Make Javascript / JQuery parallax slide effect work for classes - javascript

I have the following script, and would like to make it work also for classes instead of id's only:
<script>
function parallax(){
var prlx_1 = document.getElementById('banner-welcome');
prlx_1.style.top = -(window.pageYOffset / 8)+'px';
}
window.addEventListener("scroll", parallax, false);
</script>
I have tried to do the following, but it does not work:
<script>
function parallax(){
var prlx_1 = document.getElementsByClassName('banners');
prlx_1.style.top = -(window.pageYOffset / 8)+'px';
}
window.addEventListener("scroll", parallax, false);
</script>
I have also tried to change it to JQuery (at least I think I hope I did), neither does it work:
<script>
var prlx = $('.banners');
$(window).on('scroll', function () {
prlx.css({ 'top': -(window.pageYOffset / 8)+'px' });
});
});
</script>
Here are the two examples, one works, one does not:
1st example works:
http://jsfiddle.net/ecb3744t/
2nd example doesn't work
http://jsfiddle.net/3mc4dcus/
3rd example doesn't work
http://jsfiddle.net/wvtqke36/

I've modified your third example and this should work:
var prlx = $('.banners');
$(window).on('scroll', function () {
$(prlx).css({ 'top': -(window.pageYOffset / 2)+'px' });
});
Your Fiddle did not include jQuery and you had a syntax error in your code.
Fiddle: modified example 3
If you don't want to use jQuery, then use this code:
function parallax(){
var prlx = document.getElementsByClassName('banners');
for(var i=0; i < prlx.length; i++) {
var elem = prlx[i];
elem.style.top = -(window.pageYOffset / 2)+'px';
}
}
window.addEventListener("scroll", parallax, false);
Note that document.getElementsByClassName() returns an array of elements. Therefore you'll have to loop through each of these elements and apply the transformation.
Fiddle: modified example 1

Related

making multiple sliders with one set of jQuery code

I've made a slider with jQuery using html tags which have classes instead of IDs so that I will be able to use the same jQuery code for other duplicated sliders.
The problem is, I want the width of my ul to be calculated based on the number of lis, instead of setting it manually in CSS. When there is only one slider I can set my vars outside of the function, but when I have to use it though event attributes on my html parts so that I will be able to use them for multiple sliders, I have to move the vars inside of my function, which sets the wrong width.
This is my code:
function OLAR(direction,span) {
var OurNexNPrv = $(span);
var Parent_OLAR = OurNexNPrv.parents('.OLAR');
var UL_OF_OLAR = Parent_OLAR.find('.OLAR_CONTENT ul');
var LI_OF_OLAR = UL_OF_OLAR.find('li');
var LI_OF_OLAR_LENGTH = LI_OF_OLAR.length;
var Quantity_OF_OLAR_PAGES = LI_OF_OLAR_LENGTH / 3;
var Max_Margin_LEFT = -(Quantity_OF_OLAR_PAGES - 1) * 576;
UL_OF_OLAR.css('width',LI_OF_OLAR_LENGTH*192);
var AffectedLeftMargin;
var CurrentLeftMargin = UL_OF_OLAR.css('margin-left');
CurrentLeftMargin = parseFloat(CurrentLeftMargin);
if (direction == 'right') {
AffectedLeftMargin = CurrentLeftMargin - 576;
}
if (direction == 'left') {
AffectedLeftMargin = CurrentLeftMargin + 576;
}
if (AffectedLeftMargin < Max_Margin_LEFT) {
AffectedLeftMargin = 0;
}
if (AffectedLeftMargin > 0) {
AffectedLeftMargin = Max_Margin_LEFT;
}
UL_OF_OLAR.animate({'marginLeft': AffectedLeftMargin}, 1000);
}
$('.CIRCLE_LOAD_RIGHT').click(function () {
OLAR('right');
});
$('.CIRCLE_LOAD_LEFT').click(function () {
OLAR('left');
});
How can I set the width for each of my uls individually, through css commands outside of that function?
Okay, my ul tag did not have the absolute position; after giving it the right position and left:0 and bottom:0 or right:0 and bottom:0 (based on your language)the given width which comes from JQuery code can rhyme perfectly with everything else. I've tried it with multiple sliders and it works perfectly :)
So, we need an anchor point in order to make this work. And there is nothing wrong with this JQuery code which has been mentioned above!
Have a great day.

