How to speed up incremental builds with Gatsby’s Slice API

Incremental builds are an important part of the development process for any Gatsby site. They allow you to make changes to your site and see the results in real time without having to wait for a full build to complete.

However, incremental builds can become slow if you have a large amount of data or a complex build process. This can be frustrating and hinder your productivity.

One way to speed up incremental builds with Gatsby is to use the new Slice API. In this article, we will explore Gatsby’s Slice API, including how to use it, what its advantages are, how it works under the hood, and more.

We will cover:

• Getting started with the Slice API in Gatsby
  • Defining a slice
  • Creating a slice component
  • Rendering the slice on a page
• Advantages of the Slice API
  • Breaking down and storing data
  • Comparing the Slice API to traditional Gatsby patterns
• Implementation tradeoffs to consider when using the Slice API
• Exploring the Gatsby Slice API under the hood

To follow this tutorial, it would help if you’re already familiar with incremental builds in Gatsby.

Getting started with the Slice API in Gatsby

The Slice API allows you to break down large amounts of data into smaller chunks, or “slices,” which can be loaded on demand. Slices can help improve your site’s performance by reducing the amount of data that needs to be processed during each build.

Before we dive in, note that the Slice API is only available from Gatsby 5. You will need to upgrade to v5 to use it or start a brand new Gatsby 5 project.

Defining a slice

To use the Slice API, you’ll first need to define a slice using a GraphQL query. This query specifies which fields should be included in the slice and how they should be filtered and sorted.

For example, let’s say you have a large collection of blog posts. If you want to create a slice for the most recent posts, you might define a query like this:

query RecentPostsSlice {
  allMdx(sort: {fields: frontmatter___date, order: DESC}, limit: 10) {
    nodes {
      frontmatter {
        title
        date
      }
      excerpt
    }
  }
}

Creating a slice component

Next, you’ll need to create a slice component that is responsible for rendering the slice. This component should receive the data for the slice as a prop, and use it to render the slice in any way you choose.

For example, you might create a RecentPosts component that renders a list of links to the most recent blog posts:

const RecentPosts = ({ data }) => (
  <ul>
    {data.allMdx.nodes.map((post, index) => (
      <li key={index}>
        <Link to={post.frontmatter.slug}>{post.frontmatter.title}</Link>
      </li>
    ))}
  </ul>
)

Rendering the slice on a page

To load the slice on a page, you can use the StaticQuery component, which allows you to specify a GraphQL query and a render function. The render function will receive the data for the slice as a prop, and you can use this data to render the slice on your page.

For example, you might use the RecentPosts component like this:

import { StaticQuery, graphql } from "gatsby"

const BlogSidebar = () => (
  <StaticQuery
    query={graphql`
      query RecentPostsSlice {
        allMdx(sort: {fields: frontmatter___date, order: DESC}, limit: 10) {
          nodes {
            frontmatter {
              title
              date
            }
            excerpt
          }
        }
      }
    `}
    render={data => <RecentPosts data={data} />}
  />
)

Using the Slice API in this way can help improve your site’s performance by reducing the amount of data that needs to be processed during each build. This can make incremental builds much faster, particularly if you have a large amount of data or a complex build process.

In addition to slicing data, the Gatsby Slice API also includes support for pagination, which can be useful if you have a large amount of data.

Advantages of the Slice API

Prior to the introduction of the Slice API, there were several other ways to optimize the performance of a Gatsby site. These options included lazy loading components, optimizing images, and using the gatsby-image plugin.

These approaches can help improve your site’s performance. However, they also have their respective limitations, and they do not provide a way to easily load large amounts of data on demand.

Breaking down and storing data

One of the main advantages of the Slice API is that it allows you to easily break down large amounts of data into smaller chunks that can be loaded on demand. This can be especially useful if you have a large amount of data that is not needed on every page.

By slicing data into smaller chunks, the Slice API allows you to only load the data that is needed, reducing the overall amount of data that needs to be processed.

