Preparing the list of pages for static generation or export in JSS Next.js apps

Current version: 22.x

The Next.js JSS app has a single dynamic catch-all route. Without some assistance, the application does not know which page you are accessing. To inform the application about the available paths for dynamic routes, the routes must implement and export the GetStaticPaths function.

GetStaticPaths and the sitemap fetcher

The function GetStaticPaths is responsible for identifying which paths/pages to fetch data for and prerender based on the received data.

The function uses an instance of the SitecoreSitemapFetcher class, defined in the src/lib/sitemap-fetcher.ts file, that gathers the list of available paths for the route, as follows:

  • In disconnected development mode, the SitemapFetcher instance, through an instance of the DisconnectedSitemapService, generates the list of pages using a ManifestInstance.

    The Manifest file is stored in sitecore/manifest/sitecore-import.json , and it can be generated by running the JSS CLI command jss manifest or starting the Next.js application with the scripts jss start or jss start:disconnected-proxy. The DisconnectedSitemapService iterates over the manifest routes and generates all the paths for prerendering. You do not have prerendered pages because getStaticPaths runs on every request.

  • In production mode, the SitemapFetcher instance uses an instance of GraphQLSitemapService or MultisiteGraphQLSitemapService to fetch the paths for prerendering.

The GraphQL sitemap services

The sitemap fetcher can use one of the two available GraphQL sitemap services:

  • The MultisiteGraphQLSitemapService (if the app has the Next.js Multisite add-on).

  • The GraphQLSitemapService (without the Next.js Multisite add-on).

The sitemap services fetch the list of site paths from Sitecore GraphQL endpoints for one or multiple sites (if using the Next.js Multisite add-on). The services are commonly used in conjunction with a GetStaticPaths implementation. Next.js uses the list of paths to fetch data for Static Generation and Export functionality.

Configuration

In the sample application, in /src/lib/sitemap-fetcher/plugins/graphql-sitemap-service.ts , you can inspect and modify the default SitecoreSitemapFetcher configuration.

The service comes preconfigured with:

  • endpoint - from temp/config.graphQLEndpoint.

  • apiKey - from temp/config.sitecoreApiKey.

  • When using the Multisite add-on, a sites list from the Multisite site resolver plugin. Otherwise siteName - from temp/config.jssAppName.

Functions and process

Both sitemap services extend the BaseGraphQLSitemapService class, exposing the methods fetchSSGSitemap and fetchExportSitemap.

For static export, the base service uses fetchExportSitemap. Because static export does not support multilingual apps, this function accepts one language and only runs GraphQL queries for that language.

For static generation (SG), it uses fetchSSGSitemap. This function accepts an array of supported languages. It includes the locale property because the sample application enables internationalization by default. It runs a GraphQL query for each language.

When you invoke fetchSSGSitemap/fetchExportSitemap, the service runs the following steps:

  • It fetches items using the provided locale.

  • It merges loaded items in the correct format for SG or static HTML export.

Queries

You can replace the default GraphQL query used by the GraphQL Sitemap Service to fetch items and generate the sitemap with a custom query. To do so, extend the GraphQLSitemapService class, overriding the fetchSitemap method used internally by fetchSSGSitemap and fetchExportSitemap.

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