Module: Casting::Context::InstanceMethods

Defined in:
lib/casting/context.rb

Instance Method Summary collapse

Instance Method Details

#assign(object, role_name) ⇒ Object

Keep track of objects and their behaviors



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# File 'lib/casting/context.rb', line 68

def assign(object, role_name)
  instance_variable_set("@#{role_name}", object)
  assignments << [object, role_for(role_name)]
end

#assigned_roles(object) ⇒ Object

Get the roles for the given object



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# File 'lib/casting/context.rb', line 92

def assigned_roles(object)
  assignments.select { |pair|
    pair.first == object
  }.map(&:last)
end

#assignments ⇒ Object 



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# File 'lib/casting/context.rb', line 63

def assignments
  @assignments ||= []
end

#contains?(obj) ⇒ Boolean

Returns:

  • (Boolean) 


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# File 'lib/casting/context.rb', line 73

def contains?(obj)
  assignments.map(&:first).include?(obj)
end

#context ⇒ Object 



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# File 'lib/casting/context.rb', line 59

def context
  self
end

#dispatch(object, method_name) ⇒ Object

Execute the behavior from the role on the specifed object



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# File 'lib/casting/context.rb', line 78

def dispatch(object, method_name, ...)
  if object.respond_to?(:cast)
    object.cast(method_name, context.role_implementing(object, method_name), ...)
  else
    Casting::Delegation.prepare(method_name, object).to(role_implementing(object, method_name)).with(...).call
  end
end

#role_for(name) ⇒ Object

Get the behavior module for the named role. This role constant for special_person is SpecialPerson.



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# File 'lib/casting/context.rb', line 100

def role_for(name)
  role_name = name.to_s.gsub(/(?:^|_)([a-z])/) { $1.upcase }
  self.class.const_get(role_name)
rescue NameError
  Module.new
end

#role_implementing(object, method_name) ⇒ Object

Find the first assigned role which implements a response for the given method name



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# File 'lib/casting/context.rb', line 87

def role_implementing(object, method_name)
  assigned_roles(object).find { |role| role.method_defined?(method_name) } || raise(NoMethodError, "unknown method '#{method_name}' expected for #{object}")
end