Ticket #933: upload_progress_send_ajax.rb

# helper function to send a javascript command to the client.
 # options hash should have:
 # :action => (:insert, :replace, :delete, :empty, :formfill)
 # :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
 # pass in a block of captured erb html for functions that make sense to do so.
 def send_ajax(options, text = "", &block)
   
   if block then
     # execute the block=  
     # this code stolen from the capture helper
     buffer = eval("_erbout", block.binding)
     pos = buffer.length
     block.call
     
     # extract the block 
     data = buffer[pos..-1]
     
     # replace it in the original with empty string
     buffer[pos..-1] = ''
     text = data
   end
   
   text = escape_javascript(text)
     
   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
       "$('#{options[:target]}').innerHTML = '#{text}'"         
     when :empty
       "$('#{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