Creating an endless scrollable div in a page - javascript

I'm trying to create an endless scrollable div in my page. To do so I'm trying to use the following code --> http://jsfiddle.net/cyrus2013/Qq85d/
$(document).ready(function(){
function lastAddedLiveFunc()
{
$('div#lastPostsLoader').html('<img src="../bigLoader.gif">');
$.get("loadmore.php", function(data){
if (data != "") {
//console.log('add data..');
$(".items").append(data);
}
$('div#lastPostsLoader').empty();
});
};
//lastAddedLiveFunc();
$(window).scroll(function(){
var wintop = $(window).scrollTop(), docheight = $(document).height(), winheight = $(window).height();
var scrolltrigger = 0.95;
if ((wintop/(docheight-winheight)) > scrolltrigger) {
//console.log('scroll bottom');
lastAddedLiveFunc();
}
});
});
But, here the code is for creating the same for an entire page (window) where as I need to create it for a specific 'div' in a webpage.
In this part of the page I have difficulty figuring out the dimensions of the 'div'.
var wintop = $(window).scrollTop(), docheight = $(document).height(), winheight = $(window).height();
var scrolltrigger = 0.95;
A similar thing would the "Ticker" section on Facebook on the right side of the page, which tells us what our friends are doing in real time.
Please help me in figure out the code for this requirement... Thanks in advance!

How about this (the randomPara stuff is there only to simulate the content):
DEMO
var scroller;
var initContents = 10;
var shown = 0;
var content = [];
function init(){
var scroller = document.getElementById('scroller');
for(var i=0;i<100;i++){
var randomPara = "";
var words = Math.floor(Math.random()*100);
for(var j=0;j<words;j++) randomPara += "word ";
content.push(randomPara+"<br>");
}
for(var i=0;i<initContents;i++){
scroller.innerHTML += content[shown];
shown++;
}
scroller.onscroll = function(){
if(shown < content.length) if(this.scrollTop >= this.scrollHeight-this.clientHeight)
scroller.innerHTML += content[shown];
shown++;
}
}

Related

Multiple Morphs on Scroll

Struggling to get multiple SVGs to animate on scroll. I followed the CodePen and the first animation works fine, but the second doesn't. I need to be able to run like 4-5 of these on the homepage.
var scrollMorph1 = new TimelineLite({paused:true})
.to("#headerBottomMask",1, {morphSVG:"#headerBottomMask2"},0)
.to("#headerBottom01a",1, {morphSVG:"#headerBottom01b"},0)
.to("#headerBottom02a",1, {morphSVG:"#headerBottom02b"},0)
.to("#headerBottom03a",1, {morphSVG:"#headerBottom03b"},0)
.to("#headerBottom04a",1, {morphSVG:"#headerBottom04b"},0)
$(window).scroll(function() {
var scrolled = $(window).scrollTop();
var diff = 50;
var object1 = $('#header h1');
var topOfRange1 = object1.offset().top + diff;
if (scrolled > topOfRange1 ) {
scrollMorph1.play().timeScale(1);
} else {scrollMorph1.reverse().timeScale(1);}
});
var scrollMorph2 = new TimelineLite({paused:true})
.to("#clientsMask",1, {morphSVG:"#clientsMask2"},0)
$(window).scroll(function() {
var scrolled = $(window).scrollTop();
var diff = 50;
var object2 = $('#weare a');
var topOfRange2 = object2.offset().top + diff;
if (scrolled > topOfRange2 ) {
scrollMorph2.play().timeScale(1);
} else {scrollMorph2.reverse().timeScale(1);}
});
Code works fine. Wasn't targeting the Path, but rather the SVG's ID on the second one. Have to target the path.

