Class: OptionsHash

Inherits:
Hash
  • Object
show all
Defined in:
lib/options_hash.rb

Overview

Taken brazenly from ActiveSupport

Class Method Summary collapse

Instance Method Summary collapse

Constructor Details

#initialize(constructor = {}) ⇒ OptionsHash

Returns a new instance of OptionsHash.



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# File 'lib/options_hash.rb', line 51

def initialize(constructor = {})
  if constructor.is_a?(Hash)
    super()
    update(constructor)
  else
    super(constructor)
  end
end

Class Method Details

.new_from_hash_copying_default(hash) ⇒ Object 



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# File 'lib/options_hash.rb', line 68

def self.new_from_hash_copying_default(hash)
  OptionsHash.new(hash).tap do |new_hash|
    new_hash.default = hash.default
  end
end

Instance Method Details

#[]=(key, value) ⇒ Object

Assigns a new value to the hash:

hash = OptionsHash.new
hash[:key] = "value"



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# File 'lib/options_hash.rb', line 82

def []=(key, value)
  regular_writer(convert_key(key), convert_value(value))
end

#assert_valid_keys(*valid_keys) ⇒ Object

Validate all keys in a hash match *valid keys, raising ArgumentError on a mismatch. Note that keys are NOT treated indifferently, meaning if you use strings for keys but assert symbols as keys, this will fail.

Examples

{ :name => "Rob", :years => "28" }.assert_valid_keys(:name, :age) # => raises "ArgumentError: Unknown key(s): years"
{ :name => "Rob", :age => "28" }.assert_valid_keys("name", "age") # => raises "ArgumentError: Unknown key(s): name, age"
{ :name => "Rob", :age => "28" }.assert_valid_keys(:name, :age) # => passes, raises nothing

Raises:

  • (ArgumentError) 


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# File 'lib/options_hash.rb', line 42

def assert_valid_keys(*valid_keys)
  unknown_keys = keys - [valid_keys].flatten
  raise(ArgumentError, "Unknown key(s): #{unknown_keys.join(", ")}") unless unknown_keys.empty?
end

#default(key = nil) ⇒ Object 



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# File 'lib/options_hash.rb', line 60

def default(key = nil)
  if key.is_a?(Symbol) && include?(key = key.to_s)
    self[key]
  else
    super
  end
end

#delete(key) ⇒ Object

Removes a specified key from the hash.



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# File 'lib/options_hash.rb', line 156

def delete(key)
  super(convert_key(key))
end

#dup ⇒ Object

Returns an exact copy of the hash.



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# File 'lib/options_hash.rb', line 135

def dup
  OptionsHash.new(self)
end

#extractable_options? ⇒ Boolean

Returns:

  • (Boolean) 


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# File 'lib/options_hash.rb', line 47

def extractable_options?
  true
end

#fetch(key, *extras) ⇒ Object

Fetches the value for the specified key, same as doing hash



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# File 'lib/options_hash.rb', line 119

def fetch(key, *extras)
  super(convert_key(key), *extras)
end

#key?(key) ⇒ Boolean Also known as: include?, has_key?, member?

Checks the hash for a key matching the argument passed in:

hash = OptionsHash.new
hash["key"] = "value"
hash.key? :key  # => true
hash.key? "key" # => true

Returns:

  • (Boolean) 


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# File 'lib/options_hash.rb', line 110

def key?(key)
  super(convert_key(key))
end

#merge(hash) ⇒ Object

Merges the instantized and the specified hashes together, giving precedence to the values from the second hash Does not overwrite the existing hash.



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# File 'lib/options_hash.rb', line 141

def merge(hash)
  self.dup.update(hash)
end

#regular_update ⇒ Object 



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# File 'lib/options_hash.rb', line 75

alias_method :regular_update, :update

#regular_writer ⇒ Object 



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# File 'lib/options_hash.rb', line 74

alias_method :regular_writer, :[]=

#reverse_merge(other_hash) ⇒ Object

Performs the opposite of merge, with the keys and values from the first hash taking precedence over the second. This overloaded definition prevents returning a regular hash, if reverse_merge is called on a OptionsHash.



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# File 'lib/options_hash.rb', line 147

def reverse_merge(other_hash)
  super self.class.new_from_hash_copying_default(other_hash)
end

#reverse_merge!(other_hash) ⇒ Object 



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# File 'lib/options_hash.rb', line 151

def reverse_merge!(other_hash)
  replace(reverse_merge( other_hash ))
end

#stringify_keys ⇒ Object

Return a new hash with all keys converted to strings.



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# File 'lib/options_hash.rb', line 4

def stringify_keys
  dup.stringify_keys!
end

#stringify_keys! ⇒ Object

Destructively convert all keys to strings.



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# File 'lib/options_hash.rb', line 9

def stringify_keys!
  keys.each do |key|
    self[key.to_s] = delete(key)
  end
  self
end

#symbolize_keys ⇒ Object

Return a new hash with all keys converted to symbols, as long as they respond to to_sym.



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# File 'lib/options_hash.rb', line 18

def symbolize_keys
  dup.symbolize_keys!
end

#symbolize_keys! ⇒ Object Also known as: to_options!

Destructively convert all keys to symbols, as long as they respond to to_sym.



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# File 'lib/options_hash.rb', line 24

def symbolize_keys!
  keys.each do |key|
    self[(key.to_sym rescue key) || key] = delete(key)
  end
  self
end

#to_hash ⇒ Object

Convert to a Hash with String keys.



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# File 'lib/options_hash.rb', line 167

def to_hash
  Hash.new(default).merge!(self)
end

#to_options ⇒ Object

Return a new hash with all keys converted to symbols, as long as they respond to to_sym.



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# File 'lib/options_hash.rb', line 31

def symbolize_keys
  dup.symbolize_keys!
end

#update(other_hash) ⇒ Object Also known as: merge!

Updates the instantized hash with values from the second:

hash_1 = OptionsHash.new
hash_1[:key] = "value"

hash_2 = OptionsHash.new
hash_2[:key] = "New Value!"

hash_1.update(hash_2) # => {"key"=>"New Value!"}



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# File 'lib/options_hash.rb', line 96

def update(other_hash)
  other_hash.each_pair { |key, value| regular_writer(convert_key(key), convert_value(value)) }
  self
end

#values_at(*indices) ⇒ Object

Returns an array of the values at the specified indices:

hash = OptionsHash.new
hash[:a] = "x"
hash[:b] = "y"
hash.values_at("a", "b") # => ["x", "y"]



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# File 'lib/options_hash.rb', line 130

def values_at(*indices)
  indices.collect {|key| self[convert_key(key)]}
end