Get form data as name => value pair in ES6.

example.js

const form = document.getElementById( 'acme-form' );

// Checkboxe, select and radios are handled differently
const dataArray = Array
  .from( form.elements )
  .filter( input => ( input.type === 'text' || input.type === 'textarea' ) )
  .map( input => {
    return { [input.name] : input.value }
  } );

// Convert collected data array into object.
const data = Object.assing( ...dataArray );