Have you ever created new clean XHTML template, applied it to a CMS with years of back content, and discovered that the years of legacy HTML looks terrible? Because you’re using a new XHTML doctype many, if not all, of the presentational attributes in the old HTML no longer work, however, CSS can be used to fix this.
You may say that the whole point of building a new template with XHTML & CSS is so that we won’t have any of the old <p align="right"> in our code, and you are right, but in situations when there can be thousands of pages of content it is often not practical to re-code them all using CSS, that’s where the attribute selectors come in.
Here is a very basic stylesheet that will help get you started:
img[align="right"], table[align="right"] {float:right;}
img[align="left"], table[align="left"] {float:left;}
img[align="center"], table[align="center"] {display:block;margin-left:auto;margin-right:auto;}
p[align="center"] {text-align:center;}
p[align="left"] {text-align:left;}
p[align="right"] {text-align:right;}
table[border="2"], table[border="2"] td {border:1px solid #000;}
table[border="1"], table[border="1"] td {border:1px solid #000;}
table[border="0"], table[border="0"] td {border:0;}
Although it would be nice to have one master stylesheet that we could drop in to a document and automatically have the old HTML look great, I believe that stylesheet would have to be extremely large, so I recommend using a base set of styles, (like the one above), and adding any extra styles to it that may be needed, (for example, img[border="5"] {border:5px solid #000} would not be needed every time).
What about browser compatibility? I’ve tested in FireFox 3, Safari 3, Internet Explorer 7, and Internet Explorer 6, and, if I remember correctly, Opera 9. The only browser that didn’t render the styles as I would have liked to see them was IE6, which is no surprise, but also has a rapidly diminishing market share.
If you are looking for a way to keep your legacy HTML from looking terrible that doesn’t involve recoding it all, this may be the way for you to go.