OpenStruct

Parent:Object

OpenStruct是一个类似于Hash的数据结构，允许定义任意属性及其伴随的值。这是通过使用Ruby的元编程来定义类本身的方法来实现的。

例子：

require 'ostruct'

person = OpenStruct.new
person.name    = "John Smith"
person.age     = 70
person.pension = 300

puts person.name     # -> "John Smith"
puts person.age      # -> 70
puts person.address  # -> nil

OpenStruct在内部使用Hash来存储方法和值，甚至可以用一个来初始化：

australia = OpenStruct.new(:country => "Australia", :population => 20_000_000)
p australia   # -> <OpenStruct country="Australia" population=20000000>

具有空格或字符的散列键通常不能用于方法调用（例如（）[] *），并不会立即作为检索或赋值的方法在OpenStruct对象上使用，但仍可通过对象＃发送方法。

measurements = OpenStruct.new("length (in inches)" => 24)
measurements.send("length (in inches)")  # -> 24

data_point = OpenStruct.new(:queued? => true)
data_point.queued?                       # -> true
data_point.send("queued?=",false)
data_point.queued?                       # -> false

除去方法的存在需要执行#delete_field方法，因为将属性值设置为nil不会删除该方法。

first_pet = OpenStruct.new(:name => 'Rowdy', :owner => 'John Smith')
first_pet.owner = nil
second_pet = OpenStruct.new(:name => 'Rowdy')

first_pet == second_pet   # -> false

first_pet.delete_field(:owner)
first_pet == second_pet   # -> true

执行：

OpenStruct使用Ruby的方法查找结构来查找和定义属性的必要方法。这是通过method_missing和define_method方法完成的。

如果担心创建的对象的性能，这应该是一个考虑因素，因为与使用散列或结构相比，设置这些属性的开销要多得多。

Public Class Methods

json_create(object) Show source

通过构造具有t序列化值的新结构对象来反序列化JSON字符串to_json。

# File ext/json/lib/json/add/ostruct.rb, line 11
def self.json_create(object)
  new(object['t'] || object[:t])
end

new(hash=nil) Show source

创建一个新的OpenStruct对象。默认情况下，生成的OpenStruct对象将没有属性。

可选的hash，如果给出的话，将会生成属性和值（可以是Hash，OpenStruct或Struct）。例如：

require 'ostruct'
hash = { "country" => "Australia", :population => 20_000_000 }
data = OpenStruct.new(hash)

p data        # -> <OpenStruct country="Australia" population=20000000>

# File lib/ostruct.rb, line 91
def initialize(hash=nil)
  @table = {}
  if hash
    hash.each_pair do |k, v|
      k = k.to_sym
      @table[k] = v
    end
  end
end

公共实例方法

==(other) Show source

比较这个对象和other平等。OpenStruct等于other什么时候other是OpenStruct，并且两个对象的哈希表是相等的。

# File lib/ostruct.rb, line 311
def ==(other)
  return false unless other.kind_of?(OpenStruct)
  @table == other.table!
end

显示来源

返回成员的值。

person = OpenStruct.new('name' => 'John Smith', 'age' => 70)
person[:age] # => 70, same as ostruct.age

# File lib/ostruct.rb, line 220
def [](name)
  @table[name.to_sym]
end

[]=(name, value) Show source

设置成员的值。

person = OpenStruct.new('name' => 'John Smith', 'age' => 70)
person[:age] = 42 # => equivalent to ostruct.age = 42
person.age # => 42

# File lib/ostruct.rb, line 231
def []=(name, value)
  modifiable?[new_ostruct_member!(name)] = value
end

as_json(*) Show source

返回一个散列，它将变成一个JSON对象并表示这个对象。

# File ext/json/lib/json/add/ostruct.rb, line 17
def as_json(*)
  klass = self.class.name
  klass.to_s.empty? and raise JSON::JSONError, "Only named structs are supported!"
  {
    JSON.create_id => klass,
    't'            => table,
  }
end

delete_field(name) Show source

从对象中删除命名的字段。返回字段包含的值，如果它已被定义。

require 'ostruct'

person = OpenStruct.new('name' => 'John Smith', 'age' => 70)

person.delete_field('name')  # => 'John Smith'

