15

I try to create a web page with a fixed navigation bar at the top that covers the content underneath. When loading the page with an anchor in the url the normal behaviour is that the page scrolls the anchor to the top of the window. But then that content is hidden under the navigation bar. So I try to solve this problem with JavaScript scrollTo(). My solution works fine with Firefox and Opera but not in Chrome. Please try the example. Any ideas how to fix this issue in Chrome? Thank you.

test.htm:

<!DOCTYPE HTML>
<html>
  <head>
    <title>Test</title>
    <meta charset='UTF-8'>
    <style type='text/css'>
      #navi { position:fixed; left:0; top:0; width:100%; height:100px; background-color:yellow; }
      #spacer { background-color:cyan; height:100px; }
      #spacer2 { height:1000px; }
      .style1 { background-color:green; height:200px; }
    </style>
    <script type='text/javascript'>
      /* <![CDATA[ */
      function scrollAnchor() {  // doesn't work in Chrome
        var y = document.getElementById(window.location.hash.substr(1)).offsetTop - 110;
        window.scrollTo(0, y);
        //alert(y);
      }
      /* ]]> */
    </script>
  </head>
  <body id='top' onload='scrollAnchor();'>
    <div id='navi'>
      <a href='./test2.htm'>Menu</a>
    </div>
    <div id='main'>
      <div id='spacer'></div>
      <h3 id='1'>Heading 1</h3><p class='style1'></p>
      <h3 id='2'>Heading 2</h3><p class='style1'></p>
      <h3 id='3'>Heading 3</h3><p class='style1'></p>
      <h3 id='4'>Heading 4</h3><p class='style1'></p>
      <h3 id='5'>Heading 5</h3><p class='style1'></p>
      <h3 id='6'>Heading 6</h3><p class='style1'></p>
      <div id='spacer2'></div>
    </div>
  </body>
</html>

test2.htm:

<!DOCTYPE HTML>
<html>
  <head>
    <title>Test</title>
    <meta charset='UTF-8'>
  </head>
  <body>
    <a href='test.htm#1'>Heading 1</a>
    <a href='test.htm#2'>Heading 2</a>
    <a href='test.htm#3'>Heading 3</a>
    <a href='test.htm#4'>Heading 4</a>
    <a href='test.htm#5'>Heading 5</a>
    <a href='test.htm#6'>Heading 6</a>
  </body>
</html>
atarax
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2 Answers2

42

Chrome is so fast that your scrollTo() action fires before Chrome's default scroll to html anchor event.

Give it a tiny delay by using 

setTimeout(function() {window.scrollTo(0, y);},1)

Or simply avoid using the actual element id as hash name

instead of using

test.htm#6

use

test.htm#link_6

then you can get the real id by doing something like

window.location.hash.split('_')[1]

Hope it helps.

Mark Ni
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1

I would suggest avoiding the use of JavaScript in favor of creating a dedicated anchor element and then offsetting it above the heading by at least your header height.

This has already been well described in https://stackoverflow.com/a/13184714/5951116.

Your code would then look something like this:

<div id='navi'>
  <a href='./test2.htm'>Menu</a>
</div>
<div id='main'>
  <div id='spacer'></div>
  <div class='article-wrapper'>
    <a class='anchor' id='1'></a>
    <h3>Heading 1</h3><p class='style1'></p>
  </div>
  <div class='article-wrapper'>
    <a class='anchor' id='2'></a>
    <h3>Heading 2</h3><p class='style1'></p>
  </div>
  ...
</div>

#navi {
  height: 50px;
}

#main a.anchor {
    display: block;
    position: relative;
    top: -50px;
    visibility: hidden;
}

Or use CSS variables to remove as much tight coupling as possible:

:root {
  --header-height: 50px;
}

#navi {
  height: var(--header-height);
}

#main a.anchor {
    display: block;
    position: relative;
    top: -var(--header-height);
    visibility: hidden;
}
mik13ST
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