Implements a hash where keys :foo
and "foo"
are considered to be the same.
rgb = ActiveSupport::HashWithIndifferentAccess.new
rgb[:black] = '#000000'
rgb[:black] # => '#000000'
rgb['black'] # => '#000000'
rgb['white'] = '#FFFFFF'
rgb[:white] # => '#FFFFFF'
rgb['white'] # => '#FFFFFF'
Internally symbols are mapped to strings when used as keys in the entire writing interface (calling []=
, merge
, etc). This mapping belongs to the public interface. For example, given:
hash = ActiveSupport::HashWithIndifferentAccess.new(a: 1)
You are guaranteed that the key is returned as a string:
hash.keys # => ["a"]
Technically other types of keys are accepted:
hash = ActiveSupport::HashWithIndifferentAccess.new(a: 1)
hash[0] = 0
hash # => {"a"=>1, 0=>0}
but this class is intended for use cases where strings or symbols are the expected keys and it is convenient to understand both as the same. For example the params
hash in Ruby on Rails.
Note that core extensions define Hash#with_indifferent_access
:
rgb = { black: '#000000', white: '#FFFFFF' }.with_indifferent_access
which may be handy.
To access this class outside of Rails, require the core extension with:
require "active_support/core_ext/hash/indifferent_access"
which will, in turn, require this file.
Methods
- []
- []
- []=
- assoc
- compact
- deep_stringify_keys
- deep_stringify_keys!
- deep_symbolize_keys
- default
- delete
- dig
- dup
- except
- extractable_options?
- fetch
- fetch_values
- has_key?
- include?
- key?
- member?
- merge
- merge!
- nested_under_indifferent_access
- new
- regular_update
- regular_writer
- reject
- replace
- reverse_merge
- reverse_merge!
- select
- slice
- slice!
- store
- stringify_keys
- stringify_keys!
- symbolize_keys
- to_hash
- to_options
- to_options!
- transform_keys
- transform_keys!
- transform_values
- update
- values_at
- with_defaults
- with_defaults!
- with_indifferent_access
- without
Class Public methods
[](*args)
Source:
# File activesupport/lib/active_support/hash_with_indifferent_access.rb, line 81
def self.[](*args)
new.merge!(Hash[*args])
end
new(constructor = {})
Source:
# File activesupport/lib/active_support/hash_with_indifferent_access.rb, line 68
def initialize(constructor = {})
if constructor.respond_to?(:to_hash)
super()
update(constructor)
hash = constructor.is_a?(Hash) ? constructor : constructor.to_hash
self.default = hash.default if hash.default
self.default_proc = hash.default_proc if hash.default_proc
else
super(constructor)
end
end
Instance Public methods
[](key)
Same as Hash#[]
where the key passed as argument can be either a string or a symbol:
counters = ActiveSupport::HashWithIndifferentAccess.new
counters[:foo] = 1
counters['foo'] # => 1
counters[:foo] # => 1
counters[:zoo] # => nil
Source:
# File activesupport/lib/active_support/hash_with_indifferent_access.rb, line 164
def [](key)
super(convert_key(key))
end
[]=(key, value)
Assigns a new value to the hash:
hash = ActiveSupport::HashWithIndifferentAccess.new
hash[:key] = 'value'
This value can be later fetched using either :key
or 'key'
.
Source:
# File activesupport/lib/active_support/hash_with_indifferent_access.rb, line 94
def []=(key, value)
regular_writer(convert_key(key), convert_value(value, conversion: :assignment))
end
assoc(key)
Same as Hash#assoc
where the key passed as argument can be either a string or a symbol:
counters = ActiveSupport::HashWithIndifferentAccess.new
counters[:foo] = 1
counters.assoc('foo') # => ["foo", 1]
counters.assoc(:foo) # => ["foo", 1]
counters.assoc(:zoo) # => nil
Source:
# File activesupport/lib/active_support/hash_with_indifferent_access.rb, line 177
def assoc(key)
super(convert_key(key))
end
compact()
Source:
# File activesupport/lib/active_support/hash_with_indifferent_access.rb, line 355
def compact
dup.tap(&:compact!)
end
deep_stringify_keys()
Source:
# File activesupport/lib/active_support/hash_with_indifferent_access.rb, line 309
def deep_stringify_keys; dup end
deep_stringify_keys!()
Source:
# File activesupport/lib/active_support/hash_with_indifferent_access.rb, line 307
def deep_stringify_keys!; self end
deep_symbolize_keys()
Source:
# File activesupport/lib/active_support/hash_with_indifferent_access.rb, line 314
def deep_symbolize_keys; to_hash.deep_symbolize_keys! end
default(*args)
Same as Hash#default
where the key passed as argument can be either a string or a symbol:
hash = ActiveSupport::HashWithIndifferentAccess.new(1)
hash.default # => 1
hash = ActiveSupport::HashWithIndifferentAccess.new { |hash, key| key }
hash.default # => nil
hash.default('foo') # => 'foo'
hash.default(:foo) # => 'foo'
Source:
# File activesupport/lib/active_support/hash_with_indifferent_access.rb, line 219
def default(*args)
super(*args.map { |arg| convert_key(arg) })
end
delete(key)
Removes the specified key from the hash.
