Module: ActionFacade::Retrieval

Defined in:
lib/action_facade/retrieval.rb

Overview

Action Facade Retrieval

This module provides ‘retrieve` method to the class which includes the module. The `retrieve` method can be used for obtaining data from the external facade. In Ruby on Rails controllers, this module can be used for assing many instance variables by extracting Active Record queries to the class that is inherited from ActionFacade::Base.

Defined Under Namespace

Classes: FacadeNotFoundError

Instance Method Summary collapse

Instance Method Details

#retrieve(facade_or_other, *variable_names) ⇒ Object

Retrieve data from ‘facade`

If ‘facade_or_other` is a facade, retrieve data from it. If it is a string or a symbol, it will be merged to `variable_names` and retrieve_from method called with controller params. If it is a hash, retrieve_from method will be called with the hash as a payload.

‘variable_names` are symbols for the method names in the facade and they will be set as instance variables in the class that includes the module.



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# File 'lib/action_facade/retrieval.rb', line 24

def retrieve(facade_or_other, *variable_names)
  facade = nil
  names = variable_names.dup
  case facade_or_other
  when ActionFacade::Base
    facade = facade_or_other
  when String, Symbol
    if defined?(params)
      names.unshift(facade_or_other)
      return retrieve_from(params, *names)
    else
      raise ArgumentError.new("Can't call the method with #{facade_or_other.class} if params is undefined.")
    end
  when Hash
    return retrieve_from(facade_or_other, *variable_names)
  else
    raise ArgumentError.new("First parameter must be instance of ActionFacade::Base, String, Symbol or Hash")
  end
  names.each do |name|
    instance_variable_set("@#{name}", facade.send(name.to_sym))
  end
end

#retrieve_from(payload, *variable_names) ⇒ Object

Retrieve data from given payload

If the class which includes the module is Rails controller, guessed facade name will be “Controller” is replaced by the action name + “Facade”. If the class is not Rails controller, the name will be suffixed by “Facade”.

‘payload` is the initialization parameter for the facade.

‘variable_names` are symbols for the method names in the facade and they will be set as instance variables in the class that includes the module.



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# File 'lib/action_facade/retrieval.rb', line 58

def retrieve_from(payload, *variable_names)
  facade = guess_facade
  if facade.nil?
    raise FacadeNotFoundError.new("Could not find Facade class #{guess_facade_name}.")
  end
  retrieve(facade.new(payload), *variable_names)
end