A quick one-way data binder which will change the textContent of the nodes which have a data-key attribute when calling DataBind function

DataBind.js

// gets all html elements with data-key attribute and stores them in a dictonary.
// later, using DataBind function triggers a setter function for that key
// which applies the assigned value to the associated node.textContent
var DataBind = (() => {
  // private member
  var _binder = Array.from(document.querySelectorAll('[data-key]'))
    .reduce((dict, node) => {
      Object.defineProperty(dict, node.dataset.key, {
        set(new_value) {
          // node is in the closure
          node.textContent = new_value
        }
      })
      return dict
    }, {})

  // DataBind function
  return (kv_pairs) => {
    for (var [k, v] of kv_pairs.entries()) {
      _binder[k] = v
    }
  }
})()