How to do a drop-down search

Question

So, I made a dropdown using bootstrapp.

The code I adopted here: http://getbootstrap.com/docs/4.0/components/dropdowns/

<div class="dropdown">
  <button class="btn btn-secondary dropdown-toggle" type="button" id="dropdownMenuButton" data-toggle="dropdown" aria-haspopup="true" aria-expanded="false">
    Dropdown button
  </button>
  <div class="dropdown-menu" aria-labelledby="dropdownMenuButton">
    <a class="dropdown-item" href="#">Action</a>
    <a class="dropdown-item" href="#">Another action</a>
    <a class="dropdown-item" href="#">Something else here</a>
  </div>
</div>

Now I want to add the search box to the drop-down list so that people can enter it and it will be reduced to a more suitable drop-down list.

I try to find many ways, some of them use an external plugin, such as Select2, however, they require a dropdown menu encoded using tags <select>and <option>. On the contrary, my code use button and the built-in Bootstrapp dropdown list class.

Someone please help me.

Answer 1

, list.js. , Boostrap-4 , :

https://jsfiddle.net/o9b17p2d/29/

HTML:

<div class="dropdown">
  <button class="btn btn-secondary dropdown-toggle" type="button" id="dropdownMenu2" data-toggle="dropdown" aria-haspopup="true" aria-expanded="false">
    Dropdown
  </button>
  <div class="dropdown-menu" aria-labelledby="dropdownMenu2" id="dropdown-sorted-list">
    <ul class="dropdown-menu-list list">
      <li>
        <button class="dropdown-item dropdown-item-name" type="button">Action</button>
      </li>
      <li>
        <button class="dropdown-item dropdown-item-name" type="button">Another action</button>
      </li>
    </ul>
    <input type="text" class="form-control dropdown-item search" placeholder="Filter" aria-label="Filter" aria-describedby="basic-addon1">
  </div>
</div>

JS: . 5 list.js list.js.

$(document).ready(function() {
  var options = {
    valueNames: ['dropdown-item-name']
  };

  var hackerList = new List('dropdown-sorted-list', options);
});

CSS

.dropdown-menu-list {
  list-style-type: none;
  padding-left: 0;
}

Bootstrap 4 , <button>.

Answer 2

, , . ,

function searchBox() {
    var input, filter, ul, li, a, i;
    input = document.getElementById("myInput");
    filter = input.value.toUpperCase();
    ul = document.getElementById("myUL");
    li = ul.getElementsByTagName("li");
    for (i = 0; i < li.length; i++) {
        a = li[i].getElementsByTagName("a")[0];
        if (a.innerHTML.toUpperCase().indexOf(filter) > -1) {
            li[i].style.display = "";
        } else {
            li[i].style.display = "none";

        }
    }
}