Source:
# File activesupport/lib/active_support/hash_with_indifferent_access.rb, line 293
def delete(key)
super(convert_key(key))
end
dig(*args)
Same as Hash#dig
where the key passed as argument can be either a string or a symbol:
counters = ActiveSupport::HashWithIndifferentAccess.new
counters[:foo] = { bar: 1 }
counters.dig('foo', 'bar') # => 1
counters.dig(:foo, :bar) # => 1
counters.dig(:zoo) # => nil
Source:
# File activesupport/lib/active_support/hash_with_indifferent_access.rb, line 204
def dig(*args)
args[0] = convert_key(args[0]) if args.size > 0
super(*args)
end
dup()
Returns a shallow copy of the hash.
hash = ActiveSupport::HashWithIndifferentAccess.new({ a: { b: 'b' } })
dup = hash.dup
dup[:a][:c] = 'c'
hash[:a][:c] # => "c"
dup[:a][:c] # => "c"
Source:
# File activesupport/lib/active_support/hash_with_indifferent_access.rb, line 254
def dup
self.class.new(self).tap do |new_hash|
set_defaults(new_hash)
end
end
except(*keys)
Returns a hash with indifferent access that includes everything except given keys.
hash = { a: "x", b: "y", c: 10 }.with_indifferent_access
hash.except(:a, "b") # => {c: 10}.with_indifferent_access
hash # => { a: "x", b: "y", c: 10 }.with_indifferent_access
Source:
# File activesupport/lib/active_support/hash_with_indifferent_access.rb, line 301
def except(*keys)
slice(*self.keys - keys.map { |key| convert_key(key) })
end
extractable_options?()
Returns true
so that Array#extract_options!
finds members of this class.
Source:
# File activesupport/lib/active_support/hash_with_indifferent_access.rb, line 56
def extractable_options?
true
end
fetch(key, *extras)
Same as Hash#fetch
where the key passed as argument can be either a string or a symbol:
counters = ActiveSupport::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"
Source:
# File activesupport/lib/active_support/hash_with_indifferent_access.rb, line 191
def fetch(key, *extras)
super(convert_key(key), *extras)
end
fetch_values(*indices, &block)
Returns an array of the values at the specified indices, but also raises an exception when one of the keys can't be found.
hash = ActiveSupport::HashWithIndifferentAccess.new
hash[:a] = 'x'
hash[:b] = 'y'
hash.fetch_values('a', 'b') # => ["x", "y"]
hash.fetch_values('a', 'c') { |key| 'z' } # => ["x", "z"]
hash.fetch_values('a', 'c') # => KeyError: key not found: "c"
Source:
# File activesupport/lib/active_support/hash_with_indifferent_access.rb, line 242
def fetch_values(*indices, &block)
super(*indices.map { |key| convert_key(key) }, &block)
end
key?(key)
Checks the hash for a key matching the argument passed in:
hash = ActiveSupport::HashWithIndifferentAccess.new
hash['key'] = 'value'
hash.key?(:key) # => true
hash.key?('key') # => true
Source:
# File activesupport/lib/active_support/hash_with_indifferent_access.rb, line 147
def key?(key)
super(convert_key(key))
end
merge(*hashes, &block)
This method has the same semantics of update
, except it does not modify the receiver but rather returns a new hash with indifferent access with the result of the merge.
Source:
# File activesupport/lib/active_support/hash_with_indifferent_access.rb, line 263
def merge(*hashes, &block)
dup.update(*hashes, &block)
end
nested_under_indifferent_access()
Source:
# File activesupport/lib/active_support/hash_with_indifferent_access.rb, line 64
def nested_under_indifferent_access
self
end
reject(*args, &block)
Source:
# File activesupport/lib/active_support/hash_with_indifferent_access.rb, line 322
def reject(*args, &block)
return to_enum(:reject) unless block_given?
dup.tap { |hash| hash.reject!(*args, &block) }
end
replace(other_hash)
Replaces the contents of this hash with other_hash.
h = { "a" => 100, "b" => 200 }
h.replace({ "c" => 300, "d" => 400 }) # => {"c"=>300, "d"=>400}
Source:
# File activesupport/lib/active_support/hash_with_indifferent_access.rb, line 288
def replace(other_hash)
super(self.class.new(other_hash))
end
reverse_merge(other_hash)
Like merge
but the other way around: Merges the receiver into the argument and returns a new hash with indifferent access as result:
hash = ActiveSupport::HashWithIndifferentAccess.new
hash['a'] = nil
hash.reverse_merge(a: 0, b: 1) # => {"a"=>nil, "b"=>1}
Source:
# File activesupport/lib/active_support/hash_with_indifferent_access.rb, line 273
def reverse_merge(other_hash)
super(self.class.new(other_hash))
end
reverse_merge!(other_hash)
Same semantics as reverse_merge
but modifies the receiver in-place.
