Class: ActiveSupport::HashWithIndifferentAccess
| Relationships & Source Files | |
| Extension / Inclusion / Inheritance Descendants | |
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Subclasses:
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| Super Chains via Extension / Inclusion / Inheritance | |
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Class Chain:
self,
::Hash
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Instance Chain:
self,
::Hash,
DeepMergeable
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| Inherits: | Hash |
| Defined in: | activesupport/lib/active_support/hash_with_indifferent_access.rb |
Overview
Hash With Indifferent Access
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.
Constant Summary
-
NOT_GIVEN =
Internal use only
# File 'activesupport/lib/active_support/hash_with_indifferent_access.rb', line 400Object.new.freeze
Class Method Summary
::Hash - Inherited
| .from_trusted_xml | Builds a |
| .from_xml | Returns a |
Instance Attribute Summary
-
#extractable_options? ⇒ Boolean
readonly
Returns
trueso that Array#extract_options! finds members of this class.
::Hash - Inherited
| #extractable_options? | By default, only instances of |
| #present? | |
Instance Method Summary
-
#[](key)
Same as
Hash#[]where the key passed as argument can be either a string or a symbol: -
#[]=(key, value)
Assigns a new value to the hash:
-
#assoc(key)
Same as
Hash#assocwhere the key passed as argument can be either a string or a symbol: - #compact
- #deep_symbolize_keys
-
#default(key = (no_key = true))
Same as
Hash#defaultwhere the key passed as argument can be either a string or a symbol: -
#delete(key)
Removes the specified key from the hash.
-
#dig(*args)
Same as
Hash#digwhere the key passed as argument can be either a string or a symbol: -
#dup
Returns a shallow copy of the hash.
-
#except(*keys)
(also: #without)
Returns a hash with indifferent access that includes everything except given keys.
-
#fetch(key, *extras)
Same as
Hash#fetchwhere the key passed as argument can be either a string or a symbol: -
#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.
-
#filter(*args, &block)
Alias for #select.
-
#has_key?(key)
Alias for #key?.
-
#include?(key)
Alias for #key?.
-
#key?(key) ⇒ Boolean
(also: #include?, #has_key?, #member?)
Checks the hash for a key matching the argument passed in:
-
#member?(key)
Alias for #key?.
-
#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.
-
#merge!(*other_hashes, &block)
Alias for #update.
- #nested_under_indifferent_access
- #regular_update
- #regular_writer
- #reject(*args, &block)
-
#replace(other_hash)
Replaces the contents of this hash with other_hash.
-
#reverse_merge(other_hash)
(also: #with_defaults)
Like #merge but the other way around: Merges the receiver into the argument and returns a new hash with indifferent access as result:
-
#reverse_merge!(other_hash)
(also: #with_defaults!)
Same semantics as #reverse_merge but modifies the receiver in-place.
- #select(*args, &block) (also: #filter)
- #slice(*keys)
- #slice!(*keys)
-
#store(key, value, convert_value: true)
Assigns a new value to the hash:
- #symbolize_keys (also: #to_options)
-
#to_hash
Convert to a regular hash with string keys.
-
#to_options
Alias for #symbolize_keys.
- #to_options!
- #to_proc
- #transform_keys(hash = NOT_GIVEN, &block)
- #transform_keys!(hash = NOT_GIVEN, &block)
- #transform_values(&block)
-
#update(*other_hashes, &block)
(also: #merge!)
Updates the receiver in-place, merging in the hashes passed as arguments:
-
#values_at(*keys)
Returns an array of the values at the specified indices:
-
#with_defaults(other_hash)
Alias for #reverse_merge.
-
#with_defaults!(other_hash)
Alias for #reverse_merge!.
- #with_indifferent_access
-
#without(*keys)
Alias for #except.
