vendor/rails/actionpack/lib/action_view/renderable.rb

   1 module ActionView
   2   # NOTE: The template that this mixin is being included into is frozen
   3   # so you cannot set or modify any instance variables
   4   module Renderable #:nodoc:
   5     extend ActiveSupport::Memoizable
   6
   7     def self.included(base)
   8       @@mutex = Mutex.new
   9     end
  10
  11     def filename
  12       'compiled-template'
  13     end
  14
  15     def handler
  16       Template.handler_class_for_extension(extension)
  17     end
  18     memoize :handler
  19
  20     def compiled_source
  21       handler.call(self)
  22     end
  23     memoize :compiled_source
  24
  25     def render(view, local_assigns = {})
  26       compile(local_assigns)
  27
  28       stack = view.instance_variable_get(:@_render_stack)
  29       stack.push(self)
  30
  31       # This is only used for TestResponse to set rendered_template
  32       unless is_a?(InlineTemplate) || view.instance_variable_get(:@_first_render)
  33         view.instance_variable_set(:@_first_render, self)
  34       end
  35
  36       view.send(:_evaluate_assigns_and_ivars)
  37       view.send(:_set_controller_content_type, mime_type) if respond_to?(:mime_type)
  38
  39       result = view.send(method_name(local_assigns), local_assigns) do |*names|
  40         ivar = :@_proc_for_layout
  41         if !view.instance_variable_defined?(:"@content_for_#{names.first}") && view.instance_variable_defined?(ivar) && (proc = view.instance_variable_get(ivar))
  42           view.capture(*names, &proc)
  43         elsif view.instance_variable_defined?(ivar = :"@content_for_#{names.first || :layout}")
  44           view.instance_variable_get(ivar)
  45         end
  46       end
  47
  48       stack.pop
  49       result
  50     end
  51
  52     def method_name(local_assigns)
  53       if local_assigns && local_assigns.any?
  54         local_assigns_keys = "locals_#{local_assigns.keys.map { |k| k.to_s }.sort.join('_')}"
  55       end
  56       ['_run', extension, method_segment, local_assigns_keys].compact.join('_').to_sym
  57     end
  58
  59     private
  60       # Compile and evaluate the template's code (if necessary)
  61       def compile(local_assigns)
  62         render_symbol = method_name(local_assigns)
  63
  64         @@mutex.synchronize do
  65           if recompile?(render_symbol)
  66             compile!(render_symbol, local_assigns)
  67           end
  68         end
  69       end
  70
  71       def compile!(render_symbol, local_assigns)
  72         locals_code = local_assigns.keys.map { |key| "#{key} = local_assigns[:#{key}];" }.join
  73
  74         source = <<-end_src
  75           def #{render_symbol}(local_assigns)
  76             old_output_buffer = output_buffer;#{locals_code};#{compiled_source}
  77           ensure
  78             self.output_buffer = old_output_buffer
  79           end
  80         end_src
  81
  82         begin
  83           ActionView::Base::CompiledTemplates.module_eval(source, filename, 0)
  84         rescue Exception => e # errors from template code
  85           if logger = defined?(ActionController) && Base.logger
  86             logger.debug "ERROR: compiling #{render_symbol} RAISED #{e}"
  87             logger.debug "Function body: #{source}"
  88             logger.debug "Backtrace: #{e.backtrace.join("\n")}"
  89           end
  90
  91           raise ActionView::TemplateError.new(self, {}, e)
  92         end
  93       end
  94
  95       # Method to check whether template compilation is necessary.
  96       # The template will be compiled if the file has not been compiled yet, or
  97       # if local_assigns has a new key, which isn't supported by the compiled code yet.
  98       def recompile?(symbol)
  99         !(ActionView::PathSet::Path.eager_load_templates? && Base::CompiledTemplates.method_defined?(symbol))
 100       end
 101   end
 102 end