How to avoid dropdown menu to close menu items on clicking inside ?

09 Jul, 2019
The default behavior of a dropdown menu is to close the menu list items when clicked inside. In this article, We will use stropPropagation method to prevent the dropdown menu from closing the menu list.
stopPropagation(): The stopPropagation() method is used to stop propagation of event calling i.e. the parent event is called we can stop the propagation of calling its children by using the stopProagration() method and vice-versa.
Syntax:
event.stopPropagation();
Example:
<!DOCTYPE html><html>  <head>    <title>        How to avoid dropdown menu to close        menu items on click inside ?    </title>          <style>        .dropbutton {            background-color: #4CAF50;            color: white;            padding: 14px;            font-size: 14px;            border: none;            cursor: pointer;        }                  .dropbutton:hover, .dropbutton:focus {            background-color: #3e8e41;        }                  .dropdownmenu {            position: relative;            display: inline-block;            outline: none;         }                  .dropdownmenu-content {            display: none;            position: absolute;            background-color: #f9f9f9;            min-width: 140px;            overflow: auto;            box-shadow: 0px 8px 16px rgba(0,0,0,0.3);        }                  .dropdownmenu-content a {            color: black;            padding: 12px 14px;            text-decoration: none;            display: block;        }                  .dropdownmenu a:hover {            background-color: #f1f1f1        }                  .show {            display:block;        }    </style></head>  <body style="text-align:center;">      <h1 style="color:green">GeeksforGeeks</h1>           <p>        Clicking outside will close        the drop down menu.    </p>      <div class="dropdownmenu">                  <button onclick="btnToggle()" class="dropbutton">            Dropdown        </button>                  <div id="Dropdown" class="dropdownmenu-content" >            <a href="#Java">Java</a>            <a href="#HTML">HTML</a>            <a href="#CSS">CSS</a>            <a href="#JS">JavaScript</a>        </div>    </div>              <script>              // JavaScript code to avoid dropdown        // menu close                  // Clicking dropdown button will toggle display        function btnToggle() {            document.getElementById("Dropdown").classList.toggle("show");        }                  // Prevents menu from closing when clicked inside        document.getElementById("Dropdown").addEventListener('click', function (event) {            alert("click outside");            event.stopPropagation();        });                  // Closes the menu in the event of outside click        window.onclick = function(event) {            if (!event.target.matches('.dropbutton')) {                              var dropdowns =                 document.getElementsByClassName("dropdownmenu-content");                                  var i;                for (i = 0; i < dropdowns.length; i++) {                    var openDropdown = dropdowns[i];                    if (openDropdown.classList.contains('show')) {                        openDropdown.classList.remove('show');                    }                }            }        }    </script>    </body>  </html>                         
Output:
Click Inside:
Click Outside:
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