How to display selected file name?

[iraszl]

Without the bootstrap_form gem by default the rails forms show the filename or the number of files when selected, so the user knows they successfully selected a file to be uploaded in the form.

However, when I use bootstrap_form, the file name and count is gone. Is there a way to bring it back, otherwise the users think that they failed to select the file and try again, and sometimes give up thinking the file select in the form is broken.

[lcreid]

Thanks for the feedback. I know that the file upload control is implemented in a different way than some of the other controls. I don't know why, as it was done before I was a maintainer. I'm sure there was a good reason. I will add this to my list of issues to look at.

In the meantime, you can implement your own fields to give feedback. That's what I've done.

[iraszl]

Thanks for the kind comment. What do you mean by your own fields? Do you have an example of what you've done please?

[lcreid]

I have one example I can share:

<%= bootstrap_form_with(model: @document, local: true) do |f| %>
  <div class="row">
    <div class="col-sm-6">
      <%= f.text_field(:uri, label: "File Name", disabled: true) %>
    </div>
    <div class="col-sm-6">
      <%= content_tag(:div, "&#8203;".html_safe, class: "mb-2 d-none d-sm-block") %>
      <%= f.file_field(:uri, hide_label: true, label: "URI") %>
    </div>
  </div>
  <div class="row">
    <div class="col">
      <%= link_to "Cancel", :back, class: "btn btn-primary" %>
    </div>
    <div class="col">
      <%= f.primary "Upload", class: "btn btn-primary float-right", disabled: true %>
    </div>
  </div>
<% end %>

The text field named uri (never mind why I called it that) actually is the file name of the file that was uploaded. If you were uploading the document with an AJAX request you'd have to add some JavaScript to the solution. In my case, it was simply doing a round trip to the server, so when the page re-rendered, the file name was shown.

I don't have any examples where I was uploading multiple files and showing a count on the screen. Sorry.

I hope this helps.

[iraszl]

Thank you for being so helpful!

[codeandclay]

@iraszl Here's a naive way of showing the name of the file immediately after the file has been selected. No need for custom fields.

// Workaround for displaying selected file
$(document).on('ready turbolinks:load', function() {
  $('.custom-file-input').change(function(){
    $('.custom-file-label').text(this.value);
  });
});

This works for my file field:

<%= bootstrap_form_for @listing do |form| %>
...
 <%= form.file_field :image, direct_upload: true, accept: "image/png,image/gif,image/jpeg", label: "Add an image" %>
...
<% end %>

Before file has been selected:

After file has been selected:

[iraszl]

@codeandclay Thank you so much! I'm going to test this out ASAP!

[hwhelchel]

This is the recommended solution by the bootstrap folks

import bsCustomFileInput from 'bs-custom-file-input';
$(document).ready(function () {
  bsCustomFileInput.init();
})

[hwhelchel]

https://www.npmjs.com/package/bs-custom-file-input

[iraszl]

@codeandclay Solution works.
@hwhelchel Doesn't seem to work. Do I need to add some class to the form to make it work?

[lcreid]

@iraszl If you're using Turbolinks (by default Rails does), perhaps @hwhelchel 's solution will work if you change the second line as follows:

import bsCustomFileInput from 'bs-custom-file-input';
$(document).on('ready turbolinks:load', function() {
  bsCustomFileInput.init();
})

You'll also have to make sure you include the package. Follow the link in this comment for instructions.

[lcreid]

This is an elegant solution. At the moment, bootstrap_form doesn't ship any JavaScript. Do you think it's good enough to document this solution in the README, rather than change the code?

[iraszl]

@lcreid Works great. But note that this line is not needed in the javascript if you load the library:
import bsCustomFileInput from 'bs-custom-file-input';
Can you confirm if I'm correct or not?

[Halloran]

FWIW, while this issue is open, you can solve the issue by sprinkling a bit of script into your form:

<script type="application/javascript">
    $('input[type="file"]').change(function(e){
        var fileName = e.target.files[0].name;
        $('.custom-file-label').html(fileName);
    });
</script>

[davidray]

If you have multiple file fields, you could do something like this so they all don't get updated to show the same value:

$('.custom-file-input').change(function(e){
  var fileName = e.target.files[0].name;
  $(`.custom-file-label[for=${e.currentTarget['id']}]`).html(fileName);
});

[Halloran]

@davidray nice catch. Your solution works both when multiple: true and multiple: false Thanks

[barriault]

Here is the solution that worked for me on a Rails 6 app. A big thanks to @hwhelchel and @lcreid for their comments above. From the terminal run:

yarn add bs-custom-file-input

Add the following to your project's javascript/packs/application.js file:

import bsCustomFileInput from 'bs-custom-file-input';
$(document).on('ready turbolinks:load', function() {
  bsCustomFileInput.init();
})

Use one of these in your view:

<%= f.file_field(:image) %>
<%= f.file_field(:images, multiple: true, placeholder: "Choose files") %>

[anastaszi]

For novices like me and who work just with plain JS (in case you use turbolinks) [based on the solution by @codeandclay]:

Add this function to app/assets/javascript/custom/[file_name].js:

document.addEventListener('turbolinks:load', function() {
  var fileInput = document.querySelector('.custom-file-input');
  var fileLabel = document.querySelector('.custom-file-label');
  fileInput.addEventListener("change", (e) => {fileLabel.textContent = e.target.value.replace(/^.*[\\\/]/, ''); });
}, false);

And in your file_field you don't need to change a thing

<%= bootstrap_form_for(@project, local: true) do |form| %>
    <%= form.file_field :attachments, label_class: "text-muted", label: "Add attachment"  %>
    <%= form.submit %>
<% end %>

After file was selected you'll see this: