Develop Reference

Problem with JavaScript dropdown & external JavaScript

I have a problem to make my JavaScript dropdown work when placing my js code in an external js file. The button needs to be pressed twice to show the links. I have no problem to make the code work if i place the js code in the body section using script tags.
I have been trying to understand the difference, but not yet come up with a solution. At first I thought it would be enough to make a function of it in the js file and then use onlick="dropdownfunc()" in the html file like bellow, but seems like I am wrong.
What do I need to think about to make it work?
function dropdownfunc() {
var dropdown = document.getElementsByClassName("dropdown-btn");
var i;
for (i = 0; i < dropdown.length; i++) {
dropdown[i].addEventListener("click", function () {
this.classList.toggle("active");
var dropdownContent = this.nextElementSibling;
if (dropdownContent.style.display === "block") {
dropdownContent.style.display = "none";
} else {
dropdownContent.style.display = "block";
}
});
}
}
.dropdown-btn {
color: gray;
font-size: 1.8rem;
cursor: pointer;
}
.dropdown-container {
display: none;
border-left: 2px solid #818181;
}
.dropdown-links {
display: table;
font-size: 1.4rem;
margin-left: 18px;
}
.active {
color: black;
}
<button class="dropdown-btn" onclick="dropdownfunc()">Dropdown</button>
<div class="dropdown-container">
<a class="dropdown-links" href="#">Link 1</a>
<a class="dropdown-links" href="#">Link 2</a>
</div>

This is becasue you are attaching the click event handler again after the click, which you already defined in onclick="dropdownfunc()". Instead, you can simply add this as a parameter to your onclick function and display the dropdown. And no need to loop thru your buttons. Here is an example:
function dropdownfunc(el) {
el.classList.toggle("active");
var dropdownContent = el.nextElementSibling;
if (dropdownContent.style.display === "block") {
dropdownContent.style.display = "none";
} else {
dropdownContent.style.display = "block";
}
}
.dropdown-btn {
color: gray;
font-size: 1.8rem;
cursor: pointer;
}
.dropdown-container {
display: none;
border-left: 2px solid #818181;
}
.dropdown-links {
display: table;
font-size: 1.4rem;
margin-left: 18px;
}
.active {
color: black;
}
<button class="dropdown-btn" onclick="dropdownfunc(this)">Dropdown</button>
<div class="dropdown-container">
<a class="dropdown-links" href="#">Link 1</a>
<a class="dropdown-links" href="#">Link 2</a>
</div>

This is unrelated to the js being external or not.
Here is what happens:
On the first click, dropdownfunc is called. It attaches another event listener for click, and does nothing else, so nothing happens on the UI.
On the second click, the second listener will be called and the drop list will display. By the way, dropdownfunc will also be called again!
Actually, each time the button is clicked dropdownfunc will add the same listener. So you are piling listeners. You should avoid that!

Mouse on one element and another do the action and only the other one has action. (html)

Mouse on one element and another do the action, and only the other one has action.
I want to make a mouse on and change background colour effect, but it works on only one.
Whatever the mouse is pointing on, only one will change the colour.
Here is the code (HTML with JS)
<div class = science style = "position:absolute; left:20px">
<script language="javascript">
function hightback() {
document.getElementById("part1").style.backgroundColor = "#744e4e";
}
function removehightback() {
document.getElementById("part1").style.backgroundColor = "#524c44";
}
</script>
<button id = "part1" onclick="window.location.href='science.html';" value="science" onmouseover="hightback()" onmouseout="removehightback()">
<div class = science1 style = "position:absolute; left:40px; top:45px;">
<h1>Science</h1>
</div>
</button>
</div>
<div class=art style="position:absolute; left:280px">
<script language="javascript">
function hightback() {
document.getElementById("part2").style.backgroundColor = "#744e4e";
}
function removehightback() {
document.getElementById("part2").style.backgroundColor = "#524c44";
}
</script>
<button id="part2" onclick="window.location.href='art.html';" value="art" onmouseover="hightback()" onmouseout="removehightback()">
<div class=art1 style="position:absolute; left:40px; top:45px;">
<h1>Art</h1>
</div>
</button>
</div>
Here is the CSS:
.science1 h1 {
color: #b6ab8f;
size: 55;
font-family: "Josefin Sans", sans-serif;
text-align: left;
}
.science button {
border-radius: 50px;
background: #524c44;
padding: 20px;
width: 230px;
height: 300px;
}
.art1 h1 {
color: #b6ab8f;
size: 55;
font-family: "Josefin Sans", sans-serif;
text-align: left;
}
.art button {
border-radius: 50px;
background: #524c44;
padding: 20px;
width: 230px;
height: 300px;
}

