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.
{ 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/ext/hash/keys.rb, line 67 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 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"}}
# File lib/ext/hash/keys.rb, line 109 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.
# File lib/ext/hash/keys.rb, line 116 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"}}
# File lib/ext/hash/keys.rb, line 128 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.
# File lib/ext/hash/keys.rb, line 135 def deep_symbolize_keys! deep_transform_keys!{ |key| key.to_sym rescue key } 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"}}
# File lib/ext/hash/keys.rb, line 82 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.
# File lib/ext/hash/keys.rb, line 93 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 hash that includes everything but the given keys. This is useful for limiting a set of parameters to everything but a few known toggles:
@person.update(params[:person].except(:admin))
# File lib/ext/hash/except.rb, line 6 def except(*keys) dup.except!(*keys) end
Replaces the hash without the given keys.
# File lib/ext/hash/except.rb, line 11 def except!(*keys) keys.each { |key| delete(key) } self end
Removes and returns the key/value pairs matching the given keys.
{ a: 1, b: 2, c: 3, d: 4 }.extract!(:a, :b) # => {:a=>1, :b=>2} { a: 1, b: 2 }.extract!(:a, :x) # => {:a=>1}
# File lib/ext/hash/slice.rb, line 39 def extract!(*keys) keys.each_with_object(self.class.new) { |key, result| result[key] = delete(key) if has_key?(key) } end
Slice a hash to include only the given keys. This is useful for limiting an options hash to valid keys before passing to a method:
def search(criteria = {}) criteria.assert_valid_keys(:mass, :velocity, :time) end search(options.slice(:mass, :velocity, :time))
If you have an array of keys you want to limit to, you should splat them:
valid_keys = [:mass, :velocity, :time] search(options.slice(*valid_keys))
# File lib/ext/hash/slice.rb, line 15 def slice(*keys) keys.map! { |key| convert_key(key) } if respond_to?(:convert_key, true) keys.each_with_object(self.class.new) { |k, hash| hash[k] = self[k] if has_key?(k) } end
Replaces the hash with only the given keys. Returns a hash containing the removed key/value pairs.
{ a: 1, b: 2, c: 3, d: 4 }.slice!(:a, :b) # => {:c=>3, :d=>4}
# File lib/ext/hash/slice.rb, line 25 def slice!(*keys) keys.map! { |key| convert_key(key) } if respond_to?(:convert_key, true) omit = slice(*self.keys - keys) hash = slice(*keys) hash.default = default hash.default_proc = default_proc if default_proc replace(hash) omit end
Return a new hash with all keys converted to strings.
hash = { name: 'Rob', age: '28' } hash.stringify_keys # => {"name"=>"Rob", "age"=>"28"}
# File lib/ext/hash/keys.rb, line 31 def stringify_keys transform_keys{ |key| key.to_s } end
Destructively convert all keys to strings. Same as stringify_keys
, but modifies self
.
# File lib/ext/hash/keys.rb, line 37 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"}
# File lib/ext/hash/keys.rb, line 48 def symbolize_keys transform_keys{ |key| key.to_sym rescue key } end
Destructively convert all keys to symbols, as long as they respond to to_sym
. Same as symbolize_keys
, but modifies self
.
# File lib/ext/hash/keys.rb, line 55 def symbolize_keys! transform_keys!{ |key| key.to_sym rescue key } end
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"}
# File lib/ext/hash/keys.rb, line 8 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
.
# File lib/ext/hash/keys.rb, line 18 def transform_keys! keys.each do |key| self[yield(key)] = delete(key) end self end