changing scroll top inside angular directive doesn't work

In my directive I wrote my logic for dynamic pagination (lazy loading), each time the user scroll to the bottom of the page I append more elements to it , this works fine but I want to to change the scroll position after that but it doesn't work.
This is my code :
link: function(scope, element) {
var usersArea = $(".usersArea");
usersArea.bind("scroll", function() {
var scrollHeight = $(this)[0].scrollHeight;
var scrollTop = $(this)[0].scrollTop;
var clientHeight = $(this)[0].clientHeight;
var downloadMore = scrollHeight - scrollTop - clientHeight < 50;
if (downloadMore) {
var childScope = scope.$new();
usersContainer = scope.displayPortion(usersContainer);
if (usersContainer) {
$compile(usersContainer)(childScope);
//This doesn't work !!
$(this)[0].scrollTop = 500;
}
}
});
}
I tried to change the scroll position using native javascript and with JQuery but nothings seem to work, any suggestions ?
Since the compile is not immediate procedure I would suggest to postpone any operations with the result of compiling. The easiest (but not the best) way is to use simple timer:
var elt = $(this)[0];
var scrollHeight = elt.scrollHeight;
var scrollTop = elt.scrollTop;
var clientHeight = elt.clientHeight;
var downloadMore = scrollHeight - scrollTop - clientHeight < 50;
if (downloadMore) {
var childScope = scope.$new();
usersContainer = scope.displayPortion(usersContainer);
if (usersContainer) {
$compile(usersContainer)(childScope);
setTimeout(function() {
elt.scrollTop = 500;
});
}
}

Jquery typing effect on scroll bug

Hi I have some js code that do typing effect on my web page it start typing when you scroll down end of page. For first it work normally but when you start scroll faster down to up the typing effect goes crazy how can I fix that
demo page
code
$(window).scroll(function (e) {
var elem = $(".hello-page");
var scrollTop = $(window).scrollTop();
var blockTop = elem.offset().top;
var docHeight = $(document).height();
var windowH = $(window).height();
if (scrollTop >= blockTop) {
var helloPageA = $(".hello-page").find("a");
var text = helloPageA.attr("data-text");
helloPageA.text('');
$.each(text.split(''), function (i, letter) {
setTimeout(function () {
helloPageA.html(helloPageA.html() + letter);
}, 150 * i);
});
} else {
elem.find("a").text('');
}
});
jsfiddle example
Thanks for your help
So, here is the solution - http://jsfiddle.net/u3ojjx8r/1/
I borrowed initial structure of the code from previous answer here and it was removed unfortunately, therefore I can't mention one of the co-authors. Though the code looked quite similar to topic-starter's one.
The idea of the code below is to separate the queuing of characters to render and the actual rendering. Another important improvement is always have control over timeouts, i.e. never schedule more than one timeout. That allows you to cancel them any time without unpredicted/uncontrolled behavior.
var timeoutVar;
var queue = [];
var drawQueueTimeout = -1;
var helloPageA = $(".hello-page").find("a");
function pushQueue (element) {
console.log('pushQUeue', element.char);
queue.push(element);
checkQueue();
}
function flushQueue () {
console.log('flushQueue');
queue = [];
clearTimeout(drawQueueTimeout);
drawQueueTimeout = -1;
}
function checkQueue () {
console.log('checkQueue', queue.length, drawQueueTimeout);
if (queue.length > 0 && drawQueueTimeout < 0) {
console.log('schedule drawQueue');
drawQueueTimeout = setTimeout(drawQueue, 150);
}
}
function drawQueue () {
drawQueueTimeout = -1;
console.log('draw queue');
if (queue.length > 0) {
var element = queue.shift();
console.log('drawQueue', element.char);
helloPageA.html(helloPageA.html() + element.char);
}
checkQueue();
}
$(window).scroll(function (e) {
var elem = $(".hello-page");
var scrollTop = $(window).scrollTop();
var blockTop = elem.offset().top;
var docHeight = $(document).height();
var windowH = $(window).height();
if (scrollTop + windowH == docHeight) {
// Empty anything typed so far
helloPageA.empty();
flushQueue();
var text = helloPageA.attr("data-text");
helloPageA.text('');
$.each(text.split(''), function (i, letter) {
pushQueue({
char: letter,
index: i
});
});
} else {
helloPageA.empty();
flushQueue();
}
});

