Could you make it blink? [closed]

I found this code but I could not figure out how to make the cursor blink

var TxtType = function(el, toRotate, period) {
  this.toRotate = toRotate;
  this.el = el;
  this.loopNum = 0;
  this.period = parseInt(period, 10) || 2000;
  this.txt = '';
  this.tick();
  this.isDeleting = false;
};

TxtType.prototype.tick = function() {
  var i = this.loopNum % this.toRotate.length;
  var fullTxt = this.toRotate[i];

  if (this.isDeleting) {
    this.txt = fullTxt.substring(0, this.txt.length - 1);
  } else {
    this.txt = fullTxt.substring(0, this.txt.length + 1);
  }

  this.el.innerHTML = '<span class="wrap">' + this.txt + '</span>';

  var that = this;
  var delta = 200 - Math.random() * 100;

  if (this.isDeleting) {
    delta /= 2;
  }

  if (!this.isDeleting && this.txt === fullTxt) {
    delta = this.period;
    this.isDeleting = true;
  } else if (this.isDeleting && this.txt === '') {
    this.isDeleting = false;
    this.loopNum++;
    delta = 500;
  }

  setTimeout(function() {
    that.tick();
  }, delta);
};

window.onload = function() {
  var elements = document.getElementsByClassName('typewrite');
  for (var i = 0; i < elements.length; i++) {
    var toRotate = elements[i].getAttribute('data-type');
    var period = elements[i].getAttribute('data-period');
    if (toRotate) {
      new TxtType(elements[i], JSON.parse(toRotate), period);
    }
  }
  // INJECT CSS
  var css = document.createElement("style");
  css.type = "text/css";
  css.innerHTML = ".typewrite > .wrap { border-right: 0.05em solid #32CD32}";
  document.body.appendChild(css);
};

<a href="pages/guitar.html" target="_self">
  <h5 class="typewrite" data-period="2000" data-type='[ "fundamental", "simplified" ]'>
    <span class="wrap blink-caret"></span>
  </h5>
</a>

Answer

I found a simple way to do it with a CSS blinking right-border.

It blinks every 0.5s, however, the <span> gets reconstructed every time a letter is typed, so the CSS timer resets. You can see the cursor blinking when the letters pause typing and wait for more than 0.5s.

var TxtType = function(el, toRotate, period) {
  this.toRotate = toRotate;
  this.el = el;
  this.loopNum = 0;
  this.period = parseInt(period, 10) || 2000;
  this.txt = '';
  this.tick();
  this.isDeleting = false;
};

TxtType.prototype.tick = function() {
  var i = this.loopNum % this.toRotate.length;
  var fullTxt = this.toRotate[i];

  if (this.isDeleting) {
    this.txt = fullTxt.substring(0, this.txt.length - 1);
  } else {
    this.txt = fullTxt.substring(0, this.txt.length + 1);
  }

  this.el.innerHTML = '<span class="wrap">' + this.txt + '</span>';

  var that = this;
  var delta = 200 - Math.random() * 100;

  if (this.isDeleting) {
    delta /= 2;
  }

  if (!this.isDeleting && this.txt === fullTxt) {
    delta = this.period;
    this.isDeleting = true;
  } else if (this.isDeleting && this.txt === '') {
    this.isDeleting = false;
    this.loopNum++;
    delta = 500;
  }

  setTimeout(function() {
    that.tick();
  }, delta);
};

window.onload = function() {
  var elements = document.getElementsByClassName('typewrite');
  for (var i = 0; i < elements.length; i++) {
    var toRotate = elements[i].getAttribute('data-type');
    var period = elements[i].getAttribute('data-period');
    if (toRotate) {
      new TxtType(elements[i], JSON.parse(toRotate), period);
    }
  }
};

.typewrite > .wrap {
  animation: blink .5s step-end infinite alternate;
  border-right: solid 3px #32CD32;
}

@keyframes blink {
  50% {
    border-color: transparent;
  }
}

<a href="pages/guitar.html" target="_self">
  <h5 class="typewrite" data-period="2000" data-type='[ "fundamental", "simplified" ]'>
    <span class="wrap blink-caret"></span>
  </h5>
</a>