You overwrite your functions for part2. Why not make one unique function for all elements?
Please check below example:
function changeBgColor(id, color) {
document.getElementById(id).style.backgroundColor = color;
}
And now you can use them in such way
<button id="part1"
onclick="window.location.href='art.html';"
value="art"
onmouseover="changeBgColor('part1', '#744e4e')"
onmouseout="changeBgColor('part1', '#524c44')" >
<div class=art1 style="position:absolute; left:40px; top:45px;">
<h1>Art</h1>
</div>
</button>
<button id="part2"
onclick="window.location.href='art.html';"
value="art"
onmouseover="changeBgColor('part2', '#744e4e')"
onmouseout="changeBgColor('part2', '#524c44')" >
<div class=art1 style="position:absolute; left:40px; top:45px;">
<h1>Art</h1>
</div>
</button>
Also you can simplify your code and instead of js use css styles
#part1, #part2 {
backgound-color: #524c44;
}
#part1:hover, #part2:hover {
backgound-color: #744e4e;
}

Your problem here is overlapping JS code as it is calling the second version of the function in the next script tag. I suggest using css hover instead.
Example:
#part_1:hover {
background-color: black;
}

Trouble with javascript and making it work with my exsisting code

I am using jQuery, and I'm have not used it a lot before so I'm a newbie.
I'm trying to make a slide in menu, and I found code for it. The problem, however, is when I insert it into my existing code in Sublime Text. For some reason the javascript does not work.
$(".myButton").click(function() {
var effect = 'slide';
var options = {
direction: $('.mySelect').val()
};
var duration = 500;
$('#myDiv').toggle(effect, options, duration);
});
.myButton {
font-size: 1em;
cursor: pointer;
font-weight: bold;
}
.mySelect {
padding: .2em 0;
font-size: 1em;
display: none;
}
#myDiv {
color: #fff;
background-color: pink;
border: 2px solid #000;
display: none;
text-align: justify;
padding-left: 100px;
}
<script src="https://ajax.googleapis.com/ajax/libs/jquery/2.1.1/jquery.min.js"></script>
<div class="myButton">
run effect
</div>
<select class="mySelect">
<option value="left">Left</option>
</select>
<div id="myDiv">
<ul>
<li> episoder </li>
<li> - </li>
<li> karakterer </li>
<li> - </li>
<li> medvirkende </li>
<li> - </li>
<li> produksjon </li>
</ul>
</div>
I have set, .mySelect { display: none; }, because I don't want the user to be able to choose which side it will enter from.

You need to make sure your jQuery code runs when the DOM has been loaded. To do that you can place the <script> block just before the </body> tag. Alternatively you can place it in the <head> and wrap your JS code in a document.ready event handler, like this:
$(function() {
$(".myButton").click(function() {
var effect = 'slide';
var options = {
direction: $('.mySelect').val()
};
var duration = 500;
$('#myDiv').toggle(effect, options, duration);
});
});

Button click Triggers Text Below

I want to set up a functionality for a button that causes text to appear underneath it on click.
For example, when you click a button that says "Sign up now", text would appear underneath the button that says "Are you a member, yes or no?".
"Yes" and "No" would be links that bring you to a different page depending on how you answer.
My button code so far (just html and styling done):
<a href="/ticket-link" target="_blank" class="ticket-button">Sign Up
Now</a>
I'm new with this kind of functionality so any help would be greatly appreciated!
Thanks!

