feat: add caching layer with ISR and unstable_cache for improved performance (#1441)

* feat: add ISR configuration to page files

Add revalidate exports to enable Incremental Static Regeneration:
- Homepage and events: 12 hours (43200s)
- Podcast and members pages: 24 hours (86400s)

* feat: add unstable_cache to events data fetching

Wrap getEvents with unstable_cache for 12-hour caching with 'events' tag.

* feat: add unstable_cache to sponsors data fetching

Wrap getSponsors with unstable_cache for 24-hour caching with 'sponsors' tag.
Also fix null safety issue when sponsor.tier is null.

* feat: add unstable_cache to podcast data fetching

Wrap getEpisodes, getEpisode, and getTranscript with unstable_cache
for 24-hour caching with 'podcast' tag.

* feat: add unstable_cache to members data fetching

Wrap getMembers with unstable_cache for 24-hour caching with 'members' tag.

* feat: add tag-based revalidation to cache route

Support revalidating by cache tag in addition to path:
- /_cache?tag=events - invalidates events cache
- /_cache?tag=sponsors - invalidates sponsors cache
- /_cache?tag=podcast - invalidates podcast cache
- /_cache?tag=members - invalidates members cache

* Add path type parameter

* update type

* add revalidate to a few more

---------

Co-authored-by: Dan Ott <[email protected]>

Author: JoeKarow

src/app/%5Fcache/route.ts

@@ -1,19 +1,29 @@
 import { type NextRequest } from 'next/server';
-import { revalidatePath } from 'next/cache';
+import { revalidatePath, revalidateTag } from 'next/cache';
 import { redirect } from 'next/navigation';
 
 export const dynamic = 'force-dynamic';
 
 export async function GET(request: NextRequest) {
 	const searchParams = request.nextUrl.searchParams;
-	const queryparam = searchParams.get('path');
-	let path = typeof queryparam === 'string' ? queryparam : '/';
+	const tagParam = searchParams.get('tag');
+	const pathParam = searchParams.get('path');
+	const pathTypeParam = searchParams.get('pathType');
+
+	// Handle tag-based revalidation if provided
+	if (tagParam) {
+		revalidateTag(tagParam);
+	}
+
+	// Handle path-based revalidation if provided
+	let path = typeof pathParam === 'string' ? pathParam : '/';
 	if (!path.startsWith('/')) {
 		path = '/' + path;
 	}
 
-	// Invalidate the /posts route in the cache
-	revalidatePath(path);
+	if (pathParam) {
+		revalidatePath(path, pathTypeParam === 'layout' ? 'layout' : 'page');
+	}
 
 	redirect(path);
 }

src/app/(simple-mdx)/[...slug]/page.tsx

@@ -9,6 +9,9 @@ import { MDXProps } from 'mdx/types';
 import { Metadata } from 'next';
 import { notFound } from 'next/navigation';
 
+// ISR: Revalidate every 24 hours
+export const revalidate = 86400;
+
 export function generateStaticParams() {
 	const allFiles = loadMdxDirectory({
 		baseDirectory: 'content/simple-mdx-pages',

src/app/events/page.tsx

@@ -9,6 +9,9 @@ import { Google } from '@/svg/calendar/Google';
 import { Outlook } from '@/svg/calendar/Outlook';
 import { Ics } from '@/svg/calendar/Ics';
 
+// ISR: Revalidate every 12 hours
+export const revalidate = 43200;
+
 export const metadata = createMetaData({
 	title: 'Virtual Coffee Community Events',
 	description: 'See our upcoming events!',

src/app/join/page.tsx

@@ -2,6 +2,9 @@ import DefaultLayout from '@/components/layouts/DefaultLayout';
 import { createMetaData } from '@/util/createMetaData.server';
 import Link from 'next/link';
 
+// ISR: Revalidate every 24 hours
+export const revalidate = 86400;
+
 export const metadata = createMetaData({
 	title: 'Join Virtual Coffee',
 	description: `Virtual Coffee is an intimate community that welcomes people at all stages of their tech journey.`,

src/app/join/thank-you/page.tsx

@@ -1,5 +1,8 @@
 import DefaultLayout from '@/components/layouts/DefaultLayout';
 
+// ISR: Revalidate every 24 hours
+export const revalidate = 86400;
+
 export const metadata = {
 	title: 'Membership Form Received!',
 	description: `You're now on the membership waiting list!`,

src/app/members/page.tsx

@@ -10,6 +10,9 @@ import 'leaflet/dist/leaflet.css';
 import { Suspense } from 'react';
 import { MapLoader, MapLoaderDev } from './map-loader';
 
+// ISR: Revalidate every 24 hours
+export const revalidate = 86400;
+
 export const metadata = createMetaData({
 	title: 'Virtual Coffee Members',
 	description: 'Meet our amazing members!',

src/app/monthlychallenges/page.tsx

@@ -3,6 +3,9 @@ import { getTotalPairingSessions } from '@/data/monthlyChallenges/pairing-challe
 import { createMetaData } from '@/util/createMetaData.server';
 import Link from 'next/link';
 
+// ISR: Revalidate every 24 hours
+export const revalidate = 86400;
+
 export const metadata = createMetaData({
 	title: 'Virtual Coffee Monthly Challenges',
 	description:

src/app/page.tsx

@@ -11,6 +11,9 @@ import { getNewsletters } from '@/data/newsletters';
 import { getSponsors } from '@/data/sponsors';
 import { homePageLinks } from '@/util/homePageLinks';
 
+// ISR: Revalidate every 12 hours
+export const revalidate = 43200;
+
 export default async function Home() {
 	const resources = loadMdxDirectory({
 		baseDirectory: 'content/resources',

src/app/podcast/[slug]/page.tsx

@@ -10,6 +10,9 @@ import { sanitizeCmsData } from '@/util/sanitizeCmsData';
 import createCmsImage from '@/util/cmsimage';
 import { Metadata } from 'next';
 
+// ISR: Revalidate every 24 hours
+export const revalidate = 86400;
+
 export async function generateStaticParams() {
 	const podcastEpisodes = await getEpisodes({ limit: 99 });
 

src/app/podcast/page.tsx

@@ -6,6 +6,9 @@ import { getEpisodes } from '@/data/podcast';
 import { createMetaData } from '@/util/createMetaData.server';
 import createCmsImage from '@/util/cmsimage';
 
+// ISR: Revalidate every 24 hours
+export const revalidate = 86400;
+
 export const metadata = createMetaData({
 	title: 'Virtual Coffee Podcast',
 	description: