Sourcing from WordPress
Examples
This guide will walk you through the process of using Gatsby with WordPress and WPGraphQL.
WordPress is a free and open-source content management system (CMS). Let’s say you have a site built with WordPress and you want to pull the existing data into your static Gatsby site. You can do that with gatsby-source-wordpress. Let’s begin!
Note: this guide uses the gatsby-starter-default to provide you with the knowledge necessary to start working with WordPress but if you get stuck at some point of the guide feel free to use
this example to gain extra insights.
Setup
Quick start
This guide assumes that you have a Gatsby project set up along with a WordPress instance with the appropriate plugins. If you need to set up a Gatsby project, head to the Quick Start guide, then come back. For information on configuring your WordPress instance, checkout the docs before continuing.
gatsby-config.js
Essentially the Gatsby home base. The two things defined here initially (in the starter) are siteMetadata and plugins you can add to enable new functionalities on your site.
Gatsby Plugin: gatsby-source-wordpress
Now that you have some understanding of project structure let’s add fetching WordPress data functionality. There’s a plugin for that. gatsby-source-wordpress is Gatsby’s plugin for sourcing data from WordPress sites using the WPGraphQL API. You can install it by running the following command:
Configuring the plugin
In gatsby-config.js, add your WordPress site’s url, all other config is optional but recommended.
Note: If your config varies from what is shown above, for instance, if you are securing your WordPress instance with Basic Auth, please refer to the plugin docs for more information on how to set up other options required for your use case.
Using WordPress data
Once your source plugin is pulling data, you can construct your site pages by implementing the createPages API in gatsby-node.js. When this is called, your data has already been fetched and is available to query with GraphQL. Gatsby uses GraphQL at build time; Your source plugin (in this case, gatsby-source-wordpress) fetches your data, and Gatsby uses that data to ”automatically infer a GraphQL schema” that you can query against.
The createPages API exposes the graphql function:
The GraphQL function allows us to run arbitrary queries against the local WordPress GraphQL schema… like the site has a built-in database constructed from the fetched data that you can run queries against. (Source)
You can use the gatsby-node.js from the plugin demo to get started. For the purpose of this guide, the code to construct posts works out of the box. It queries your local WordPress GraphQL schema for all Posts, iterates through each Post node and constructs a static page for each, based on the defined template.
For example:
After fetching data from WordPress via the query, all posts are iterated over, calling createPage for each one.
A Gatsby page is defined as “a site page with a pathname, a template component, and an optional GraphQL query and Layout component.”
When you restart your server with the gatsby develop command, you’ll be able to navigate to the new pages created for each of your posts at their respective paths.
In the GraphiQL IDE at http://localhost:8000/__graphql you should now see queryable fields for allWpPosts in the docs or explorer sidebar.
Wrapping up
This was a very basic example meant to help you understand how you can fetch data from WordPress and use it with Gatsby. As the guide mentioned already, if you got stuck, you can have a look at example repo, which is a working example created to support this guide.