Adjust the href attribute as you want.
$('#btn').click(function() {
$('#modal').fadeIn();
});
a {
display: block;
text-decoration: none;
color: white;
background-color: #333;
width: 100px;
padding: 20px;
border-radius: 5px;
margin: 0 auto;
}
#modal {
width: 300px;
height: 120px;
background-color: #ccc;
border-radius: 5px;
margin: 0 auto;
display: none;
}
#modal h3 {
text-align: center;
padding: 10px;
}
#modal a {
width: 50px;
display: inline-block;
text-align: center;
margin: 0 auto;
height: 10px;
vertical-align: middle;
line-height: 10px;
}
.btns {
width: 200px;
margin: auto;
}
a:hover {
background-color: #666;
}
<script src="https://ajax.googleapis.com/ajax/libs/jquery/2.1.1/jquery.min.js"></script>
<a href="/ticket-link" target="_blank" class="ticket-button" id='btn'>Sign Up Now</a>
<div id='modal'>
<h3>Are you a member?</h3>
<div class='btns'>
Yes
No
</div>
</div>

You could use the onClick function to unhide text, or elements, below it.
Sign Up Now
<span style="display:none;" id="text">This is some text :D</span>

simple way:
Sign Up Now
<script>
function confirmSignup(){
if(confirm("Are you sure?"))
{
window.location.href="http://somelocation.com/sign-up";
}
}
</script>

Like #Pety Howell said, you can use the onClick function to unhide the text. Here's a pretty straightforward way to do it with jQuery.
$(function() {
$('.link').on('click', function() {
$('.span').addClass('open');
});
});
.span {
display: none;
}
.open {
display: block;
}
<script src="https://ajax.googleapis.com/ajax/libs/jquery/2.1.1/jquery.min.js"></script>
Click me
<span class="span">I'm hidden!</span>
Working fiddle: https://jsfiddle.net/3gr03yzn/4/

You could use jQuery toggle() function.
HTML :
<button id="member">
Are you Member ?
</button>
<div class="answer">
Yes<br />
No
</div>
JS :
$("#member").click(function() {
$(".answer").toggle();
});
CSS :
.answer {
display:none;
}
The working example on jsFiddle.
Hope this helps

Try this code.
please vote if this code helpful to you
function execute(){
var x = document.getElementById('link_list');
var y =document.getElementById('btn');
if(x.style.visibility==="hidden"){
y.style.visibility="hidden";
x.style.visibility="visible";
}
}
<button onclick="execute()" id="btn">sign up</button>
<div id="link_list" style="visibility:hidden">
Are you a member, <button onclick="window.open('http://sparrolite.blogspot.in')">Yes</button> or <button onclick="window.open('google.com')">no</button>
</div>

Most answers mentioned here either uses
jQuery or,
onclick attribute which is obtrusive javascript.
Here's how to achieve the desired behavior using vanilla, unobtrusive JavaScript.
window.onload = function() {
var button = document.querySelector('.ticket-button');
var info = document.querySelector('.info');
info.style.display = 'none';
var dispalyInfo = false;
button.onclick = function(e) {
e.preventDefault(); /* prevent page from navigating to a new page onclick */
if (dispalyInfo) {
info.style.display = 'none';
dispalyInfo = false;
} else {
info.style.display = 'initial';
dispalyInfo = true;
}
}
}
.ticket-button {
display: block;
}
Sign Up Now
<span class="info">Are you a member, yes or no?</span>
References:
Document.querySelector()
HTMLElement.style

Upfront active menu link

I use Javascript that will decorate an active link after it's been clicked. Question is, how can I load the page with one of the menu items already active?
Example: http://moschalkx.nl/
Javascript code:
function hlite_menu(obj) {
var lnk = document.getElementById('menu').getElementsByTagName('A');
for (var i in lnk) {
lnk[i].className = (lnk[i] === obj) ? 'menu_active' : 'menu_idle';
}
}
function set_menu() {
var lnk = document.getElementById('menu').getElementsByTagName('A');
for (var i in lnk) {
lnk[i].className = 'menu_idle';
lnk[i].onclick = function () {
hlite_menu(this);
}
}
if (lnk[i]) { /* ??? how do you know whether this is the link to activeate up front? */
hlist_menu(lnk[i]);
}
}
window.onload = set_menu;
CSS:
a.menu_idle {color:#333333; text-decoration:none;}
a.menu_active {color:#333333; text-decoration:underline;}
a:visited {color:#333333; text-decoration:none;}
a:hover {color:#333333; text-decoration:underline;}
I need to put in the logic somewhere inside
if (lnk[i]) { /* ??? how do you know whether this is the link to activeate up front? */
hlist_menu(lnk[i]);
}
to let the script know which link will be active upfront. As i'm not familiar with coding, i have no clue how to do this!

