Class: OpenStruct

Inherits:
Object
  • Object
show all
Defined in:
lib/ostruct.rb

Overview

OpenStruct allows you to create data objects and set arbitrary attributes. For example:

require 'ostruct' 

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

puts record.name     # -> "John Smith"
puts record.address  # -> nil

It is like a hash with a different way to access the data. In fact, it is implemented with a hash, and you can initialize it with one.

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

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

Constant Summary collapse

InspectKey =

:nodoc:

:__inspect_key__

Instance Method Summary collapse

Constructor Details

#initialize(hash = nil) ⇒ OpenStruct

Create a new OpenStruct object. The optional hash, if given, will generate attributes and values. For example.

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

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

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



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# File 'lib/ostruct.rb', line 46

def initialize(hash=nil)
  @table = {}
  if hash
    for k,v in hash
      @table[k.to_sym] = v
      new_ostruct_member(k)
    end
  end
end

Dynamic Method Handling

This class handles dynamic methods through the method_missing method

#method_missing(mid, *args) ⇒ Object

:nodoc:



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# File 'lib/ostruct.rb', line 79

def method_missing(mid, *args) # :nodoc:
  mname = mid.id2name
  len = args.length
  if mname =~ /=$/
    if len != 1
      raise ArgumentError, "wrong number of arguments (#{len} for 1)", caller(1)
    end
    if self.frozen?
      raise TypeError, "can't modify frozen #{self.class}", caller(1)
    end
    mname.chop!
    self.new_ostruct_member(mname)
    @table[mname.intern] = args[0]
  elsif len == 0
    @table[mid]
  else
    raise NoMethodError, "undefined method `#{mname}' for #{self}", caller(1)
  end
end

Instance Method Details

#==(other) ⇒ Object

Compare this object and other for equality.



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# File 'lib/ostruct.rb', line 142

def ==(other)
  return false unless(other.kind_of?(OpenStruct))
  return @table == other.table
end

#delete_field(name) ⇒ Object

Remove the named field from the object.



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# File 'lib/ostruct.rb', line 102

def delete_field(name)
  @table.delete name.to_sym
end

#initialize_copy(orig) ⇒ Object

Duplicate an OpenStruct object members.



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# File 'lib/ostruct.rb', line 57

def initialize_copy(orig)
  super
  @table = @table.dup
end

#inspect ⇒ Object Also known as: to_s

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



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# File 'lib/ostruct.rb', line 111

def inspect
  str = "#<#{self.class}"

  Thread.current[InspectKey] ||= []
  if Thread.current[InspectKey].include?(self) then
    str << " ..."
  else
    first = true
    for k,v in @table
      str << "," unless first
      first = false

      Thread.current[InspectKey] << v
      begin
        str << " #{k}=#{v.inspect}"
      ensure
        Thread.current[InspectKey].pop
      end
    end
  end

  str << ">"
end

#marshal_dump ⇒ Object 



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# File 'lib/ostruct.rb', line 62

def marshal_dump
  @table
end

#marshal_load(x) ⇒ Object 



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# File 'lib/ostruct.rb', line 65

def marshal_load(x)
  @table = x
  @table.each_key{|key| new_ostruct_member(key)}
end

#new_ostruct_member(name) ⇒ Object 



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# File 'lib/ostruct.rb', line 70

def new_ostruct_member(name)
  name = name.to_sym
  unless self.respond_to?(name)
    meta = class << self; self; end
    meta.send(:define_method, name) { @table[name] }
    meta.send(:define_method, :"#{name}=") { |x| @table[name] = x }
  end
end