Class: Struct

Inherits:

Object

• Object
• Struct

Defined in:

lib/casual_support/struct/from_h.rb,
lib/casual_support/struct/assign_attributes.rb

Class Method Summary

• .from_h(attributes) ⇒ self.new

  Constructs an instance of a subclass of Struct, and assigns the values of the given attribute Hash to the instance.

Instance Method Summary

• #assign_attributes(new_attributes) ⇒ self

  Assigns values in the given Hash to corresponding attributes of the Struct.

Class Method Details

.from_h(attributes) ⇒ self.new

Constructs an instance of a subclass of Struct, and assigns the values of the given attribute Hash to the instance. This method is intended for use only with subclasses of Struct which do not alter the default signature of the initialize method. See also #assign_attributes.

Examples:

Point = Struct.new(:x, :y, :z)
p = Point.from_h(x: 10, y: 20, z: 30)  # == Point.new(10, 20, 30)

Parameters:

• attributes (Hash<Symbol, Object>, Hash<String, Object>)

Returns:

• (self.new)

# File 'lib/casual_support/struct/from_h.rb', line 17

def self.from_h(attributes)
  raise "Struct.from_h is for use only with subclasses of Struct" if self == Struct
  self.new.assign_attributes(attributes)
end

Instance Method Details

#assign_attributes(new_attributes) ⇒ self

Assigns values in the given Hash to corresponding attributes of the Struct. Both Symbol keys and String keys are accepted. Keys which don’t correspond to an attribute of the Struct are ignored. Mutates the Struct and returns it.

Examples:

Point = Struct.new(:x, :y, :z)
point = Point.new(10, 20, 30)

point.assign_attributes(y: 30, z: 50)  # == point
point.to_h                             # == { x: 10, y: 30, z: 50 }

Parameters:

• new_attributes (Hash<Symbol, Object>, Hash<String, Object>)

Returns:

• (self)

# File 'lib/casual_support/struct/assign_attributes.rb', line 17

def assign_attributes(new_attributes)
  ms = self.members
  new_attributes.each do |k, v|
    m = k.to_sym
    self[m] = v if ms.include?(m)
  end
  self
end