Ticket #933: ajax_render.rb

module AjaxRender
    
      #original code by dgm. modied by Gunther Schulz (freedumb on freenode).
      
      # helper function to render a javascript command to the client.
      # options hash should have:
                        # :template => erb template. If omitted the default template for the action is used.
      # :action => (:insert, :replace, :delete, :empty, :formfill). 
                        # on :replace all elements with a tag name of 'javascript'  will be evaled in the client.
      # :target => DOM element. (string name)
      # :position => (:before, :top, :bottom, :after) 
      #   postion is only used in the insert routines
      # :formobject => ActiveRecord Object - values to fill into form
      #   :formobject is used only by :formfill action
                        
        def render_ajax(options)
                render_text render_ajax_to_string(options)
        end
        
        def render_ajax_to_string(options)
                                
                                if options[:template]
                                        text = escape_javascript(render_to_string(options[:template]))
                                else
          text = escape_javascript(render_to_string)
                                end
                                
        case options[:action]
          when :insert
            case options[:position]
              when :before
                "new Insertion.Before('#{options[:target]}', '#{text}');"
              when :top
               "new Insertion.Top('#{options[:target]}', '#{text}');"
              when :bottom
                "new Insertion.Bottom('#{options[:target]}', '#{text}');"
              when :after
                "new Insertion.After('#{options[:target]}', '#{text}');"
              else
                raise ArgumentError, "Invalid position, choose one of :before, :top, :bottom, :after"
            end
          when :replace
            "$('#{options[:target]}').innerHTML = '#{text}'; for (i = 0; i < #{options[:target]}.getElementsByTagName('script').length; ++i){eval(#{options[:target]}.getElementsByTagName('script')[i].firstChild.data)};"         
          when :empty
            "$('#{options[:target]}').innerHTML = '';"
          when :delete
            "$('#{options[:target]}').parentNode.removeChild($('#{options[:target]}'));"
          when :formfill
            raise ArgumentError, ":formfill requires :formobject" unless options[:formobject]
            ret = ''
           objectname = options[:formobject].class.to_s.underscore
            for key,value in options[:formobject].attributes
              ret << "$('#{objectname}_#{key}').value = '#{escape_javascript(value.to_s)}';\n"
            end
            return ret
          else
            raise ArgumentError, "Invalid action, choose one of :insert, :replace, :delete, :empty, :formfill"
        end
                                
      end
                
        def escape_javascript(javascript)
         javascript.gsub(/\r\n|\n|\r/, "\\n").gsub(/["']/) { |m| "\\#{m}" }
        end
                
end