- #cast(other) private
- #convert_key(key) private
- #convert_value(value, conversion: nil) private
- #convert_value_to_hash(value) private
- #copy_defaults(target) private
- #update_with_single_argument(other_hash, block) private
::Hash - Inherited
| #assert_valid_keys | Validates all keys in a hash match |
| #blank? | A hash is blank if it's empty: |
| #compact_blank! | Removes all blank values from the |
| #deep_dup | Returns a deep copy of hash. |
| #deep_merge | Returns a new hash with |
| #deep_merge! | Same as |
| #deep_stringify_keys | Returns a new hash with all keys converted to strings. |
| #deep_stringify_keys! | Destructively converts all keys to strings. |
| #deep_symbolize_keys | Returns a new hash with all keys converted to symbols, as long as they respond to |
| #deep_symbolize_keys! | Destructively converts all keys to symbols, as long as they respond to |
| #deep_transform_keys | Returns a new hash with all keys converted by the block operation. |
| #deep_transform_keys! | Destructively converts all keys by using the block operation. |
| #deep_transform_values | Returns a new hash with all values converted by the block operation. |
| #deep_transform_values! | Destructively converts all values by using the block operation. |
| #except! | Removes the given keys from hash and returns it. |
| #extract! | Removes and returns the key/value pairs matching the given keys. |
| #nested_under_indifferent_access | Alias for Hash#with_indifferent_access. |
| #reverse_merge | Merges the caller into |
| #reverse_merge! | Destructive #reverse_merge. |
| #reverse_update | Alias for Hash#reverse_merge!. |
| #slice! | Replaces the hash with only the given keys. |
| #stringify_keys | Returns a new hash with all keys converted to strings. |
| #stringify_keys! | Destructively converts all keys to strings. |
| #symbolize_keys | Returns a new hash with all keys converted to symbols, as long as they respond to |
| #symbolize_keys! | Destructively converts all keys to symbols, as long as they respond to |
| #to_options | Alias for Hash#symbolize_keys. |
| #to_options! | Alias for Hash#symbolize_keys!. |
| #to_param | Alias for Hash#to_query. |
| #to_query | Returns a string representation of the receiver suitable for use as a URL query string: |
| #to_xml | Returns a string containing an XML representation of its receiver: |
| #with_defaults | Alias for Hash#reverse_merge. |
| #with_defaults! | Alias for Hash#reverse_merge!. |
| #with_indifferent_access | Returns an |
| #_deep_transform_keys_in_object | Support methods for deep transforming nested hashes and arrays. |
| #_deep_transform_keys_in_object!, | |
| #_deep_transform_values_in_object | Support methods for deep transforming nested hashes and arrays. |
| #_deep_transform_values_in_object!, #as_json, | |
| #compact_blank |
|
| #deep_merge? | |
DeepMergeable - Included
| #deep_merge | Returns a new instance with the values from |
| #deep_merge! | Same as |
| #deep_merge? | Returns true if |
Constructor Details
.new(constructor = nil) ⇒ HashWithIndifferentAccess
# File 'activesupport/lib/active_support/hash_with_indifferent_access.rb', line 84
def initialize(constructor = nil) if constructor.nil? super() elsif constructor.respond_to?(:to_hash) super() update(constructor) hash = constructor.is_a?(Hash) ? constructor : constructor.to_hash self.default = hash.default unless hash.default.nil? self.default_proc = hash.default_proc if hash.default_proc else super(constructor) end end
Class Method Details
.[](*args)
[ GitHub ]Instance Attribute Details
#extractable_options? ⇒ Boolean (readonly)
Returns true so that Array#extract_options! finds members of
this class.
# File 'activesupport/lib/active_support/hash_with_indifferent_access.rb', line 72
def true end
Instance Method Details
#[](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
# File 'activesupport/lib/active_support/hash_with_indifferent_access.rb', line 210
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'.
If the value is a Hash or contains one or multiple Hashes, they will be
converted to HashWithIndifferentAccess.
# File 'activesupport/lib/active_support/hash_with_indifferent_access.rb', line 117
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
# File 'activesupport/lib/active_support/hash_with_indifferent_access.rb', line 225
def assoc(key) super(convert_key(key)) end
#cast(other) (private)
[ GitHub ]# File 'activesupport/lib/active_support/hash_with_indifferent_access.rb', line 455
def cast(other) self.class === other ? other : self.class.new(other) end
#compact
[ GitHub ]# File 'activesupport/lib/active_support/hash_with_indifferent_access.rb', line 439
def compact dup.tap(&:compact!) end
#convert_key(key) (private)
[ GitHub ]# File 'activesupport/lib/active_support/hash_with_indifferent_access.rb', line 459
def convert_key(key) Symbol === key ? key.name : key end
#convert_value(value, conversion: nil) (private)
[ GitHub ]# File 'activesupport/lib/active_support/hash_with_indifferent_access.rb', line 463
def convert_value(value, conversion: nil) if value.is_a? Hash value.nested_under_indifferent_access elsif value.is_a?(Array) if conversion != :assignment || value.frozen? value = value.dup end value.map! { |e| convert_value(e, conversion: conversion) } else value end end
#convert_value_to_hash(value) (private)
[ GitHub ]#copy_defaults(target) (private)
[ GitHub ]#deep_symbolize_keys
[ GitHub ]# File 'activesupport/lib/active_support/hash_with_indifferent_access.rb', line 381
def deep_symbolize_keys; to_hash.deep_symbolize_keys! end
#default(key = (no_key = true))
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'
# File 'activesupport/lib/active_support/hash_with_indifferent_access.rb', line 273
def default(key = (no_key = true)) if no_key super() else super(convert_key(key)) end end
#delete(key)
Removes the specified key from the hash.
