Drag and drop file upload and conversion to data URL

dnDUploadConversion.js

const handleOnChange = (e, callback) => {
    console.log('onChanged');
    const fReader = new FileReader();
    fReader.readAsDataURL(
      e.type === 'drop' ? e.dataTransfer.files[0] : e.target.files[0]
    );
    fReader.onloadend = (event) => {
      callback(event.target.result);
    };
  };