Combining a table and hierarchical list in HTML

Question

I\'m working to redesign a legacy toolset and I\'m looking at how to better display some information both presentationally and semantically.

The data hierarchically in n

Answer 1

The challenge here is that the information you want to represent is in one respect tabular (it's a set of items which have identically-labelled attributes), and in another hierarchical (items have parents).

Unfortunately, there's no nested grouping mechanism for table rows in HTML: tbody can be used to group rows, but nesting it is illegal (except with an intermediate table inside a td, which is pretty horrible).

That leaves you with two choices:

1. Represent the information with nested lists of some sort, and rely on CSS to make the result look like a table.

2. Represent the information as a table, and rely on attributes of some sort to represent its hierarchical relationships.

Here are some examples of how you could implement those choices:

Using nested lists (naïve approach):

<ul>
  <li>
    <dl>
      <dt>Seq</dt> <dd>1</dd>
      <dt>Item Name</dt> <dd>Identifier</dd>
      <dt>Min</dt> <dd>1</dd>
      <dt>Max</dt> <dd>1</dd>
    </dl>
  </li>
  <li>
    <dl>
      <dt>Seq</dt> <dd>2</dd>
      <dt>Item Name</dt> <dd>Name</dd>
      <dt>Min</dt> <dd>1</dd>
      <dt>Max</dt> <dd>1</dd>
    </dl>
    <ul>
      <li>
        <dl>
          <dt>Seq</dt> <dd>2.1</dd>
          <dt>Item Name</dt> <dd>First Name</dd>
          <dt>Min</dt> <dd>1</dd>
          <dt>Max</dt> <dd>1</dd>
        </dl>
      </li>
      <li>
        <dl>
          <dt>Seq</dt> <dd>2.2</dd>
          <dt>Item Name</dt> <dd>Middle Name</dd>
          <dt>Min</dt> <dd>-</dd>
          <dt>Max</dt> <dd>-</dd>
        </dl>
      </li>
      <li>
        <dl>
          <dt>Seq</dt> <dd>2.3</dd>
          <dt>Item Name</dt> <dd>Last Name</dd>
          <dt>Min</dt> <dd>1</dd>
          <dt>Max</dt> <dd>1</dd>
        </dl>
      </li>
    </ul>
  </li>
  <li>
    <dl>
      <dt>Seq</dt> <dd>3</dd>
      <dt>Item Name</dt> <dd>Age</dd>
      <dt>Min</dt> <dd>-</dd>
      <dt>Max</dt> <dd>1</dd>
    </dl>
  </li>
<ul>

This handles the hierarchical aspect of the information, but you end up repeating yourself a lot, and are going to have to jump through some hoops in the CSS to display the result in a tabular way. It's likely doable with judicious use of :first-child, but the end result is that you've gone out of your way to mark something up that you want to present as a table in a non-tabular way, and as a result given yourself more work pulling it back into shape.

It also makes the genuinely tabular nature of the relationships between the items implicit rather than explicit in the markup - without referring to the rendered output, it isn't clear that these items will always have the same number and kind of attributes.

Using nested lists ("clever" approach):

<dl>
  <dt>
    <ul> <li>Seq</li> <li>Item Name</li> <li>Min</li> <li>Max</li> </ul>
  </dt>
  <dd>
    <ul> <li>1</li> <li>Identifier</li> <li>1</li> <li>1</li> </ul>
  </dd>
  <dd>
    <dl>
      <dt>
        <ul> <li>2</li> <li>Name</li> <li>1</li> <li>1</li> </ul>
      </dt>
      <dd>
        <ul> <li>2.1</li> <li>First Name</li> <li>1</li> <li>1</li> </ul>
      </dd>
      <dd>
        <ul> <li>2.2</li> <li>Middle Name</li> <li>-</li> <li>-</li> </ul>
      </dd>
      <dd>
        <ul> <li>2.3</li> <li>Last Name</li> <li>1</li> <li>1</li> </ul>
      </dd>
    </dl>
  </dd>
  <dd>
    <ul> <li>3</li> <li>Age</li> <li>-</li> <li>1</li> </ul>
  </dd>
</dl>

Here, we're using description lists to describe two things:

1. The header/detail relationship between e.g. 'Item Name' and 'Identifier' etc.

2. The parent/child relationship between e.g. the 'Name' unit and the 'First Name' unit.

It's certainly more compact, but unfortunately the specific relationship between each header and its detail elements is implicit at best, and without additional styling to visually organize the information in a tabular way, it'll be even less obvious when rendered what's actually being represented.

