You Don’t Need JavaScript for That!
Web development today can be a whirlwind of various technologies, and even the simplest of widgets can often be complex under the hood.
With that in mind, I’d like to focus on a variety of things you can do with just HTML and CSS, no JavaScript required. Why, you ask? While some of these solutions may not be practical for every use case, they do inspire outside-the-box thinking that promotes lowered complexity, and a wider array of browser support. Here are a few cool things you can do without having to write a single line of JavaScript.
Building a Tabs Widget
We’ve all seen how the checkbox hack can be used for interactivity without JavaScript, but unfortunately, this comes at a cost to accessibility. So instead of another checkbox tutorial, I’d like to show how you can create an accessible tabs widget using the :focus
pseudo-class in CSS.
Using :focus
The :focus
pseudo-class is used to target an element that has received focus by the user (either by using the keyboard or the mouse). It is supported in every browser including IE8+. Additionally, you can apply a :focus
state to any HTML element as long as you give it a tabindex
attribute.
Using the tabindex
Attribute
HTML’s tabindex
attribute indicates if an element can receive focus. It can take several values, including a negative value, zero, or a positive value. Each of these values determines what order an element should be focused on.
Demo for the Tabs Widget
See the Pen Pure CSS Tabs Widget by SitePoint (@SitePoint) on CodePen.
In the HTML, each tab is a button with the content for each tab inside of a paragraph element. Each paragraph element is hidden, then set to position: absolute
so that the content will display in the same area for each tab. The first button element has the autofocus
attribute, so that the first tab will be visible on the initial page load. Each tab is wrapped in a div, and each div is given a tabindex
value, which allows the <div>
to be focusable.
As for the CSS, each button is set to display: inline-block
, allowing for the tabs to appear side by side. We apply the :focus
psuedo-class to the button and use the adjacent sibling selector to show the related paragraph element when the button is focused. I’ve also added focus styles to the tab’s container div
, which means that the tab will keep its focused state until the user clicks outside the entire widget.
Caveats for the Tabs Widget
Because this widget depends on the :focus
psuedo-class, the tabbed content will be visible only when the tabs have a focused state. This means that the user will always have to click on a tab to see content. The autofocus
attribute does allow one of the tabs to be visible on initial page load, but as soon as the user interacts with the page, the focus will be lost.
Browser Support for the Tabs Widget
I’ve tested this in IE8, and everything works as expected, except for the autofocus
attribute, being that it’s an HTML5 feature. Chrome, Firefox, and Opera also work as expected, but the demo does not work in Safari unless the tab key is being used to apply focus. In the following demo the :focus
pseudo-class doesn’t work in any of the versions of Safari that I’ve tested, which I suspect is due to a WebKit bug. I haven’t found a way around this issue, but as long as the WebKit bug is addressed, this technique should work just fine when the user clicks on the tabs.
Overall, the :focus
pseudo-class can be a great way to add functionality to HTML and CSS, without having to invoke the use of JavaScript. If you enjoyed this demo, be sure to leave a comment, and more importantly, file a bug with Safari!
Building an Image Slider
If you need a simple static site with an image slider, a CSS only approach is a great way to keep your website fast an light. Let’s look at a quick example.
HTML and CSS for the Slider
We start with an outer container using a section
element with a class of slideshow
. Inside is a slideshow container where the images are placed. This slideshow also works with content other than images. To highlight that, we have a div
with a class of text-container
that is used to hold our non-image content.
The outermost container of the demo has a fixed width, and its overflow
property is set to “hidden”. The container inside of this, which holds our slide content, has a much larger width, so that the images and text content can be placed next to each other without wrapping to a new line. It’s important to note that this container has to be exactly as wide as our slide content, or else the slides won’t transition properly.
Using CSS Animation
The slide
class is where we apply the animation. The animation uses the translateX
property to drag the long row of content across the outer container, which forms a mask, simulating the transition of slides.
The animation timing is one of the most important factors here. To get an even number of seconds between slide transitions, we need to multiply our desired transition time by the number of slides in our slider. Here we have four slides, and our desired transition is six seconds per slide – so our animation time needs to be 24 seconds long before it repeats. The infinite repetition is controlled by the “infinite” value on the animation-iteration-count
property.
Setting up the Keyframes for this animation can be tedious. The goal is to get the animation to look like it pauses for each image, even though it never really does. To do this we need to define at least two empty keyframes per slide. This creates the pause effect, because the keyframes define key intervals in which the translateX
property does not update. You can see this in the demo on line 66 of the CSS.
As an added bonus, hovering over the slider will pause the animation. This is done by setting the animation-play-state
property to “paused” when targeting the slideshow-container
element’s :hover
state.
The Image Slider Demo
See the Pen Pure CSS Image Slider by SitePoint (@SitePoint) on CodePen.
Browser Support for the Image Slider
Works as expected in all browsers including IE10 and up!
Creating Icons with File Type Indicators
A while ago I was working on a WordPress site when I came across a potentially challenging design. In this case, different icons were needed to represent links based on their file types. This was a great time to present a JavaScript-free solution on a JavaScript-heavy website. The following demo shows how to get information from a block of HTML and display it with the CSS content
property.
HTML and CSS for the File Type Icons
In this demo, I’m using data attributes to display the type of file that the user will be redirected to when they click the link.
The CSS content
property takes as a value an attr()
function that allows us to get the value of our HTML data attribute. Using the ::after
pseudo-element, we create a small black bar that holds the tet in the content property, and we position it to display on the left side of our icon.
The CSS attr()
function represents an exciting part of the specification, but currently does not have any browser support for use outside of the content
property.
File Type Icons Demo
See the Pen File Type Icons with Data Attributes by SitePoint (@SitePoint) on CodePen.
Browser Support for the File Type Icons
I was surprised to find that this demo worked in every browser I tested it in, except for IE8 of course!
Conclusion
It’s becoming more common for developers to build things without JavaScript. These might not be great solutions for all use cases, but they’re options to consider and learning the concepts involved can deepen our understanding of CSS.