HTML Table with Scrolling Header Row

by Aniesh Joseph

HTML

<link rel="stylesheet" href="https://maxcdn.bootstrapcdn.com/bootstrap/3.3.7/css/bootstrap.min.css">
<script src="https://ajax.googleapis.com/ajax/libs/jquery/1.12.4/jquery.min.js"></script>
<script src="https://maxcdn.bootstrapcdn.com/bootstrap/3.3.7/js/bootstrap.min.js"></script>
 <!-- Based on StackOverflow Answer: http://stackoverflow.com/a/15983876/281087 -->
  
  <div id="table-container">
  <table class="table table-bordered table-fixed" id="maintable">
    <thead>
      <tr>
        <th>Firstname</th>
        <th>Lastname</th>
        <th>Email</th>
      </tr>
    </thead>
    <tbody>
      <tr>
        <td>John</td>
        <td>Doe</td>
        <td>john@example.com</td>
      </tr>
      <tr>
        <td>Mary</td>
        <td>Moe</td>
        <td>mary@example.com</td>
      </tr>
      <tr>
        <td>July</td>
        <td>Dooley</td>
        <td>july@example.com</td>
      </tr>
      <tr>
        <td>July</td>
        <td>Dooley</td>
        <td>july@example.com</td>
      </tr>
      <tr>
        <td>July</td>
        <td>Dooley</td>
        <td>july@example.com</td>
      </tr>
      <tr>
        <td>July</td>
        <td>Dooley</td>
        <td>july@example.com</td>
      </tr>  
      <tr>
        <td>John</td>
        <td>Doe</td>
        <td>john@example.com</td>
      </tr>
      <tr>
        <td>Mary</td>
        <td>Moe</td>
        <td>mary@example.com</td>
      </tr>
      <tr>
        <td>July</td>
        <td>Dooley</td>
        <td>july@example.com</td>
      </tr>
      <tr>
        <td>July</td>
        <td>Dooley</td>
        <td>july@example.com</td>
      </tr>
      <tr>
        <td>July</td>
        <td>Dooley</td>
        <td>july@example.com</td>
      </tr>
            <tr>
        <td>John</td>
        <td>Doe</td>
        <td>john@example.com</td>
      </tr>
      <tr>
        <td>Mary</td>
        <td>Moe</td>
        <td>mary@example.com</td>
      </tr>
      <tr>
        <td>July</td>
        <td>Dooley</td>
       ...

CSS

thead{
    background-color:white;
}
#maintable{width: 100%}

JavaScript

function moveScroll(){
    var scroll = $(window).scrollTop();
    var anchor_top = $("#maintable").offset().top;
    var anchor_bottom = $("#bottom_anchor").offset().top;
    if (scroll > anchor_top && scroll < anchor_bottom) {
        clone_table = $("#clone");
        if(clone_table.length === 0) {          
            clone_table = $("#maintable").clone();
            clone_table.attr({id: "clone"})
            .css({
                position: "fixed",
                "pointer-events": "none",
                 top:0
            })
            .width($("#maintable").width());

            $("#table-container").append(clone_table);
            // dont hide the whole table or you lose border style & 
            // actively match the inline width to the #maintable width if the 
            // container holding the table (window, iframe, div) changes width          
            $("#clone").width($("#maintable").width());
            // only the clone thead remains visible
            $("#clone thead").css({
                visibility:"visible"
            });
            // clone tbody is hidden
            $("#clone tbody").css({
                visibility:"hidden"
            });
            // add support for a tfoot element
            // and hide its cloned version too
            var footEl = $("#clone tfoot");
            if(footEl.length){
                footEl.css({
                    visibility:"hidden"
                });
            }
        }
    } 
    else {
        $("#clone").remove();
    }
}
$(window).scroll(moveScroll);