CSS3 Attribute Selector Presentation

During the fog of a summer cold and pressing deadlines… I gave a presentation today at the Yahoo! Front End Engineering Summit about CSS3 Attribute Selectors. The presentation briefly touched on some of my previous posts on this site as well as a few new concepts and ideas.

Here is the full presentation (HTML): CSS3 Attribute Lovin’. Feel free to copy, share, or do whatever you like with it.

I’ll post some more information on the new topics soon. Right now I’ve got to get back to my massive list of outstanding bugs on my project.

Create a tabbed search form with YUI

Yahoo! makes it easy to create an accessible, handsome tabbed interface. I used their Tab View library to create the tabbed search form for V3GGIE.com. While Tab View can create the tabbed content dynamically, I’m using it to hide/show hard-coded individual forms.

Update: I’ve removed the tabbed interface from V3GGIE.com. This particular use of the tabbed module seemed to have created some confusion in users. The approach is still valid, just not the way I originally implemented it. See the tabbed search form on V3GGIE.com

Step 1. Create the basic HTML code.

The tabbed code is a simple pattern:

  1. Start with a parent div and give it an id and class=”yui-navset”.

  2. Create an unordered list inside this div with class=”yui-nav”.
  3. Each list includes a deep link to a corresponding div that is also a child of the parent div. The link text in an em tag.

  4. V3GGIE Search
  5. Create a div with class=”yui-content” and create a set of content containing divs. Each div has an id.

    ...
    ...
    ...

  6. Insert the Tabview CSS at the top of the page, the Tab View JS at the bottom of the page, create a small js that instantiates the tab-view module.
  7. For easier styling, use the sam_skin CSS package and add class=”yui-skin-sam” to the body.

Step 2. Use PHP to make it more interesting

Each page calls this chunk of code to insert the tabbed form, it also sets a variable ($selected), determining which tab is selected on page load. I’m also inserting the last search query into the text input to make it easier on the user. This is easily done by grabbing the query from the Request object.

The finished code:




Try "San Francisco Pho", "Paris Fromage", or "92104 tofu"


Try "corn chowder" or "vegan pizza"


Try "Vegetarian Chinese Olympics"


Try a subject: "PETA", "Tempeh", or "Paris -Hilton Vegetarian"

View the source as a text file

The Final Product

We now have a tabbed module that allows the user to find recipes, news, blogs, and local restaurants from any page. This is an easy introduction to the YUI libraries. However, I came across the following surprises:

  • The order of the tabs must match the order of the target divs. I moved my tabs around and discovered they were toggling the wrong forms.
  • The links that generate the tabs need to have em tags surrounding the text
  • You’ll need to download the entire YUI package to gain access to the CSS and sprites needed for the library. The examples on the YUI site assume relative links to files, you will either need to duplicate that file structure or upload the skin’s sprite and change the CSS accordingly.

Adding style to your rel attributes with CSS

View the finished example: Adding style to your rel link.

There’s a little attribute in HTML links that is starting to get a bit of attention lately. The “rel” attribute is a sparsely defined attribute that applies some meta information about a link’s relationship to other documents. Unfortunately, this information is usually hidden from your users. Let’s take a light-hearted stab at turning it into a visual element.

Rel attribute usage

While the W3C originally considered the rel attribute to describe the relationship of pages to each other, i.e. next, previous, directory, and start. The attribute has been adopted by the Microformat community for its inherit usefulness. The rel attribute is now used for tags, to define your relationship to someone, and even to tell search engines not to bother following a link.

The opportunities to use the rel attribute are seemingly endless. There are more proposals to define people you don’t like and links for voting.

But all of this flexibility comes at a small price. To remain valid, you need to tell the browser what these new rel values may actually mean. This is handled by linking to appropriate profiles. Just simply insert the profiles into your head tag. Multiple profiles may throw a validation error, but it’s ok. You don’t need to do this for the standard rel values.



We will be using the CSS3 attribute selector functionality to look at the value of the rel attribute and apply some style accordingly. First we’ll add some padding and a background image to any link that has a rel attribute. We’ll then use background positioning to display an icon that is appropriate for the link. It’s a fairly simple hack.

For more information on using attribute selectors, check out my previous posts:

Sample HTML Code

  • This link is ignored by search engines (rel="no-follow")
  • (rel="tag")
  • Sample CSS


    a[rel] {padding-left:20px; background:url(rel-sprite.png) no-repeat 0 0; }
    a[rel~="help"] {background-position: 0 -350px ;}
    a[rel~="license"] {background-position: 0 -1347px ;}
    a[rel~="no-follow"] {background-position: 0 -1200px ;}
    a[rel~="tag"] {background-position: 0 -47px ;}

    It’s all fun and games

    I’ll be the first to admit this exercise has significant issues. I’m assuming the following elements are true:

    1. All possible rel attribute values are accounted for in my CSS, if not there will be a blank space generated by the first rule
    2. You can only have one relationship defined by XFN. Unfortunately, most people are defined by multiple values, i.e. rel=”met friend colleague”. This CSS does not account for multiple values.

    So, the display of your rel attributes may be a bit off in the edge cases. Keep the spirit light and nobody will say anything… I hope. Have fun with your rel attributes. They’re just sitting there waiting to be used.

    View the finished rel attribute style example.

    Related Information