Using a table:

<table>
  <thead>
    <tr>
      <th>Seq</th> <th>Item Name</th> <th>Min</th> <th>Max</th>
    </tr>
  </thead>
  <tbody>
    <tr id=100>
      <td>1</th> <th>Identifier</th> <td>1</td> <td>1</td>
    </tr>
    <tr id=200>
      <th>2</th> <th>Name</th> <td>1</td> <td>1</td>
    </tr>
    <tr id=210 data-parent=200 class=level-1>
      <th>2.1</th> <th>First Name</th> <td>1</td> <td>1</td>
    </tr>
    <tr id=220 data-parent=200 class=level-1>
      <th>2.2</th> <th>Middle Name</th> <td>-</td> <td>-</td>
    </tr>
    <tr id=230 data-parent=200 class=level-1>
      <th>2.3</th> <th>Last Name</th> <td>1</td> <td>1</td>
    </tr>
    <tr id=300>
      <th>3</th> <th>Age</th> <td>-</td> <td>1</td>
    </tr>
  </tbody>
</table>

Here, the parent/child relationships are explicitly described by the data-parent attribute (which can be accessed via javascript if necessary), and a class=level-{n} attribute provides a hook that can be used by the CSS:

.level-1 > th {
  padding-left: 1em;
}

Ultimately it's a matter of personal preference and convenience, but I think the <table> approach is better simply because it satisfies the "does it look reasonable with no CSS?" rule of thumb much better than either of the nested-lists approaches above.

Answer 2

My suggestion would be to use nested ordered lists to retain your hierarchical structure, and then description lists to represent the "columns" for each row.

For example, the description list for the first row could look something like this:

<dl>
  <dt>Item Name</dt>
  <dd>Identifier</dd>
  <dt>Min</dt>
  <dd>1</dd>
  <dt>Max</dt>
  <dd>1</dd>
  <dt>Notes</dt>
  <dd>(Required)</dd>
</dl>

You would have to use CSS to hide the description terms (since you don't want them showing up on every row) and to adjust the layout to look more like a table.

The downside to this format is that you are going to be duplicating the column headings on every single row. But semantically I think that makes the most sense, and it should also make the content more meaningful to a screen reader.

I've made a first attempt at the CSS for this so you can get an idea of how it could work. This is probably not very well done, but at least it'll give you something to start with.

CodePen Link

Answer 3

Why not both? A tree grid is a good way to represent tabular data that also conforms to a hierarchy.

This is one such example.

However, having used Extjs on two very large projects, my own personal recommendation is to stay away from it if you're going to be producing a large application. While it may be fine for a one-off grid, I personally find that it's poorly implemented and can become more cumbersome as the size of the project increases. However, it is very feature rich, so the examples panel may give you some more ideas on grids (tables) that might help you.

Keep in mind that you should always be asking yourself, "what questions are my users trying to answer?" Then, ask yourself, "which graphical devices give the clearest and simplest path to answering that question?"

One book that really helped me with these questions was the dashboard design book. Even though you may not be building a dashboard, it has many UX techniques and theories that have made it easier for me when selecting the appropriate UI element (with respect to data).

Hope that helps...

Answer 4

I think you should use a table. True, the hierarchy is more important, but it also can be displayed through manually writing down the first column. But the attributes min, max and item name could not be shown as easily in a list as in a table. My opinion: use a table and provide the seq column manually!

