class Hash
Public Instance Methods
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: 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
# File lib/active_support/core_ext/hash/keys.rb, line 48 def assert_valid_keys(*valid_keys) valid_keys.flatten! each_key do |k| raise(ArgumentError, "Unknown key: #{k}") unless valid_keys.include?(k) end end
Called when object is nested under an object that receives with_indifferent_access
. This method will be called on the current object by the enclosing object and is aliased to with_indifferent_access
by default. Subclasses of Hash
may overwrite this method to return self
if converting to an ActiveSupport::HashWithIndifferentAccess
would not be desirable.
b = {:b => 1} {:a => b}.with_indifferent_access["a"] # calls b.nested_under_indifferent_access
Return a new hash with all keys converted to strings.
{ :name => 'Rob', :years => '28' }.stringify_keys #=> { "name" => "Rob", "years" => "28" }
# File lib/active_support/core_ext/hash/keys.rb, line 6 def stringify_keys dup.stringify_keys! end
Destructively convert all keys to strings. Same as stringify_keys
, but modifies self
.
# File lib/active_support/core_ext/hash/keys.rb, line 12 def stringify_keys! keys.each do |key| self[key.to_s] = delete(key) end self end
Return a new hash with all keys converted to symbols, as long as they respond to to_sym
.
{ 'name' => 'Rob', 'years' => '28' }.symbolize_keys #=> { :name => "Rob", :years => "28" }
# File lib/active_support/core_ext/hash/keys.rb, line 24 def symbolize_keys dup.symbolize_keys! end
Destructively convert all keys to symbols, as long as they respond to to_sym
. Same as symbolize_keys
, but modifies self
.
# File lib/active_support/core_ext/hash/keys.rb, line 30 def symbolize_keys! keys.each do |key| self[(key.to_sym rescue key) || key] = delete(key) end self end
Returns an ActiveSupport::HashWithIndifferentAccess
out of its receiver:
{:a => 1}.with_indifferent_access["a"] # => 1
# File lib/active_support/core_ext/hash/indifferent_access.rb, line 8 def with_indifferent_access ActiveSupport::HashWithIndifferentAccess.new_from_hash_copying_default(self) end