app/views/shared/partials/_image_upload.html.erb
<div class="image-upload-wrapper">
<button class="btn btn-primary image-upload-toggle" type="button" data-index="<%= index %>">
Bild vom Computer hochladen
</button>
<div class="mt-3">
<input style="display: none" class="form-control-file image-input image-input-<%= index %>" type="file" data-index="<%= index %>">
<div class="upload-progress upload-progress-<%= index %>">
<div class="progress">
<div
class="progress-bar upload-progress-bar upload-progress-bar-<%= index %>"
role="progressbar"
aria-valuenow="0"
aria-valuemin="0"
aria-valuemax="100">
</div>
</div>
</div>
</div>
</div>