Equivalent to setting html and body height to window height in vanillajs - javascript

What is the equivalent code in vanilla js to this line of javascript?
$('html, body, #wrapper').height($(window).height());
This was my attempt, but it doesn't seem to be working properly (it seems to not set any height on all 3 elements at all):
var w=window,d=document,
e=d.documentElement,
g=d.getElementsByTagName("body")[0];
x=w.innerWidth || e.clientWidth || g.clientWidth,y=w.innerHeight || e.clientHeight || g.clientHeight;
document.querySelector("html").clientHeight = g.clientHeight = document.getElementById("wrapper").clientHeight = y;

You can get the height of the window using Window#innerHeight, select the target using Document#querySelectorAll. To iterate the elementList that querySelectorAll returns, we'll use NodeList#forEach (if not supported convert the element list to an array - see below), and set the height on each element:
var height = window.innerHeight + 'px';
document.querySelectorAll('html, body, #wrapper').forEach(function(el) {
el.style.height = height;
});
#wrapper {
background: red;
}
<div id="wrapper"></div>
If you need to convert the the element list to an array:
[].slice.call(document.querySelectorAll('html, body, #wrapper'), 0)
or
Array.from(document.querySelectorAll('html, body, #wrapper'))

Related

JS - check if element's declared style property is set in vh

Say we have an element
<div class="vh-100">
Content
</div>
.vh-100 { height: 100vh }
How can I get to read that exact value 100vh, because
var computedHeight = window.getComputedStyle(element).height; // will simply return the `window.clientHeight` value in pixels in this case.
var styleAttributeHeight = element.style.height // will return '', which is empty
To put it simply, I need to find a way to determine if the value is set in vh because the child elements of the example <div class="vh-100"> have the box model broken and return incorrect offsetTop and offsetLeft for some reason.
I need a simple solution excluding checking the rules in the CSS file.
Here is a link to hopefully explain why I need this.
Directly no way, but i convert pixels to vh(1vh is 1/100 browser height). Here is code snippet, i hope it will help you.
/*var z = getComputedStyle(document.getElementsByClassName('deneme')[0],null).height.replace('px','');*/
/*var b = Math.max(document.documentElement.clientHeight, window.innerHeight || 0);*/
//deactive variables for detailed usings.
var a = document.getElementsByClassName('sample')[0].clientHeight;
var b = window.innerHeight;
var c = Math.round((a / b) * 100) + "vh";
console.log(a)
console.log(b)
console.log(c)//it's your "vh"
.sample{
width: 10vw;
height: 1vh;
background:dodgerblue;
}
<div class="sample"></div>
if what you want is the unit of the height
yourElement.style.height
Normally it will return a string of height in it unit that you settled for the element (so '100vh' in your case).

jQuery each() function not working after if/else statement has been completed for both if and else outputs

I am using jQuery & javascript to switch the classes for images based on whether the viewport width is less than or greater than twice the width of the image.
I am using $(window).resize to detect when the widow is resized and then the each() function to iterate through all images of a certain class.
An if statement checks whether the width of the viewport is less than twice the width of the image and if so removes one class and adds another. The else statement does the reverse.
One page load it works fine for as many widow width changes as I do, until both the if and the else have been executed, then they stop working. Any suggestions would be greatly appreciated!
Thanks
Here's my code:
function updateViewportDimensions() {
var w = window,
d = document,
e = d.documentElement,
g = d.getElementsByTagName("body")[0],
x = w.innerWidth || e.clientWidth || g.clientWidth,
y = w.innerHeight || e.clientHeight || g.clientHeight;
return { width: x, height: y };
};
jQuery(window).resize(function() {
var viewport = updateViewportDimensions();
var viewport_width = viewport['width'];
console.log('Viewport width = ' + viewport_width);
jQuery(document).ready(function($) {
$('.alignright').each(function(i, obj){
// get the width of each image
var image_width = $(this).width();
// if the viewport width is less than twice the image width then switch the classes
if(viewport_width < (image_width * 2)) {
$(this).removeClass('alignright');
$(this).addClass('aligncenter');
console.log('Viewport is less than twice image width');
} else {
console.log('Viewport is more than twice image width');
$(this).addClass('alignright');
$(this).removeClass('aligncenter');
};
});
});
});
If I am reading this correctly, (this).removeClass('alignright'); is changing your dom. Because of this all the link to the class alignright is now new but your jquery is still looking for the instances that have been removed.
Update $('.alignright').each(function(i, obj){ to be one level higher than what is being altered.
if the code is
<div id="outer-wrapper">
<div class="alignright">
content
</div>
</div>
use $('#outer-wrapper .alignright').each(function(i, obj){