# File 'activesupport/lib/active_support/hash_with_indifferent_access.rb', line 361
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, :) # => 1
counters.dig(:zoo) # => nil
# File 'activesupport/lib/active_support/hash_with_indifferent_access.rb', line 256
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"
# File 'activesupport/lib/active_support/hash_with_indifferent_access.rb', line 320
def dup copy_defaults(self.class.new(self)) end
#except(*keys) Also known as: #without
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
# File 'activesupport/lib/active_support/hash_with_indifferent_access.rb', line 372
def except(*keys) dup.except!(*keys) 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(:, 0) # => 0
counters.fetch(:) { |key| 0 } # => 0
counters.fetch(:zoo) # => KeyError: key not found: "zoo"
# File 'activesupport/lib/active_support/hash_with_indifferent_access.rb', line 241
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"
# File 'activesupport/lib/active_support/hash_with_indifferent_access.rb', line 305
def fetch_values(*indices, &block) indices.map! { |key| convert_key(key) } super end
#filter(*args, &block)
Alias for #select.
# File 'activesupport/lib/active_support/hash_with_indifferent_access.rb', line 388
alias_method :filter, :select
#has_key?(key)
Alias for #key?.
# File 'activesupport/lib/active_support/hash_with_indifferent_access.rb', line 196
alias_method :has_key?, :key?
#include?(key)
Alias for #key?.
# File 'activesupport/lib/active_support/hash_with_indifferent_access.rb', line 195
alias_method :include?, :key?
#key?(key) ⇒ Boolean
Also known as: #include?, #has_key?, #member?
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
# File 'activesupport/lib/active_support/hash_with_indifferent_access.rb', line 191
def key?(key) super(convert_key(key)) end
#member?(key)
Alias for #key?.
# File 'activesupport/lib/active_support/hash_with_indifferent_access.rb', line 197
alias_method :member?, :key?
#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.
#merge!(*other_hashes, &block)
Alias for #update.
# File 'activesupport/lib/active_support/hash_with_indifferent_access.rb', line 181
alias_method :merge!, :update
#nested_under_indifferent_access
[ GitHub ]# File 'activesupport/lib/active_support/hash_with_indifferent_access.rb', line 80
def nested_under_indifferent_access self end
#regular_update
[ GitHub ]# File 'activesupport/lib/active_support/hash_with_indifferent_access.rb', line 104
alias_method :regular_update, :update unless method_defined?(:regular_update)
#regular_writer
[ GitHub ]# File 'activesupport/lib/active_support/hash_with_indifferent_access.rb', line 103
alias_method :regular_writer, :[]= unless method_defined?(:regular_writer)
#reject(*args, &block)
[ GitHub ]# File 'activesupport/lib/active_support/hash_with_indifferent_access.rb', line 390
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}
# File 'activesupport/lib/active_support/hash_with_indifferent_access.rb', line 356
def replace(other_hash) super(cast(other_hash)) end
#reverse_merge(other_hash) Also known as: #with_defaults
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}
# File 'activesupport/lib/active_support/hash_with_indifferent_access.rb', line 339
def reverse_merge(other_hash) super(cast(other_hash)) end
#reverse_merge!(other_hash) Also known as: #with_defaults!
Same semantics as #reverse_merge but modifies the receiver in-place.
# File 'activesupport/lib/active_support/hash_with_indifferent_access.rb', line 345
def reverse_merge!(other_hash) super(cast(other_hash)) end
#select(*args, &block) Also known as: #filter
[ GitHub ]# File 'activesupport/lib/active_support/hash_with_indifferent_access.rb', line 384
def select(*args, &block) return to_enum(:select) unless block_given? dup.tap { |hash| hash.select!(*args, &block) } end
#slice(*keys)
[ GitHub ]# File 'activesupport/lib/active_support/hash_with_indifferent_access.rb', line 429
def slice(*keys) keys.map! { |key| convert_key(key) } self.class.new(super) end
#slice!(*keys)
[ GitHub ]# File 'activesupport/lib/active_support/hash_with_indifferent_access.rb', line 434
def slice!(*keys) keys.map! { |key| convert_key(key) } super end
#store(key, value, convert_value: true)
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'.
