From 3c7237169f14b0d1e867a5373d068f0591fb5864 Mon Sep 17 00:00:00 2001
From: =?UTF-8?q?S=C3=A9bastien=20Dubois?=
 <sedubois@users.noreply.github.com>
Date: Tue, 14 Feb 2017 18:31:50 +0200
Subject: [PATCH] ssr-caching: document way to configure cache key (#1133)

* ssr-caching: document way to configure cache key

* simplify comment
---
 examples/ssr-caching/server.js | 20 +++++++++++++++-----
 1 file changed, 15 insertions(+), 5 deletions(-)

diff --git a/examples/ssr-caching/server.js b/examples/ssr-caching/server.js
index 1d94c96d..1f16da64 100644
--- a/examples/ssr-caching/server.js
+++ b/examples/ssr-caching/server.js
@@ -36,11 +36,21 @@ app.prepare()
   })
 })
 
+/*
+ * NB: make sure to modify this to take into account anything that should trigger
+ * an immediate page change (e.g a locale stored in req.session)
+ */
+function getCacheKey (req) {
+  return `${req.url}`
+}
+
 function renderAndCache (req, res, pagePath, queryParams) {
+  const key = getCacheKey(req)
+
   // If we have a page in the cache, let's serve it
-  if (ssrCache.has(req.url)) {
-    console.log(`CACHE HIT: ${req.url}`)
-    res.send(ssrCache.get(req.url))
+  if (ssrCache.has(key)) {
+    console.log(`CACHE HIT: ${key}`)
+    res.send(ssrCache.get(key))
     return
   }
 
@@ -48,8 +58,8 @@ function renderAndCache (req, res, pagePath, queryParams) {
   app.renderToHTML(req, res, pagePath, queryParams)
     .then((html) => {
       // Let's cache this page
-      console.log(`CACHE MISS: ${req.url}`)
-      ssrCache.set(req.url, html)
+      console.log(`CACHE MISS: ${key}`)
+      ssrCache.set(key, html)
 
       res.send(html)
     })