Class: ActiveSupport::HashWithIndifferentAccess
Relationships & Source Files | |
Extension / Inclusion / Inheritance Descendants | |
Subclasses:
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Super Chains via Extension / Inclusion / Inheritance | |
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 354Object.new
Class Method Summary
::Hash
- Inherited
.from_trusted_xml | Builds a |
.from_xml | Returns a |
Instance Attribute Summary
-
#extractable_options? ⇒ Boolean
readonly
Returns
true
so 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#assoc
where 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#default
where 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#dig
where 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#fetch
where 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.
-
#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)
- #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.
- #convert_key(key) private
- #convert_value(value, conversion: nil) private
- #convert_value_to_hash(value) private
- #set_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 70
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 if hash.default 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 58
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 184
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 101
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 197
def assoc(key) super(convert_key(key)) end
#compact
[ GitHub ]# File 'activesupport/lib/active_support/hash_with_indifferent_access.rb', line 387
def compact dup.tap(&:compact!) end
#convert_key(key) (private)
[ GitHub ]# File 'activesupport/lib/active_support/hash_with_indifferent_access.rb', line 404
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 408
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 ]#deep_symbolize_keys
[ GitHub ]# File 'activesupport/lib/active_support/hash_with_indifferent_access.rb', line 336
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 239
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 319
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 224
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 280
def dup self.class.new(self).tap do |new_hash| set_defaults(new_hash) end 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 327
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 211
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 267
def fetch_values(*indices, &block) indices.map! { |key| convert_key(key) } super end
#has_key?(key)
Alias for #key?.
# File 'activesupport/lib/active_support/hash_with_indifferent_access.rb', line 172
alias_method :has_key?, :key?
#include?(key)
Alias for #key?.
# File 'activesupport/lib/active_support/hash_with_indifferent_access.rb', line 171
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 167
def key?(key) super(convert_key(key)) end
#member?(key)
Alias for #key?.
# File 'activesupport/lib/active_support/hash_with_indifferent_access.rb', line 173
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 159
alias_method :merge!, :update
#nested_under_indifferent_access
[ GitHub ]# File 'activesupport/lib/active_support/hash_with_indifferent_access.rb', line 66
def nested_under_indifferent_access self end
#regular_update
[ GitHub ]# File 'activesupport/lib/active_support/hash_with_indifferent_access.rb', line 90
alias_method :regular_update, :update unless method_defined?(:regular_update)
#regular_writer
[ GitHub ]# File 'activesupport/lib/active_support/hash_with_indifferent_access.rb', line 89
alias_method :regular_writer, :[]= unless method_defined?(:regular_writer)
#reject(*args, &block)
[ GitHub ]# File 'activesupport/lib/active_support/hash_with_indifferent_access.rb', line 344
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 314
def replace(other_hash) super(self.class.new(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 299
def reverse_merge(other_hash) super(self.class.new(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 305
def reverse_merge!(other_hash) super(self.class.new(other_hash)) end
#select(*args, &block)
[ GitHub ]# File 'activesupport/lib/active_support/hash_with_indifferent_access.rb', line 339
def select(*args, &block) return to_enum(:select) unless block_given? dup.tap { |hash| hash.select!(*args, &block) } end
#set_defaults(target) (private)
[ GitHub ]#slice(*keys)
[ GitHub ]# File 'activesupport/lib/active_support/hash_with_indifferent_access.rb', line 377
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 382
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 115
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 334
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 392
def to_hash copy = Hash[self] copy.transform_values! { |v| convert_value_to_hash(v) } set_defaults(copy) copy end
#to_options
Alias for #symbolize_keys.
# File 'activesupport/lib/active_support/hash_with_indifferent_access.rb', line 335
alias_method :, :symbolize_keys
#to_options!
[ GitHub ]# File 'activesupport/lib/active_support/hash_with_indifferent_access.rb', line 337
def ; self end
#to_proc
[ GitHub ]# File 'activesupport/lib/active_support/hash_with_indifferent_access.rb', line 399
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 356
def transform_keys(hash = NOT_GIVEN, &block) return to_enum(:transform_keys) if NOT_GIVEN.equal?(hash) && !block_given? dup.tap { |h| h.transform_keys!(hash, &block) } end
#transform_keys!(hash = NOT_GIVEN, &block)
[ GitHub ]# File 'activesupport/lib/active_support/hash_with_indifferent_access.rb', line 361
def transform_keys!(hash = NOT_GIVEN, &block) return to_enum(:transform_keys!) if NOT_GIVEN.equal?(hash) && !block_given? if hash.nil? super elsif NOT_GIVEN.equal?(hash) keys.each { |key| self[yield(key)] = delete(key) } elsif block_given? keys.each { |key| self[hash[key] || yield(key)] = delete(key) } else keys.each { |key| self[hash[key] || key] = delete(key) } end self end
#transform_values(&block)
[ GitHub ]# File 'activesupport/lib/active_support/hash_with_indifferent_access.rb', line 349
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 148
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 440
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 253
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 302
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 308
alias_method :with_defaults!, :reverse_merge!
#with_indifferent_access
[ GitHub ]# File 'activesupport/lib/active_support/hash_with_indifferent_access.rb', line 62
def with_indifferent_access dup end
#without(*keys)
Alias for #except.
# File 'activesupport/lib/active_support/hash_with_indifferent_access.rb', line 330
alias_method :without, :except