Onload, check if window.location.hash has a value. If it does, grab the element with an id that matches the hash value. Find the position of the element (recursive calls to offsetTop/offsetLeft) and then pass those values into the window.scrollTo(x, y) method.
This should scroll the page to the desired element.
This solution is no longer recommended due to changes in browser behavior. See other answers.
Basically, if an anchor is used we bind to the windows scroll event. The idea being that the first scroll event has to belong to the automatic repositioning done by the browser. When this occurs we do our own repositioning and then remove the bound event. This prevents subsequent page scrolls from borking the system.
$(document).ready(function() {
if (window.location.hash) {
//bind to scroll function
$(document).scroll( function() {
var hash = window.location.hash
var hashName = hash.substring(1, hash.length);
var element;
//if element has this id then scroll to it
if ($(hash).length != 0) {
element = $(hash);
}
//catch cases of links that use anchor name
else if ($('a[name="' + hashName + '"]').length != 0)
{
//just use the first one in case there are multiples
element = $('a[name="' + hashName + '"]:first');
}
//if we have a target then go to it
if (element != undefined) {
window.scrollTo(0, element.position().top);
}
//unbind the scroll event
$(document).unbind("scroll");
});
}
});
Here's a a more general approach. Instead of trying to prevent the browser from scrolling (or jumping to the top as it would look like) I just restore the previous position on the page.
I.e. I'm recording the current y-offset of the page in localStorage and scroll to this position once the page has loaded.
function storePagePosition() {
var page_y = window.pageYOffset;
localStorage.setItem("page_y", page_y);
}
window.addEventListener("scroll", storePagePosition);
var currentPageY;
try {
currentPageY = localStorage.getItem("page_y");
if (currentPageY === undefined) {
localStorage.setItem("page_y") = 0;
}
window.scrollTo( 0, currentPageY );
} catch (e) {
// no localStorage available
}
After number of failures finally I managed to do the trick. anzo is correct here as using beforeunload will make the page jump to top when a user reloads the page or clicks a link. So unload is the clearly way to do this.