jQuery window width not equal to CSS's window width

I'm using the following two pieces of CSS and JS code:
#media (max-width: 720px) {
// a code to make arrows in a carousel disappear
}
if(jQuery(window).width() <= 720){
// a code to make arrows in the carousel stop working
}
The problem with them is that the latter executes on exactly width=738px and not 720px. I suspect that this is because of browser's vertical scrollbar that has width equal to 18px in Chrome.
Is there a way to unify this? I'd like these actions to happen at the same moment in all browsers regardless of the scrollbar's width.
Tests (when browser is # 720px and CSS has already executed):
jQuery(document).innerWidth() = 703
jQuery(window).innerWidth() = 703
jQuery(document).width() = 703
jQuery(window).width() = 703
jQuery('body').width() = 703
jQuery('html').width() = 703
I had to tackle the same problem a while ago, and so far the most correct solution I found is to use media queries to pass the actual window size to Javascript. You have to follow these steps:
Add a hidden element to your page,
Use media queries to alter the max-width property of that element,
Read back the max-width property of that element through Javascript.
For instance, add the following element to your page:
<div id="currentMedia"></div>
Then write the following CSS rules:
#currentMedia {
display: none;
}
#media (max-width: 720px) {
/* Make arrows in the carousel disappear... */
#currentMedia {
max-width: 720px;
}
}
Then, from the Javascript side, you can write:
if (parseInt(jQuery("#currentMedia").css("max-width"), 10) <= 720) {
// Make arrows in the carousel stop working...
}
And it will be accurate regardless of the scrollbar size, since the value comes from the same media query that triggers the carousel's disappearance.
I tested this solution on all major recent browsers, and it gives correct results.
You will find the big summary of what properties are supported on what browsers on this page on quirksmode.org.
Your best bet is probably to grab an element in the page (using document.body where supported, or document.getElementById or whatever), walk its offsetParent chain to find the topmost element, then examine that element's clientWidth and clientHeight.
innerWidth documentation
innerWidth() says this method is not applicable to window and document objects; for these, use .width()
try
How can I get the browser's scrollbar sizes?
From Alexandre Gomes Blog
function getScrollBarWidth () {
var inner = document.createElement('p');
inner.style.width = "100%";
inner.style.height = "200px";
var outer = document.createElement('div');
outer.style.position = "absolute";
outer.style.top = "0px";
outer.style.left = "0px";
outer.style.visibility = "hidden";
outer.style.width = "200px";
outer.style.height = "150px";
outer.style.overflow = "hidden";
outer.appendChild (inner);
document.body.appendChild (outer);
var w1 = inner.offsetWidth;
outer.style.overflow = 'scroll';
var w2 = inner.offsetWidth;
if (w1 == w2) w2 = outer.clientWidth;
document.body.removeChild (outer);
return (w1 - w2);
};
in your code
if(jQuery(window).width()-getScrollBarWidth(); <= 720){
// a code to make arrows in the carousel stop working
}
A bit outdated thread, but i've found this solution
function getWidth(){
return ((window.innerWidth > 0) ? window.innerWidth : screen.width);
}
If you are using Bootstrap > 3 then I will suggest you something.
Bootstrap ships with .container class in its Css and predefined. And its altering with #media queries.So my working code sample for this is below.
function detectWidth(){
var width = $('.container').eq(0).outerWidth() ;
console.log(width);
if(width<750){
// do something for XS element
}else if(width>=750 && width<970){
// do something for SM element
}else if(width>=970 && width<1170){
// do something for MD element
}else{
// do something for LG element
}
}
I realize this is an old thread, but I think it can still benefit from this answer.
var width = window.outerWidth;
This will give you the width of the window including scrollbars, which is what media queries use, I believe.

