One by one multiple file (image) upload [Ruby on Rails] [StimulusJS]

_form.html.erb

<%= form_with(model: content, id: 'content_form',
              data: {controller: 'image-upload',
                     target: 'image-upload.form',
                     action: 'ajax:beforeSend->image-upload#submit'}) do |form| %>
                     
  <div data-target="image-upload.imagePreviews"></div>
  
  <%= form.file_field :photos, multiple: true,
                               accept: "image/*;capture=camera|library",
                               data: { action: "image-upload#multiImageDisplay" } %>
                            
 <%= form.submit "Add", data: {target: "content-form.submitButton", disable_with: 'Please wait...'} %>
  
<% end %>

image-upload_controller.js

import {Controller} from "stimulus"

export default class extends Controller {
    static targets = ["imagePreviews", "form"];

    connect() {
        console.log('image-upload_controller connected...');
    }

    multiImageDisplay(event) {
        const files = Array.from(event.target.files); // Get files as array from FileList object
        // Read files and append them to view
        if (files && files[0]){
            files.forEach((file) => {
                const reader = new FileReader();

                const readSuccess = (e) => {
                    const child = document.createElement("DIV");
                    const image_html = `<img width="75" src="${e.target.result}">`;
                    child.innerHTML = image_html;

                    this.imagePreviewsTarget.appendChild(child);
                };

                reader.onload = readSuccess;
                reader.readAsDataURL(file);
            });
        }
        // Keep files on 'window.uploaded_images' because file input can only keep last selected files
        if (window.uploaded_images)
            window.uploaded_images = [...Array.from(event.target.files),...window.uploaded_images];
        else
            window.uploaded_images = Array.from(event.target.files);
    }

    submit(e){
        e.preventDefault();

        const formData = new FormData(this.formTarget);
        if(window.uploaded_images){
            formData.delete('content[photos][]'); // Remove last state of file_input to prevent duplication
            // Add files from 'window.uploaded_images' to our FormData
            window.uploaded_images.map((file)=>{
                formData.append('content[photos][]',file);
            });
        }
        // Submit form with simple ajax
        $.ajax({
            url: 'contents',
            type: 'POST',
            data: formData,
            contentType: false,
            processData: false
        });

        window.uploaded_images = undefined; // Clean 'window.uploaded_images' after submit
    }
}