# File actionpack/lib/abstract_controller/callbacks.rb, line 96
def _insert_callbacks(callbacks, block = nil)
  options = callbacks.extract_options!
  _normalize_callback_options(options)
  callbacks.push(block) if block
  callbacks.each do |callback|
    yield callback, options
  end
end

Take callback names and an optional callback proc, normalize them, then call the block with each callback. This allows us to abstract the normalization across several methods that use it.

Parameters

• callbacks - An array of callbacks, with an optional options hash as the last parameter.

• block - A proc that should be added to the callbacks.

Block Parameters

• name - The callback to be added.

• options - A hash of options to be used when adding the callback.

# File actionpack/lib/abstract_controller/callbacks.rb, line 72
def _normalize_callback_options(options)
  _normalize_callback_option(options, :only, :if)
  _normalize_callback_option(options, :except, :unless)
end

If :only or :except are used, convert the options into the :if and :unless options of ActiveSupport::Callbacks.

The basic idea is that :only => :index gets converted to :if => proc {|c| c.action_name == "index" }.

Note that :only has priority over :if in case they are used together.

only: :index, if: -> { true } # the :if option will be ignored.

Note that :if has priority over :except in case they are used together.

except: :index, if: -> { true } # the :except option will be ignored.

Options

• only - The callback should be run only for this action.

• except - The callback should be run for all actions except this action.

# File actionpack/lib/abstract_controller/callbacks.rb, line 146
      

Append a callback after actions. See _insert_callbacks for parameter details.

# File actionpack/lib/abstract_controller/callbacks.rb, line 167
      

Append a callback after actions. See _insert_callbacks for parameter details.

# File actionpack/lib/abstract_controller/callbacks.rb, line 195
      

Append a callback around actions. See _insert_callbacks for parameter details.

# File actionpack/lib/abstract_controller/callbacks.rb, line 135
      

Append a callback before actions. See _insert_callbacks for parameter details.

If the callback renders or redirects, the action will not run. If there are additional callbacks scheduled to run after that callback, they are also cancelled.

# File actionpack/lib/abstract_controller/callbacks.rb, line 174
      

Append a callback around actions. See _insert_callbacks for parameter details.

# File actionpack/lib/abstract_controller/callbacks.rb, line 106
      

Append a callback before actions. See _insert_callbacks for parameter details.

If the callback renders or redirects, the action will not run. If there are additional callbacks scheduled to run after that callback, they are also cancelled.

# File actionpack/lib/abstract_controller/callbacks.rb, line 153
      

Prepend a callback after actions. See _insert_callbacks for parameter details.

# File actionpack/lib/abstract_controller/callbacks.rb, line 181
      

Prepend a callback around actions. See _insert_callbacks for parameter details.

# File actionpack/lib/abstract_controller/callbacks.rb, line 117
      

Prepend a callback before actions. See _insert_callbacks for parameter details.

If the callback renders or redirects, the action will not run. If there are additional callbacks scheduled to run after that callback, they are also cancelled.

# File actionpack/lib/abstract_controller/callbacks.rb, line 160
      

Skip a callback after actions. See _insert_callbacks for parameter details.

# File actionpack/lib/abstract_controller/callbacks.rb, line 188
      

Skip a callback around actions. See _insert_callbacks for parameter details.

# File actionpack/lib/abstract_controller/callbacks.rb, line 128
      

Skip a callback before actions. See _insert_callbacks for parameter details.