Answer 5

I think there are two sensible ways how to represent this in HTML:

• use a table and make the relation/hierarchy explicit with natural language
• use sectioning elements (resp. headings if you use HTML 4.01)

table with a column explaining the hierarchy

If there is no markup for defining this relationship, you should use text. If the visual representation is unambiguous, you could visually hide this text so that it is only accessible for screenreader/text browser users.

In your case, you could add a column that explains the relationship of rows that are "sub items":

<table>

  <tr>
    <th>Seq</th> 
    <th>Relation</th> <!-- or some clever better label -->
    <th>Item Name</th>
    <th>Min</th>
    <th>Max</th>
  </tr>

  <!-- … -->

  <tr id="2">
    <td>2</td>
    <td></td> <!-- "parent", "root", "container", empty -- whatever makes sense for your case -->
    <td>Name</td>
    <td>1</td>
    <td>1</td>
  </tr>

  <tr id="2.1">
    <td>2.1</td>
    <td>child of <a href="#2">Name</a></td>
    <td>First Name</td>
    <td>1</td>
    <td>1</td>
  </tr>

</table>

Each row could get an id (with value of Seq or Item Name), so that this row can be linked {note that id values starting with a digit are not allowed in HTML 4.01; you could use something like id="seq-2.1" there}. If an item is a child of another item, you could link to the row of the parent item.

This way you make it clear for humans, and machines still see that these rows are connected, although the specific semantics of this relation is not machine-readable. You could use a link type (rel value) here if to make the meaning of the relation explicitly clear. In HTML 4.01 you could create a value yourself, in HTML5 it would need to be registered first.

sectioning elements / headings

Instead of using a table, you could make use of HTML’s outlining. {The following example uses HTML5’s sectioning elements. If you use HTML 4.01, simply replace the sectioning elements with div (or no element at all) and use headings only.}

Each section (introduced by a heading) represents an item. The outline of the headings (resp. nesting of the sectioning elements) represents the hierarchy of your items.

Here is an example to see the whole structure:

 <article>

   <h1><!-- heading for the whole data --></h1>

   <section class="item" id="1">
     <h2>Identifier</h2>
   </section>

   <section class="item" id="2">
     <h2>Name</h2>

     <section class="item" id="2.1">
       <h3>First Name</h3>
     </section>

     <section class="item" id="2.2">
       <h3>Middle Name</h3>
     </section>

     <section class="item" id="2.3">
       <h3>Last Name</h3>
     </section>

   </section>

   <section class="item" id="3">
     <h2>Age</h2>
   </section>

 </article>

Each section could contain a dl for the properties:

<section class="item" id="3">
  <h2>Age</h2>

  <dl>
    <dt>Min</dt>
    <dd>1</dd>
    <dt>Max</dt>
    <dd>1</dd>
  </dl>

</section>

Depending of the actual meaning of your content, you could use the code element for the item names (e.g. if it describes elements of a markup language, for example), and/or the dfn element, if the following content is a definition of that item.

Answer 6

I would present it by using a table and by adding custom data attributes to the td tags:

<table id="myTable" class="table">
    <tr>
        <td data-indent="0">1</td>
        <td data-indent="0">Test</td>
        <td data-indent="0">Test 1</td>
    </tr>
    <tr>
        <td data-indent="1">1.1</td>
        <td data-indent="1">Another</td>
        <td data-indent="0">Test 1.1</td>
    </tr>
    <tr>
        <td data-indent="2">1.1.1</td>
        <td data-indent="3">Another</td>
        <td data-indent="0">Test 1.1.1</td>
    </tr>
        <tr>
        <td data-indent="2">1.1.2</td>
        <td data-indent="3">Another one</td>
        <td data-indent="0">Another test 1.1.2</td>
    </tr>
    <tr>
        <td data-indent="0">2</td>
        <td data-indent="0">Test</td>
        <td data-indent="0">Test 2</td>
    </tr>
</table>

Then, with the help of jQuery, set the padding of each cell value in your table:

$("td")
    .css("padding-left", function (index) {
    return 10 * parseInt($(this).data("indent")) + "px";
});

See it working on jsFiddle.