Class: ActiveSupport::Callbacks::Callback

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

Overview

:nodoc:#

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 89

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

#chain ⇒ Object

Returns the value of attribute chain.



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# File 'lib/active_support/callbacks.rb', line 87

def chain
  @chain
end

#filter ⇒ Object

Returns the value of attribute filter.



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# File 'lib/active_support/callbacks.rb', line 87

def filter
  @filter
end

#kind ⇒ Object

Returns the value of attribute kind.



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# File 'lib/active_support/callbacks.rb', line 87

def kind
  @kind
end

#klass ⇒ Object

Returns the value of attribute klass.



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# File 'lib/active_support/callbacks.rb', line 87

def klass
  @klass
end

#options ⇒ Object

Returns the value of attribute options.



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# File 'lib/active_support/callbacks.rb', line 87

def options
  @options
end

#per_key ⇒ Object

Returns the value of attribute per_key.



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# File 'lib/active_support/callbacks.rb', line 87

def per_key
  @per_key
end

#raw_filter ⇒ Object

Returns the value of attribute raw_filter.



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# File 'lib/active_support/callbacks.rb', line 87

def raw_filter
  @raw_filter
end

Instance Method Details

#_compile_per_key_options ⇒ Object 



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# File 'lib/active_support/callbacks.rb', line 151

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 136

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 102

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 220

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

  case @kind
  when :after
    # if condition    # after_save :filter_name, :if => :condition
    #   filter_name
    # end
    [@compiled_options[0], @filter, @compiled_options[1]].compact.join("\n")
  when :around
    <<-RUBY_EVAL
      value
    end
    RUBY_EVAL
  end
end

#matches?(_kind, _filter) ⇒ Boolean

Returns:

  • (Boolean) 


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

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

#name ⇒ Object 



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# File 'lib/active_support/callbacks.rb', line 124

def name
  chain.name
end

#next_id ⇒ Object 



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# File 'lib/active_support/callbacks.rb', line 128

def next_id
  @@_callback_sequence += 1
end

#normalize_options!(options) ⇒ Object 



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# File 'lib/active_support/callbacks.rb', line 115

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 141

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 163

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
  #
  case @kind
  when :before
    # if condition    # before_save :filter_name, :if => :condition
    #   filter_name
    # end
    filter = <<-RUBY_EVAL
      unless halted
        # This double assignment is to prevent warnings in 1.9.3.  I would
        # remove the `result` variable, but apparently some other
        # generated code is depending on this variable being set sometimes
        # and sometimes not.
        result = result = #{@filter}
        halted = (#{chain.config[:terminator]})
      end
    RUBY_EVAL

    [@compiled_options[0], filter, @compiled_options[1]].compact.join("\n")
  when :around
    # 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