Class: Hashie::Mash
- Includes:
- PrettyInspect
- Defined in:
- lib/hashie/mash.rb
Overview
Mash allows you to create pseudo-objects that have method-like accessors for hash keys. This is useful for such implementations as an API-accessing library that wants to fake robust objects without the overhead of actually doing so. Think of it as OpenStruct with some additional goodies.
A Mash will look at the methods you pass it and perform operations based on the following rules:
- No punctuation: Returns the value of the hash for that key, or nil if none exists.
- Assignment (=): Sets the attribute of the given method name.
- Existence (?): Returns true or false depending on whether that key has been set.
- Bang (!): Forces the existence of this key, used for deep Mashes. Think of it as "touch" for mashes.
- Under Bang (_): Like Bang, but returns a new Mash rather than creating a key. Used to test existance in deep Mashes.
== Basic Example
mash = Mash.new mash.name? # => false mash.name = "Bob" mash.name # => "Bob" mash.name? # => true
== Hash Conversion Example
hash = => {:b => 23, :d => {:e => "abc"}, :f => [=> 44, :h => 29, 12]} mash = Mash.new(hash) mash.a.b # => 23 mash.a.d.e # => "abc" mash.f.first.g # => 44 mash.f.last # => 12
== Bang Example
mash = Mash.new
mash.author # => nil
mash.author! # =>
mash = Mash.new
mash.author!.name = "Michael Bleigh"
mash.author # =>
== Under Bang Example
mash = Mash.new
mash.author # => nil
mash.author_ # =>
mash = Mash.new
mash.author_.name = "Michael Bleigh" (assigned to temp object)
mash.author # =>
Instance Method Summary collapse
-
#[](key) {|value| ... } ⇒ Object
Retrieves an attribute set in the Mash.
-
#[]=(key, value) ⇒ Object
Sets an attribute in the Mash.
-
#deep_merge(other_hash, &blk) ⇒ Object
(also: #merge)
Performs a deep_update on a duplicate of the current mash.
-
#deep_update(other_hash, &blk) ⇒ Object
(also: #deep_merge!, #update)
Recursively merges this mash with the passed in hash, merging each hash in the hierarchy.
- #delete(key) ⇒ Object
-
#dup ⇒ Object
Duplicates the current mash as a new mash.
- #fetch(key, *args) ⇒ Object
-
#id ⇒ Object
:nodoc:.
-
#initialize(source_hash = nil, default = nil, &blk) ⇒ Mash
constructor
If you pass in an existing hash, it will convert it to a Mash including recursively descending into arrays and hashes, converting them as well.
-
#initializing_reader(key) ⇒ Object
This is the bang method reader, it will return a new Mash if there isn't a value already assigned to the key requested.
- #key?(key) ⇒ Boolean (also: #has_key?, #include?, #member?)
- #method_missing(method_name, *args, &blk) ⇒ Object
- #regular_dup ⇒ Object
- #regular_reader ⇒ Object
- #regular_writer ⇒ Object
- #replace(other_hash) ⇒ Object
-
#respond_to?(method_name, include_private = false) ⇒ Boolean
Will return true if the Mash has had a key set in addition to normal respond_to? functionality.
-
#shallow_merge(other_hash) ⇒ Object
Performs a shallow_update on a duplicate of the current mash.
-
#shallow_update(other_hash) ⇒ Object
Merges (non-recursively) the hash from the argument, changing the receiving hash.
-
#type ⇒ Object
:nodoc:.
-
#underbang_reader(key) ⇒ Object
This is the under bang method reader, it will return a temporary new Mash if there isn't a value already assigned to the key requested.
Methods included from PrettyInspect
Methods inherited from Hash
Methods included from HashExtensions
#hashie_stringify_keys, #hashie_stringify_keys!, included, #to_mash
Constructor Details
#initialize(source_hash = nil, default = nil, &blk) ⇒ Mash
If you pass in an existing hash, it will convert it to a Mash including recursively descending into arrays and hashes, converting them as well.
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# File 'lib/hashie/mash.rb', line 65 def initialize(source_hash = nil, default = nil, &blk) deep_update(source_hash) if source_hash default ? super(default) : super(&blk) end |
Dynamic Method Handling
This class handles dynamic methods through the method_missing method
#method_missing(method_name, *args, &blk) ⇒ Object
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# File 'lib/hashie/mash.rb', line 191 def method_missing(method_name, *args, &blk) return self.[](method_name, &blk) if key?(method_name) match = method_name.to_s.match(/(.*?)([?=!_]?)$/) case match[2] when "=" self[match[1]] = args.first when "?" !!self[match[1]] when "!" initializing_reader(match[1]) when "_" underbang_reader(match[1]) else default(method_name, *args, &blk) end end |
Instance Method Details
#[](key) {|value| ... } ⇒ Object
Retrieves an attribute set in the Mash. Will convert any key passed in to a string before retrieving.
