vendor/rails/activesupport/lib/active_support/core_ext/hash/keys.rb

   1 module ActiveSupport #:nodoc:
   2   module CoreExtensions #:nodoc:
   3     module Hash #:nodoc:
   4       module Keys
   5         # Return a new hash with all keys converted to strings.
   6         def stringify_keys
   7           inject({}) do |options, (key, value)|
   8             options[key.to_s] = value
   9             options
  10           end
  11         end
  12
  13         # Destructively convert all keys to strings.
  14         def stringify_keys!
  15           keys.each do |key|
  16             self[key.to_s] = delete(key)
  17           end
  18           self
  19         end
  20
  21         # Return a new hash with all keys converted to symbols.
  22         def symbolize_keys
  23           inject({}) do |options, (key, value)|
  24             options[(key.to_sym rescue key) || key] = value
  25             options
  26           end
  27         end
  28
  29         # Destructively convert all keys to symbols.
  30         def symbolize_keys!
  31           self.replace(self.symbolize_keys)
  32         end
  33
  34         alias_method :to_options,  :symbolize_keys
  35         alias_method :to_options!, :symbolize_keys!
  36
  37         # Validate all keys in a hash match *valid keys, raising ArgumentError on a mismatch.
  38         # Note that keys are NOT treated indifferently, meaning if you use strings for keys but assert symbols
  39         # as keys, this will fail.
  40         #
  41         # ==== Examples:
  42         #   { :name => "Rob", :years => "28" }.assert_valid_keys(:name, :age) # => raises "ArgumentError: Unknown key(s): years"
  43         #   { :name => "Rob", :age => "28" }.assert_valid_keys("name", "age") # => raises "ArgumentError: Unknown key(s): name, age"
  44         #   { :name => "Rob", :age => "28" }.assert_valid_keys(:name, :age) # => passes, raises nothing
  45         def assert_valid_keys(*valid_keys)
  46           unknown_keys = keys - [valid_keys].flatten
  47           raise(ArgumentError, "Unknown key(s): #{unknown_keys.join(", ")}") unless unknown_keys.empty?
  48         end
  49       end
  50     end
  51   end
  52 end