Paperclip: ActionController::ParameterMissing when attribute is blank

Question

I am using the paperclip gem for image uploads and am having trouble getting it to display an error message when my :photo atrribute is not present.

My model is Image.rb:

validates_attachment :photo, :presence => true,
  :content_type => { :content_type => ["image/jpeg", "image/png"], :message => "must be a jpeg or png" },
  :size => { :in => 0..1.megabytes, :message => "must be less than 1 MB" }

My controller create action:

  def create
    @images = Image.all
    @image = Image.new(image_params)

    if @image.save
      redirect_to new_image_url, notice: 'Image uploaded.'
    else
      @image.errors.delete(:photo)
      render :new
    end
  end

When I submit the form without attaching an image, it raises an exception and shows the page:

ActionController::ParameterMissing in ImagesController#create
param is missing or the value is empty: image

    def image_params
      params.require(:image).permit(:photo)
    end

I would except it to pass an error message to the errors hash like the rest of them, hence just displaying an error to full_messages. But it is not doing that.

Any idea what I am doing wrong?

Update: Adding form to upload

<%= simple_form_for @image, html: { multipart: true } do |f| %>
  <% if @image.errors.any? %>
    <div class="panel panel-default border-danger">
      <div class="panel-heading background-color-danger"><%= pluralize(@image.errors.count, "error") %>:</div>
      <div class="panel-body">
        <ul class="list-unstyled">
        <% @image.errors.full_messages.each do |message| %>
          <li><%= message %></li>
        <% end %>
        </ul>
      </div>
    </div>
  <% end %>

    <div class="form-group">
        <%= f.file_field :photo, error: false, input_html: { class: "form-control" } %>
    </div>

  <hr />

  <div class="form-group">
    <%= f.button :submit, "Upload", class: "btn btn-default" %>
  </div>

<% end %>

** I realize the error: false doesn't look good, but it just disables the simple_form inline errors. That isn't the problem.

UPDATED SOLUTION:

Based on the accepted answer, here is my new create action and strong parameters which I've used to form a viable solution to this problem.

ImagesController.rb #create

  # POST /images
  def create
    @images = Image.all
    @image = Image.new(image_params)

    if params[:image]
      if @image.save
        redirect_to new_image_path, notice: 'Photo uploaded.'
      else
        @image.errors.delete(:photo)
        render :new
      end
    else
      redirect_to new_image_path, alert: 'Photo cannot be blank.'
    end
  end

Strong params

def image_params
  params.require(:image).permit(:photo) if params[:image]
end

One one the possible reasons could be that the `params[:image]` is not being sent to server. Like Rajarshi said, can you please post your relevant view code? — Surya, Aug 15 '14 at 05:39
added the upload form. the "view" just includes the form. thanks for taking a look. — sidewalksalsa, Aug 15 '14 at 14:38

score 4 · Accepted Answer · edited May 23 '17 at 12:34

4

From here, this should work:

def image_params
  params.require(:image).permit(:photo) if params[:image]
end

edited May 23 '17 at 12:34

Community

1
1

answered Aug 19 '14 at 02:43

Excellent, this did work and I updated my create action. I've posted my new create action in my OP. Thanks! – sidewalksalsa Aug 21 '14 at 20:16

score 0 · Answer 2 · edited May 23 '17 at 10:29

0

Ok so I think I found something that can help you; check out THIS.

I'm also using the Paperclip gem in my app. if an :image, or in your case :photo, is not attached you get an error message "Image can't be blank".

All I did is this:

Image model:

has_attached_file :photo
validates_attachment :photo, content_type: { content_type: ["image/jpg", "image/jpeg", "image/png", "image/gif"] }
validates :photo, presence: true

edited May 23 '17 at 10:29

Community

1
1

answered Aug 15 '14 at 06:07

Cyzanfar

6,997
9
43
81

thanks for the reply. I had indeed already tried including a separate validates as you do above and even overriding the paperclip default validations as the link suggests. However, I had no luck. It still doesn't display "image cannot be blank" - it raises the error I had in my OP. – sidewalksalsa Aug 15 '14 at 14:42

Paperclip: ActionController::ParameterMissing when attribute is blank

2 Answers2