Hide Div on Scroll with JQuery - javascript

I'm sure this is a trivial problem but I cannot seem to figure it out. I'm trying to fade a side bar in and out, and because I have a few of them in my website, I need to give them individual IDs for Javascript.
This code works
$(window).on("scroll", function() {
var scrollPos = $(window).scrollTop() - 100 ;
if (scrollPos < 100) {
$("#menu").fadeOut();
} else {
$("#menu").fadeIn();
}
});
This doesn't
$(window).on("scroll", function() {
var menu = document.getElementById("menu");
var scrollPos = $(window).scrollTop() - 100 ;
if (scrollPos < 100) {
menu.fadeOut();
} else {
menu.fadeIn();
}
});
In the latter piece, all I'm trying to do is assign a variable.
Here's the fiddle: https://jsfiddle.net/gavinfriel/nhovvj6q/1/
Your help would be appreciated.

You have to wrap it in a jQuery call to make it a jQuery object. Otherwise it cannot find the fadeOut and fadeIn functions:
var menu = $("#menu");
or
var menu = $(document.getElementById("menu"));

You need to use jquery to convert menu to jQuery object.
So it will have the fade property
$(window).on("scroll", function() {
var menu = document.getElementById("menu");
var scrollPos = $(window).scrollTop() - 100 ;
if (scrollPos < 100) {
$(menu).fadeOut();
} else {
$(menu).fadeIn();
}
});
Because if you use menu.fadeOut() it will generate error because menudoesn't have fade property

Checkout this it will work.
$(window).on("scroll", function() {
var menu = $("#menu");
var scrollPos = $(window).scrollTop() - 100 ;
if (scrollPos < 100) {
menu.fadeOut();
} else {
menu.fadeIn();
}
});

As others have mentioned, you've declared a JavaScript variable but are trying to use it as a jQuery object.
I would personally go with PierreDuc's answer but if you refactor your code slightly you can carry on using the vanilla JS declared vaiable, but pass the variable slightly differently:
var test = document.getElementById("test");
$(test).hide();
<script src="https://ajax.googleapis.com/ajax/libs/jquery/1.11.0/jquery.min.js"></script>
<div id="test">
TEST
</div>
In your 2nd code, this might look as follows:
$(window).on("scroll", function() {
var menu = document.getElementById("menu");
var scrollPos = $(window).scrollTop() - 100 ;
if (scrollPos < 100) {
$(menu).fadeOut();
} else {
$(menu).fadeIn();
}
});

Related

Make element stick to top when scrolling

I've written a function to make a div element stick to top when scrolling.
it works when it's written like this('#sticky-anchor-for-social' is to detect moving distance of the element, '#social-media' is the element sticks):
function sticky_socialmedia() {
var window_top = $(window).scrollTop();
var social_top = $('#sticky-anchor-for-social').offset().top - 88;
if (window_top >= social_top) {
$('#social-media').addClass('stick-social');
} else {
$('#social-media').removeClass('stick-social');
}
}
$(window).scroll(sticky_socialmedia);
sticky_socialmedia();
but it doesn't work when I write it like this:
function stickyWhenScroll(anchor, sticky) {
var window_top = $(window).scrollTop();
var filter_top = $(anchor).offset().top - 88;
if (window_top >= filter_top) {
$(sticky).addClass('stick-filter');
} else {
$(sticky).removeClass('stick-filter');
}
}
$(window).scroll(stickyWhenScroll);
stickyWhenScroll('#sticky-anchor-for-social','#social-media');
what could possibly go wrong?
many thanks!
You need to send your parameters to your function when adding the event, you can do that with bind:
$(window).bind('scroll', {
anchor: '#sticky-anchor-for-social',
sticky: '#social-media'
}, stickyWhenScroll).trigger('scroll');
By passing trigger('scroll') you can trigger the function straight away.
And in your function you can retrieve them by accesing the event.data:
function stickyWhenScroll(event) {
var data = event.data;
var anchor = data.anchor;
var sticky = data.sticky;
...
}
Fiddle
Because in your 2nd snippet the scroll event handler hasn't received any params. You could either pass params both times (load and scroll) or declare those as global variables and use them within the function.
(function stickyWhenScroll(anchor, sticky) {
var window_top = $(window).scrollTop();
var filter_top = $(anchor).offset().top - 88;
if (window_top >= filter_top) {
$(sticky).addClass('stick-filter');
} else {
$(sticky).removeClass('stick-filter');
}
}('#sticky-anchor-for-social', '#social-media'));
$(window).scroll(function() {
stickyWhenScroll('#sticky-anchor-for-social','#social-media');
});

