After all these years, we have finally reached the point where we’ve separated page organization from presentation, and now we’re about to embark on the same mistakes again, but this time with presentation and semantics.
I’ve been following the issues associated with the vocabindex Drupal module, including one where the person submitting the bug stated the vocabindex use of UL was incorrect. We’re supposed to, MXT writes, use definition lists rather than unordered lists for any lists of terms with associated definition.
At first glance, it does seem as if the vocabindex module is using the unordered list incorrectly. After all, look at any of my category pages (such as the one for the Semantic Web)—what you see is a list of “terms” and their associated definitions. An obvious candidate for definitions lists.
Look more closely, though. In my sidebar menu I list the vocabindex terms as links to web page URIs, but there is no definition attached to any item. The description, if one is given, is, instead, added as a title attribute to the item and displayed only when the item has cursor focus. Yet, it’s the same data. Does this mean, then, I’m somehow not properly displaying my menu items? Should I have a huge sidebar, with the item description given underneath?
More importantly, whether I have a given text description for each item is purely optional, some do, some don’t. Yet the items in the list have meaning without any associated description. In fact, each item in the list is really nothing more than a label for a bucket to hold content. I could just as easily use foo, bar, silly, putty as labels, except that I’m trying to use “meaningful” labels in order to enable you all to better find past content.
In the absolutely ancient W3C page where lists are covered a list of ingredients is given as an example of an unordered list:
- 1 cup sugar
- 1 cup oil
- 2 cups flour
However, I don’t see that anyone would have a problem with adding parenthetical information to this list in order to further clarify the items:
- 1 cup sugar (light brown granulated by C & H)
- 1 cup oil (canola or corn, but not olive)
- 2 cups flour (white or mixed white and whole wheat)
This is really nothing more than what the vocabindex is doing with the vocabulary index terms within both the index pages and my sidebar menu: a listing of items and a (parenthetical) description to clarify what that item is. However, it’s only when the description is displayed as a “tooltip” that one sees the item as a clarification phrase, only. When presented in the index pages, it “looks” like a definition list, and so we want to have it marked up this way— mixing up semantics and presentation.
A definition list is assumed to have two pieces of information; the term or phrase and an associated definition. Even when not present, the definition is still assumed to be forthcoming at some point— not having it is the exception, not the rule. An unordered list is just that: a list of items. They can be a list of items to buy at the store, select from in a form, or click on in a web page. There’s no assumption that any additional information is necessary for the item. If there was, Drupal would make this information mandatory rather than optional. The application and associated developers would definitely discourage the use of the items in a tag cloud or other format where only the term is given because the term, by itself, would be meaningless.
Yet we look at how the terms are portrayed in a page like the vocabindex page I linked above, and that’s enough for us to say we should use one form of markup over another because it’s more “semantical”. Further exploration online at other sites who attempt to define the differences between unordered lists and definition lists shows the same thing: if we see two pieces of data, we’re assuming a definition list, because that’s what it looks like—not what it is.
The HTML5 document adds another key element to the discussion of definition lists by stating that definition lists are name-value pairs. From this can we deduce, then, that the name has no meaning without the value. That’s my interpretation: that a definition list is the proper semantic markup only when data is defined within a context of names and associated values, both of which are meaningless without the other. If, however, *HTML5 allows us to list the names without values, or the values without the names, then the HTML5 document is imprecise, and we should just use whatever we want to use— semantics can not be derived from imprecision.
Currently, in Drupal, vocabulary terms are discrete labels, nothing more. Any description is for clarification not definition, and isn’t essential to the meaning of the term. Forget how the vocabindex pages “look”, and focus on what the data means. If we can’t do that, then this whole semantic markup thing is a bit of a farce, really.
*Confirmed: it doesn’t