Modify external CSS values

Hi I am trying to dynamicly change the height of a division using JavaScript but I can only get the JS to read the Height element of the div if it defined using style tags inside the HTML mark-up.
If its in a separate sheet it returns NaN, I'm assuming because it can't find a value and is actually returning null (I'm using ParseInt to make it work).
Here is the HTML:
<div id="dropdown_container">
<div id="dropdown" style="height:100px;">
a
</div>
</div>
(Wish the HTML stlye markup)
And here is the JS:
function clickDown() {
var el = document.getElementById('dropdown');
var maxHeight = 200;
getHeight = parseInt(el.style.height.substring(0,(el.style.height.length)-2));
console.log(getHeight);
getHeight += 2;
el.style.height = getHeight + 'px';
timeoutHeightInc = setTimeout('clickDown()',15);
if(getHeight >= maxHeight){
clearTimeout(timeoutHeightInc);
}
}
Does anyone know of a reason for this (mis?)functionaility. And a solution for it?
Here is a jsFiddle.
Try moving the height over to the CSS to see the issue i'm having.
ParseInt is missing it's radix.
You say:
I can only get the JS to read the Height element of the div if it
defined using style tags inside the HTML mark-up
Now you are only reading the div's attribute style. Which you set inline. So if you remove that, than you can not read it anymore. Make sense?
You want to get the computed height. Try: .offsetHeight
Basis of test-case to play with inc. fixed radix. this fiddle
UPDATE: tada: fixed, see this updated fiddle
function clickDown() {
var el = document.getElementById('dropdown');
var maxHeight = 200;
getHeight = parseInt(el.offsetHeight,10);
console.log(getHeight);
getHeight += 2;
el.style.height = getHeight + 'px';
timeoutHeightInc = setTimeout('clickDown()',15);
if(getHeight >= maxHeight){
clearTimeout(timeoutHeightInc);
}
}

How can I check if a scrollbar is visible?

