In this chapter, we will learn how to use JS/CSS to implement the drop-down menu search or filter function.
First look at the effect as follows:
View online examples: Try It!
HTML Codes
Example
<div class="dropdown"> <button onclick="myFunction()" class="dropbtn">Drop-down Menu</button> <div id="myDropdown" class="dropdown-content"> <input type="text" placeholder="Search.." id="myInput" onkeyup="filterFunction()"> <a href="#about">Google</a> <a href="#base">TutorialFish</a> <a href="#blog">Bing</a> <a href="#contact">Yahoo</a> <a href="#custom">EBay</a> <a href="#support">Facebook</a> <a href="#tools">Twitter</a> </div> </div>
CSS Codes
The following styles of search search box and association menu:
Example
/* drop-down menu button */
.dropbtn {
background-color: #04AA6D;
color: white;
padding: 16px;
font-size: 16px;
border: none;
cursor: pointer;
}
/* Move the mouse to the drop-down menu button to the style*/
.dropbtn:hover, .dropbtn:focus {
background-color: #3e8e41;
}
/* search bar */
#myInput {
box-sizing: border-box;
background-image: url('searchicon.png');
background-position: 14px 12px;
background-repeat: no-repeat;
font-size: 16px;
padding: 14px 20px 12px 45px;
border: none;
border-bottom: 1px solid #ddd;
}
/* The style of the search box to get the focus */
#myInput:focus {outline: 3px solid #ddd;}
/* Container <div>-Position the drop-down menu */
.dropdown {
position: relative;
display: inline-block;
}
/* Drop-down menu content (hidden by default) */
.dropdown-content {
display: none;
position: absolute;
background-color: #f6f6f6;
min-width: 230px;
border: 1px solid #ddd;
z-index: 1;
}
/* Drop-down menu link style */
.dropdown-content a {
color: black;
padding: 12px 16px;
text-decoration: none;
display: block;
}
/* Move the mouse to the style of the link */
.dropdown-content a:hover {background-color: #f1f1f1}
/* Show the drop-down menu (use JS to add the .dropdown-content class) */
.show {display:block;}JavaScript Codes
The following is the JavaScript code for searching the search box and the association menu:
Example
/* Click the button to set the display and hide of the drop-down menu */
function myFunction() {
document.getElementById("myDropdown").classList.toggle("show");
}
/* Search function */
function filterFunction() {
var input, filter, ul, li, a, i;
input = document.getElementById("myInput");
filter = input.value.toUpperCase();
div = document.getElementById("myDropdown");
a = div.getElementsByTagName("a");
for (i = 0; i <a.length; i++) {
txtValue = a[i].textContent || a[i].innerText;
if (txtValue.toUpperCase().indexOf(filter)> -1) {
a[i].style.display = "";
} else {
a[i].style.display = "none";
}
}
}