Method: ActionView::Layouts::ClassMethods#_write_layout_method

Defined in:
actionview/lib/action_view/layouts.rb

#_write_layout_method ⇒ Object

Creates a _layout method to be called by _default_layout .

If a layout is not explicitly mentioned then look for a layout with the controller’s name. if nothing is found then try same procedure to find super class’s layout.



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# File 'actionview/lib/action_view/layouts.rb', line 283

def _write_layout_method # :nodoc:
  silence_redefinition_of_method(:_layout)

  prefixes = /\blayouts/.match?(_implied_layout_name) ? [] : ["layouts"]
  default_behavior = "lookup_context.find_all('#{_implied_layout_name}', #{prefixes.inspect}, false, keys, { formats: formats }).first || super"
  name_clause = if name
    default_behavior
  else
    "      super\n    RUBY\n  end\n\n  layout_definition = \\\n    case _layout\n    when String\n      _layout.inspect\n    when Symbol\n      <<-RUBY\n        \#{_layout}.tap do |layout|\n          return \#{default_behavior} if layout.nil?\n          unless layout.is_a?(String) || !layout\n            raise ArgumentError, \"Your layout method :\#{_layout} returned \\\#{layout}. It \" \\\n              \"should have returned a String, false, or nil\"\n          end\n        end\n      RUBY\n    when Proc\n      define_method :_layout_from_proc, &_layout\n      private :_layout_from_proc\n      <<-RUBY\n        result = _layout_from_proc(\#{_layout.arity == 0 ? '' : 'self'})\n        return \#{default_behavior} if result.nil?\n        result\n      RUBY\n    when false\n      nil\n    when true\n      raise ArgumentError, \"Layouts must be specified as a String, Symbol, Proc, false, or nil\"\n    when nil\n      name_clause\n    end\n\n  class_eval <<-RUBY, __FILE__, __LINE__ + 1\n    # frozen_string_literal: true\n    def _layout(lookup_context, formats, keys)\n      if _conditional_layout?\n        \#{layout_definition}\n      else\n        \#{name_clause}\n      end\n    end\n    private :_layout\n  RUBY\nend\n"