Pseudo Element ::After Does Not Show Up

Question

I am trying to make a list of categories where the selected option is underlined, I tried using a pseudo-element ::after to achieve this, but the underline is not showing up.

Is there something else that has to be added to the code to make an ::after element show up?

Intended Result:

.on::after {
            content: "";
            position: absolute;
            bottom: -3px;
            left: 0;
            width: 100%;
            border-bottom: 1px solid #000;
            opacity: 1;
        
    }

<div class="filter-mobile">
    <span>I'm Looking For:</span>
        <select>
            <option value="1" class="button on">All</option>
            <option value="1" class="button">Category 1</option>
            <option value="2" class="button">Category 2</option>
            <option value="3" class="button">Category 3</option>
            <option value="4" class="button">Category 4</option>
            <option value="5" class="button">Category 5</option>
        </select>
    </div>

`::after` is supposed to render as if an actual child element had been inserted - but `option` is not allowed to have child elements. — CBroe, Jun 13 '23 at 13:11

Charles Lavalard · Answer 1 · 2023-06-15T07:36:54.617

You are trying to style an <option> tag and as said in this question

There are only a few style attributes that can be applied to an <option> element. This is because this type of element is an example of a "replaced element". They are OS-dependent and are not part of the HTML/browser. It cannot be styled via CSS.

There are replacement plug-ins/libraries that look like a <select> but are actually composed of regular HTML elements that CAN be styled.

If you want to achieve that you can have a custom <select>

Here is an example from w3schools

var x, i, j, l, ll, selElmnt, a, b, c;
/* Look for any elements with the class "custom-select": */
x = document.getElementsByClassName("custom-select");
l = x.length;
for (i = 0; i < l; i++) {
  selElmnt = x[i].getElementsByTagName("select")[0];
  ll = selElmnt.length;
  /* For each element, create a new DIV that will act as the selected item: */
  a = document.createElement("DIV");
  a.setAttribute("class", "select-selected");
  a.innerHTML = selElmnt.options[selElmnt.selectedIndex].innerHTML;
  x[i].appendChild(a);
  /* For each element, create a new DIV that will contain the option list: */
  b = document.createElement("DIV");
  b.setAttribute("class", "select-items select-hide");
  for (j = 1; j < ll; j++) {
    /* For each option in the original select element,
    create a new DIV that will act as an option item: */
    c = document.createElement("DIV");
    c.innerHTML = selElmnt.options[j].innerHTML;
    c.addEventListener("click", function(e) {
        /* When an item is clicked, update the original select box,
        and the selected item: */
        var y, i, k, s, h, sl, yl;
        s = this.parentNode.parentNode.getElementsByTagName("select")[0];
        sl = s.length;
        h = this.parentNode.previousSibling;
        for (i = 0; i < sl; i++) {
          if (s.options[i].innerHTML == this.innerHTML) {
            s.selectedIndex = i;
            h.innerHTML = this.innerHTML;
            y = this.parentNode.getElementsByClassName("same-as-selected");
            yl = y.length;
            for (k = 0; k < yl; k++) {
              y[k].removeAttribute("class");
            }
            this.setAttribute("class", "same-as-selected");
            break;
          }
        }
        h.click();
    });
    b.appendChild(c);
  }
  x[i].appendChild(b);
  a.addEventListener("click", function(e) {
    /* When the select box is clicked, close any other select boxes,
    and open/close the current select box: */
    e.stopPropagation();
    closeAllSelect(this);
    this.nextSibling.classList.toggle("select-hide");
    this.classList.toggle("select-arrow-active");
  });
}

function closeAllSelect(elmnt) {
  /* A function that will close all select boxes in the document,
  except the current select box: */
  var x, y, i, xl, yl, arrNo = [];
  x = document.getElementsByClassName("select-items");
  y = document.getElementsByClassName("select-selected");
  xl = x.length;
  yl = y.length;
  for (i = 0; i < yl; i++) {
    if (elmnt == y[i]) {
      arrNo.push(i)
    } else {
      y[i].classList.remove("select-arrow-active");
    }
  }
  for (i = 0; i < xl; i++) {
    if (arrNo.indexOf(i)) {
      x[i].classList.add("select-hide");
    }
  }
}

/* If the user clicks anywhere outside the select box,
then close all select boxes: */
document.addEventListener("click", closeAllSelect);

/* The container must be positioned relative: */
.custom-select {
  position: relative;
  font-family: Arial;
}

.custom-select select {
  display: none; /*hide original SELECT element: */
}

.select-selected {
  background-color: DodgerBlue;
}

/* Style the arrow inside the select element: */
.select-selected:after {
  position: absolute;
  content: "";
  top: 14px;
  right: 10px;
  width: 0;
  height: 0;
  border: 6px solid transparent;
  border-color: #fff transparent transparent transparent;
}

/* Point the arrow upwards when the select box is open (active): */
.select-selected.select-arrow-active:after {
  border-color: transparent transparent #fff transparent;
  top: 7px;
}

/* style the items (options), including the selected item: */
.select-items div,.select-selected {
  color: #ffffff;
  padding: 8px 16px;
  border: 1px solid transparent;
  border-color: transparent transparent rgba(0, 0, 0, 0.1) transparent;
  cursor: pointer;
}

/* Style items (options): */
.select-items {
  position: absolute;
  background-color: DodgerBlue;
  top: 100%;
  left: 0;
  right: 0;
  z-index: 99;
}

/* Hide the items when the select box is closed: */
.select-hide {
  display: none;
}

.select-items div:hover, .same-as-selected {
  background-color: rgba(0, 0, 0, 0.1);
}

<div class="custom-select" style="width:200px;">
  <select>
    <option value="0">Select car:</option>
    <option value="1">Audi</option>
    <option value="2">BMW</option>
    <option value="3">Citroen</option>
    <option value="4">Ford</option>
    <option value="5">Honda</option>
    <option value="6">Jaguar</option>
    <option value="7">Land Rover</option>
    <option value="8">Mercedes</option>
    <option value="9">Mini</option>
    <option value="10">Nissan</option>
    <option value="11">Toyota</option>
    <option value="12">Volvo</option>
  </select>
</div>

Thanks, I understand: do you have any recommendations for custom select plug-ins as mentioned in the answer ? — Robert Carmichael, Jun 14 '23 at 08:06
I edited the answer so you can have a "home made" custom idea on how to do it — Charles Lavalard, Jun 15 '23 at 07:37
Thanks, I ended up using jquery selectric... this is something that should be fundamentally changed though I think, it's a pain for everyone and the workarounds are a lot of time and wasted effort. — Robert Carmichael, Jun 15 '23 at 07:43

Pseudo Element ::After Does Not Show Up

1 Answers1