Append more files

[fabrouy]

Hi guys,

This is what I have:

class Foo < ActiveRecord::Base
    mount_uploaders :images, FooUploader
end

:images is stored as json in the DB.

Also I am sending files in chunks using dropzone, so for example If I drop two images at the same time they get stored together in the json field.
The problem comes when I want to drop another image after waiting a while, I would like to "append" this new image to the other two in an update action.

I would like to do something like this:

u = User.find(xxx)
u.images << params[:files] # Assign an array of files like this
u.save!

Is this possible to accomplish?

[Uelb]

@fabrouy, It think it seems odd to use the << method to add an array to another. Something like

u = User.find(xxx)
u.images += params[:files]
u.save!

is more intuitive. (It may already work, I have no idea).

[evg2108]

Hello.

I have a question. When i try do like this

u = User.find(xxx)
u.images += params[:files]
u.save!

then in tmp directory created all files which have already been in the array u.images + files from params[:files]. I use generation uniq file names, and when i add new files, all old files regenerated and all their names are changed. What can I do to avoid this?

Sorry for my english

[thomasfedb]

@Uelb In fact << is a more sensible operator than += as it implies appending to an existing collection, rather than assigning a new summation of the existing and new collections.

[Uelb]

<< implies appending a single element to a collection whereas += appends a collection to another one.

[1,2,3] << [4,5,6] # => [1,2,3, [4,5,6]]
[1,2,3] += [4,5,6] # => [1,2,3,4,5,6]

[thomasfedb]

@Uelb this is true, so in fact the right API would be #concat

# Using << appends a single item to an existing array.
arr = [1,2,3] #=> [1, 2, 3] 
arr.object_id #=> 10564640 
arr << 4 #=> [1, 2, 3, 4] 
arr.object_id #=> 10564640

# Using += creates a new array.
arr = [1,2,3] #=> [1, 2, 3] 
arr.object_id #=> 11147760 
arr += [4] #=> [1, 2, 3, 4] 
arr.object_id #=> 11277560

# Using #concat can append multiple items.
arr = [1,2,3] #=> [1, 2, 3] 
arr.object_id #=> 11329480 
arr.concat([4]) #=> [1, 2, 3, 4] 
arr.object_id #=> 11329480 

[Uelb]

I totally agree with you :D !
concat would be the right way to go

[evg2108]

concat is not work. When i do this

class Author < ActiveRecord::Base
  mount_uploaders :photos, AuthorPhotoUploader
  # ...
end

author.photos.concat(get_photos)
author.save

i get error:

NoMethodError (undefined method `identifier' for #ActionDispatch::Http::UploadedFile:0x0000000a727950)

[thomasfedb]

Hi @evg2108, I never said that concat would work, only that it might be the way that it should work.

[evg2108]

But I still don't know how do this right. Do you have any suggestion?

[bastengao]

When will be mount_uploaders feature ready for release ? I see implementation is already in master.

[juanbrein]

I managed to append images. My use case is a post model with an images field. The code changes are:

post.rb

 def append_images post_params                          
   appended_images = post_params[:images].map do |image|
     uploader = PostImageUploader.new(self)             
     uploader.store! image                              
     uploader
   end
   self.images = self.images + appended_images          
 end

post_controller.rb

  def update                                                                       
    respond_to do |format|                                                         
      @post.append_images post_params if post_params[:images]                               
      if @post.update(post_params_without_images)                                  
        format.html { redirect_to @post, notice: 'Post was successfully updated.' }
        format.json { render :show, status: :ok, location: @post }                 
      else                                                                         
        format.html { render :edit }                                               
        format.json { render json: @post.errors, status: :unprocessable_entity }   
      end                                                                          
    end                                                                            
  end                                                                              

post_controller.rb (private)

    def post_params_without_images                                                                   
      params.require(:post).permit(:title, :body, :published)   
    end                                                                                              

Hope it helps

[bastengao]

@juanbrein Thank you. My solution is Post has many Image model and use accepts_nested_attributes_for.

class Post < ActiveRecord::Base
    has_many :images
    accepts_nested_attributes_for :images, reject_if: :all_blank, allow_destroy: true
end

class Image < ActiveRecord::Base
  mount_uploader :file, ImageUploader
end

class PostsController < ApplicationController

  private 
  def post_params
    params.require(:post).permit(:title, :imagess_attributes => [:id, :file, :_destroy]}
  end
end

But these solutions are little complicated. I really hope mount_uploaders is available in new release.

[evg2108]

@juanbrein when you append new images all old images will be re-processed. And appending every new image will be slower.

I change your code:

in model

def append_images post_params                          
   appended_images = post_params[:images].map do |image|
     uploader = PostImageUploader.new(self)             
     uploader.store! image                              
     uploader
   end
    self[:images] ||= []
    self[:images] += appended_images.map{ |uploader| uploader.file.filename }
end

in controller

   @post.append_images post_params if post_params[:images]
   @post.save

[unmanbearpig]

I've written a test to demonstrate the issue unmanbearpig@972945a

I think the biggest problem is not that it's not possible to use << on images but that the error is very confusing, it crashes on save! instead of << call, so it took me some time to figure out what was going on. I think we could at least freeze theimages array to make it crash on << and make it obvious that it's not supported. Or maybe we could use an enumerable object that would support it by tracking changes to it, instead of a plain Ruby array.
I can work on a PR if someone would point me in the right direction.

[60mm]

I solved this issue by adding this to the model with the images attached. I am a novice coder so I can't promise it is the fastest, but it does work. I have the images stored as JSON.

before_validation { self.previous_images }
before_save { self.add_previous_images }

def previous_images
  if self.images
    @images = self[:images]
  end
end  

def add_previous_images
  if defined?(@images)
    @images.each do |a|
      if !self[:images].include?(a)
        self[:images] << a
      end	
    end	
  end	
end

[mshibuya]

Closed by #2401.