Getting filename before saving in ActiveStorage - Rails 5.2.1

Question

I am trying to get the name of the file uploaded by a user before ActiveStorage goes on to save it. The form is generated using form_with and is shown below:

<%= form_with model: upload do |form| %>
  <div class="">
    <%= form.file_field :files, multiple: true, direct_upload: true, required: true %>
    <%= form.label :files, '', class: 'icon ion-ios-cloud-upload' do %>
      <span>click the icon to select files</span>
    <% end %>

    <div class="actions">
      <%= form.submit "Upload", class: "btn btn-primary" %>
    </div>
 </div>
<% end %>

I have tried accessing params[:upload][files] and calling .original_filename on it as described here but I get the error NoMethodError: undefined method `original_filename' for #<String:0x007fac77fd18c8>.

The file does come back as a string when I inspect the params, so how do I get the filename or how do I get original_filename to work?

Answer 1

I was finally able to get the file name by doing file.blob.filename after the file had been attached.

Answer 2

You need to add multipart: true to your form.

https://guides.rubyonrails.org/form_helpers.html#uploading-files

The other thing is that if you have multiple files you'll have multiple filenames.

params[:upload][files].each do |file|
  file.original_filename
end

Answer 3

Based on the ActiveStorage documentation, I found this worked for me:

file.filename.to_s

In my case I have a model with

has_one_attached :file

OP's situation is slightly different and your situation may differ too, so adjust accordingly.

Troy's solution did not work for me as-is. I had to add the .to_s to get the file name instead of an ActiveStorage::Filename object. But I'm not sure why he's using .blob in there. I didn't need it, but perhaps there's a good reason.