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# File 'lib/hashie/mash.rb', line 85 def [](key) value = regular_reader(convert_key(key)) yield value if block_given? value end |
#[]=(key, value) ⇒ Object
Sets an attribute in the Mash. Key will be converted to a string before it is set, and Hashes will be converted into Mashes for nesting purposes.
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# File 'lib/hashie/mash.rb', line 94 def []=(key,value) #:nodoc: regular_writer(convert_key(key), convert_value(value)) end |
#deep_merge(other_hash, &blk) ⇒ Object Also known as: merge
Performs a deep_update on a duplicate of the current mash.
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# File 'lib/hashie/mash.rb', line 140 def deep_merge(other_hash, &blk) dup.deep_update(other_hash, &blk) end |
#deep_update(other_hash, &blk) ⇒ Object Also known as: deep_merge!, update
Recursively merges this mash with the passed in hash, merging each hash in the hierarchy.
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# File 'lib/hashie/mash.rb', line 147 def deep_update(other_hash, &blk) other_hash.each_pair do |k,v| key = convert_key(k) if regular_reader(key).is_a?(Mash) and v.is_a?(::Hash) regular_reader(key).deep_update(v, &blk) else value = convert_value(v, true) value = blk.call(key, self[k], value) if blk regular_writer(key, value) end end self end |
#delete(key) ⇒ Object
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# File 'lib/hashie/mash.rb', line 121 def delete(key) super(convert_key(key)) end |
#dup ⇒ Object
Duplicates the current mash as a new mash.
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# File 'lib/hashie/mash.rb', line 127 def dup self.class.new(self, self.default) end |
#fetch(key, *args) ⇒ Object
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# File 'lib/hashie/mash.rb', line 117 def fetch(key, *args) super(convert_key(key), *args) end |
#id ⇒ Object
:nodoc:
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# File 'lib/hashie/mash.rb', line 72 def id #:nodoc: self["id"] end |
#initializing_reader(key) ⇒ Object
This is the bang method reader, it will return a new Mash if there isn't a value already assigned to the key requested.
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# File 'lib/hashie/mash.rb', line 100 def initializing_reader(key) ck = convert_key(key) regular_writer(ck, self.class.new) unless key?(ck) regular_reader(ck) end |
#key?(key) ⇒ Boolean Also known as: has_key?, include?, member?
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# File 'lib/hashie/mash.rb', line 131 def key?(key) super(convert_key(key)) end |
#regular_dup ⇒ Object
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# File 'lib/hashie/mash.rb', line 125 alias_method :regular_dup, :dup |
#regular_reader ⇒ Object
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# File 'lib/hashie/mash.rb', line 80 alias_method :regular_reader, :[] |
#regular_writer ⇒ Object
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# File 'lib/hashie/mash.rb', line 81 alias_method :regular_writer, :[]= |
#replace(other_hash) ⇒ Object
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# File 'lib/hashie/mash.rb', line 178 def replace(other_hash) (keys - other_hash.keys).each { |key| delete(key) } other_hash.each { |key, value| self[key] = value } self end |
#respond_to?(method_name, include_private = false) ⇒ Boolean
Will return true if the Mash has had a key set in addition to normal respond_to? functionality.
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# File 'lib/hashie/mash.rb', line 186 def respond_to?(method_name, include_private=false) return true if key?(method_name) || method_name.to_s.slice(/[=?!_]\Z/) super end |
#shallow_merge(other_hash) ⇒ Object
Performs a shallow_update on a duplicate of the current mash
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# File 'lib/hashie/mash.rb', line 165 def shallow_merge(other_hash) dup.shallow_update(other_hash) end |
#shallow_update(other_hash) ⇒ Object
Merges (non-recursively) the hash from the argument, changing the receiving hash
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# File 'lib/hashie/mash.rb', line 171 def shallow_update(other_hash) other_hash.each_pair do |k,v| regular_writer(convert_key(k), convert_value(v, true)) end self end |
#type ⇒ Object
:nodoc:
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# File 'lib/hashie/mash.rb', line 76 def type #:nodoc: self["type"] end |
#underbang_reader(key) ⇒ Object
This is the under bang method reader, it will return a temporary new Mash if there isn't a value already assigned to the key requested.
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# File 'lib/hashie/mash.rb', line 108 def underbang_reader(key) ck = convert_key(key) if key?(ck) regular_reader(ck) else self.class.new end end |