Rails 4: How to upload multiple images using carri

Question

I can upload a file with using carrierwave as shown in the following code. How can I edit the code to make it possible to upload images up to 3 files in one article?

views\articles\new.html.erb

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<div class="span8">
    <%= render 'shared/article_form' %>
</div>
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.

views\shared\ _article_form.html.erb

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<%= form_for(@article) do |f| %>
  <div class="field">
  <%= f.hidden_field :category_id %>
  <%= f.fields_for :photos do |p| %>
    <%= p.hidden_field :article_id %>
    <% if p.object.image and p.object.image.file %>
      <%= image_tag p.object.image.thumb.url %>
      <p><%= p.object.image.file.filename %></p>
    <% end %>
    <%= p.file_field :image %>
  <% end %>
  <%= f.text_area :content, placeholder: "Enter contents..." %>
  </div>
  <%= f.submit class: "btn btn-large btn-primary" %>
<% end %>
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\models\article.rb

class Article < ActiveRecord::Base
  belongs_to :user
  belongs_to :category
  has_many :photos, dependent: :destroy
  accepts_nested_attributes_for :photos
  .
  .
end

\models\photo.rb

class Photo < ActiveRecord::Base
  belongs_to :article
  mount_uploader :image, ImageUploader
  validates :image, presence: true
end

\controllers\articles_controller.rb

class ArticlesController < ApplicationController
  .
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def new
  @article = Article.new
  @category = Category.find(params[:category])
  @article.category_id = @category.id
  @article.photos.build
end

def create
  @article = current_user.articles.build(article_params)
  if @article.save
    flash[:success] = "article created!"
    redirect_to current_user #root_url
  else
    @feed_items = []
    render 'new'
  end
end

def edit
  @article = Article.find(params[:id])
end

def update
  @article = Article.find(params[:id])
  if @article.update(article_params)
    redirect_to current_user
  else
    render 'edit'
  end
end
  .
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private

  def article_params
    params.require(:article).permit(:content, :category_id, photos_attributes: [:id, :article_id, :image])
  end
  .
  .
end

Answer 1

You just have to add :html => { :multipart => true } to your form to upload multiple files.

<%= form_for(@article,:html => { :multipart => true }) do |f| %>

And also you have to change this line <%= p.file_field :image %> to <%= p.file_field :image, :multiple => true %>

Answer 2

Change your new action to this:

def new
  @article = Article.new
  @category = Category.find(params[:category])
  @article.category_id = @category.id
  @photo = @article.photos.build
end

and in your file_field you need to use multiple option so your form will look like this:

<%= form_for(@article,:html => { :multipart => true }) do |f| %>
  // article fields
  <%= f.fields_for @photo do |p| %>
    <%= p.file_field :image, multiple: true %>
  <% end %>
<% end %>

Update

Change your new action and build a photo 3 times

def new
  @article = Article.new
  @category = Category.find(params[:category])
  @article.category_id = @category.id
  3.times { @article.photos.build } 
end

and your form

<%= form_for(@article,:html => { :multipart => true }) do |f| %>
  // article fields
  <%= f.fields_for :photos do |p| %>
    <%= p.file_field :image %>
  <% end %>
<% end %>

Also you'll have to modify your model a bit too in order to reject blank values

class Article < ActiveRecord::Base
  belongs_to :user
  belongs_to :category
  has_many :photos, dependent: :destroy
  accepts_nested_attributes_for :photos, reject_if: proc { |attributes| attributes[:image].blank? }
  .
  .
end