CODEWITHSUNDEEP
ruby-on-railsruby
user3382880
user3382880

Reputation: 33

Accessing instance variable when defined in global in controller ruby on rails

Here I declare instance variable as global. In the input statement, I'm not getting output "home/abc.txt". What is the syntax to access instance variable inputs?

class AbcController
  @filename = 'home/abc.txt'  

  def querypass
    puts @filename
  end

  ...
end

Upvotes: 1

Views: 102

Answers (1)

BroiSatse
BroiSatse

Reputation: 44685

When declared like that, @filename asssignment is run in context of the class and is sth called class instance variable. querypass method is defined on class instance and has no access to it. Probably what you want to do is:

class AbcController

  def initialize 
    @filename = 'home/abc.txt'
  end

  def querypass
    puts @filename
  end

  ...
end

In this case each instance will have its own copy of the variable and each of them will start with same initial value. However, if you really want to have a single variable for the whole class, you can do:

class AbcController
  class << self
    attr_accessor :filename  # or attr_reader
  end
  @filename = 'home/abc.txt'  

  def querypass
    puts self.class.filename
  end

  ...
end

Or if you don't want to create any class setter or reader:

class AbcController
  @filename = 'home/abc.txt'  

  def querypass
    puts self.class.instance_variable_get(:@filename)
  end

  ...
end

Upvotes: 2

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