# module ActiveSupport::Deprecation

### Constants

DEFAULT_BEHAVIORS

  Default warning behaviors per Rails.env.

### Attributes

debug[RW]

Whether to print a backtrace along with the warning.

deprecation_horizon[RW]

The version the deprecated behavior will be removed, by default.

silenced[RW]

### Public Class Methods

behavior() click to toggle source

Returns the set behavior or if one isn’t set, defaults to `:stderr`

    # File lib/active_support/deprecation/behaviors.rb, line 11
    def behavior
      @behavior ||= [DEFAULT_BEHAVIORS[:stderr]]
    end

behavior=(behavior) click to toggle source

Sets the behavior to the specified value. Can be a single value or an array.

Examples

    ActiveSupport::Deprecation.behavior = :stderr
    ActiveSupport::Deprecation.behavior = [:stderr, :log]

    # File lib/active_support/deprecation/behaviors.rb, line 21
    def behavior=(behavior)
      @behavior = Array.wrap(behavior).map { |b| DEFAULT_BEHAVIORS[b] || b }
    end

deprecate_methods(target_module, *method_names) click to toggle source

Declare that a method has been deprecated.

    # File lib/active_support/deprecation/method_wrappers.rb, line 8
        def deprecate_methods(target_module, *method_names)
          options = method_names.extract_options!
          method_names += options.keys

          method_names.each do |method_name|
            target_module.alias_method_chain(method_name, :deprecation) do |target, punctuation|
              target_module.module_eval("            def #{target}_with_deprecation#{punctuation}(*args, &block)
                  ::ActiveSupport::Deprecation.warn(
                    ::ActiveSupport::Deprecation.deprecated_method_warning(
                      :#{method_name},
                      #{options[method_name].inspect}),
                    caller
                  )
                  send(:#{target}_without_deprecation#{punctuation}, *args, &block)
                end
    ", __FILE__, __LINE__ + 1)
            end
          end
        end

deprecated_method_warning(method_name, message = nil) click to toggle source

    # File lib/active_support/deprecation/reporting.rb, line 25
    def deprecated_method_warning(method_name, message = nil)
      warning = "#{method_name} is deprecated and will be removed from Rails #{deprecation_horizon}"
      case message
        when Symbol then "#{warning} (use #{message} instead)"
        when String then "#{warning} (#{message})"
        else warning
      end
    end

silence() { || ... } click to toggle source

Silence deprecation warnings within the block.

    # File lib/active_support/deprecation/reporting.rb, line 18
    def silence
      old_silenced, @silenced = @silenced, true
      yield
    ensure
      @silenced = old_silenced
    end

warn(message = nil, callstack = caller) click to toggle source

Outputs a deprecation warning to the output configured by `ActiveSupport::Deprecation.behavior`

    ActiveSupport::Deprecation.warn("something broke!")
    # => "DEPRECATION WARNING: something broke! (called from your_code.rb:1)"

    # File lib/active_support/deprecation/reporting.rb, line 10
    def warn(message = nil, callstack = caller)
      return if silenced
      deprecation_message(callstack, message).tap do |m|
        behavior.each { |b| b.call(m, callstack) }
      end
    end