add page context logic

packages/next/src/build/templates/app-route.ts

@@ -32,8 +32,12 @@ const routeModule = new AppRouteRouteModule({
 // Pull out the exports that we need to expose from the module. This should
 // be eliminated when we've moved the other routes to the new format. These
 // are used to hook into the route.
-const { requestAsyncStorage, staticGenerationAsyncStorage, serverHooks } =
-  routeModule
+const {
+  requestAsyncStorage,
+  staticGenerationAsyncStorage,
+  pageContextAsyncStorage,
+  serverHooks,
+} = routeModule
 
 const originalPathname = 'VAR_ORIGINAL_PATHNAME'
 
@@ -45,6 +49,7 @@ export {
   routeModule,
   requestAsyncStorage,
   staticGenerationAsyncStorage,
+  pageContextAsyncStorage,
   serverHooks,
   originalPathname,
   patchFetch,

packages/next/src/client/components/get-page-context.ts

@@ -0,0 +1,5 @@
+import { pageContextAsyncStorage } from './page-context-async-storage.external'
+
+export const getPageContext = <T>() => {
+  return pageContextAsyncStorage.getStore() as T
+}

packages/next/src/client/components/page-context-async-storage-instance.ts

@@ -0,0 +1,5 @@
+import type { PageContextAsyncStorage } from './page-context-async-storage.external'
+import { createAsyncLocalStorage } from './async-local-storage'
+
+export const pageContextAsyncStorage: PageContextAsyncStorage =
+  createAsyncLocalStorage()

packages/next/src/client/components/page-context-async-storage.external.ts

@@ -0,0 +1,10 @@
+import type { AsyncLocalStorage } from 'async_hooks'
+
+// Share the instance module in the next-shared layer
+import { pageContextAsyncStorage } from './page-context-async-storage-instance' with { 'turbopack-transition': 'next-shared' }
+
+export type PageStore = { [key: string]: unknown }
+
+export type PageContextAsyncStorage = AsyncLocalStorage<PageStore>
+
+export { pageContextAsyncStorage }

packages/next/src/server/app-render/app-render.tsx

@@ -11,7 +11,7 @@ import type {
 import type { StaticGenerationStore } from '../../client/components/static-generation-async-storage.external'
 import type { RequestStore } from '../../client/components/request-async-storage.external'
 import type { NextParsedUrlQuery } from '../request-meta'
-import type { LoaderTree } from '../lib/app-dir-module'
+import { getLayoutOrPageModule, type LoaderTree } from '../lib/app-dir-module'
 import type { AppPageModule } from '../future/route-modules/app-page/module'
 import type { ClientReferenceManifest } from '../../build/webpack/plugins/flight-manifest-plugin'
 import type { Revalidate } from '../lib/revalidate'
@@ -113,6 +113,7 @@ import {
 import { createServerModuleMap } from './action-utils'
 import { isNodeNextRequest } from '../base-http/helpers'
 import { parseParameter } from '../../shared/lib/router/utils/route-regex'
+import { PageContextAsyncStorageWrapper } from '../async-storage/page-context-async-storage-wrapper'
 
 export type GetDynamicParamFromSegment = (
   // [slug] / [[slug]] / [...slug]
@@ -1487,6 +1488,52 @@ export type AppPageRender = (
   renderOpts: RenderOpts
 ) => Promise<RenderResult<AppPageRenderResultMetadata>>
 
