Class: ActiveSupport::Callbacks::Callback

Inherits:
Object
  • Object
show all
Defined in:
lib/active_support/callbacks.rb

Constant Summary collapse

@@_callback_sequence =
0

Instance Attribute Summary collapse

Instance Method Summary collapse

Constructor Details

#initialize(chain, filter, kind, options, klass) ⇒ Callback

Returns a new instance of Callback.


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# File 'lib/active_support/callbacks.rb', line 106

def initialize(chain, filter, kind, options, klass)
  @chain, @kind, @klass = chain, kind, klass
  normalize_options!(options)

  @per_key              = options.delete(:per_key)
  @raw_filter, @options = filter, options
  @filter               = _compile_filter(filter)
  @compiled_options     = _compile_options(options)
  @callback_id          = next_id

  _compile_per_key_options
end

Instance Attribute Details

#chainObject

Returns the value of attribute chain


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# File 'lib/active_support/callbacks.rb', line 104

def chain
  @chain
end

#filterObject

Returns the value of attribute filter


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# File 'lib/active_support/callbacks.rb', line 104

def filter
  @filter
end

#kindObject

Returns the value of attribute kind


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# File 'lib/active_support/callbacks.rb', line 104

def kind
  @kind
end

#klassObject

Returns the value of attribute klass


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# File 'lib/active_support/callbacks.rb', line 104

def klass
  @klass
end

#optionsObject

Returns the value of attribute options


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# File 'lib/active_support/callbacks.rb', line 104

def options
  @options
end

#per_keyObject

Returns the value of attribute per_key


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# File 'lib/active_support/callbacks.rb', line 104

def per_key
  @per_key
end

#raw_filterObject

Returns the value of attribute raw_filter


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# File 'lib/active_support/callbacks.rb', line 104

def raw_filter
  @raw_filter
end

Instance Method Details

#_compile_per_key_optionsObject


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# File 'lib/active_support/callbacks.rb', line 168

def _compile_per_key_options
  key_options  = _compile_options(@per_key)

  @klass.class_eval <<-RUBY_EVAL, __FILE__, __LINE__ + 1
    def _one_time_conditions_valid_#{@callback_id}?
      true #{key_options[0]}
    end
  RUBY_EVAL
end

#_update_filter(filter_options, new_options) ⇒ Object


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# File 'lib/active_support/callbacks.rb', line 153

def _update_filter(filter_options, new_options)
  filter_options[:if].push(new_options[:unless]) if new_options.key?(:unless)
  filter_options[:unless].push(new_options[:if]) if new_options.key?(:if)
end

#clone(chain, klass) ⇒ Object


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# File 'lib/active_support/callbacks.rb', line 119

def clone(chain, klass)
  obj                  = super()
  obj.chain            = chain
  obj.klass            = klass
  obj.per_key          = @per_key.dup
  obj.options          = @options.dup
  obj.per_key[:if]     = @per_key[:if].dup
  obj.per_key[:unless] = @per_key[:unless].dup
  obj.options[:if]     = @options[:if].dup
  obj.options[:unless] = @options[:unless].dup
  obj
end

#end(key = nil, object = nil) ⇒ Object

This will supply contents for around and after filters, but not before filters (for the backward pass).


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# File 'lib/active_support/callbacks.rb', line 234

def end(key=nil, object=nil)
  return if key && !object.send("_one_time_conditions_valid_#{@callback_id}?")

  if @kind == :around || @kind == :after
    # if condition    # after_save :filter_name, :if => :condition
    #   filter_name
    # end
    if @kind == :after
      [@compiled_options[0], @filter, @compiled_options[1]].compact.join("\n")
    else
      "end"
    end
  end
end

#matches?(_kind, _filter) ⇒ Boolean

Returns:

  • (Boolean)

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# File 'lib/active_support/callbacks.rb', line 149

def matches?(_kind, _filter)
  @kind == _kind && @filter == _filter
end

#nameObject


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# File 'lib/active_support/callbacks.rb', line 141

def name
  chain.name
end

#next_idObject


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# File 'lib/active_support/callbacks.rb', line 145

def next_id
  @@_callback_sequence += 1
end

#normalize_options!(options) ⇒ Object


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# File 'lib/active_support/callbacks.rb', line 132

def normalize_options!(options)
  options[:if] = Array.wrap(options[:if])
  options[:unless] = Array.wrap(options[:unless])

  options[:per_key] ||= {}
  options[:per_key][:if] = Array.wrap(options[:per_key][:if])
  options[:per_key][:unless] = Array.wrap(options[:per_key][:unless])
end

#recompile!(_options, _per_key) ⇒ Object


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# File 'lib/active_support/callbacks.rb', line 158

def recompile!(_options, _per_key)
  _update_filter(self.options, _options)
  _update_filter(self.per_key, _per_key)

  @callback_id      = next_id
  @filter           = _compile_filter(@raw_filter)
  @compiled_options = _compile_options(@options)
                      _compile_per_key_options
end

#start(key = nil, object = nil) ⇒ Object

This will supply contents for before and around filters, and no contents for after filters (for the forward pass).


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# File 'lib/active_support/callbacks.rb', line 180

def start(key=nil, object=nil)
  return if key && !object.send("_one_time_conditions_valid_#{@callback_id}?")

  # options[0] is the compiled form of supplied conditions
  # options[1] is the "end" for the conditional
  #
  if @kind == :before || @kind == :around
    if @kind == :before
      # if condition    # before_save :filter_name, :if => :condition
      #   filter_name
      # end
      filter = <<-RUBY_EVAL
        unless halted
          result = #{@filter}
          halted = (#{chain.config[:terminator]})
        end
      RUBY_EVAL

      [@compiled_options[0], filter, @compiled_options[1]].compact.join("\n")
    else
      # Compile around filters with conditions into proxy methods
      # that contain the conditions.
      #
      # For `around_save :filter_name, :if => :condition':
      #
      # def _conditional_callback_save_17
      #   if condition
      #     filter_name do
      #       yield self
      #     end
      #   else
      #     yield self
      #   end
      # end
      #
      name = "_conditional_callback_#{@kind}_#{next_id}"
      @klass.class_eval <<-RUBY_EVAL,  __FILE__, __LINE__ + 1
         def #{name}(halted)
          #{@compiled_options[0] || "if true"} && !halted
            #{@filter} do
              yield self
            end
          else
            yield self
          end
        end
      RUBY_EVAL
      "#{name}(halted) do"
    end
  end
end