Rails4 : How do I display and edit uploaded file using carrierwave?

carrierwave, ruby-on-rails, ruby-on-rails-4

Solution

I had came up with the same problem earlier but didn't found any solution. What i did is here

<%= form_for(@article) do |f| %>
  <div class="field">
    <%= f.text_area :content, placeholder: "Compose new article..." %>
    <%= f.fields_for :photos, @article.photos do |p| %>
      <%= p.hidden_field :article_id %>
      <%= p.label :image %>
      <% if p.object.image %>
        <%= image_tag p.object.image.url %>
        <p><%= p.object.image.file.filename %></p>
      <% end %>
      <%= p.file_field :image %>
    <% end %>
  </div>
  <%= f.submit "Post", class: "btn btn-large btn-primary" %>
<% end %>

Even if you try to set the image file name to file_field via js , you will get following error

Failed to set the 'value' property on 'HTMLInputElement': This input element accepts a filename, which may only be programmatically set to the empty string.

Problem

I can upload a file and save the file name in the database. But the file name doesn't appear when I edit. I'd like to: - display the file name and the uploaded image when click "Edit" link in _article.html.erb. - display the uploaded image in _article.html.erb. article.rb ``` class Article < ActiveRecord::Base . . has_many :photos, dependent: :destroy accepts_nested_attributes_for :photos . . end ``` photo.rb ``` class Photo < ActiveRecord::Base belongs_to :article mount_uploader :image, ImageUploader validates :image, presence: true #validates :article_id, presence: true end ``` .schema articles ``` CREATE TABLE "articles" ("id" INTEGER PRIMARY KEY AUTOINCREMENT NOT NULL, "content" varchar(255), "user_id" integer, "created_at" datetime, "updated_at" datetime,); ``` .schema photos ``` CREATE TABLE "photos" ("id" INTEGER PRIMARY KEY AUTOINCREMENT NOT NULL, "article_id" integer, "image" varchar(255), "created_at" datetime, "updated_at" datetime); ``` articles_controller.rb ``` class ArticlesController < ApplicationController . . def new @article = Article.new @article.photos.build . . end def create @article = current_user.articles.build(article_params) . . 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 . . private def article_params params.require(:article).permit(:content, photos_attributes: [:id, :article_id, :image]) end . . end ``` articles\ _article.html.erb I'd like to display the uploaded image and the file name here and after clicking "Edit" link (_article_form.html.erb) ``` <li> . . <span class="content"><%= article.content %></span> <% if current_user?(article.user) %> <%= link_to "Edit", edit_article_path(article.id), class: "btn btn-default" %> <% end %> </li> ``` articles\edit.html.erb ``` <h1>Update article</h1> <div class="row"> <%= render 'shared/article_form' %> </div> ``` shared\ _article_form.html.erb When I edit, ":content" is displayed. But ":image" is "no file selected" ... ``` <%= form_for(@article) do |f| %> <div class="field"> <%= f.text_area :content, placeholder: "Compose new article..." %> <%= f.fields_for :photos do |p| %> <%= p.hidden_field :article_id %> <%= p.label :image %> <%= p.file_field :image %> <% end %> </div> <%= f.submit "Post", class: "btn btn-large btn-primary" %> <% end %> ``` development.log (when I submit new article) ``` Started POST "/articles" for 127.0.0.1 at 2014-07-05 16:31:11 +0900 Processing by ArticlesController#create as HTML Parameters: {"utf8"=>"?","authenticity_token"=>"uaWcqBZ6rhS/NIal/...=", "article"=>{"category_id"=>"6", "content"=>"last", "photos_attributes"=>{"0"=>{"article_id"=>"", "image"=>#<ActionDispatch::Http::UploadedFile:0x3cb0910 @tempfile=#<File:C:/.../AppData/Local/Temp/RackMultipart20140705-6112-1q9t7r6>, @original_filename="DSCN0721_080.JPG", @content_type="image/jpeg", @headers="Content-Disposition: form-data; name=\"article[photos_attributes][0][image]\"; filename=\"DSCN0721_080.JPG\"\r\nContent-Type: image/jpeg\r\n">}}}, "commit"=>"Post"} [1m[35mUser Load (1.0ms)[0m SELECT "users".* FROM "users" WHERE "users"."remember_token" = '...' LIMIT 1 [1m[36m (0.0ms)[0m [1mbegin transaction[0m [1m[35mSQL (3.0ms)[0m INSERT INTO "articles" ("content", "created_at", "category_id", "updated_at", "user_id") VALUES (?, ?, ?, ?, ?) [["content", "last"], ["created_at", Sat, 05 Jul 2014 07:31:11 UTC +00:00], ["category_id", 6], ["updated_at", Sat, 05 Jul 2014 07:31:11 UTC +00:00], ["user_id", 1]] [1m[36mSQL (27.0ms)[0m [1mINSERT INTO "photos" ("article_id", "created_at", "image", "updated_at") VALUES (?, ?, ?, ?)[0m [["article_id", 306], ["created_at", Sat, 05 Jul 2014 07:31:11 UTC +00:00], ["image", "DSCN0721_080.JPG"], ["updated_at", Sat, 05 Jul 2014 07:31:11 UTC +00:00]] [1m[35m (5.0ms)[0m commit transaction Redirected to http://localhost:3000/users/1 Completed 302 Found in 128ms (ActiveRecord: 36.0ms) ```

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