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Class: ActiveSupport::Deprecation::DeprecatedInstanceVariableProxy

Relationships & Source Files
Super Chains via Extension / Inclusion / Inheritance
Class Chain:
Instance Chain:
Inherits: ActiveSupport::Deprecation::DeprecationProxy
Defined in: activesupport/lib/active_support/deprecation/proxy_wrappers.rb

Overview

DeprecatedInstanceVariableProxy transforms an instance variable into a deprecated one. It takes an instance of a class, a method on that class, an instance variable, and a deprecator as the last argument.

Trying to use the deprecated instance variable will result in a deprecation warning, pointing to the method as a replacement.

class Example
  def initialize
    @request = ActiveSupport::Deprecation::DeprecatedInstanceVariableProxy.new(self, :request, :@request, ActiveSupport::Deprecation.new)
    @_request = :special_request
  end

  def request
    @_request
  end

  def old_request
    @request
  end
end

example = Example.new
# => #<Example:0x007fb9b31090b8 @_request=:special_request, @request=:special_request>

example.old_request.to_s
# => DEPRECATION WARNING: @request is deprecated! Call request.to_s instead of
   @request.to_s
   (Backtrace information…)
   "special_request"

example.request.to_s
# => "special_request"

Class Method Summary

Instance Method Summary

DeprecationProxy - Inherited

#inspect

Don’t give a deprecation warning on inspect since test/unit and error logs rely on it for diagnostics.

#method_missing

Constructor Details

.new(instance, method, var = "@#{method}", deprecator:) ⇒ DeprecatedInstanceVariableProxy

[ GitHub ]

  
# File 'activesupport/lib/active_support/deprecation/proxy_wrappers.rb', line 88

def initialize(instance, method, var = "@#{method}", deprecator:)
  @instance = instance
  @method = method
  @var = var
  @deprecator = deprecator
end

Dynamic Method Handling

This class handles dynamic methods through the method_missing method in the class ActiveSupport::Deprecation::DeprecationProxy

Instance Method Details

#target (private)

[ GitHub ]

  
# File 'activesupport/lib/active_support/deprecation/proxy_wrappers.rb', line 96

def target
  @instance.__send__(@method)
end

#warn(callstack, called, args) (private)

[ GitHub ]

  
# File 'activesupport/lib/active_support/deprecation/proxy_wrappers.rb', line 100

def warn(callstack, called, args)
  @deprecator.warn("#{@var} is deprecated! Call #{@method}.#{called} instead of #{@var}.#{called}. Args: #{args.inspect}", callstack)
end