Reprocessing images of different versions in Carrierwave

问题

Using Carrierwave, I created 3 versions of an avatar - an original, a small_thumb and a large_thumb using the following lines:

process :resize_to_limit => [400, 400]  

   version :big_thumb do
     process :resize_to_limit => [80, 80]
   end

   version :small_thumb do
     process :resize_to_limit => [50, 50]
   end

I added an additional method in my AvatarUploader class:

def reprocess(x,y,w,h)
        manipulate! do |img|
            img.crop(x.to_i, y.to_i, w.to_i, h.to_i, true) 

            end
resize_to_limit(180,180)  
end

which is called in my model after an update is performed:

attr_accessor :crop_x, :crop_y, :crop_w, :crop_h
after_update :reprocess_image, :if => :cropping?

def cropping?
    !crop_x.blank? && !crop_y.blank? && !crop_w.blank? && !crop_h.blank?
end

private

def reprocess_image
image.reprocess(crop_x,crop_y,crop_w,crop_h)

end

I have managed to crop and resize the original version, but I can't seem to update the 2 thumbnails along with it. I tried a few different techniques to no avail.

Any suggestions?

回答1:

Try

image.recreate_versions!

Sorry, on the bus. I can't expound on that.

回答2:

You need to call image.cache_stored_file! before calling recreate_versions!

It's weird because the method itself calls that if the file is cached, but for some reason it wasn't working.

So that would be something like:

def reprocess_image
  image.reprocess(crop_x, crop_y, crop_w, crop_h)
  image.cache_stored_file!
  image.recreate_versions!
end

回答3:

This HowTo was most helpful for me (even if I don't use fog):

https://github.com/carrierwaveuploader/carrierwave/wiki/How-to:-Recreate-and-reprocess-your-files-stored-on-fog

I added a reprocess method on my model and then called it in for each loop in my rake task:

  def reprocess
    begin
      self.process_photo_upload = true
      self.photo.cache_stored_file!
      self.photo.retrieve_from_cache!(photo.cache_name)
      self.photo.recreate_versions!
      self.save!
    rescue => e
      STDERR.puts  "ERROR: MyModel: #{id} -> #{e.to_s}"
    end
  end

Rake:

task :reprocess_photos => :environment do MyModel.all.each{|mm| mm.reprocess} end

PS: Rails 4.2

回答4:

I haven't tried but maybe putting something like.

def reprocess_image
  image.reprocess(crop_x,crop_y,crop_w,crop_h)
  image.recreate_versions!
end

回答5:

check this latest RailsCast:

http://railscasts.com/episodes/182-cropping-images-revised

after cropping one version of the image, you can then either calculate the cropping coordinates for the other versions, or probably easier, scale down the cropped image with the same aspect ratios as the other versions of the original image

来源：https://stackoverflow.com/questions/5132426/reprocessing-images-of-different-versions-in-carrierwave

标签

ruby-on-rails

image

upload

carrierwave