If the value is a Hash or contains one or multiple Hashes, they will be
converted to HashWithIndifferentAccess. unless convert_value: false
is set.
# File 'activesupport/lib/active_support/hash_with_indifferent_access.rb', line 133
def store(key, value, convert_value: true) value = convert_value(value, conversion: :assignment) if convert_value regular_writer(convert_key(key), value) end
#symbolize_keys Also known as: #to_options
[ GitHub ]# File 'activesupport/lib/active_support/hash_with_indifferent_access.rb', line 379
def symbolize_keys; to_hash.symbolize_keys! end
#to_hash
Convert to a regular hash with string keys.
# File 'activesupport/lib/active_support/hash_with_indifferent_access.rb', line 444
def to_hash copy = Hash[self] copy.transform_values! { |v| convert_value_to_hash(v) } copy_defaults(copy) end
#to_options
Alias for #symbolize_keys.
# File 'activesupport/lib/active_support/hash_with_indifferent_access.rb', line 380
alias_method :, :symbolize_keys
#to_options!
[ GitHub ]# File 'activesupport/lib/active_support/hash_with_indifferent_access.rb', line 382
def ; self end
#to_proc
[ GitHub ]# File 'activesupport/lib/active_support/hash_with_indifferent_access.rb', line 450
def to_proc proc { |key| self[key] } end
#transform_keys(hash = NOT_GIVEN, &block)
[ GitHub ]# File 'activesupport/lib/active_support/hash_with_indifferent_access.rb', line 402
def transform_keys(hash = NOT_GIVEN, &block) if NOT_GIVEN.equal?(hash) if block_given? self.class.new(super(&block)) else to_enum(:transform_keys) end else hash = hash.transform_keys { |key| convert_key(key) } if hash.is_a?(Hash) self.class.new(super) end end
#transform_keys!(hash = NOT_GIVEN, &block)
[ GitHub ]# File 'activesupport/lib/active_support/hash_with_indifferent_access.rb', line 415
def transform_keys!(hash = NOT_GIVEN, &block) if NOT_GIVEN.equal?(hash) if block_given? replace(copy_defaults(transform_keys(&block))) else return to_enum(:transform_keys!) end else replace(copy_defaults(transform_keys(hash, &block))) end self end
#transform_values(&block)
[ GitHub ]# File 'activesupport/lib/active_support/hash_with_indifferent_access.rb', line 395
def transform_values(&block) return to_enum(:transform_values) unless block_given? dup.tap { |hash| hash.transform_values!(&block) } end
#update(*other_hashes, &block) Also known as: #merge!
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
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}
# File 'activesupport/lib/active_support/hash_with_indifferent_access.rb', line 170
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
#update_with_single_argument(other_hash, block) (private)
[ GitHub ]# File 'activesupport/lib/active_support/hash_with_indifferent_access.rb', line 496
def update_with_single_argument(other_hash, block) if other_hash.is_a? HashWithIndifferentAccess regular_update(other_hash, &block) else other_hash.to_hash.each_pair do |key, value| if block && key?(key) value = block.call(convert_key(key), self[key], value) end regular_writer(convert_key(key), convert_value(value)) end end 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"]
# File 'activesupport/lib/active_support/hash_with_indifferent_access.rb', line 289
def values_at(*keys) keys.map! { |key| convert_key(key) } super end
#with_defaults(other_hash)
Alias for #reverse_merge.
# File 'activesupport/lib/active_support/hash_with_indifferent_access.rb', line 342
alias_method :with_defaults, :reverse_merge
#with_defaults!(other_hash)
Alias for #reverse_merge!.
# File 'activesupport/lib/active_support/hash_with_indifferent_access.rb', line 348
alias_method :with_defaults!, :reverse_merge!
#with_indifferent_access
[ GitHub ]# File 'activesupport/lib/active_support/hash_with_indifferent_access.rb', line 76
def with_indifferent_access dup end
#without(*keys)
Alias for #except.
# File 'activesupport/lib/active_support/hash_with_indifferent_access.rb', line 375
alias_method :without, :except