This Gatsby post was written for Gatsby 3 and is no longer maintained. If you would like to try out SvelteKit or Astro, check out the maintained posts which are based on those. Astro lets you continue to use React but also with partial hydration which can be used to provide an enhanced user experience. SvelteKit offers server side rendering as well as static site generation. See the post on how performance improved switching from Gatsby to Astro for more background.
😕 Why Build a CSS only Carousel in Gatsby? #
Let's build a CSS only Carousel in Gatsby. We are going to add a slider which stops at discrete positions (snap feature). As well as that, we will give it a little flip animation. We will do all of that using CSS. On top, we take the new Gatsby Image Plugin out for a spin.
Why build a CSS only Carousel in Gatsby? I thought this might be something interesting for anyone new to Gatsby and React, but with some web development experience with other technologies. Although there is nothing to fear in React, this guide will help you ease into React. However, even if you are already a Gatsby pro and can code this all up using advanced React features, you might appreciate the opportunity to step back and simplify your Gatsby logic, letting CSS do some heavy lifting and hopefully make the page more efficient.
The carousel is such a useful pattern to add to your toolkit. It's probably best known for its use on online stores, letting you flip through a catalogue of products. It is not only useful for e-commerce sites, though. Even if a package like flickity is your current first choice for an image gallery slider. A CSS only carousel is an alternative which doesn't need extra dependencies. Basically, the pattern can be used anywhere where you have a number of items you want to present using a limit screen footprint.
🧱 What are we Building? #
We will use a carousel to showcase recent projects on the home page of an MDX photography blog. The smooth-sliding carousel serves up a hero image for each project. On hover (or tap for mobile), a nice flip animation reveals some project details. We do all of that in CSS, using gatsby-image-plugin for the responsive images. Here's a short video of our CSS only carousel in action:
🔧 What Tools are we Using #
- Gatsby v3 : to make the site blazing fast.
- gatsby-plugin-image : optimal image sizing, plus automatically generated AVIF and WebP images.
- gatsby-starter-climate : this gives us a minimal Gatsby v3 MDX blog site to add the carousel to. It also saves us having to write a bit of boilerplate code.
🖥 CSS only Carousel in Gatsby: Let’s get Cracking #
To speed things up, we’ll use a Gatsby 3 MDX Blog starter . To begin, clone the repo from GitHub and fire up Gatsby from the terminal:
Have a quick look through the folders just to get used to the setup. Once you have a feel for it,
we'll carry on. OK, let’s do this! We'll warm up with some Gatsby before getting into the
CSS. Create a new Projects
component in src/components/Projects.jsx
:
This is a basic shell for the component. We need to define a few bits and pieces before we wire it
up. First, though, let's have a quick look at the GraphQL queries. In lines 98
– 110
we define a fragment which we can use
on any page we place the component on. We'll see that later. You'll note it includes another fragment
— the ProjectCarouselFragment
— no fewer than three times!
This illustrates one practical use of fragments. You can see that fragment's code above. Its body is
eight lines long. Defining the fragment once and then referencing it when we need it saves us writing
those eight lines over and over. On top, if we need to change anything in the query we just change
it once, so the code is more robust using fragments. You can learn more about Gatsby GraphQL Fragments in the Gatsby docs .
Gatsby Plugin Image #
The ProjectCarouselFragment
uses the new Gatsby Image Plugin API. This
creates an image object from the file. In the component body (lines 97–103) we will render the
image. Note the inclusion of width
and height
attributes. Generally this is best practice as it gives the user's browser an earlier indication
of the image aspect ratio. Including these can help reduce cumulative layout shift as the page loads. You will need to download three images (camera-restoration-project.jpg , film-lab-project.jpg and film-exchange-project.jpg ) and save them to a new folder: src/images
.
I downsized the images and optimized them locally before uploading, so they are ready for you to use. Even though gatsby-plugin-image can optimize images, it is best practice to do some work yourself. This reduces the size of your repo and also speeds up site build. The images are 1344 pixels wide, this is double the widest display width needed. I use double because of the way Retina works. Some stock images are huge, so be sure to downsize before using them.
There are some defaults for gatsby-pluin-image already set in gatsby-config.js
(lines 92
– 113
). This saves us having to repeat them in each GraphQL query.
Gatsby Config #
To be able to access the images in the GraphQL query, we need to update our gatsby-config.js
file:
Next, let’s start an SCSS file for the Project component:
Extra Icons #
Then, finally, we add some missing icons to src/components/Icons.jsx
. Add these to the existing icons:
Fire it up #
We should now be able to get the component rendered to the home page, once we wire it up. Edit src/pages/index.jsx
:
There's nothing fancy here, I think it's self-explanatory, but let me know if it is not. Just
note, we have used the ProjectsFragment
defined earlier. It was not
at all necessary to use a fragment. I just wanted to show that fragments can be used outside the files
they are defined in. As an aside, with Gatsby v3, you can now use fragments in GraphiQL.
If you have Gatsby running in develop mode, you should now have the component rendered on the home page. The images aren't in a carousel yet, but that will come next.
CSS only Carousel in Gatsby: Styling Time #
This is supposed to be a CSS only carousel in Gatsby, so let’s break out the CSS. Just before that, we will update the Projects component. We'll put all the CSS classes in now, so we can see the page blossom as we crank out the CSS.
