Modifying location.hash without page scrolling

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We've got a few pages using ajax to load in content and there's a few occasions where we need to deep link into a page. Instead of having a link to "Users" and telling people to click "settings" it's helpful to be able to link people to user.aspx#settings

To allow people to provide us with correct links to sections (for tech support, etc.) I've got it set up to automatically modify the hash in the URL whenever a button is clicked. The only issue of course is that when this happens, it also scrolls the page to this element.

Is there a way to disable this? Below is how I'm doing this so far.

$(function(){
    //This emulates a click on the correct button on page load
    if(document.location.hash){
     $("#buttons li a").removeClass('selected');
     s=$(document.location.hash).addClass('selected').attr("href").replace("javascript:","");
     eval(s);
    }

    //Click a button to change the hash
    $("#buttons li a").click(function(){
            $("#buttons li a").removeClass('selected');
            $(this).addClass('selected');
            document.location.hash=$(this).attr("id")
            //return false;
    });
});

I had hoped the return false; would stop the page from scrolling - but it just makes the link not work at all. So that's just commented out for now so I can navigate.

Any ideas?

18 Answers

Okay, this is a rather old topic but I thought I'd chip in as the 'correct' answer doesn't work well with CSS.

This solution basically prevents the click event from moving the page so we can get the scroll position first. Then we manually add the hash and the browser automatically triggers a hashchange event. We capture the hashchange event and scroll back to the correct position. A callback separates and prevents your code causing a delay by keeping your hash hacking in one place.

var hashThis = function( $elem, callback ){
    var scrollLocation;
    $( $elem ).on( "click", function( event ){
        event.preventDefault();
        scrollLocation = $( window ).scrollTop();
        window.location.hash = $( event.target ).attr('href').substr(1);
    });
    $( window ).on( "hashchange", function( event ){
        $( window ).scrollTop( scrollLocation );
        if( typeof callback === "function" ){
            callback();
        }
    });
}
hashThis( $( ".myAnchor" ), function(){
    // do something useful!
});

The other way to do this is to add a div that's hidden at the top of the viewport. This div is then assigned the id of the hash before the hash is added to the url....so then you don't get a scroll.

If on your page you use id as sort of an anchor point, and you have scenarios where you want to have users to append #something to the end of the url and have the page scroll to that #something section by using your own defined animated javascript function, hashchange event listener will not be able to do that.

If you simply put a debugger immediate after hashchange event, for example, something like this(well, I use jquery, but you get the point):

$(window).on('hashchange', function(){debugger});

You will notice that as soon as you change your url and hit the enter button, the page stops at the corresponding section immediately, only after that, your own defined scrolling function will get triggered, and it sort of scrolls to that section, which looks very bad.

My suggestion is:

  1. do not use id as your anchor point to the section you want to scroll to.

  2. If you must use ID, like I do. Use 'popstate' event listener instead, it will not automatically scroll to the very section you append to the url, instead, you can call your own defined function inside the popstate event.

    $(window).on('popstate', function(){myscrollfunction()});

Finally you need to do a bit trick in your own defined scrolling function:

    let hash = window.location.hash.replace(/^#/, '');
    let node = $('#' + hash);
    if (node.length) {
        node.attr('id', '');
    }
    if (node.length) {
        node.attr('id', hash);
    }

delete id on your tag and reset it.

This should do the trick.

  1. Save scroll position before changing url fragment.
  2. Change url fragment.
  3. Restore old scroll position.
let oldScrollPosition = window.scrollY;
window.location.hash = addressFragment;
window.scrollTo(0, oldScrollPosition);

It's fast, so client won't notice anything.

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