class Hash
# Return a new hash with all keys converted using the block operation.
#
# hash = { name: 'Rob', age: '28' }
#
# hash.transform_keys{ |key| key.to_s.upcase }
# # => { "NAME" => "Rob", "AGE" => "28" }
def transform_keys
result = {}
each_key do |key|
result[yield(key)] = self[key]
end
result
end
# Destructively convert all keys using the block operations.
# Same as transform_keys but modifies +self+.
def transform_keys!
keys.each do |key|
self[yield(key)] = delete(key)
end
self
end
# Return a new hash with all keys converted to strings.
#
# hash = { name: 'Rob', age: '28' }
#
# hash.stringify_keys
# #=> { "name" => "Rob", "age" => "28" }
def stringify_keys
transform_keys{ |key| key.to_s }
end
# Destructively convert all keys to strings. Same as
# +stringify_keys+, but modifies +self+.
def stringify_keys!
transform_keys!{ |key| key.to_s }
end
# Return a new hash with all keys converted to symbols, as long as
# they respond to +to_sym+.
#
# hash = { 'name' => 'Rob', 'age' => '28' }
#
# hash.symbolize_keys
# #=> { name: "Rob", age: "28" }
def symbolize_keys
transform_keys{ |key| key.to_sym rescue key }
end
alias_method :to_options, :symbolize_keys
# Destructively convert all keys to symbols, as long as they respond
# to +to_sym+. Same as +symbolize_keys+, but modifies +self+.
def symbolize_keys!
transform_keys!{ |key| key.to_sym rescue key }
end
alias_method :to_options!, :symbolize_keys!
# Validate all keys in a hash match <tt>*valid_keys</tt>, 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.
#
# { name: 'Rob', years: '28' }.assert_valid_keys(:name, :age) # => raises "ArgumentError: Unknown key: years"
# { name: 'Rob', age: '28' }.assert_valid_keys('name', 'age') # => raises "ArgumentError: Unknown key: name"
# { name: 'Rob', age: '28' }.assert_valid_keys(:name, :age) # => passes, raises nothing
def assert_valid_keys(*valid_keys)
valid_keys.flatten!
each_key do |k|
raise ArgumentError.new("Unknown key: #{k}") unless valid_keys.include?(k)
end
end
# Return a new hash with all keys converted by the block operation.
# This includes the keys from the root hash and from all
# nested hashes.
#
# hash = { person: { name: 'Rob', age: '28' } }
#
# hash.deep_transform_keys{ |key| key.to_s.upcase }
# # => { "PERSON" => { "NAME" => "Rob", "AGE" => "28" } }
def deep_transform_keys(&block)
result = {}
each do |key, value|
result[yield(key)] = value.is_a?(Hash) ? value.deep_transform_keys(&block) : value
end
result
end
# Destructively convert all keys by using the block operation.
# This includes the keys from the root hash and from all
# nested hashes.
def deep_transform_keys!(&block)
keys.each do |key|
value = delete(key)
self[yield(key)] = value.is_a?(Hash) ? value.deep_transform_keys!(&block) : value
end
self
end
# Return a new hash with all keys converted to strings.
# This includes the keys from the root hash and from all
# nested hashes.
#
# hash = { person: { name: 'Rob', age: '28' } }
#
# hash.deep_stringify_keys
# # => { "person" => { "name" => "Rob", "age" => "28" } }
def deep_stringify_keys
deep_transform_keys{ |key| key.to_s }
end
# Destructively convert all keys to strings.
# This includes the keys from the root hash and from all
# nested hashes.
def deep_stringify_keys!
deep_transform_keys!{ |key| key.to_s }
end
# Return a new hash with all keys converted to symbols, as long as
# they respond to +to_sym+. This includes the keys from the root hash
# and from all nested hashes.
#
# hash = { 'person' => { 'name' => 'Rob', 'age' => '28' } }
#
# hash.deep_symbolize_keys
# # => { person: { name: "Rob", age: "28" } }
def deep_symbolize_keys
deep_transform_keys{ |key| key.to_sym rescue key }
end
# Destructively convert all keys to symbols, as long as they respond
# to +to_sym+. This includes the keys from the root hash and from all
# nested hashes.
def deep_symbolize_keys!
deep_transform_keys!{ |key| key.to_sym rescue key }
end
end