Is it possible to check the overflow:auto of a div?
For example:
HTML
<div id="my_div" style="width: 100px; height:100px; overflow:auto;" class="my_class">
* content
</div>
JQUERY
$('.my_class').live('hover', function (event)
{
if (event.type == 'mouseenter')
{
if( ... if scrollbar visible ? ... )
{
alert('true'):
}
else
{
alert('false'):
}
}
});
Sometimes is the content short (no scrollbar) and sometimes long (scrollbar visible).
a little plugin for it.
(function($) {
$.fn.hasScrollBar = function() {
return this.get(0).scrollHeight > this.height();
}
})(jQuery);
use it like this,
$('#my_div1').hasScrollBar(); // returns true if there's a `vertical` scrollbar, false otherwise..
tested working on Firefox, Chrome, IE6,7,8
but not working properly on body tag selector
demo
Edit
I found out that when you have horizontal scrollbar that causes vertical scrollbar to appear, this function does not work....
I found out another solution... use clientHeight
return this.get(0).scrollHeight > this.get(0).clientHeight;
You can do this using a combination of the Element.scrollHeight and Element.clientHeight attributes.
According to MDN:
The Element.scrollHeight read-only attribute is a measurement of the height of an element's content, including content not visible on the screen due to overflow. The scrollHeight value is equal to the minimum clientHeight the element would require in order to fit all the content in the viewpoint without using a vertical scrollbar. It includes the element padding but not its margin.
And:
The Element.clientHeight read-only property returns the inner height of an element in pixels, including padding but not the horizontal scrollbar height, border, or margin.
clientHeight can be calculated as CSS height + CSS padding - height of horizontal scrollbar (if present).
Therefore, the element will display a scrollbar if the scroll height is greater than the client height, so the answer to your question is:
function scrollbarVisible(element) {
return element.scrollHeight > element.clientHeight;
}
Maybe a more simple solution.
if ($(document).height() > $(window).height()) {
// scrollbar
}
I should change a little thing of what Reigel said:
(function($) {
$.fn.hasScrollBar = function() {
return this[0] ? this[0].scrollHeight > this.innerHeight() : false;
}
})(jQuery);
innerHeight counts control's height and its top and bottom paddings
This expands on #Reigel's answer. It will return an answer for horizontal or vertical scrollbars.
(function($) {
$.fn.hasScrollBar = function() {
var e = this.get(0);
return {
vertical: e.scrollHeight > e.clientHeight,
horizontal: e.scrollWidth > e.clientWidth
};
}
})(jQuery);
Example:
element.hasScrollBar() // Returns { vertical: true/false, horizontal: true/false }
element.hasScrollBar().vertical // Returns true/false
element.hasScrollBar().horizontal // Returns true/false
You need element.scrollHeight. Compare it with $(element).height().
I made a new custom :pseudo selector for jQuery to test whether an item has one of the following css properties:
overflow: [scroll|auto]
overflow-x: [scroll|auto]
overflow-y: [scroll|auto]
I wanted to find the closest scrollable parent of another element so I also wrote another little jQuery plugin to find the closest parent with overflow.
This solution probably doesn't perform the best, but it does appear to work. I used it in conjunction with the $.scrollTo plugin. Sometimes I need to know whether an element is inside another scrollable container. In that case I want to scroll the parent scrollable element vs the window.
I probably should have wrapped this up in a single plugin and added the psuedo selector as a part of the plugin, as well as exposing a 'closest' method to find the closest (parent) scrollable container.
Anywho....here it is.
$.isScrollable jQuery plugin:
$.fn.isScrollable = function(){
var elem = $(this);
return (
elem.css('overflow') == 'scroll'
|| elem.css('overflow') == 'auto'
|| elem.css('overflow-x') == 'scroll'
|| elem.css('overflow-x') == 'auto'
|| elem.css('overflow-y') == 'scroll'
|| elem.css('overflow-y') == 'auto'
);
};
$(':scrollable') jQuery pseudo selector:
$.expr[":"].scrollable = function(a) {
var elem = $(a);
return elem.isScrollable();
};
$.scrollableparent() jQuery plugin:
$.fn.scrollableparent = function(){
return $(this).closest(':scrollable') || $(window); //default to $('html') instead?
};
Implementation is pretty simple
//does a specific element have overflow scroll?
var somedivIsScrollable = $(this).isScrollable();
//use :scrollable psuedo selector to find a collection of child scrollable elements
var scrollableChildren = $(this).find(':scrollable');
//use $.scrollableparent to find closest scrollable container
var scrollableparent = $(this).scrollableparent();
UPDATE: I found that Robert Koritnik already came up with a much more powerful :scrollable pseudo selector that will identify the scrollable axes and height of scrollable containers, as a part of his $.scrollintoview() jQuery plugin. scrollintoview plugin
Here is his fancy pseudo selector (props):
$.extend($.expr[":"], {
