Class: Oj::Bag

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

Overview

A generic class that is used only for storing attributes. It is the base Class for auto-generated classes in the storage system. Instance variables are added using the instance_variable_set() method. All instance variables can be accessed using the variable name (without the @ prefix). No setters are provided as the Class is intended for reading only.

Class Method Summary collapse

Instance Method Summary collapse

Constructor Details

#initialize(args = { }) ⇒ Bag

The initializer can take multiple arguments in the form of key values where the key is the variable name and the value is the variable value. This is intended for testing purposes only.

Examples:

Oj::Bag.new(:@x => 42, :@y => 57)

Parameters:

  • args (Hash) (defaults to: { })

    instance variable symbols and their values



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# File 'lib/oj/bag.rb', line 16

def initialize(args={ })
  args.each do |k,v|
    self.instance_variable_set(k, v)
  end
end

Dynamic Method Handling

This class handles dynamic methods through the method_missing method

#method_missing(m, *args, &block) ⇒ Boolean

Handles requests for variable values. Others cause an Exception to be raised.

Parameters:

  • m (Symbol)

    method symbol

Returns:

  • (Boolean)

    the value of the specified instance variable.

Raises:

  • (ArgumentError)

    if an argument is given. Zero arguments expected.

  • (NoMethodError)

    if the instance variable is not defined.



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# File 'lib/oj/bag.rb', line 38

def method_missing(m, *args, &block)
  raise ArgumentError.new("wrong number of arguments (#{args.size} for 0) to method #{m}") unless args.nil? or args.empty?
  at_m = ('@' + m.to_s).to_sym
  raise NoMethodError.new("undefined method #{m}", m) unless instance_variable_defined?(at_m)
  instance_variable_get(at_m)
end

Class Method Details

.define_class(classname) ⇒ Object

Define a new class based on the Oj::Bag class. This is used internally in the Oj module and is available to service wrappers that receive XML requests that include Objects of Classes not defined in the storage process.

Parameters:

  • classname (String)

    Class name or symbol that includes Module names.

Returns:

  • (Object)

    an instance of the specified Class.

Raises:

  • (NameError)

    if the classname is invalid.



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# File 'lib/oj/bag.rb', line 67

def self.define_class(classname)
  classname = classname.to_s unless classname.is_a?(String)
  tokens = classname.split('::').map { |n| n.to_sym }
  raise NameError.new("Invalid classname '#{classname}") if tokens.empty?
  m = Object
  tokens[0..-2].each do |sym|
    if m.const_defined?(sym)
      m = m.const_get(sym)
    else
      c = Module.new
      m.const_set(sym, c)
      m = c
    end
  end
  sym = tokens[-1]
  if m.const_defined?(sym)
    c = m.const_get(sym)
  else
    c = Class.new(Oj::Bag)
    m.const_set(sym, c)
  end
  c
end

Instance Method Details

#eql?(other) ⇒ Boolean Also known as: ==

Replaces eql?() with something more reasonable for this Class.

Parameters:

  • other (Object)

    Object to compare self to

Returns:

  • (Boolean)

    true if each variable and value are the same, otherwise false.



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# File 'lib/oj/bag.rb', line 48

def eql?(other)
  return false if (other.nil? or self.class != other.class)
  ova = other.instance_variables
  iv = instance_variables
  return false if ova.size != iv.size
  iv.each do |vid|
    return false if instance_variable_get(vid) != other.instance_variable_get(vid)
  end
  true
end

#respond_to?(m) ⇒ Boolean

Replaces the Object.respond_to?() method.

Parameters:

  • m (Symbol)

    method symbol

Returns:

  • (Boolean)

    true for any method that matches an instance variable reader, otherwise false.



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# File 'lib/oj/bag.rb', line 26

def respond_to?(m)
  return true if super
  at_m = ('@' + m.to_s).to_sym
  instance_variables.include?(at_m)
end