# File lib/ostruct.rb, line 263
def delete_field(name)
  sym = name.to_sym
  begin
    singleton_class.__send__(:remove_method, sym, "#{sym}=")
  rescue NameError
  end
  @table.delete(sym) do
    raise NameError.new("no field `#{sym}' in #{self}", sym)
  end
end

dig(name, *names) Show source

name重复检索与每个对象相对应的值对象。

address = OpenStruct.new('city' => "Anytown NC", 'zip' => 12345)
person = OpenStruct.new('name' => 'John Smith', 'address' => address)
person.dig(:address, 'zip') # => 12345
person.dig(:business_address, 'zip') # => nil

# File lib/ostruct.rb, line 244
def dig(name, *names)
  begin
    name = name.to_sym
  rescue NoMethodError
    raise TypeError, "#{name} is not a symbol nor a string"
  end
  @table.dig(name, *names)
end

each_pair() { |p| ... } Show source

如果未给出块，则产生所有属性​​（作为符号）以及相应的值或返回枚举器。例：

require 'ostruct'
data = OpenStruct.new("country" => "Australia", :population => 20_000_000)
data.each_pair.to_a  # => [[:country, "Australia"], [:population, 20000000]]

# File lib/ostruct.rb, line 129
def each_pair
  return to_enum(__method__) { @table.size } unless block_given?
  @table.each_pair{|p| yield p}
  self
end

eql?(other) Show source

比较这个对象和other平等。OpenStruct是eql？到other什么时候other是OpenStruct和两个对象的哈希表是eql ?.

# File lib/ostruct.rb, line 321
def eql?(other)
  return false unless other.kind_of?(OpenStruct)
  @table.eql?(other.table!)
end

freeze() Show source

调用超类方法Object＃freeze

# File lib/ostruct.rb, line 186
def freeze
  @table.each_key {|key| new_ostruct_member!(key)}
  super
end

hash() Show source

计算这个OpenStruct的散列码。两个具有相同内容的散列将具有相同的散列码（并且将是eql？）。

# File lib/ostruct.rb, line 329
def hash
  @table.hash
end

initialize_copy(orig) Show source

复制一个OpenStruct对象成员。

调用超类方法

# File lib/ostruct.rb, line 102
def initialize_copy(orig)
  super
  @table = @table.dup
end

inspect() Show source

返回一个字符串，其中包含键和值的详细摘要。

# File lib/ostruct.rb, line 279
def inspect
  str = "#<#{self.class}"

  ids = (Thread.current[InspectKey] ||= [])
  if ids.include?(object_id)
    return str << ' ...>'
  end

  ids << object_id
  begin
    first = true
    for k,v in @table
      str << "," unless first
      first = false
      str << " #{k}=#{v.inspect}"
    end
    return str << '>'
  ensure
    ids.pop
  end
end

另外别名为：to_s

marshal_dump() Show source

提供编组支持以供元帅图书馆使用。

# File lib/ostruct.rb, line 138
def marshal_dump
  @table
end

marshal_load(x) Show source

提供编组支持以供元帅图书馆使用。

# File lib/ostruct.rb, line 145
def marshal_load(x)
  @table = x
end

respond_to_missing?(mid, include_private = false) Show source

调用超类方法Object＃respond_to_missing？

# File lib/ostruct.rb, line 191
def respond_to_missing?(mid, include_private = false)
  mname = mid.to_s.chomp("=").to_sym
  @table.key?(mname) || super
end

to_h() Show source

使用表示每个属性（作为符号）和它们对应的值的键将OpenStruct转换为散列。示例：

require 'ostruct'
data = OpenStruct.new("country" => "Australia", :population => 20_000_000)
data.to_h   # => {:country => "Australia", :population => 20000000 }

# File lib/ostruct.rb, line 116
def to_h
  @table.dup
end

to_json(*args) Show source

将此结构的值存储为类名（OpenStruct）v作为JSON字符串。

# File ext/json/lib/json/add/ostruct.rb, line 28
def to_json(*args)
  as_json.to_json(*args)
end

to_s()

别名为：检查

	OpenStruct