Source:
# File activesupport/lib/active_support/hash_with_indifferent_access.rb, line 279
def reverse_merge!(other_hash)
super(self.class.new(other_hash))
end
select(*args, &block)
Source:
# File activesupport/lib/active_support/hash_with_indifferent_access.rb, line 317
def select(*args, &block)
return to_enum(:select) unless block_given?
dup.tap { |hash| hash.select!(*args, &block) }
end
slice(*keys)
Source:
# File activesupport/lib/active_support/hash_with_indifferent_access.rb, line 345
def slice(*keys)
keys.map! { |key| convert_key(key) }
self.class.new(super)
end
slice!(*keys)
Source:
# File activesupport/lib/active_support/hash_with_indifferent_access.rb, line 350
def slice!(*keys)
keys.map! { |key| convert_key(key) }
super
end
stringify_keys()
Source:
# File activesupport/lib/active_support/hash_with_indifferent_access.rb, line 308
def stringify_keys; dup end
stringify_keys!()
Source:
# File activesupport/lib/active_support/hash_with_indifferent_access.rb, line 306
def stringify_keys!; self end
symbolize_keys()
Source:
# File activesupport/lib/active_support/hash_with_indifferent_access.rb, line 312
def symbolize_keys; to_hash.symbolize_keys! end
to_hash()
Convert to a regular hash with string keys.
Source:
# File activesupport/lib/active_support/hash_with_indifferent_access.rb, line 360
def to_hash
_new_hash = Hash.new
set_defaults(_new_hash)
each do |key, value|
_new_hash[key] = convert_value(value, conversion: :to_hash)
end
_new_hash
end
to_options!()
Source:
# File activesupport/lib/active_support/hash_with_indifferent_access.rb, line 315
def to_options!; self end
transform_keys(*args, &block)
Source:
# File activesupport/lib/active_support/hash_with_indifferent_access.rb, line 332
def transform_keys(*args, &block)
return to_enum(:transform_keys) unless block_given?
dup.tap { |hash| hash.transform_keys!(*args, &block) }
end
transform_keys!()
Source:
# File activesupport/lib/active_support/hash_with_indifferent_access.rb, line 337
def transform_keys!
return enum_for(:transform_keys!) { size } unless block_given?
keys.each do |key|
self[yield(key)] = delete(key)
end
self
end
transform_values(*args, &block)
Source:
# File activesupport/lib/active_support/hash_with_indifferent_access.rb, line 327
def transform_values(*args, &block)
return to_enum(:transform_values) unless block_given?
dup.tap { |hash| hash.transform_values!(*args, &block) }
end
update(*other_hashes, &block)
Updates the receiver in-place, merging in the hashes passed as arguments:
hash_1 = ActiveSupport::HashWithIndifferentAccess.new
hash_1[:key] = 'value'
hash_2 = ActiveSupport::HashWithIndifferentAccess.new
hash_2[:key] = 'New Value!'
hash_1.update(hash_2) # => {"key"=>"New Value!"}
hash = ActiveSupport::HashWithIndifferentAccess.new
hash.update({ "a" => 1 }, { "b" => 2 }) # => { "a" => 1, "b" => 2 }
The arguments can be either an ActiveSupport::HashWithIndifferentAccess
or a regular Hash
. In either case the merge respects the semantics of indifferent access.
If the argument is a regular hash with keys :key
and "key"
only one of the values end up in the receiver, but which one is unspecified.
When given a block, the value for duplicated keys will be determined by the result of invoking the block with the duplicated key, the value in the receiver, and the value in other_hash
. The rules for duplicated keys follow the semantics of indifferent access:
hash_1[:key] = 10
hash_2['key'] = 12
hash_1.update(hash_2) { |key, old, new| old + new } # => {"key"=>22}
Source:
# File activesupport/lib/active_support/hash_with_indifferent_access.rb, line 128
def update(*other_hashes, &block)
if other_hashes.size == 1
update_with_single_argument(other_hashes.first, block)
else
other_hashes.each do |other_hash|
update_with_single_argument(other_hash, block)
end
end
self
end
values_at(*keys)
Returns an array of the values at the specified indices:
hash = ActiveSupport::HashWithIndifferentAccess.new
hash[:a] = 'x'
hash[:b] = 'y'
hash.values_at('a', 'b') # => ["x", "y"]
Source:
# File activesupport/lib/active_support/hash_with_indifferent_access.rb, line 229
def values_at(*keys)
super(*keys.map { |key| convert_key(key) })
end
with_indifferent_access()
Source:
# File activesupport/lib/active_support/hash_with_indifferent_access.rb, line 60
def with_indifferent_access
dup
end