I have added a bit of new code here, so let's run through the logic. I have based the
implementation off a Chris Coyier post written to show how far HTML and CSS can take you . You might have noticed before that each of the images was given an id
tag on their parent element. Interestingly, even if the images are in a carousel, we can jump to
any image and have it show, front and centre in the carousel using default browser behaviour. See the
post on using Scroll to Anchor for some background on how IDs and hashes work together.
The logic in lines 92
– 100
gets the current hash from the browser window location. We need this because we are not using React
to track the carousel's state. We have a check that the code is running in a browser (and not on the
server as it does during build). Without this check, we will run the site fine in develop mode, but
get errors when we try to build. As this check is something that might be needed in other components,
we will define it in a utilities file later.
Accessibility #
There are a few accessibility attributes to improve user experience. The tabIndex
in line 109 allows users to focus the carousel by tabbing to it. Once focussed, users can scroll
through carousel slides using the keyboard. I learned about aria-current
(line 135) from the University of Twitter via a Wes Bos question answered by Scott Vinkle. It is
used here on the dots below the carousel. There is a visual indication of which slide is selected (red,
instead of blue dot), aria-current
is used to communicate that message to assistive technology .
Just before we go on to flesh out the CSS, we should define our isBrowser
utility function, which we mentioned previously. Create a new utilities
folder in /src
and add a utilities.js
file to it:
CSS only Carousel in Gatsby: CSS Time #
Finally, it's time to put the CSS into our CSS only carousel in Gatsby. We will do this in three phases:
- carousel slider with animation;
- flip animation; and
- add responsive support.
If you are short on time, just paste the three main chunks of highlighted code below, one after the other, into your editor (ignore the short alternative implementation block).
CSS only Carousel in Gatsby: Carousel Slider and Animation #
Add the code below to src/components/Projects.module.scss
to add
the carousel animations.
Now you should have something which looks more like a carousel. If you click a blue dot below the image, you should trigger a slide transition. Look in your browser address bar, and you will see a hash has been tacked on the end of the address.
CSS only Carousel in Gatsby: What Have we Got Here? #
A few things to note in the CSS. We set smooth scrolling in line 3. This improves the UX. Motion
is slow, so it’s probably not necessary to consider coding up a prefers-reduced-motion
alternative. The scroll-padding-top
setting in the next line helps
make sure the entire slide is visible when the user clicks one of the dots. There is an alternative,
which was not working in this case in Chrome or Safari, but did work in Firefox:
You might try it elsewhere, depending on your use case. It has the advantage of not having to apply the style to the entire HTML section of the DOM.
The scroll-snap-type: x mandatory
in line 43 ensures the slider stops
at discrete positions which line up with the slides. This is the behaviour in Chrome and Firefox.
I would say the best way to understand what the other lines of CSS do is to play around with them.
Much customisation is possible. When applying this code to your own site, be careful with the contrast
levels of the overlay text against the background. To maintain accessibility, you might want to add
a linear gradient over the image. I am playing around with some Rust code to check overlay text / image contrast but this is still in its infancy.
If you’re ready, let’s move on to look at the flip animation.
CSS only Carousel in Gatsby: Slide Flip Animation #
Next, we add a flip animation to the carousel. Each project has a little summary detail, already
included in the React component (but not yet visibly rendered). When we hover over a slide, it
will flip, revealing the project details. Add the code below to the end of src/components/Projects.module.scss
to add the carousel animations.
Let me know if there is anything in there I should add an explanation for. This flip animation
is not rendering correctly in Safari at the moment, so I have included some CSS to disable the
flip on hover (lines 140
– 144
), just for Safari. The block at the
end is kind of related to the carousel styling, it hides the dots where scroll-snap-type is not
supported.
CSS only Carousel in Gatsby: Mobile Friendly #
The last bit is probably the most important. We add a little CSS to make sure the code is
responsive and mobile users have fantastic UX too. Update the code in src/components/Projects.module.scss
to match this:
Mission Accomplished! #
That's it! What do you think of the CSS only carousel in Gatsby? I think this is the first component I have coded where there are more lines of CSS code than JSX 😀. It started out as a much shorter post, but I wanted to flesh it out to a fully featured, real-world example, so it would have more practical use. Thanks for following all the way through to the end 🙏🏽.
Share your own CSS only carousel in Gatsby implementation on Twitter. Use the #askRodney
hashtag, so you can find other coders' work too.
🙏🏽 Feedback #
How did you find this guide? What extensions do you want to implement on your CSS only carousel in Gatsby? Let me know if I should do a follow-up post on using React to mirror the carousel state. If you do this, you can synchronize elements outside the slider. As an example, scroll down to the bottom of this page to the “Similar Posts” block. You will see that if you scroll, the orange dot indicator tracks the current slide (this only works in reverse, i.e. click dot and slide changes in the CSS only version). On top, the post title shortcuts are synchronized. I will write a post on how to build that extra level of interaction if you are interested.
Have you found this post useful? I do hope it was easy enough to follow. Please let me know in any case. I would love to know your thoughts on the starter. Did it save you a bit of time by not having, firstly, to code a whole website from scratch to try out this code? Was it easy to download and start with Gatsby v3? Also, get in touch if you have ideas for posts showing other new Gatsby v3 features. If you have found this post useful and can afford even a small contribution, please consider supporting me through Buy me a Coffee.
Finally, feel free to share the post on your social media accounts for all your followers who will find it useful. You can get in touch via @askRodney on Twitter and also askRodney on Telegram . Also, see further ways to get in touch with Rodney Lab. We post regularly on online privacy and security, as well as Gatsby v3. Also, subscribe to the newsletter to keep up-to-date with our latest projects.