Another advantage of the Slice API is that it provides built-in caching support. This can further improve performance by storing the results of GraphQL queries in a cache so they don’t have to be re-executed on every page load.

Comparing the Slice API to traditional Gatsby patterns

In comparison to the existing Layout Component and Page Component patterns, the Slice API comes first in terms of reusability, scalability, dynamic content, and performance.

The Slice API allows you to create reusable components that can be used across multiple pages, making it easier to maintain consistency in your design and reduce duplication of code.

It also helps you scale your website as your content needs change over time. You can add or remove components as needed without having to update your entire codebase.

Furthermore, Gatsby’s Slice API provides a more flexible way to handle dynamic content compared to the Page Component pattern and the Layout Component pattern. With the Slice API, you can easily retrieve and display data from your content management system.

Finally, the Slice API enables you to optimize your website’s performance by only loading the necessary components on each page. This results in faster page loads and a better user experience.

Implementation tradeoffs to consider when using the Slice API

One of the main tradeoffs of the Slice API is the lack of support for nested slice placeholders. This means that if you have a high-level component — like a layout that includes a slice — you cannot have other slice components within that layout.

This can limit the flexibility of your page layouts and require some extra workarounds to achieve certain designs.

Additionally, to use the Slice API, you need to follow a specific folder structure and naming conventions. This can take some getting used to and require you to restructure your existing codebase.

The Slice API also requires a deeper understanding of GraphQL fragments and queries, which can be more complex than the regular Gatsby pattern. You’ll also need to manage additional template files and slices, which can add some extra overhead to your development workflow.

Finally, there is a learning curve to using the Slice API, especially if you’re new to Gatsby or GraphQL. While it can be a powerful tool once you’re comfortable with it, it may take some time to get up to speed and start seeing the benefits.

Exploring the Gatsby Slice API under the hood

We’ve seen how and why to use the Slice API. Now, let’s take a look at how the Slice API works under the hood so we can better understand this useful tool.

When you use the Slice API to load data on a page, the data for the slice is only loaded when the page is rendered. This means that if you make a change to a shared component, only the pages that are currently being rendered will be rebuilt, rather than all the pages on your site.

For example, imagine you have a shared component called RecentPosts that displays a list of the most recent blog posts. Let’s say you then make a change to this component and rebuild your site.

In such a situation, only the pages that are currently being rendered will be rebuilt, rather than all the pages on your site. This can significantly reduce the time it takes to rebuild your site, particularly if you have a large number of pages.

Of course, there are still some situations where you may need to rebuild all the pages on your site, such as when you make a change to a shared component that is used on every page.

However, in most cases, the Slice API can help reduce the number of pages that need to be rebuilt, improving the performance and efficiency of your site.

Conclusion

We’ve discussed many reasons for using the Slice API. Let’s review some of the top reasons why I would recommend it to you.

The Gatsby Slice API is a feature that allows developers to build modular and reusable components in Gatsby projects.

Developers can create smaller, more focused components that can be easily reused throughout the site. This makes development more efficient, flexible, and maintainable while avoiding the need to repeat the same code over and over again.

Additionally, the Slice API allows for better separation of concerns in Gatsby projects. Developers can create components that are specific to a particular section or functionality of the site rather than having to create large, monolithic components that handle multiple responsibilities.

The Slice API works in Gatsby by allowing developers to create a component that exports a GraphQL query. This component can then be queried and composed by other components, making it easy to build modular and reusable components.

Furthermore, the Gatsby Slice API offers advantages over other patterns commonly used in Gatsby projects.

Finally, the Gatsby Slice API is relatively new and is expected to become more powerful in future releases, providing even more flexibility and ease of use.

Overall, the Slice API is a powerful tool for optimizing the performance of a Gatsby site, and it provides an easy way to load large amounts of data on demand, improving the speed and efficiency of your site.