Get string in block
    if block_given?
      str1 = yield str1
      str2 = yield str2
    end
    
    min = lambda { |a,b| a < b ? a : b }

    # Split the strings into digits and non-digits
    strArrays = [str1,str2].inject(Array.new) do |arr, str|
      arr << str.tr(" \t\r\n", '').split(/(\d+)/)
    end

    # Loop through all the digit parts and convert to integers if neither of them begin with a zero
    1.step(min.call(strArrays[0].size, strArrays[1].size)-1, 2) do |idx|
      if (strArrays[0][idx] !~ /^0/) and (strArrays[1][idx] !~ /^0/)
        strArrays.each { |arr| arr[idx] = arr[idx].to_i }
      end
    end

    strArrays[0] <=> strArrays[1]      
  end
end