+async function getPage(treeArg: any): Promise<any> {
+  const [, parallelRoutes, { page }] = treeArg
+  const isPage = typeof page !== 'undefined'
+  if (isPage) {
+    const [mod] = await getLayoutOrPageModule(treeArg)
+    return mod
+  }
+  for (const key in parallelRoutes) {
+    const childTree = parallelRoutes[key]
+    const mod = await getPage(childTree)
+    if (mod) return mod
+  }
+}
+
+async function renderToHTMLOrFlightImplWrapper(
+  req: BaseNextRequest,
+  res: BaseNextResponse,
+  pagePath: string,
+  query: NextParsedUrlQuery,
+  renderOpts: RenderOpts,
+  baseCtx: AppRenderBaseContext,
+  requestEndedState: { ended?: boolean }
+) {
+  const pageModule = await getPage(renderOpts.ComponentMod.tree)
+
+  let data = null
+  if (typeof pageModule.createPageContext === 'function') {
+    data = await pageModule.createPageContext({ params: renderOpts.params })
+  }
+
+  return PageContextAsyncStorageWrapper.wrap(
+    renderOpts.ComponentMod.pageContextAsyncStorage,
+    data,
+    () =>
+      renderToHTMLOrFlightImpl(
+        req,
+        res,
+        pagePath,
+        query,
+        renderOpts,
+        baseCtx,
+        requestEndedState
+      )
+  )
+}
+
 export const renderToHTMLOrFlight: AppPageRender = (
   req,
   res,
@@ -1509,7 +1556,7 @@ export const renderToHTMLOrFlight: AppPageRender = (
           requestEndedState: { ended: false },
         },
         (staticGenerationStore) =>
-          renderToHTMLOrFlightImpl(
+          renderToHTMLOrFlightImplWrapper(
             req,
             res,
             pagePath,

packages/next/src/server/app-render/entry-base.ts

@@ -11,6 +11,7 @@ import LayoutRouter from '../../client/components/layout-router'
 import RenderFromTemplateContext from '../../client/components/render-from-template-context'
 import { staticGenerationAsyncStorage } from '../../client/components/static-generation-async-storage.external'
 import { requestAsyncStorage } from '../../client/components/request-async-storage.external'
+import { pageContextAsyncStorage } from '../../client/components/page-context-async-storage.external'
 import { actionAsyncStorage } from '../../client/components/action-async-storage.external'
 import { ClientPageRoot } from '../../client/components/client-page'
 import {
@@ -43,6 +44,7 @@ export {
   RenderFromTemplateContext,
   staticGenerationAsyncStorage,
   requestAsyncStorage,
+  pageContextAsyncStorage,
   actionAsyncStorage,
   createUntrackedSearchParams,
   createDynamicallyTrackedSearchParams,

packages/next/src/server/async-storage/page-context-async-storage-wrapper.ts

@@ -0,0 +1,21 @@
+import type { AsyncStorageWrapper } from './async-storage-wrapper'
+import type { PageStore } from '../../client/components/page-context-async-storage.external'
+import type { AsyncLocalStorage } from 'async_hooks'
+
+type PageContext = { [key: string]: unknown }
+
+export const PageContextAsyncStorageWrapper: AsyncStorageWrapper<
+  PageStore,
+  PageContext
+> = {
+  wrap<Result>(
+    storage: AsyncLocalStorage<PageStore>,
+    ctx: PageContext,
+    callback: (store: PageStore) => Result
+  ): Result {
+    // renderOpts.params
+    const store: PageStore = ctx
+
+    return storage.run(store, callback, store)
+  },
+}

packages/next/src/server/future/route-modules/app-route/module.ts

@@ -44,6 +44,7 @@ import { DynamicServerError } from '../../../../client/components/hooks-server-c
 
 import { requestAsyncStorage } from '../../../../client/components/request-async-storage.external'
 import { staticGenerationAsyncStorage } from '../../../../client/components/static-generation-async-storage.external'
+import { pageContextAsyncStorage } from '../../../../client/components/page-context-async-storage.external'
 import { actionAsyncStorage } from '../../../../client/components/action-async-storage.external'
 import * as sharedModules from './shared-modules'
 import { getIsServerAction } from '../../../lib/server-action-request-meta'
@@ -136,6 +137,11 @@ export class AppRouteRouteModule extends RouteModule<
    */
   public readonly staticGenerationAsyncStorage = staticGenerationAsyncStorage
 
+  /**
+   * A reference to the page context async storage.
+   */
+  public readonly pageContextAsyncStorage = pageContextAsyncStorage
+
   /**
    * An interface to call server hooks which interact with the underlying
    * storage.

packages/next/src/server/typescript/constant.ts

@@ -15,6 +15,7 @@ export const NEXT_TS_ERRORS = {
 export const ALLOWED_EXPORTS = [
   'config',
   'generateStaticParams',
+  'createPageContext',
   'metadata',
   'generateMetadata',
   'viewport',