Setting data type value to an element when it reaches the top of the viewport

I have a hex colour value stored on each section and when a section reaches the top of the screen (-180px for the header) I want to assign a css property to the header element in order to change the text colour as you scroll through the sections. I am not getting any errors and I am having trouble debugging this issue.
http://www.amypreston.co.uk/
$(window).load(function() {
var $header = $("header");
var numberOfSections = $("section").length;
var sectionOffsets = [];
var sectionColour = $("section").eq(i).data("colour");
for(var i = 0; i < numberOfSections; i++) {
sectionOffsets.push($("section").eq(i).offset().top);
}
$(window).scroll(function() {
var scrollTop = $(this).scrollTop();
for(var i = 0; i < numberOfSections; i++) {
if(scrollTop > sectionOffsets[i] - 180) {
$header.css('color', 'sectionColour');
}
}
});
});
I dont know if it happened by accident, but the line
var sectionColour = $("section").eq(i).data("colour");
is out of place. it uses a variable i which is only defined in the window scroll handler.
notice that you need to retrieve the section color each time the scroll handler runs, and not only on window load. you need to place this line from above in the loop inside the scroll handler.
Plus, as stated on the comments, you need to use the sectionColour as a variable, and not as a string like you do now. the single quote marks must be removed, so 'sectionColour' turns into sectionColour.
here is your fixed code:
$(window).load(function() {
var $header = $("header");
var numberOfSections = $("section").length;
var sectionOffsets = [];
for(var i = 0; i < numberOfSections; i++) {
sectionOffsets.push($("section").eq(i).offset().top);
}
$(window).scroll(function() {
var scrollTop = $(this).scrollTop();
for(var i = 0; i < numberOfSections; i++) {
if(scrollTop > sectionOffsets[i] - 180) {
var sectionColour = $("section").eq(i).data("colour");
$header.css('color', sectionColour);
}
}
});
});
On a side note, you could shorten your code into this:
$(window).scroll(function () {
$("section").each(function () {
if ($(window).scrollTop() > $(this).offset().top - 180) {
$("header").css('color', $(this).data("colour"));
}
});
}).scroll();

Getting Javascript/jQuery scrolling function to work on successive divs

I'm currently trying to implement functionality similar to infinite/continuous/bottomless scrolling, but am coming up with my own approach (as an intern, my boss wants to see what I can come up with on my own). So far, I have divs of a fixed size that populate the page, and as the user scrolls, each div will be populated with an image. As of now, the function I've written works on the first div, but no longer works on successive divs.
$(window).scroll(function () {
var windowOffset = $(this).scrollTop();
var windowHeight = $(this).height();
var totalHeight = $(document).height();
var bottomOffset = $(window).scrollTop() + $(window).height();
var contentLoadTriggered = new Boolean();
var nextImageCount = parseInt($("#nextImageCount").attr("value"));
var totalCount = #ViewBag.totalCount;
var loadedPageIndex = parseInt($("#loadedPageIndex").attr("value"));
var calcScroll = totalHeight - windowOffset - windowHeight;
$("#message").html(calcScroll);
contentLoadTriggered = false;
if (bottomOffset >= ($(".patentPageNew[id='" + loadedPageIndex + "']").offset().top - 1000)
&& bottomOffset <= $(".patentPageNew[id='" + loadedPageIndex + "']").offset().top && contentLoadTriggered == false
&& loadedPageIndex == $(".patentPageNew").attr("id"))
{
contentLoadTriggered = true;
$("#message").html("Loading new images");
loadImages(loadedPageIndex, nextImageCount);
}
});
This is the image-loading function:
function loadImages(loadedPageIndex, nextImageCount) {
var index = loadedPageIndex;
for(var i = 0; i < nextImageCount; i++)
{
window.setTimeout(function () {
$(".patentPageNew[id='" + index + "']").html("<img src='/Patent/GetPatentImage/#Model.Id?pageIndex=" + index + "' />");
index++;
var setValue = index;
$("#loadedPageIndex").attr("value", setValue);
}, 2000);
}
}
I was wondering what may be causing the function to stop working after the first div, or if there might be a better approach to what I'm attempting?
EDIT: It seems that loadedPageIndex == $(".patentPageNew").attr("id") within the if statement was the culprit.
#ViewBag.totalCount; is not a JavaScript, it's .NET, so your script probably stops after encountering an error.
Also: ".patentPageNew[id='" + loadedPageIndex + "']" is inefficient. Since IDs must be unique, just query by ID instead of by class name then by ID.

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