Module | StateMachine::EvalHelpers |
In: |
lib/state_machine/eval_helpers.rb
|
Provides a set of helper methods for evaluating methods within the context of an object.
Evaluates one of several different types of methods within the context of the given object. Methods can be one of the following types:
Below are examples of the various ways that a method can be evaluated on an object:
class Person def initialize(name) @name = name end def name @name end end class PersonCallback def self.run(person) person.name end end person = Person.new('John Smith') evaluate_method(person, :name) # => "John Smith" evaluate_method(person, PersonCallback.method(:run)) # => "John Smith" evaluate_method(person, Proc.new {|person| person.name}) # => "John Smith" evaluate_method(person, lambda {|person| person.name}) # => "John Smith" evaluate_method(person, '@name') # => "John Smith"
Additional arguments can be passed to the methods being evaluated. If the method defines additional arguments other than the object context, then all arguments are required.
For example,
person = Person.new('John Smith') evaluate_method(person, lambda {|person| person.name}, 21) # => "John Smith" evaluate_method(person, lambda {|person, age| "#{person.name} is #{age}"}, 21) # => "John Smith is 21" evaluate_method(person, lambda {|person, age| "#{person.name} is #{age}"}, 21, 'male') # => ArgumentError: wrong number of arguments (3 for 2)