Changing multiple images source using jquery (and some other thing as well)

I am a beginner of javascript and jquery and i have 11 image tags in html. I want to
basically change sources of these tags using js and jquery. This code is not working and I am not getting any errors in firebug, can some one please tell me where I am doing wrong?
var imagesArray2=["01.png","02.png","03.png","04.png","05.png","06.png","07.png","08.png","09.png","10.png","11.png"];
var elementArray2 = ["#img1","#img2","#img3","#img4","#img5","#img6","#img7","#img8","#img9","#img10","#img11"];
var imagesArray,elementArray;
var elementInArray;
document ready
$(function(){
setInterval(Myfunction(),1000);});
my function code which has a loop based on elementsInArray variable value and it calls imageFadeAnimations function
function Myfunction(){
if(elementsInArray === 0){
imagesArray = imagesArray2;
elementArray = elementArray2;
elementsInArray = elementArray.length;
var imageChanges = Math.floor(Math.random()*elementsInArray);
imageFadeAnimations(imageChanges);
}
else
{
elementsInArray=elementArray.length;
imageChanges = Math.floor(Math.random()*elementsInArray);
imageFadeAnimations(imageChanges);
}
}
takes an integer as argument
function imageFadeAnimations(imageChanges){
for(var k = 0;k<imageChanges;k++){
var element = Math.floor(Math.random()*elementsinArray);
var image=Math.floor(Math.random()*elementsinArray);
imageChanger(elementArray[element],imageArray[image]);
elementArray.splice(element,1);
imagesArray.splice(image,1);
}
}
function imageChanger(b1,b2){
$(b1).fadeOut(500,function(){
$(b1).attr("src",b2);
$(b1).fadeIn(500);
});
}
You are making heavy weather out of something that jQuery can make very simple.
First wrap your images in an element (typically a div or a span) with id="imageContainer".
Now, if I understand correctly, your code will simplify to :
$(function() {
var imagesArray = ["01.png", "02.png", "03.png", "04.png", "05.png", "06.png", "07.png", "08.png", "09.png", "10.png", "11.png"],
$images = $("img", "#imageContainer");
setInterval(function() {
$images.each(function() {
var $img = $(this),
i = Math.min(imagesArray.length-1, Math.floor(Math.random() * imagesArray.length));
$img.fadeOut().promise().then(function() {
$img.attr("src", imagesArray[i]).fadeIn(500);
});
});
}, 1000);
});
EDIT 1
As #mplungjan points out below ...
If the img nodes were initialised with src attributes, then imagesArray can be composed by grabbing the srcs from the DOM as follows (replacing two lines above) :
var $images = $("img", "#imageContainer"),
imagesArray = $images.map(function() { return this.src; }).get();
I believe this jquery/zepto code is not the smaller, but the easier to understand:
function changeImg(){
$("#img1").attr('src', '01.png');
$("#img2").attr('src', '02.png');
$("#img3").attr('src', '03.png');
$("#img4").attr('src', '04.png');
$("#img5").attr('src', '05.png');
$("#img6").attr('src', '06.png');
};

Two JQuery functions for auto height on the same website

I have a question regarding using a function multiple times on the page I am trying to set a block auto height in dependence of screen resolution but I have 2 divs on different pages that need to be applied this function, it get applied only for one div for ex:
first tie I apply it to following selectors
<script>
$(function () {
resize_main_pane();
$(window).resize(resize_main_pane);
});
function resize_main_pane() {
var offset = $('.pagina-servicii').offset(),
remaining_height = parseInt($(window).height() - offset.top - 105);
$('.pagina-servicii').height(remaining_height);
}
</script>
second time to the following:
<script>
$(function () {
resize_main_pane();
$(window).resize(resize_main_pane);
});
function resize_main_pane() {
var offset = $('.another-selector').offset(),
remaining_height = parseInt($(window).height() - offset.top - 283);
$('.another-selector').height(remaining_height);
}
</script>
How can I combine them or use separately? I wonder if I need to use some no conflict setting?
Loop all selected divs and apply height to them:
function resize_main_pane() {
$.each($('#selector1, #selector2', function(){
var offsetMinus = $(this).hasClass('bigOffset') ? 283 : 105;
var offset = $(this).offset(),
remaining_height = parseInt($(window).height() - offset.top - offsetMinus);
$(this).height(remaining_height);
});
}
Put your selectors in an array and loop trough them with each.
The $(this) will be either of your class selectors and calculates the offset and height independently.
$(function () {
resize_main_pane();
$(window).resize(resize_main_pane);
// If you want to trigger this function on document load you could replace the above line with:
$(window).resize(resize_main_pane).trigger('resize');
});
function resize_main_pane() {
$('.pagina-servicii, .another-selector').each(function(index) {
var offset = $(this).offset(),
remaining_height = parseInt($(window).height() - offset.top - [105,283][index]);
$(this).height(remaining_height);
});
}

