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require 'active_support/core_ext/hash/keys'
# This class has dubious semantics and we only have it so that
# people can write <tt>params[:key]</tt> instead of <tt>params['key']</tt>
# and they get the same value for both keys.
module ActiveSupport
class HashWithIndifferentAccess < Hash
# Always returns true, so that <tt>Array#extract_options!</tt> finds members of this class.
def extractable_options?
true
end
def with_indifferent_access
dup
end
def nested_under_indifferent_access
self
end
def initialize(constructor = {})
if constructor.is_a?(Hash)
super()
update(constructor)
else
super(constructor)
end
end
def default(key = nil)
if key.is_a?(Symbol) && include?(key = key.to_s)
self[key]
else
super
end
end
def self.new_from_hash_copying_default(hash)
new(hash).tap do |new_hash|
new_hash.default = hash.default
end
end
alias_method :regular_writer, :[]= unless method_defined?(:regular_writer)
alias_method :regular_update, :update unless method_defined?(:regular_update)
# Assigns a new value to the hash:
#
# hash = HashWithIndifferentAccess.new
# hash[:key] = "value"
#
def []=(key, value)
regular_writer(convert_key(key), convert_value(value))
end
alias_method :store, :[]=
# Updates the instantized hash with values from the second:
#
# hash_1 = HashWithIndifferentAccess.new
# hash_1[:key] = "value"
#
# hash_2 = HashWithIndifferentAccess.new
# hash_2[:key] = "New Value!"
#
# hash_1.update(hash_2) # => {"key"=>"New Value!"}
#
def update(other_hash)
if other_hash.is_a? HashWithIndifferentAccess
super(other_hash)
else
other_hash.each_pair { |key, value| regular_writer(convert_key(key), convert_value(value)) }
self
end
end
alias_method :merge!, :update
# Checks the hash for a key matching the argument passed in:
#
# hash = HashWithIndifferentAccess.new
# hash["key"] = "value"
# hash.key? :key # => true
# hash.key? "key" # => true
#
def key?(key)
super(convert_key(key))
end
alias_method :include?, :key?
alias_method :has_key?, :key?
alias_method :member?, :key?
# Same as <tt>Hash#fetch</tt> where the key passed as argument can be
# either a string or a symbol:
#
# counters = HashWithIndifferentAccess.new
# counters[:foo] = 1
#
# counters.fetch("foo") # => 1
# counters.fetch(:bar, 0) # => 0
# counters.fetch(:bar) {|key| 0} # => 0
# counters.fetch(:zoo) # => KeyError: key not found: "zoo"
#
def fetch(key, *extras)
super(convert_key(key), *extras)
end
# Returns an array of the values at the specified indices:
#
# hash = HashWithIndifferentAccess.new
# hash[:a] = "x"
# hash[:b] = "y"
# hash.values_at("a", "b") # => ["x", "y"]
#
def values_at(*indices)
indices.collect {|key| self[convert_key(key)]}
end
# Returns an exact copy of the hash.
def dup
self.class.new(self).tap do |new_hash|
new_hash.default = default
end
end
# Merges the instantized and the specified hashes together, giving precedence to the values from the second hash.
# Does not overwrite the existing hash.
def merge(hash)
self.dup.update(hash)
end
# 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 <tt>HashWithDifferentAccess</tt>.
def reverse_merge(other_hash)
super self.class.new_from_hash_copying_default(other_hash)
end
def reverse_merge!(other_hash)
replace(reverse_merge( other_hash ))
end
# Removes a specified key from the hash.
def delete(key)
super(convert_key(key))
end
def stringify_keys!; self end
def stringify_keys; dup end
undef :symbolize_keys!
def symbolize_keys; to_hash.symbolize_keys end
def to_options!; self end
# Convert to a Hash with String keys.
def to_hash
Hash.new(default).merge!(self)
end
protected
def convert_key(key)
key.kind_of?(Symbol) ? key.to_s : key
end
def convert_value(value)
if value.is_a? Hash
value.nested_under_indifferent_access
elsif value.is_a?(Array)
value.dup.replace(value.map { |e| convert_value(e) })
else
value
end
end
end
end
HashWithIndifferentAccess = ActiveSupport::HashWithIndifferentAccess
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