Fbloggs Geekdom

Summary: Quirks of checkbox markup in HTML – differences between IE and FireFox…

Tables do not conform to the normal CSS box model as W3C explains .

A consequence of this is that you cannot use the margin property for cells or rows. Citing the above page: “Internal table elements generate rectangular boxes with content and borders. Cells have padding as well. Internal table elements do not have margins. (my emphasis). So, something like this:

tr.spaceme { margin-top:15px; }

does nothing.

I wanted to have a table with a ‘heading’ row followed by details, another heading row, more details, etc. So the solution is to style an empty row using the padding and/or border properties. Suppose we want to have 15 pixels of white space between the top of the next heading row. Here’s some example markup:


CSS:

<table>
<tr class="gap"><td colspan="2">&nbsp;</td></tr>
<tr><td>Customer: 1</td><td>Name: Acme</td></tr>
<tr><td>Order: foo1</td><td> Item: bar1 </td></tr>
<tr><td>Order: foo2</td><td> Item: bar2 </td></tr>
<tr class="gap"><td colspan="2">&nbsp;</td></tr>
<tr><td>Customer: 1</td><td>Name: Bolts Inc.</td></tr>
<tr><td>Order: foo3</td><td> Item: bar3 </td></tr>
<tr><td>Order: foo4</td><td> Item: bar4 </td></tr>
</table>


I don’t really like this, because it requires an unnecessary table row for each heading. My example requires a colspan, too, as I suspect in most cases tables like these will have more than one column for the headings and/or details. Anyway, I’m posting this to remind myself of this quirk in the CSS box model, as I’m bound to forget it next time I have to render tables like this.