Set the initially active link in your markup:
<a target="iframe1" class="menu_active" href="gallery/photo_menu.html">PHOTOGRAPHY</a>
Then in your set_menu function, set the iframe's src attribute to the href of that link:
for (i in lnk) {
if (lnk.hasOwnProperty(i)) {
//lnk[i].className = 'menu_idle'; // initial menu states are set in markup. This line is no longer necessary.
lnk[i].onclick = hlite_menu;
if (lnk[i].className === 'menu_active') {
iframe.src = lnk[i].href;
}
}
}
I would also strongly recommend re-writing your JavaScript to the following:
var hlite_menu = function hlite_menu() {
'use strict';
var lnk = document.getElementById('menu').getElementsByTagName('a'),
i = null;
//set all links to idle
for (i in lnk) {
if (lnk.hasOwnProperty(i)) {
lnk[i].className = 'menu_idle';
}
}
//set this link to active
this.className = 'menu_active';
},
set_menu = function set_menu() {
'use strict';
var lnk = document.getElementById('menu').getElementsByTagName('a'),
iframe = document.getElementById('iframe1'),
c = document.getElementById('copyright'),
i = null;
// set copyright
c.innerText = (new Date()).getFullYear();
// set onclicks and initial iframe src.
for (i in lnk) {
if (lnk.hasOwnProperty(i)) {
//lnk[i].className = 'menu_idle'; // initial menu states are set in markup. This line is no longer necessary.
lnk[i].onclick = hlite_menu;
if (lnk[i].className === 'menu_active') {
iframe.src = lnk[i].href;
}
}
}
};
window.onload = set_menu;
This avoids several long-term problems like readability/maintenance, variable hoisting, and the dreaded document.write (which you are using to set your copyright date). You'll also want to change the copyright section to this:
<div id="footer">
ALL IMAGES © <span id="copyright"></span>
</div>
You can also write your navigation like this (avoiding tables for layout):
<div id="header">
<div class="logo">
<span style="">MO SCHALKX</span>
</div>
<div id="menu">
<a target="iframe1" class="menu_active" href="gallery/photo_menu.html">PHOTOGRAPHY</a>
<a target="iframe1" class="menu_idle" href="gallery/film_menu.html">FILM</a>
<a target="iframe1" class="menu_idle" href="about.html">ABOUT</a>
<a target="iframe1" class="menu_idle" href="http://reflecture.tumblr.com">BLOG</a>
</div>
</div>
and add this to your CSS:
#header {
float: left;
display: inline-block;
margin: 1em;
text-align: center;
}
.logo, #menu {
background-color: #FFF;
}
.logo {
font-size: 40px;
font-weight: 500;
font-style: inherit;
}
#menu {
margin-top: 5px;
}
#menu > a {
padding-left: 0.25em;
}
#menu > a {
border-left: 1px solid #000;
}
#menu > a:first-child {
border-left: none;
}
which should make it look the same. You can also combine your CSS rules for menu_active and a:hover (likewise with menu_idle and a:visited) like so:
a.menu_idle, a:visited {
color: #333333;
text-decoration: none;
}
a.menu_active, a:hover {
color: #333333;
text-decoration: underline;
}
Finally, you've wrapped your iframe in a <form id="form1" runat="server"> element. You can remove this entirely. It won't affect your layout and you don't actually have a form with any input elements so it's unnecessary. Also, the runat="server" attribute doesn't do anything unless you're running this on ASP.Net (and you obviously are not) so you may want to keep that in mind.
Altogether, you should be able to change the entire document source to the following with no real visual changes (and I think you'll find that it's a lot cleaner to look at in the source):
<!DOCTYPE html PUBLIC "-//W3C//DTD XHTML 1.0 Transitional//EN" "http://www.w3.org/TR/xhtml1/DTD/xhtml1-transitional.dtd">
<html xmlns="http://www.w3.org/1999/xhtml">
<head runat="server">
<title>Mo Schalkx Photography</title>
<script type="text/javascript">
var hlite_menu = function hlite_menu() {
'use strict';
var lnk = document.getElementById('menu').getElementsByTagName('a'),