scrollable: function (element, index, meta, stack) {
var direction = converter[typeof (meta[3]) === "string" && meta[3].toLowerCase()] || converter.both;
var styles = (document.defaultView && document.defaultView.getComputedStyle ? document.defaultView.getComputedStyle(element, null) : element.currentStyle);
var overflow = {
x: scrollValue[styles.overflowX.toLowerCase()] || false,
y: scrollValue[styles.overflowY.toLowerCase()] || false,
isRoot: rootrx.test(element.nodeName)
};
// check if completely unscrollable (exclude HTML element because it's special)
if (!overflow.x && !overflow.y && !overflow.isRoot)
{
return false;
}
var size = {
height: {
scroll: element.scrollHeight,
client: element.clientHeight
},
width: {
scroll: element.scrollWidth,
client: element.clientWidth
},
// check overflow.x/y because iPad (and possibly other tablets) don't dislay scrollbars
scrollableX: function () {
return (overflow.x || overflow.isRoot) && this.width.scroll > this.width.client;
},
scrollableY: function () {
return (overflow.y || overflow.isRoot) && this.height.scroll > this.height.client;
}
};
return direction.y && size.scrollableY() || direction.x && size.scrollableX();
}
});
(scrollWidth/Height - clientWidth/Height) is a good indicator for the presence of a scrollbar, but it will give you a "false positive" answer on many occasions.
if you need to be accurate i would suggest using the following function.
instead of trying to guess if the element is scrollable - you can scroll it...
function isScrollable( el ){
var y1 = el.scrollTop;
el.scrollTop += 1;
var y2 = el.scrollTop;
el.scrollTop -= 1;
var y3 = el.scrollTop;
el.scrollTop = y1;
var x1 = el.scrollLeft;
el.scrollLeft += 1;
var x2 = el.scrollLeft;
el.scrollLeft -= 1;
var x3 = el.scrollLeft;
el.scrollLeft = x1;
return {
horizontallyScrollable: x1 !== x2 || x2 !== x3,
verticallyScrollable: y1 !== y2 || y2 !== y3
}
}
function check( id ){
alert( JSON.stringify( isScrollable( document.getElementById( id ))));
}
#outer1, #outer2, #outer3 {
background-color: pink;
overflow: auto;
float: left;
}
#inner {
width: 150px;
height: 150px;
}
button { margin: 2em 0 0 1em; }
<div id="outer1" style="width: 100px; height: 100px;">
<div id="inner">
<button onclick="check('outer1')">check if<br>scrollable</button>
</div>
</div>
<div id="outer2" style="width: 200px; height: 100px;">
<div id="inner">
<button onclick="check('outer2')">check if<br>scrollable</button>
</div>
</div>
<div id="outer3" style="width: 100px; height: 180px;">
<div id="inner">
<button onclick="check('outer3')">check if<br>scrollable</button>
</div>
</div>
Ugh everyone's answers on here are incomplete, and lets stop using jquery in SO answers already please. Check jquery's documentation if you want info on jquery.
Here's a generalized pure-javascript function for testing whether or not an element has scrollbars in a complete way:
// dimension - Either 'y' or 'x'
// computedStyles - (Optional) Pass in the domNodes computed styles if you already have it (since I hear its somewhat expensive)
function hasScrollBars(domNode, dimension, computedStyles) {
dimension = dimension.toUpperCase()
if(dimension === 'Y') {
var length = 'Height'
} else {
var length = 'Width'
}
var scrollLength = 'scroll'+length
var clientLength = 'client'+length
var overflowDimension = 'overflow'+dimension
var hasVScroll = domNode[scrollLength] > domNode[clientLength]
// Check the overflow and overflowY properties for "auto" and "visible" values
var cStyle = computedStyles || getComputedStyle(domNode)
return hasVScroll && (cStyle[overflowDimension] == "visible"
|| cStyle[overflowDimension] == "auto"
)
|| cStyle[overflowDimension] == "scroll"
}
The first solution above works only in IE
The second solution above works only in FF
This combination of both functions works in both browsers:
//Firefox Only!!
if ($(document).height() > $(window).height()) {
// has scrollbar
$("#mtc").addClass("AdjustOverflowWidth");
alert('scrollbar present - Firefox');
} else {
$("#mtc").removeClass("AdjustOverflowWidth");
}
//Internet Explorer Only!!
(function($) {
$.fn.hasScrollBar = function() {
return this.get(0).scrollHeight > this.innerHeight();
}
})(jQuery);
if ($('#monitorWidth1').hasScrollBar()) {
// has scrollbar
$("#mtc").addClass("AdjustOverflowWidth");
alert('scrollbar present - Internet Exploder');
} else {
$("#mtc").removeClass("AdjustOverflowWidth");
}​
Wrap in a document ready
monitorWidth1 : the div where the overflow is set to auto
mtc : a container div inside monitorWidth1
AdjustOverflowWidth : a css class applied to the #mtc div when the Scrollbar is active
*Use the alert to test cross browser, and then comment out for final production code.
HTH
I'm going to extend on this even further for those poor souls who, like me, use one of the modern js frameworks and not JQuery and have been wholly abandoned by the people of this thread :
this was written in Angular 6 but if you write React 16, Vue 2, Polymer, Ionic, React-Native, you'll know what to do to adapt it. And it's the whole component so it should be easy.
import {ElementRef, AfterViewInit} from '#angular/core';
#Component({
