declutter

Declutter

Declutters your Ruby hashes and arrays by removing empty arrays and hashes. Also has options for removing nils, redundancies and falses, and objects that respond to #declutter.

In this simple example, we create a hash structure that contains an empty array:

#!/usr/bin/ruby -w
require 'declutter'

myhash = { 'title' => 'Titus Andronicus', 'episodes' => [] }
puts myhash # => {"title"=>"Titus Andronicus", "episodes"=>[]}
Declutter.process myhash
puts myhash # => {"title"=>"Titus Andronicus"}

By running the hash through Declutter.process, we remove the empty array. If an array contains only an empty array, then the whole array structure is removed:

myhash = { 'title' => 'Titus Andronicus', 'episodes' => ['scenes'=>[]] };
puts myhash # => {"title"=>"Titus Andronicus", "episodes"=>[{"scenes"=>[]}]}
Declutter.process myhash
puts myhash # => {"title"=>"Titus Andronicus"}

The same concept goes for empty hashes:

myhash = {'title' => 'Titus Andronicus', 'notes' => {'ideas'=>{}} }
puts myhash # => {"title"=>"Titus Andronicus", "notes"=>{}}
Declutter.process myhash
puts myhash # => {"title"=>"Titus Andronicus"}

Object oriented approach

To refine what elements are deleted, instantiate Declutter to set what type of elements are deleted.

nil

To delete nils, set declutter.delete_nils to true:

myhash = { 'episodes'=>['pilot', nil, 'transition'] }
puts myhash # => {"episodes"=>["pilot", nil, "transition"]}

declutter = Declutter.new()
declutter.delete_nils = true
declutter.process myhash

puts myhash # => {"episodes"=>["pilot", "transition"]}

If deleting the nil values results in an empty array, then the array is deleted.

myhash = { 'episodes'=>[nil] }
puts myhash # => { 'episodes'=>[nil] }

declutter = Declutter.new()
declutter.delete_nils = true
declutter.process myhash

puts myhash # => {}

redundancies

To delete redundant elements in arrays, set declutter.delete_redundancies to true.

myhash = { 'episodes'=>['pilot', 'pilot'] }
puts myhash # => { 'episodes'=>['pilot', 'pilot'] }

declutter = Declutter.new()
declutter.delete_redundancies = true
declutter.process myhash

puts myhash # => { 'episodes'=>['pilot'] }

false

To delete false values, set declutter.delete_falses to true:

myhash = { 'episodes'=>['pilot', false] }
puts myhash # => {"episodes"=>["pilot", false]}

declutter = Declutter.new()
declutter.delete_falses = true
declutter.process myhash

puts myhash # => {"episodes"=>["pilot"]}

keep empty hashes and/or arrays

To keep empty hashes, set declutter.delete_empty_hashes to false:

myhash = { 'episodes'=>[], 'notes'=>{} }
puts myhash # => {"episodes"=>[], "notes"=>{}}

declutter = Declutter.new()
declutter.delete_empty_hashes = false
declutter.process myhash

puts myhash # => {"notes"=>{}}

To keep empty arrays, set declutter.delete_empty_arrays to false:

myhash = { 'episodes'=>[], 'notes'=>{} }
puts myhash # => {"episodes"=>[], "notes"=>{}}

declutter = Declutter.new()
declutter.delete_empty_arrays = false
declutter.process myhash

puts myhash # => {"episodes"=>[]}

objects of other classes

Objects of your own custom class can be decluttered if they have a #declutter method. Consider these two classes.

class KeepMe
   def declutter
      return true
   end
end

class DeleteMe
   def declutter
      return false
   end
end

Both classes have declutter methods. KeepMe#declutter returns true and DeleteMe#declutter returns false. In this first example, we use the default settings to declutter the hash.

hsh = {}
hsh['keep-it'] = KeepMe.new
hsh['delete-it'] = DeleteMe.new

Declutter.process hsh

puts hsh # => {"keep-it"=>#<KeepMe:0x0000559f8574b718>}

The keep-it element was kept because KeepMe#declutter returns true. However, the delete-it element was deleted because DeleteMe#declutter returns false.

To bypass decluttering objects that have a #declutter method, use the object oriented approach and set process_others to false:

hsh = {}
hsh['keep-it'] = KeepMe.new
hsh['delete-it'] = DeleteMe.new

declutter = Declutter.new
declutter.process_others = false
declutter.process hsh

puts hsh # => {"keep-it"=>#<KeepMe:0x000055e5ffd46f80>, "delete-it"=>#<DeleteMe:0x000055e5ffd46f30>}

History

date	version	notes
May 23, 2023	1.0	Initial upload.
May 29, 2023	1.1	Added ability to call #declutter on any object that responds to that method.
June 9, 2023	1.2	Changed tests to Minitest. No change to functionality.