Class: Hash

Inherits:
Object
  • Object
show all
Defined in:
lib/immosquare-extensions/hash.rb

Overview

##

This extension adds utility methods to the Hash class. It includes methods for handling and manipulating the keys and values of a hash in various ways.

##

Instance Method Summary collapse

Instance Method Details

#depth ⇒ Object

##

Calculate the depth (or level) of nesting within a hash.

Example: {b: {c: 1}}.depth => 3

##


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# File 'lib/immosquare-extensions/hash.rb', line 44

def depth
  1 + values.map {|v| v.is_a?(Hash) ? v.depth : 1 }.max
end

#downcase_key ⇒ Object

##

Convert all keys of the hash to lowercase. If a value is an array, it recursively processes the nested hash elements.

Example: { “A” => { “B” => “value” } }.downcase_key => “a”=>{“b”=>“value”}

##


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# File 'lib/immosquare-extensions/hash.rb', line 31

def downcase_key
  keys.each do |k|
    store(k.downcase, (v = delete(k)).is_a?(Array) ? v.map(&:downcase_key) : v)
  end
  self
end

#flatten_hash ⇒ Object

##

Flatten a nested hash into a single-level hash. Nested keys are represented with dot notation.

Reference: stackoverflow.com/questions/23521230/flattening-nested-hash-to-a-single-hash-with-ruby-rails

Example: {b: {c: 1}}.flatten_hash => Hash.:a:a.b:a.b.c=>1

##


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# File 'lib/immosquare-extensions/hash.rb', line 75

def flatten_hash
  each_with_object({}) do |(k, v), h|
    if v.is_a?(Hash)
      v.flatten_hash.map do |h_k, h_v|
        h["#{k}.#{h_k}".to_sym] = h_v
      end
    else 
      h[k] = v
    end
  end    
end

#sort_by_key(recursive = false, &block) ⇒ Object

##

Sort a hash by its keys. If the recursive flag is true, it will sort nested hashes as well.

Reference: dan.doezema.com/2012/04/recursively-sort-ruby-hash-by-key/

Example: 1, a: {d: 4, c: 3}.sort_by_key(true) => :d=>4, :b=>1}

##


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# File 'lib/immosquare-extensions/hash.rb', line 58

def sort_by_key(recursive = false, &block)
  keys.sort(&block).each_with_object({}) do |key, seed|
    seed[key] = self[key]
    seed[key] = seed[key].sort_by_key(true, &block) if recursive && seed[key].is_a?(Hash)
  end
end

#without(*keys) ⇒ Object

##

Remove multiple keys from a hash in a single command.

Reference: apidock.com/ruby/Hash/delete

Examples: 1, b: 2, c: 3.without(:a, :b) => :c=>3

##


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# File 'lib/immosquare-extensions/hash.rb', line 17

def without(*keys)
  cpy = dup
  keys.each {|key| cpy.delete(key) }
  cpy
end