Pop up text after scrolling certain distances is not working

I'm trying to get text to pop up at a fixed location at different y-scroll intervals however, I can't seem to chain the scripts correctly. It seems to skip the first action of displaying the first message.
Code: http://jsfiddle.net/k8bnd/
var startY = 1500;
var stopY = 2000;
$(window).scroll(function(){
checkY();
});
function checkY()
{
console.log($(window).scrollTop());
if($(window).scrollTop() > startY && $(window).scrollTop() <= stopY)
{
console.log("Show");
$('.titleTwo').show();
}
else
{
console.log("Hide");
$('.titleTwo').hide();
} }
checkY();
Your functions should have different names. Try
var startY1 = 900;
var stopY1 = 1800;
var startY2 = 1801;
var stopY2 = 2500;
$(window).scroll(function(){
checkY();
});
function checkY()
{
console.log($(window).scrollTop());
if($(window).scrollTop() > startY1 && $(window).scrollTop() <= stopY1)
{
console.log("Show");
$('.foxedDiv').show();
}
else
{
console.log("Hide");
$('.foxedDiv').hide();
}
if($(window).scrollTop() > startY2 && $(window).scrollTop() <= stopY2)
{
console.log("Show");
$('.foxedDivved').show();
}
else
{
console.log("Hide");
$('.foxedDivved').hide();
}
}
checkY();
Fixed Fiddle:
http://jsfiddle.net/k8bnd/1/
This is happening because you have overwritten the previous values/functions. To make this more dynamic you can add data-* attributes to each message element specifying which positions they are valid for. And then in the scroll event check each element's position data, if the window is within that range show it, otherwise hide it.
HTML
<!-- Changed the classes both elements had to foxedDiv
so that we can select them as a group and loop over them -->
<div class="foxedDiv" data-position="900,1800">
MESSAGE 1
</div>
<div class="foxedDiv" data-position="1801,2500">
MESSAGE 2
</div>
JS
//Note you do not need to make an anonymous
//function just to do the call for checkY
//just pass the function
$(window).scroll(checkY);
function checkY(){
//save this value so we dont have to call the function everytime
var top = $(window).scrollTop();
console.log(top);
$(".foxedDiv").each(function(){
var positionData = $(this).data("position").split(",");
if(top > positionData[0] && top <= positionData[1]){
console.log("Show");
$(this).show();
} else {
console.log("Hide");
$(this).hide();
}
});
}
checkY();
JSFiddle Demo

how to load more data on scroll or scrolling in jQuery?

I want to load more data while scrolling the contents. I found a solution from here:
jQuery load more data on scroll
I want to use the jQuery Waypoint plugin. Can we load more data while scrolling, and implement in this fiddle?
http://jsfiddle.net/N5LZB/32/
var pages = [page_1, page_2, page_3, page_4, page_5];
var count=0;
$("#preRealTimeContents").html(pages[count]);
$("#realTimeContents").html(pages[count+1]);
Try this,
var scrollFlag=true;
$('#fullContainer').scroll(function () {
if (scrollFlag && this.scrollHeight - $(this).scrollTop() - $(this).offset().top - $(this).height() <= 0) {
count++;
if (count >= pages.length) scrollFlag = false;
$("#preRealTimeContents").append(pages[count]);
}
});
Non-circular live demo
Updated load all div once on scrolling like,
var pages = [page_1, page_2, page_3, page_4, page_5];
var count = 0;
$("#preRealTimeContents").html(pages[count]);
var scrollFlag=true;
$('#fullContainer').scroll(function () {
for(i=1,len=pages.length;i<len;i++,count++) {
if (count >= len) break;
$("#preRealTimeContents").append(pages[count]);
}
});
Demo

Get static value from variable (scroll function)

I have a "follow scroll" function, but I want it to turn off when it returns to a certain point. My code is as follows:
scrollSidebar: function(scroll) {
var elemPos = $('#bestvideos-2').offset().top,
scroll2 = scroll;
if(scroll2 >= elemPos) {
$('#bestvideos-2').animate({
'margin-top':(scroll - 315)+'px'
},0);
} else {
$('#bestvideos-2').css('margin-top','0');
}
}
$(window).scroll(function() {
var scrollHeight = $(window).scrollTop();
Scroll.scrollSidebar(scrollHeight);
})
The problem is - every time I get up, it goes way up, not following scroll. What I'm thinking is storing a variable elemPos somewhere and keep it static (now it's changing each time I scroll).
What can I do with this?
Pass the value to the scrollSidebar function - make sure that the var elemPos = $('#bestvideos-2').offset().top is executed on dom ready
scrollSidebar: function (elemPos, scroll) {
var scroll2 = scroll;
if (scroll2 >= elemPos) {
$('#bestvideos-2').animate({
'margin-top': (scroll - 315) + 'px'
}, 0);
} else {
$('#bestvideos-2').css('margin-top', '0');
}
}
var elemPos = $('#bestvideos-2').offset().top
$(window).scroll(function () {
var scrollHeight = $(window).scrollTop();
Scroll.scrollSidebar(elemPos, scrollHeight);
})

jquery code does not work fine with differents urls

I have this jquery code:
$(function(){
var $win = $(window);
var $nav = $('.subnav');
var navTop = $('.subnav').length && $('.subnav').offset().top - 38;
var isFixed = 0;
processScroll();
$win.on('scroll', processScroll);
function processScroll() {
console.log('test');
var i, scrollTop = $win.scrollTop();
if (scrollTop >= navTop && !isFixed) {
isFixed = 1;
$nav.addClass('subnav-fixed');
} else if (scrollTop <= navTop && isFixed) {
isFixed = 0;
$nav.removeClass('subnav-fixed');
}
};
})
If I have this url for example:
http://mydomain.com/posts or http://mydomain.com or http://mydomain.com/post?utf8=✓&search=
the code does works fine, but if I have for example:
http://mydomain.com/post?utf8=✓&search=port or http://mydomain.com/post?utf8=✓&search=word
The code does not works fine...
Why if I pass a param for url with my search engine the code does not works fine?
Thank you very much!
Edited
I am using this sunspot solr for my as search engine
http://sunspot.github.com/
I found the fix in this question:
Replicating Bootstraps main nav and subnav
This is the code:
$(document).scroll(function(){
// If has not activated (has no attribute "data-top"
if (!$('.subnav').attr('data-top')) {
// If already fixed, then do nothing
if ($('.subnav').hasClass('subnav-fixed')) return;
// Remember top position
var offset = $('.subnav').offset()
$('.subnav').attr('data-top', offset.top);
}
if ($('.subnav').attr('data-top') - $('.subnav').outerHeight() <= $(this).scrollTop())
$('.subnav').addClass('subnav-fixed');
else
$('.subnav').removeClass('subnav-fixed');
});
Thank you

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