rails--rails/actionpack/lib/action_view/template.rb

# encoding: utf-8
# This is so that templates compiled in this file are UTF-8

require 'set'
require "action_view/template/resolver"

module ActionView
  class Template
    extend ActiveSupport::Autoload

    eager_autoload do
      autoload :Error
      autoload :Handler
      autoload :Handlers
      autoload :Text
    end

    extend Template::Handlers
    attr_reader :source, :identifier, :handler, :mime_type, :formats, :details

    def initialize(source, identifier, handler, details)
      @source     = source
      @identifier = identifier
      @handler    = handler
      @details    = details
      @method_names = {}

      format = details.delete(:format) || begin
        # TODO: Clean this up
        handler.respond_to?(:default_format) ? handler.default_format.to_sym.to_s : "html"
      end
      @mime_type = Mime::Type.lookup_by_extension(format.to_s)
      @formats = [format.to_sym]
      @formats << :html if format == :js
      @details[:formats] = Array.wrap(format.to_sym)
    end

    def render(view, locals, &block)
      method_name = compile(locals, view)
      view.send(method_name, locals, &block)
    rescue Exception => e
      if e.is_a?(Template::Error)
        e.sub_template_of(self)
        raise e
      else
        raise Template::Error.new(self, view.assigns, e)
      end
    end

    # TODO: Figure out how to abstract this
    def variable_name
      @variable_name ||= identifier[%r'_?(\w+)(\.\w+)*$', 1].to_sym
    end

    # TODO: Figure out how to abstract this
    def counter_name
      @counter_name ||= "#{variable_name}_counter".to_sym
    end

    # TODO: kill hax
    def partial?
      @details[:partial]
    end

    def inspect
      if defined?(Rails.root)
        identifier.sub("#{Rails.root}/", '')
      else
        identifier
      end
    end

    private
      def compile(locals, view)
        method_name = build_method_name(locals)

        return method_name if view.respond_to?(method_name)

        locals_code = locals.keys.map! { |key| "#{key} = local_assigns[:#{key}];" }.join

        code = @handler.call(self)
        if code.sub!(/\A(#.*coding.*)\n/, '')
          encoding_comment = $1
        elsif defined?(Encoding) && Encoding.respond_to?(:default_external)
          encoding_comment = "#coding:#{Encoding.default_external}"
        end

        source = <<-end_src
          def #{method_name}(local_assigns)
            old_output_buffer = output_buffer;#{locals_code};#{code}
          ensure
            self.output_buffer = old_output_buffer
          end
        end_src

        if encoding_comment
          source = "#{encoding_comment}\n#{source}"
          line = -1
        else
          line = 0
        end

        begin
          ActionView::CompiledTemplates.module_eval(source, identifier, line)
          method_name
        rescue Exception => e # errors from template code
          if logger = (view && view.logger)
            logger.debug "ERROR: compiling #{method_name} RAISED #{e}"
            logger.debug "Function body: #{source}"
            logger.debug "Backtrace: #{e.backtrace.join("\n")}"
          end

          raise ActionView::Template::Error.new(self, {}, e)
        end
      end

      def build_method_name(locals)
        # TODO: is locals.keys.hash reliably the same?
        @method_names[locals.keys.hash] ||=
          "_render_template_#{@identifier.hash}_#{__id__}_#{locals.keys.hash}".gsub('-', "_")
      end
  end
end