Resize existing images when using attachment_fu

If you use the attachment_fu plugin and want to resize all your existing image files after changing any of your thumbnail formats, write a littler runner script like this:

    1 # resize_images.rb
    2 only_this = ARGV[0]
    3 classes = [
    4   'Photo',
    5 ]
    6 classes = only_this.blank? ? classes : [only_this]
    7 classes.each do |klass|
    8   puts "resizing all #{klass.to_s.tableize}"
    9   Kernel.const_get(klass).find(:all, :conditions => 'parent_id IS NULL').each do |image|
   10     puts "...#{image.public_filename}"
   11     temp_file = image.create_temp_file
   12     image.attachment_options[:thumbnails].each { |suffix, size|
   13       image.create_or_update_thumbnail(temp_file, suffix, *size)
   14     }
   15   end
   16 end
   17 

which you can call with

./script/runner ./script/resize_images.rb 

if you want to resize all images stores with attachment_fu. Or if you only want to resize your Photo model images:

./script/runner ./script/resize_images.rb Photo