在无法在Rails中使用的方法中将属性名称作为参数传递

Question

I'm trying to define a method in a model to simplify things I'm doing in my controller as below:

models/game.rb

def build_array_for(words)
  words.downcase.split(",")
end

I'm calling the method in the controller as below

games_controller.rb

@wordsArray = @game.build_array_for(red_words)

Note that 'red_words' is an attribute of instances of Game which value is supposed to be a string

When I call the method I get:

undefined local variable or method `red_words' for GamesController

If I build the method as:

def build_array
  red_words.downcase.split(",")
end

it works but since I'm using it with other attributes for the same purpose it wouldn't make sense.

What am I missing here, could it be that the argument is passed as a string and for some reason the name of the attribute is not recognised?

Answer 1

If you need build array for existed column then you can try this:

def build_array_for(column)
  self[column].downcase.split(",")
end

If you want build array for any instance variable when:

def build_array_for(name)
  self.send(name).downcase.split(",")
end

Use symbol or string for a parameter:

@wordsArray = @game.build_array_for(:red_words)

Answer 2

Change the method to

def build_array_for(words)
  words.downcase.split(",")
end

When you are using self rails will try to find an attribute words or instance method words for Game object

EDIT

Make this changes accordingly

games_controller.rb

@wordsArray = @game.build_array_for(red_words)

models/game.rb

def build_array(red_words)
  red_words.downcase.split(",")
end