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Recently, while doing research/work on a completely unrelated topic, I came across the beautiful illustrations on Rype Arts,
which are displayed inside of a JavaScript-driven content switcher. For
some reason, I happened to visit the page with JavaScript disabled and
noticed that the content switcher was still working (albeit, with a few
flaws).
At first I couldn't figure out how it was functioning. Normally,
with JavaScript disabled, this type of content switcher (or content
slider) will just display one item, or else display all items, without
allowing any "switching" functionality. After some poking around, I
realized it's not a very difficult thing to do. The switcher utilizes
in-page anchors and overflow: hidden to keep the switchability intact.
View the Demo to preview what I'll be describing below.
Here is the HTML that I'll be using to demonstrate this effect with and without JavaScript:
<div id="content-slider">
<ul id="content-slider-inside">
<li id="one">1</li>
<li id="two">2</li>
<li id="three">3</li>
<li id="four">4</li>
<li id="five">5</li>
</ul>
</div>
<ul id="navigation">
<li><a href="#one">1</a></li>
<li><a href="#two">2</a></li>
<li><a href="#three">3</a></li>
<li><a href="#four">4</a></li>
<li><a href="#five">5</a></li>
</ul>
The key part of this code is the <div> with the id
"content-slider". Normally, that element would not be necessary, as it
seems to be doing nothing. In this case, however, it's needed in order
to hide the unselected content inside the list nested inside it. Also,
each list item inside the content switcher is given a unique id, which is needed for the switching to work even without JavaScript.
The CSS to style the content switcher is as follows (I've excluded all irrelevant styles):
#content-slider {
width: 650px;
overflow: hidden;
height: 300px;
}
#content-slider-inside {
list-style: none;
height: 320px; // these 3 lines
overflow: scroll; // help Opera
overflow-y: hidden; // behave
}
#content-slider-inside li {
width: 650px;
height: 300px;
}
A few things to note in the CSS above: The outer container has its
overflow set to "hidden". It also has a width equal to one of the
content boxes (650px). Inside the container is the <ul>
element that holds the list items that represent the content boxes.
Finally, the list items are given dimensions of 650px by 300px. Since
the container element is equal to one list item, and the container has
overflow set to "hidden", only one list item will be visible at a time.
UPDATE: I added three new lines of code in the CSS
above (commented), to get the non-JavaScript version (the first demo)
to work in Opera. Thanks to comment by Damian Muti.
How it Works
The navigation links are linked to internal anchors. An HTML page, by default will search the page for an anchor set as <a name="one"></a>, and if it doesn't find it, will then match the anchor to a corresponding id attribute. This is what allows the content switcher to still change the content inside of the container.
After the above code is in place, we just need to add some CSS to
make it look a little nicer, then we have the option to enhance the
switcher with JavaScript. The switcher also allows deep linking by
means of the hash in the URL, which works with or without JavaScript.
Compatibility
This works in every modern browser, except for Opera, and also works in IE6. Opera doesn't seem to support in-page anchors that appear in hidden sections of a <div>
- or else I'm doing something else wrong, but I couldn't figure out how
to get Opera to recognize the switching without JavaScript enabled.
Take a look at the demo, which also includes a link to a
JavaScript/jQuery-enhanced version that I coded myself, as a bonus. And
just to demonstrate the deep-linking capabilities, the demo link
appends "#three" to the URL - so you should see the number "3″ in the
content area, if it's working correctly.
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