This project uses the Prismic content management system (CMS), which is a headless CMS service that provides an API for querying content written by content authors. Prismic allows you to define custom types, which are named collections of fields describing some piece of content.
We also use the gatsby-source-prismic plugin for integrating Gatsby with Prismic. Because gatsby-source-prismic needs to understand the fields available on each custom type, there are a few extra steps we must take when adding a custom type in Prismic.
This guide assumes that you have already created the custom type in the Prismic user interface.
When adding or modifying a Prismic custom type, there is a JSON representation of the schema of that type. In the Prismic custom type editor interface, you can access the JSON schema by clicking on the JSON editor tab on the far right side of the page.
Copy and paste the JSON data into src/schemas, using a file name that matches
the custom type’s API ID (generally the name of the type in snake_case). For
example, if the API ID is blog_post, copy the JSON schema to
src/schemas/blog_post.json.
Then update gatsby-config.js to point to this new file.
This will go under the gatsby-source-prismic plugin options, under schemas.
Next, you may need to update the link resolver function. The link resolver
is a JavaScript function that is accepts a Prismic document as an argument and
returns the URL on this website corresponding to that document. For example, if
the link resolver is provided a document corresponding to a blog post with an ID
of hello-world, we may want to resolve that to /blog/hello-world.
When adding a custom type that corresponds to a new page, you must update the
linkResolver() function in
src/utils/linkResolver.js. Note that you may not
need to do this for custom types that do not correspond to new pages but that
are present across many pages, such as the site footer.