OpenStruct

Creates a new OpenStruct object. By default, the resulting OpenStruct object will have no attributes.

The optional hash, if given, will generate attributes and values (can be a Hash, an OpenStruct or a Struct). For example:

require "ostruct"
hash = { "country" => "Australia", :capital => "Canberra" }
data = OpenStruct.new(hash)

data   # => #<OpenStruct country="Australia", capital="Canberra">

 
               # File ostruct.rb, line 89
def initialize(hash=nil)
  @table = {}
  if hash
    hash.each_pair do |k, v|
      k = k.to_sym
      @table[k] = v
      new_ostruct_member(k)
    end
  end
end
            

Compares this object and other for equality. An OpenStruct is equal to other when other is an OpenStruct and the two objects' Hash tables are equal.

require "ostruct"
first_pet  = OpenStruct.new("name" => "Rowdy")
second_pet = OpenStruct.new(:name  => "Rowdy")
third_pet  = OpenStruct.new("name" => "Rowdy", :age => nil)

first_pet == second_pet   # => true
first_pet == third_pet    # => false

 
               # File ostruct.rb, line 293
def ==(other)
  return false unless other.kind_of?(OpenStruct)
  @table == other.table
end
            

Returns the value of an attribute.

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

 
               # File ostruct.rb, line 208
def [](name)
  @table[name.to_sym]
end
            

Sets the value of an attribute.

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

 
               # File ostruct.rb, line 223
def []=(name, value)
  modifiable[new_ostruct_member(name)] = value
end
            

Removes the named field from the object. Returns the value that the field contained if it was defined.

require "ostruct"

person = OpenStruct.new(name: "John", age: 70, pension: 300)

person.delete_field("age")   # => 70
person                       # => #<OpenStruct name="John", pension=300>

Setting the value to nil will not remove the attribute:

person.pension = nil
person                 # => #<OpenStruct name="John", pension=nil>

 
               # File ostruct.rb, line 243
def delete_field(name)
  sym = name.to_sym
  singleton_class.__send__(:remove_method, sym, "#{sym}=")
  @table.delete sym
end
            

Yields all attributes (as symbols) along with the corresponding values or returns an enumerator if no block is given.

require "ostruct"
data = OpenStruct.new("country" => "Australia", :capital => "Canberra")
data.each_pair.to_a   # => [[:country, "Australia"], [:capital, "Canberra"]]

 
               # File ostruct.rb, line 131
def each_pair
  return to_enum(__method__) { @table.size } unless block_given?
  @table.each_pair{|p| yield p}
  self
end
            

Compares this object and other for equality. An OpenStruct is eql? to other when other is an OpenStruct and the two objects' Hash tables are eql?.

 
               # File ostruct.rb, line 303
def eql?(other)
  return false unless other.kind_of?(OpenStruct)
  @table.eql?(other.table)
end
            

Computes a hash code for this OpenStruct. Two OpenStruct objects with the same content will have the same hash code (and will compare using eql?).

See also Object#hash.

 
               # File ostruct.rb, line 313
def hash
  @table.hash
end
            

Returns a string containing a detailed summary of the keys and values.

 
               # File ostruct.rb, line 254
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
            

Provides marshalling support for use by the Marshal library.

 
               # File ostruct.rb, line 140
def marshal_dump
  @table
end
            

Provides marshalling support for use by the Marshal library.

 
               # File ostruct.rb, line 147
def marshal_load(x)
  @table = x
  @table.each_key{|key| new_ostruct_member(key)}
end
            

Converts the OpenStruct to a hash with keys representing each attribute (as symbols) and their corresponding values.

require "ostruct"
data = OpenStruct.new("country" => "Australia", :capital => "Canberra")
data.to_h   # => {:country => "Australia", :capital => "Canberra" }

 
               # File ostruct.rb, line 115
def to_h
  @table.dup
end
            

Used internally to check if the OpenStruct is able to be modified before granting access to the internal Hash table to be modified.

 
               # File ostruct.rb, line 156
def modifiable
  begin
    @modifiable = true
  rescue
    raise RuntimeError, "can't modify frozen #{self.class}", caller(3)
  end
  @table
end
            

Used internally to defined properties on the OpenStruct. It does this by using the metaprogramming function define_singleton_method for both the getter method and the setter method.

 
               # File ostruct.rb, line 171
def new_ostruct_member(name)
  name = name.to_sym
  unless respond_to?(name)
    define_singleton_method(name) { @table[name] }
    define_singleton_method("#{name}=") { |x| modifiable[name] = x }
  end
  name
end