Ruby on Rails

I use a method that rebuilds in my attachment model class:

  # use attachment_fu protected methods to remake thumbs
  def remake_thumbnails!
    self.thumbnails.each {|thumb| thumb.destroy}
    temp_file = create_temp_file
    attachment_options[:thumbnails].each do |suffix, size|
      self.create_or_update_thumbnail(temp_file, suffix, *size)
    end
  end

If you want a rake task, just loop through all your attachment records
and call it. I'm using something similar to this:

namespace :images do
  desc "Rebuild all thumb images made by attachment_fu"
  task :rebuild_thumbnails => :environment do
    conditions =  "(whatever you need)"
    count = Image.count(:all, :conditions => conditions) # image is an
attachment_fu model
    done = 0
    chunk_size = 500
    (0...(count/chunk_size)).each do |i|
      Image.find(:all, :offset => i*chunk_size, :limit =>
chunk_size, :conditions => conditions).each do |image|
        done = done + 1
        # next if image.id < 46520 #  to resume a stopped run
        image.remake_thumbnails!
        percent = "%.2f" % ((done/count.to_f)*100)
        puts "#{i.id} #{percent}% done"
      end
    end
  end


On Nov 26, 3:47 pm, eugenio <eugenio.mode...@gmail.com> wrote:
> i'm using this plugin for files and images uploads.
> it has a very useful feature that generatethumbnailsof every
> uploaded image, based on the geometry given in the model definition.
> now i want to change the size of one of the thumbnail: how can i re-
> generate them for the already saved image?
>
> i found thishttp://github.com/kete/kete/blob/master/lib/tasks/tools.rake
> but i don't understand how to use it.