class ViewModel::Reference

Key to identify a viewmodel with some kind of inherent ID (e.g. an ViewModel::ActiveRecord)

def ==(other) 

def ==(other)
  other.class             == self.class &&
    other.viewmodel_class == viewmodel_class &&
    other.model_id        == model_id
end

def hash 

def hash
  [viewmodel_class, model_id].hash
end

def initialize(viewmodel_class, model_id) 

def initialize(viewmodel_class, model_id)
  @viewmodel_class = viewmodel_class
  @model_id        = model_id
end

def inspect 

def inspect
  "<Ref:#{self}>"
end

def stable_reference

Generate a stable reference key for this viewmodel using type name and id 
def stable_reference
  raise RuntimeError.new('Model id required to generate a stable reference') unless model_id
  hash = Digest::SHA256.base64digest("#{viewmodel_class.name}.#{model_id}")
  "ref:h:#{hash}"
end

def to_s 

def to_s
  "'#{viewmodel_class.view_name}(id=#{model_id})'"
end