selector: 'app',
templateUrl: './app.html',
styleUrls: ['./app.scss']
})
export class App implements AfterViewInit {
scrollAmount;
constructor(
private fb: FormBuilder,
private element: ElementRef
) {}
ngAfterViewInit(){
this.scrollAmount = this.element.nativeElement.querySelector('.elem-list');
this.scrollAmount.addEventListener('wheel', e => { //you can put () instead of e
// but e is usefull if you require the deltaY amount.
if(this.scrollAmount.scrollHeight > this.scrollAmount.offsetHeight){
// there is a scroll bar, do something!
}else{
// there is NO scroll bar, do something!
}
});
}
}
in the html there would be a div with class "elem-list" which is stylized in the css or scss to have a height and an overflow value that isn't hidden. (so auto or sroll )
I trigger this eval upon a scroll event because my end goal was to have "automatic focus scrolls" which decide whether they are scrolling the whole set of components horizontally if said components have no vertical scroll available and otherwise only scroll the innards of one of the components vertically.
but you can place the eval elsewhere to have it be triggered by something else.
the important thing to remember here, is you're never Forced back into using JQuery, there's always a way to access the same functionalities it has without using it.
The solutions provided above will work in the most cases, but checking the scrollHeight and overflow is sometimes not enough and can fail for body and html elements as seen here:
https://codepen.io/anon/pen/EvzXZw
1. Solution - Check if the element is scrollable:
function isScrollableY (element) {
return !!(element.scrollTop || (++element.scrollTop && element.scrollTop--));
}
Note: elements with overflow: hidden are also treated as scrollable (more info), so you might add a condition against that too if needed:
function isScrollableY (element) {
let style = window.getComputedStyle(element);
return !!(element.scrollTop || (++element.scrollTop && element.scrollTop--))
&& style["overflow"] !== "hidden" && style["overflow-y"] !== "hidden";
}
As far as I know this method only fails if the element has scroll-behavior: smooth.
Explanation: The trick is, that the attempt of scrolling down and reverting it won't be rendered by the browser. The topmost function can also be written like the following:
function isScrollableY (element) {
// if scrollTop is not 0 / larger than 0, then the element is scrolled and therefore must be scrollable
// -> true
if (element.scrollTop === 0) {
// if the element is zero it may be scrollable
// -> try scrolling about 1 pixel
element.scrollTop++;
// if the element is zero then scrolling did not succeed and therefore it is not scrollable
// -> false
if (element.scrollTop === 0) return false;
// else the element is scrollable; reset the scrollTop property
// -> true
element.scrollTop--;
}
return true;
}
2. Solution - Do all the necessary checks:
function isScrollableY (element) {
const style = window.getComputedStyle(element);
if (element.scrollHeight > element.clientHeight &&
style["overflow"] !== "hidden" && style["overflow-y"] !== "hidden" &&
style["overflow"] !== "clip" && style["overflow-y"] !== "clip"
) {
if (element === document.scrollingElement) return true;
else if (style["overflow"] !== "visible" && style["overflow-y"] !== "visible") {
// special check for body element (https://drafts.csswg.org/cssom-view/#potentially-scrollable)
if (element === document.body) {
const parentStyle = window.getComputedStyle(element.parentElement);
if (parentStyle["overflow"] !== "visible" && parentStyle["overflow-y"] !== "visible" &&
parentStyle["overflow"] !== "clip" && parentStyle["overflow-y"] !== "clip"
) {
return true;
}
}
else return true;
}
}
return false;
}
Here's an improved version of Evan's answer which seems to properly account for overflow logic.
function element_scrollbars(node) {
var element = $(node);
var overflow_x = element.css("overflow-x");
var overflow_y = element.css("overflow-y");
var overflow = element.css("overflow");
if (overflow_x == "undefined") overflow_x == "";
if (overflow_y == "undefined") overflow_y == "";
if (overflow == "undefined") overflow == "";
if (overflow_x == "") overflow_x = overflow;
if (overflow_y == "") overflow_y = overflow;
var scrollbar_vertical = (
(overflow_y == "scroll")
|| (
(
(overflow_y == "hidden")
|| (overflow_y == "visible")
)
&& (
(node.scrollHeight > node.clientHeight)
)
)
);
var scrollbar_horizontal = (
(overflow_x == "scroll")
|| (
(
(overflow_x == "hidden")
|| (overflow_x == "visible")
)
&& (
(node.scrollWidth > node.clientWidth)
)
)
);
return {
vertical: scrollbar_vertical,
horizontal: scrollbar_horizontal
};
}
Most of the answers presented got me close to where I needed to be, but not quite there.
We basically wanted to assess if the scroll bars -would- be visible in a normal situation, by that definition meaning that the size of the body element is larger than the view port. This was not a presented solution, which is why I am submitting it.
Hopefully it helps someone!
(function($) {
$.fn.hasScrollBar = function() {
