Class: Array

Inherits:
Object
  • Object
show all
Defined in:
lib/simple_helper/array/to_csv.rb,
lib/simple_helper/array/wrap.rb

Overview

Usage [‘MaJeD’, last_name: ‘BoJaN’, ‘Mohammed’, last_name: ‘majed’].to_csv(‘file_name.csv’)

Class Method Summary collapse

Instance Method Summary collapse

Class Method Details

.wrap(object) ⇒ Object

Powered by rails core Wraps its argument in an array unless it is already an array (or array-like).

Specifically:

  • If the argument is nil an empty array is returned.

  • Otherwise, if the argument responds to to_ary it is invoked, and its result returned.

  • Otherwise, returns an array with the argument as its single element.

    Array.wrap(nil)       # => []
Array.wrap([1, 2, 3]) # => [1, 2, 3]
Array.wrap(0)         # => [0]

This method is similar in purpose to Kernel#Array, but there are some differences:

  • If the argument responds to to_ary the method is invoked. Kernel#Array moves on to try to_a if the returned value is nil, but Array.wrap returns an array with the argument as its single element right away.

  • If the returned value from to_ary is neither nil nor an Array object, Kernel#Array raises an exception, while Array.wrap does not, it just returns the value.

  • It does not call to_a on the argument, if the argument does not respond to to_ary it returns an array with the argument as its single element.

The last point is easily explained with some enumerables:

Array(foo: :bar)      # => [[:foo, :bar]]
Array.wrap(foo: :bar) # => [{:foo=>:bar}]

There’s also a related idiom that uses the splat operator:

[*object]

which returns [] for nil, but calls to Array(object) otherwise.

The differences with Kernel#Array explained above apply to the rest of objects.



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# File 'lib/simple_helper/array/wrap.rb', line 40

def self.wrap(object)
  if object.nil?
    []
  elsif object.respond_to?(:to_ary)
    object.to_ary || [object]
  else
    [object]
  end
end

Instance Method Details

#to_csv(csv_filename = 'file_name.csv') ⇒ Object 



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# File 'lib/simple_helper/array/to_csv.rb', line 7

def to_csv(csv_filename = 'file_name.csv')
  CSV.open(csv_filename, 'wb') do |csv|
    csv << first.keys
    each do |hash|
      csv << hash.values # _at(*keys)
    end
  end
end