jQuery page scroll not changing navbar href to active class

Question

I have a one-page website. When I scroll down I want my (fixed) navbar links to change the status to active when reaching the position of that specific div.

I used jQuery but it doesn't work. Here is my code:

// SMOOTH SCROLLING PAGES

$(document).ready(function () {
$(document).on("scroll", onScroll);

//smoothscroll
$('a[href^="#"]').on('click', function (e) {
    e.preventDefault();
    $(document).off("scroll");

    $('a').each(function () {
        $(this).removeClass('active');
    })
    $(this).addClass('active');

    var target = this.hash,
        menu = target;
    $target = $(target);
    $('html, body').stop().animate({
        'scrollTop': $target.offset().top+2
    }, 800, 'swing', function () {
        window.location.hash = target;
        $(document).on("scroll", onScroll);
    });
  });
});

function onScroll(event){
var scrollPos = $(document).scrollTop();
$('main-navigation a').each(function () {
    var currLink = $(this);
    var refElement = $(currLink.attr("href"));
    if (refElement.position().top <= scrollPos && refElement.position().top + refElement.height() > scrollPos) {
        $('main-navigation ul li a').removeClass("active");
        currLink.addClass("active");
    }
    else{
        currLink.removeClass("active");
    }
  });
};

Here is my HTML:

<nav id="main-navigation">
  <ul>
    <li class="active"><a href="#site-main">Home</a></li>
    <li><a href="#a">A</a></li>
    <li><a href="#b">B</a></li>
    <li><a href="#c">C</a></li>
    <li><a href="#d">D</a></li>
  </ul>
</nav>
<div id="a">DIV Alpha</div>
<div id="b">DIV Bravo</div>
<div id="c">DIV Charlie</div>
<div id="d">DIV Delta</div>

The smooth scrolling works perfectly, but when I scrolling back up from div #d the navbar li active state doesn't change.

Answer 1

Here, i prepare fiddle for you, i hope it what you looking for - http://jsfiddle.net/skyr9999/dpuvcj5w

<div class="content">
    <div id="site-main">DIV Home</div>
    <div id="a">DIV Alpha</div>
    <div id="b">DIV Bravo</div>
    <div id="c">DIV Charlie</div>
    <div id="d">DIV Delta</div>
</div>

<nav id="main-navigation">
    <ul>
        <li><a class="menuitem" href="#site-main">Home</a></li>
        <li><a class="menuitem" href="#a">A</a></li>
        <li><a class="menuitem" href="#b">B</a></li>
        <li><a class="menuitem" href="#c">C</a></li>
        <li><a class="menuitem" href="#d">D</a></li>
    </ul>
</nav>

js

$(document).ready(function () {

    $('a[href^="#site-main"]').addClass('active');

//smoothscroll
    $('.menuitem').on('click', function (e) {
        e.preventDefault();
        //  $(document).off("scroll");
        var athis = this;
        var target = this.hash,
                menu = target;
        $target = $(target);
        $('html, body').stop().animate({
            'scrollTop': $target.offset().top + 2
        }, 800, 'swing', function () {
            window.location.hash = target;
            $('.menuitem').removeClass('active');
            $(athis).addClass('active');

        });    
    });    

    $(window).scroll(function (event) {
        var scrollPos = $(document).scrollTop();
        if (scrollPos === 0)
        {
            $('a[href^="#site-main"]').addClass('active');
            return;
        }    
        $('.menuitem').each(function () {
            var currLink = $(this);
            var refElement = $(currLink.attr("href"));
            if (refElement.position().top <= scrollPos && refElement.position().top + refElement.height() > scrollPos) {
                $('.menuitem').removeClass("active");
                currLink.addClass("active");
            } else {
                currLink.removeClass("active");
            }
        });    
    })    
});

Because you did not include any css, i improvise a little, but it seems works just fine.

css

#a,#b,#c,#d,#site-main { height: 400px;}
#main-navigation {
    position: fixed;
    top: 0px;
    right:10px;        
}

#main-navigation ul li {
  display: inline;
}

.active {
  background: #f00;
}

Update 1 I update code to match fiddle now it change menu item selection when you scrool to item

Answer 2

You have to loop through with the list items instead and correct the id selector with a # notation:

$('#main-navigation li').each(function () { //<---correct id selector
    var currLink = $(this);
    var refElement = $(currLink.find('a').attr("href")); //<---find the anchor here
    if (refElement.position().top <= scrollPos && refElement.position().top + refElement.height() > scrollPos) {
        $('#main-navigation ul li').removeClass("active"); //<---and here
        currLink.addClass("active");
    }
    else{
        currLink.removeClass("active");
    }
});

Answer 3

you can use this cool tiny plugin to achieve this https://github.com/davist11/jQuery-One-Page-Nav

it will add current class when you are in a specific div or section Hope this help :)

Answer 4

replace

$('a').each(function () { $(this).removeClass('active'); }) $(this).addClass('active');

with

$('a').each(function () {
    $(this).parent().removeClass('active');
})
$(this).parent().addClass('active');

complete code:

$('a[href^="#"]').on('click', function (e) {
e.preventDefault();
$(document).off("scroll");

$('a').each(function () {
    $(this).parent().removeClass('active');
})
$(this).parent().addClass('active');

var target = this.hash,
    menu = target;
$target = $(target);
$('html, body').stop().animate({
    'scrollTop': $target.offset().top+2
}, 800, 'swing', function () {
    window.location.hash = target;
});

});

No need of onScroll function