showing random value in div element with javascript

I want my div element to work like a timer and shows random numbers with an interval of 1s. http://jsfiddle.net/NHAvS/46/. That is my code:
var arrData = [];
for (i=0;i<1000;i++)
{
arrData.push({"bandwidth":Math.floor(Math.random() * 100)});
}
var div = document.getElementById('wrapper').innerHTML =arrData;
document.getElementById('wrapper').style.left = '200px';
document.getElementById('wrapper').style.top = '100px';
but the problem is that it only shows 1 data at a time. any idea how to fix it?
Thanks
Do this:
setInterval(myfun,1000);
var div = document.getElementById('wrapper');
function myfun(){
div.innerHTML ='bandwidth :'+Math.floor(Math.random() * 100);
}
Take a Look: http://jsfiddle.net/techsin/NHAvS/49/
Note: your example was messed up as on left side it was set to load in head which means your div would be undefined every time your script loads before your dom. so setting it to onload make it works little more. :D
Note: also you seem to be chaining functions as in jquery, but in javascript you don't do that. The functions are made to do that. i.e. div= ..getElementById..innerHtml='balbla'; would set div = bla... not element.
You're better off using jQuery and CSS to achieve your desired result. jQuery to find the element and to display the random number; and CSS instead of manually setting the position. (Obviously jQuery is just a personal choice and document.getElementById will suffice - but if you're planning on manipulating the DOM a lot, jQuery is probably a better route to take). See updated fiddle
$(function () {
var arrData = [];
for (i = 0; i < 1000; i++) {
arrData.push({
"bandwidth": Math.floor(Math.random() * 100)
});
}
var index = 0;
setInterval(function(){
$("#wrapper").text(arrData[index].bandwidth);
index++;
}, 1000);
});
You can do it like this:
var delay = 1000, // 1000 ms = 1 sec
i;
setTimeout(function() {
document.getElementById('wrapper').innerHTML = arrData[i];
i++;
}, delay);

Scrolling to Div IDs with Jquery

Due to css properties my scrolling to div tags has too much margin-top. So I see jquery as the best solution to get this fixed.
I'm not sure why this isn't working, I'm very new to Js and Jquery. Any help us greatly appreciated.
Here is a quick look at Js. I found that when your div ids are in containers to change the ('html, body') to ('container)
Here is my jsfiddle
jQuery(document).ready(function($){
var prevScrollTop = 0;
var $scrollDiv = jQuery('div#container');
var $currentDiv = $scrollDiv.children('div:first-child');
var $sectionid = 1;
var $numsections = 5;
$scrollDiv.scroll(function(eventObj)
{
var curScrollTop = $scrollDiv.scrollTop();
if (prevScrollTop < curScrollTop)
{
// Scrolling down:
if ($sectionid+1 > $numsections) {
console.log("End Panel Reached");
}
else {
$currentDiv = $currentDiv.next().scrollTo();
console.log("down");
console.log($currentDiv);
$sectionid=$sectionid+1;
console.log($currentDiv.attr('id'));
var divid =$currentDiv.attr('id');
jQuery('#container').animate({scrollTop:jQuery('#'+divid).position().top}, 'slow');
}
}
else if (prevScrollTop > curScrollTop)
{
// Scrolling up:
if ($sectionid-1 == 0) {
console.log("Top Panel Reached");
}
else {
$currentDiv = $currentDiv.prev().scrollTo();
console.log("up");
console.log($currentDiv);
$sectionid=$sectionid-1;
var divid =$currentDiv.attr('id');
jQuery('html, body').animate({scrollTop:jQuery('#'+divid).position().top}, 'slow');
}
}
prevScrollTop = curScrollTop;
});
});
I'm not entirely sure what you want but scrolling to a <div> with jQuery is simpler than your code.
For example this code replaces the automatic jumping behaviour of anchors with smoother scrolling:
$(document).ready(function(e){
$('.side-nav').on('click', 'a', function (e) {
var $this = $(this);
var top = $($this.attr('href')).offset().top;
$('html, body').stop().animate({
scrollTop: top
}, 'slow');
e.preventDefault();
});
});
You can of course adjust the top variable by adding or removing from it like:
var top = $($this.attr('href')).offset().top - 10;
I have also made a fiddle from it (on top of your HTML): http://jsfiddle.net/Qn5hG/8/
If this doesn't help you or your question is something different, please clarify it!
EDIT:
Problems with your fiddle:
jQuery is not referenced
You don't need jQuery(document).ready() if the jQuery framework is selected with "onLoad". Remove the first and last line of your JavaScript.
There is no div#container in your HTML so it's no reason to check where it is scrolled. And the scroll event will never fire on it.
Your HTML is invalid. There are a lot of unclosed elements and random tags at the end. Make sure it's valid.
It's very hard to figure out what your fiddle is supposed to do.

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