Performance: javascript helper tweaks to speed up escaping and reduce object allocations when building options strings

actionpack/lib/action_view/helpers/javascript_helper.rb

@@ -80,18 +80,13 @@ module ActionView
       #       return false;">Show me more</a>
       #
       def link_to_function(name, *args, &block)
-        html_options = args.extract_options!
-        function = args[0] || ''
+        html_options = args.extract_options!.symbolize_keys!
 
-        html_options.symbolize_keys!
-        function = update_page(&block) if block_given?
-        content_tag(
-          "a", name, 
-          html_options.merge({ 
-            :href => html_options[:href] || "#", 
-            :onclick => (html_options[:onclick] ? "#{html_options[:onclick]}; " : "") + "#{function}; return false;" 
-          })
-        )
+        function = block_given? ? update_page(&block) : args[0] || ''
+        onclick = "#{"#{html_options[:onclick]}; " if html_options[:onclick]}#{function}; return false;"
+        href = html_options[:href] || '#'
+
+        content_tag(:a, name, html_options.merge(:href => href, :onclick => onclick))
       end
 
       # Returns a button that'll trigger a JavaScript +function+ using the
@@ -111,15 +106,12 @@ module ActionView
       #     page[:details].visual_effect :toggle_slide
       #   end
       def button_to_function(name, *args, &block)
-        html_options = args.extract_options!
-        function = args[0] || ''
+        html_options = args.extract_options!.symbolize_keys!
 
-        html_options.symbolize_keys!
-        function = update_page(&block) if block_given?
-        tag(:input, html_options.merge({ 
-          :type => "button", :value => name, 
-          :onclick => (html_options[:onclick] ? "#{html_options[:onclick]}; " : "") + "#{function};" 
-        }))
+        function = block_given? ? update_page(&block) : args[0] || ''
+        onclick = "#{"#{html_options[:onclick]}; " if html_options[:onclick]}#{function};"
+
+        tag(:input, html_options.merge(:type => 'button', :value => name, :onclick => onclick))
       end
 
       # Includes the Action Pack JavaScript libraries inside a single <script>
@@ -147,9 +139,23 @@ module ActionView
         javascript << '</script>'
       end
 
+
+      JS_ESCAPE_MAP = {
+        '\\'    => '\\\\',
+        '</'    => '<\/',
+        "\r\n"  => '\n',
+        "\n"    => '\n',
+        "\r"    => '\n',
+        '"'     => '\\"',
+        "'"     => "\\'" }
+
       # Escape carrier returns and single and double quotes for JavaScript segments.
       def escape_javascript(javascript)
-        (javascript || '').gsub('\\','\0\0').gsub('</','<\/').gsub(/\r\n|\n|\r/, "\\n").gsub(/["']/) { |m| "\\#{m}" }
+        if javascript
+          javascript.gsub(/(\\|<\/|\r\n|[\n\r"'])/) { JS_ESCAPE_MAP[$1] }
+        else
+          ''
+        end
       end
 
       # Returns a JavaScript tag with the +content+ inside. Example:
@@ -180,9 +186,13 @@ module ActionView
             content_or_options_with_block
           end
 
-        tag = content_tag("script", javascript_cdata_section(content), html_options.merge(:type => Mime::JS))
+        tag = content_tag(:script, javascript_cdata_section(content), html_options.merge(:type => Mime::JS))
 
-        block_given? ? concat(tag) : tag
+        if block_called_from_erb?(block)
+          concat(tag)
+        else
+          tag
+        end
       end
 
       def javascript_cdata_section(content) #:nodoc:
@@ -191,16 +201,19 @@ module ActionView
 
     protected
       def options_for_javascript(options)
-        '{' + options.map {|k, v| "#{k}:#{v}"}.sort.join(', ') + '}'
+        if options.empty?
+          '{}'
+        else
+          "{#{options.keys.map { |k| "#{k}:#{options[k]}" }.sort.join(', ')}}"
+        end
       end
 
       def array_or_string_for_javascript(option)
-        js_option = if option.kind_of?(Array)
+        if option.kind_of?(Array)
           "['#{option.join('\',\'')}']"
         elsif !option.nil?
           "'#{option}'"
         end
-        js_option
       end
     end
 

actionpack/lib/action_view/helpers/tag_helper.rb

@@ -115,7 +115,7 @@ module ActionView
         # can't take an <% end %> later on, so we have to use <% ... %>
         # and implicitly concat.
         def block_called_from_erb?(block)
-          eval(BLOCK_CALLED_FROM_ERB, block)
+          block && eval(BLOCK_CALLED_FROM_ERB, block)
         end
 
         def content_tag_string(name, content, options, escape = true)

actionpack/lib/action_view/helpers/url_helper.rb

@@ -535,7 +535,7 @@ module ActionView
             when method
               "#{method_javascript_function(method, url, href)}return false;"
             when popup
-              popup_javascript_function(popup) + 'return false;'
+              "#{popup_javascript_function(popup)}return false;"
             else
               html_options["onclick"]
           end