What's the difference between calling mail's collector block with and without render?

extern-c · November 15, 2023, 4:08pm

Are the following equivalent? if not, what’s the practical difference between them?

mail(to: '', from: '', subject: '') do |format|
  format.text  { render plain: 'text' }
  format.html { render html: '<html></html>'.html_safe }
end

vs

mail(to: '', from: '', subject: '') do |format|
  format.text  { 'text' }
  format.html { '<html></html>' }
end

It seems that, in this case, render would simply populate options[:body] which is then added to the responses array @responses << options.

This is the source code I read:

github.com

carlhuda/rails-bundler-test/blob/master/actionmailer/lib/action_mailer/base.rb#L679


      
          end
          
          # Translates the +subject+ using Rails I18n class under <tt>[:actionmailer, mailer_scope, action_name]</tt> scope.
          # If it does not find a translation for the +subject+ under the specified scope it will default to a
          # humanized version of the <tt>action_name</tt>.
          def default_i18n_subject #:nodoc:
            mailer_scope = self.class.mailer_name.gsub('/', '.')
            I18n.t(:subject, :scope => [mailer_scope, action_name], :default => action_name.humanize)
          end
          
          def collect_responses_and_parts_order(headers) #:nodoc:
            responses, parts_order = [], nil
          
            if block_given?
              collector = ActionMailer::Collector.new(lookup_context) { render(action_name) }
              yield(collector)
              parts_order = collector.responses.map { |r| r[:content_type] }
              responses  = collector.responses
            elsif headers[:body]
              responses << {
                :body => headers.delete(:body),

github.com

rails/rails/blob/main/actionmailer/lib/action_mailer/collector.rb#L28


      
              def any(*args, &block)
                options = args.extract_options!
                raise ArgumentError, "You have to supply at least one format" if args.empty?
                args.each { |type| send(type, options.dup, &block) }
              end
              alias :all :any
          
              def custom(mime, options = {})
                options.reverse_merge!(content_type: mime.to_s)
                @context.formats = [mime.to_sym]
                options[:body] = block_given? ? yield : @default_render.call
                @responses << options
              end
            end
          end

github.com

rails/rails/blob/6b93fff8af32ef5e91f4ec3cfffb081d0553faf0/actionpack/lib/abstract_controller/collector.rb#L7


      
          # frozen_string_literal: true
          
          require "action_dispatch/http/mime_type"
          
          module AbstractController
            module Collector
              def self.generate_method_for_mime(mime)
                sym = mime.is_a?(Symbol) ? mime : mime.to_sym
                class_eval <<-RUBY, __FILE__, __LINE__ + 1
                  def #{sym}(*args, &block)
                    custom(Mime[:#{sym}], *args, &block)
                  end
                  ruby2_keywords(:#{sym})
                RUBY
              end
          
              Mime::SET.each do |mime|