Using slots to build layout in Astro

Coming from frameworks like NuxtJS and NextJS, I always liked the layout feature. You basically write a new component, add some original content to it and add a layout which contains all the mutual components like headers, footers and such.

When I first started learning Astro, I didn’t directly see a way to realise this. Astro feels a lot more like writing super-powered HTML, which is nice, but I hated to re-import my header component in every page.

After some time experimenting somewhat more with Astro, I actually understood that this was possible, it’s just a different way of approach then NuxtJS which I’m so used to.

Building Layouts in NuxtJS

Building layouts in Nuxt is really easy (or I’m just very used to it). There’s a layouts folder in which you create a new file

<template>
  <div>
    <TheHeader />
    <Nuxt />
    <!-- The page content will then go here -->
    <TheFooter />
  </div>
</template>

If the Nuxt layout component was named Default.vue you can just add layout: 'default in a page to use the layout. The <Nuxt /> element will then be replaced by the <template> contents of your page Vue template.

<template>
  <main>
    <h1>Look ma, a layout</h1>
    <p>works great right?</p>
  </main>
</template>

<script>
  export default {
    layout: "default",
  };
</script>

It’s an easy way to define and use templates and layouts and I actually got quite familiar with it, which is (I think) why I never used it before in Astro.

The Astro way

In Astro, it’s actually quite simple to also do this, you just gotta forget what you know about other frameworks.

Define a layout

Let’s define a new Astro template in the /src/layouts folder and call it Default.astro. In this template, we make use of the Astro <slot /> component to tell Astro where to render in the content of our page. Every page will then ofcourse have different content, with a shared <YourHeadComponent />, <YourHeaderComponent /> and <YourFooterComponent />.

---
import YourHeadComponent from "../components/layout/Head.astro";
import YourHeaderComponent from "../components/layout/Header.astro";
import YourFooterComponent from "../components/layout/Footer.astro";
---

<html lang="en">
  <head>
    <YourHeadComponent />
  </head>
  <body>
    <YourHeaderComponent />
    <slot />
    <!-- The page will render it's content here -->
    <YourFooterComponent />
  </body>
</html>

Make a page use a layout

To then also use the layout we defined above, we just have to create a new page in the /src/pages folder and import our <DefaultLayout> component we just defined.

---
import DefaultLayout from "../layouts/Default.astro";
---

<DefaultLayout>
  <main>
    <h1>Look ma, a layout</h1>
    <p>works great right?</p>
  </main>
</DefaultLayout>