Rails Paperclip how to delete attachment?

First off, when you create a check_box in a form_for (which it looks like you are), then the form should by default send :image_delete as "1" if checked and "0" if unchecked. The method declaration looks like this:

def check_box(method, options = {}, checked_value = "1", unchecked_value = "0")

Which shows that you can assign other values if you want to, but that is of course optional.

Secondly, the call to manually delete an attachment without deleting the model instance to which it is attached to is:

@page.image.destroy #Will remove the attachment and save the model@page.image.clear #Will queue the attachment to be deleted

And to accomplish your way of deleting the images through a checkbox, perhaps add something like this to your Page model:

class Page < ActiveRecord::Base  has_attached_file :image  before_save :destroy_image?  def image_delete    @image_delete ||= "0"  end  def image_delete=(value)    @image_delete = value  endprivate  def destroy_image?    self.image.clear if @image_delete == "1"  endend

This way, when you create your form and add the :image_delete checkbox, it will load the default value "0" from the User instance. And if that field is checked then the controller will update the image_delete to "1" and when the User is saved, it will check if the image is to be deleted.

has_attached_file :asset

=>

    attr_accessor :delete_asset    before_validation { asset.clear if delete_asset == '1' }

No need to destroy asset, Paperclip will do it.

In the form form.check_box(:delete_asset) will suffice.

This is Benoit's answer, but wrapped in a module, and covering the edge case of nested attribute models where the destroy tickbox is the only thing changed on the model.

It will apply to all attachments on the model.

# This needs to be included after all has_attached_file statements in a classmodule DeletableAttachment  extend ActiveSupport::Concern  included do    attachment_definitions.keys.each do |name|      attr_accessor :"delete_#{name}"      before_validation { send(name).clear if send("delete_#{name}") == '1' }      define_method :"delete_#{name}=" do |value|        instance_variable_set :"@delete_#{name}", value        send("#{name}_file_name_will_change!")      end    end  endend