return this.get(0).scrollHeight > $(window).height();
}
})(jQuery);
Essentially, we have the hasScrollbar function, but returning if the requested element is larger than the view port. For view port size, we just used $(window).height(). A quick compare of that against the element size, yields the correct results and desirable behavior.
Here's my improvement: added parseInt. for some weird reason it didn't work without it.
// usage: jQuery('#my_div1').hasVerticalScrollBar();
// Credit: http://stackoverflow.com/questions/4814398/how-can-i-check-if-a-scrollbar-is-visible
(function($) {
$.fn.hasVerticalScrollBar = function() {
return this.get(0) ? parseInt( this.get(0).scrollHeight ) > parseInt( this.innerHeight() ) : false;
};
})(jQuery);
Works on Chrome, Edge, Firefox and Opera, at least in the newer versions.
Using JQuery...
Setup this function to fix the footer:
function fixFooterCaller()
{
const body = $('body');
const footer = $('body footer');
return function ()
{
// If the scroll bar is visible
if ($(document).height() > $(window).height())
{
// Reset
footer.css('position', 'inherit');
// Erase the padding added in the above code
body.css('padding-bottom', '0');
}
// If the scrollbar is NOT visible
else
{
// Make it fixed at the bottom
footer.css('position', 'fixed');
// And put a padding to the body as the size of the footer
// This makes the footer do not cover the content and when
// it does, this event fix it
body.css('padding-bottom', footer.outerHeight());
}
}
}
It returns a function. Made this way just to set the body and footer once.
And then, set this when the document is ready.
$(document).ready(function ()
{
const fixFooter = fixFooterCaller();
// Put in a timeout call instead of just call the fixFooter function
// to prevent the page elements needed don't be ready at this time
setTimeout(fixFooter, 0);
// The function must be called every time the window is resized
$(window).resize(fixFooter);
});
Add this to your footer css:
footer {
bottom: 0;
}
Find a parent of current element that has vertical scrolling or body.
$.fn.scrollableParent = function() {
var $parents = this.parents();
var $scrollable = $parents.filter(function(idx) {
return this.scrollHeight > this.offsetHeight && this.offsetWidth !== this.clientWidth;
}).first();
if ($scrollable.length === 0) {
$scrollable = $('html, body');
}
return $scrollable;
};
It may be used to autoscroll to current element via:
var $scrollable = $elem.scrollableParent();
$scrollable.scrollTop($elem.position().top);
A No Framework JavaScript Approach, checks for both vertical and horizontal
/*
* hasScrollBars
*
* Checks to see if an element has scrollbars
*
* #returns {object}
*/
Element.prototype.hasScrollBars = function() {
return {"vertical": this.scrollHeight > this.style.height, "horizontal": this.scrollWidth > this.style.width};
}
Use it like this
if(document.getElementsByTagName("body")[0].hasScrollBars().vertical){
alert("vertical");
}
if(document.getElementsByTagName("body")[0].hasScrollBars().horizontal){
alert("horizontal");
}
There's two area sizes to consider, the window and the html. If the html width, for example, is greater than window width then a scroll bar may be present on the user interface. So it's a matter of reading the window proportions and the html proportions and doing the basic math.
As for displaying an arrow overlaid atop the page, that's done with a simple classlist toggle, e.g. .hidden{display:none}
Here's a crossbrowser method for getting these proportions. (credit W3 Schools)
|| document.body.clientWidth;
var h = window.innerHeight || document.documentElement.clientHeight ||
document.body.clientHeight; ```
I had the problem, that I needed to check, if the scrollbar is visible on the whole screen (body) or not. Chrome has the ability to hide the scrollbar despite the fact that there is an overflow happening, hence the body is scrollable.
Therefore the solutions above did not work for me. I now check, if there is a scrollbar the following way:
const isScrollbarPresent = () => {
const beforeScrollbarHidden = document.body.clientWidth;
const overflowState = document.body?.style.overflow;
document.body.style.overflow = 'hidden';
const afterScrollbarHidden = document.body.clientWidth;
document.body.style.overflow = overflowState;
return beforeScrollbarHidden !== afterScrollbarHidden;
};
I get the width of the body, with or without the scrollbar and save the current overflow state of the body. Then I hide the scrollbar. If there was a scrollbar, the width of the body is now bigger. If not, the width is the same. After that I revert the overflow state.
Another easy answer is the following:
export const isScrollbarPresent = (element?: HTMLElement) => {
const testedElement = element ?? document.body;
return testedElement.scrollHeight > testedElement.clientHeight; }
I check if the scrollHeight of the element is bigger then the clientHeight. The scrollHeight returns the absolute height of an element including all elements, that are not visible. The clientHeight returns the visible height on the screen.

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