i = null;
//set all links to idle
for (i in lnk) {
if (lnk.hasOwnProperty(i)) {
lnk[i].className = 'menu_idle';
}
}
//set this link to active
this.className = 'menu_active';
},
set_menu = function set_menu() {
'use strict';
var lnk = document.getElementById('menu').getElementsByTagName('a'),
iframe = document.getElementById('iframe1'),
c = document.getElementById('copyright'),
i = null;
// set copyright
c.innerText = (new Date()).getFullYear();
// set onclicks and initial iframe src.
for (i in lnk) {
if (lnk.hasOwnProperty(i)) {
//lnk[i].className = 'menu_idle'; // initial menu states are set in markup. This line is no longer necessary.
lnk[i].onclick = hlite_menu;
if (lnk[i].className === 'menu_active') {
iframe.src = lnk[i].href;
}
}
}
};
window.onload = set_menu;
</script>
<style type="text/css">
body {
margin: 0;
overflow: hidden;
}
#header {
float: left;
display: inline-block;
margin: 1em;
text-align: center;
}
#iframe1 {
position: absolute;
left: 0px;
top: 0px;
width: 100%;
height: 100%;
z-index: -1;
}
#footer {
font-size: 9px;
font-family: 'Helvetica Neue', Helvetica, Arial, sans-serif;
text-align: center;
position: absolute;
bottom: 0px;
left: 0px;
width: 100%;
height: 20px;
visibility: visible;
display: block;
color: #000;
opacity: 0.4;
filter: alpha(opacity=40);
text-shadow: 0px 1px 0px rgba(255,255,255,.5); /* 50% white from bottom */;
}
.logo, #menu {
background-color: #FFF;
}
.logo {
font-size: 40px;
font-weight: 500;
font-style: inherit;
}
#menu {
margin-top: 5px;
}
#menu > a {
padding-left: 0.25em;
}
#menu > a {
border-left: 1px solid #000;
}
#menu > a:first-child {
border-left: none;
}
a.menu_idle, a:visited {
color: #333333;
text-decoration: none;
}
a.menu_active, a:hover {
color: #333333;
text-decoration: underline;
}
</style>
</head>
<body>
<div id="header">
<div class="logo">
<span style="">MO SCHALKX</span>
</div>
<div id="menu">
<a target="iframe1" class="menu_active" href="gallery/photo_menu.html">PHOTOGRAPHY</a>
<a target="iframe1" class="menu_idle" href="gallery/film_menu.html">FILM</a>
<a target="iframe1" class="menu_idle" href="about.html">ABOUT</a>
<a target="iframe1" class="menu_idle" href="http://reflecture.tumblr.com">BLOG</a>
</div>
</div>
<div id="footer">
ALL IMAGES © <span id="copyright"></span>
</div>
<iframe id="iframe1" frameborder="0"></iframe>
</body>
</html>
UDPATE
To apply this on http://moschalkx.nl/gallery/film_menu.html, simply include the same JavaScript and comment out the lines that involve setting the copyright in set_menu and update the id of the iframe:
var hlite_menu = function hlite_menu() {
'use strict';
var lnk = document.getElementById('menu').getElementsByTagName('a'),
i = null;
//set all links to idle
for (i in lnk) {
if (lnk.hasOwnProperty(i)) {
lnk[i].className = 'menu_idle';
}
}
//set this link to active
this.className = 'menu_active';
},
set_menu = function set_menu() {
'use strict';
var lnk = document.getElementById('menu').getElementsByTagName('a'),
iframe = document.getElementById('gallery'),
//c = document.getElementById('copyright'),
i = null;
// set copyright
//c.innerText = (new Date()).getFullYear();
// set onclicks and initial iframe src.
for (i in lnk) {
if (lnk.hasOwnProperty(i)) {
//lnk[i].className = 'menu_idle'; // initial menu states are set in markup. This line is no longer necessary.
lnk[i].onclick = hlite_menu;
if (lnk[i].className === 'menu_active') {
iframe.src = lnk[i].href;
}
}
}
};
window.onload = set_menu;
Also, since you're including jQuery on this page, you could write that in jQuery as:
$(document).ready(function () {
$('#menu a').click(function (e) {
var self = $(this),
href = self.attr('href');
$('#menu a').not(self).removeClass('menu_active').addClass('menu_idle');
self.removeClass('menu_idle').addClass('menu_active');
$('#gallery').attr('src', href);
});
});