CODEWITHSUNDEEP
ruby-on-railspaperclipcropauto-update
sjain
sjain

Reputation: 23354

after_update callback causing never ending loop in a model

My model's cropping method is called in a loop which never ends after I update the attributes of user in the controller.

User controller code-

   def change_img  
      @user = current_user

      #this triggers the model's after_update callback
      @user.update_attributes(params[:user])  

      flash[:notice] = "Successfully updated Image."  
      render :action => 'crop'  
   end

User Model code- 

after_update :reprocess_avatar, :if => :cropping? 


  def cropping?  
   #this method is called infinitely why?

  !crop_x.blank? && !crop_y.blank? && !crop_w.blank? && !crop_h.blank? 

  end

Once the crop_x, crop_y, crop_w and crop_h are set, the cropping method will always return true which will keep on calling the reprocess_avatar method. This is probably due to the fact that reprocess_avatar method is also updating avatar attribute of user table. And so again after_update triggers causing a loop.

Is there any way to call the method only once after update?

Upvotes: 2

Views: 1742

Answers (2)

sjain
sjain

Reputation: 23354

I resolved the issue by removing the after_update from model and making a call from controller's function itself.

   def change_img  
      @user = current_user         
      @user.update_attributes(params[:user]) 

      if([email protected]_x.blank? && [email protected]_y.blank? && 
     [email protected]_w.blank? &&  [email protected]_h.blank?)
         @user.avatar.reprocess! 
      end

      flash[:notice] = "Successfully updated Image."  
      render :action => 'crop'  
   end

Thanks!

Upvotes: 7

ChuckE
ChuckE

Reputation: 5688

if the reprocess_avatar is updating something, make sure you are using any non-callback update method so you don't trigger any further callbacks in the object. If, for instance, you are settings flags or updating some id column or setting timestamps on your DB representation, use some straight-to-db method like #update_column or #touch. But without seeing what your reprocess_avatar method actually makes it hard to give a better advice.

Upvotes: 0

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