From b011f688332e8399135065f03590262799f98585 Mon Sep 17 00:00:00 2001
From: "Fernando G. Vilar" <dev@polygonal.tech>
Date: Fri, 27 Dec 2019 12:09:15 +0700
Subject: [PATCH 1/2] feat(template): support for arbitrary replacements

---
 .../src/server/middleware/get_page_handler.ts | 26 ++++++++++++++-----
 1 file changed, 20 insertions(+), 6 deletions(-)

diff --git a/runtime/src/server/middleware/get_page_handler.ts b/runtime/src/server/middleware/get_page_handler.ts
index 53f413640..db18c3c6c 100644
--- a/runtime/src/server/middleware/get_page_handler.ts
+++ b/runtime/src/server/middleware/get_page_handler.ts
@@ -320,12 +320,14 @@ export function get_page_handler(
 			// users can set a CSP nonce using res.locals.nonce
 			const nonce_attr = (res.locals && res.locals.nonce) ? ` nonce="${res.locals.nonce}"` : '';
 
-			const body = template()
-				.replace('%sapper.base%', () => `<base href="${req.baseUrl}/">`)
-				.replace('%sapper.scripts%', () => `<script${nonce_attr}>${script}</script>`)
-				.replace('%sapper.html%', () => html)
-				.replace('%sapper.head%', () => `<noscript id='sapper-head-start'></noscript>${head}<noscript id='sapper-head-end'></noscript>`)
-				.replace('%sapper.styles%', () => styles);
+			const body = replace(template(), {
+				...res.replacers,
+				base: () => `<base href="${req.baseUrl}/">`,
+				scripts: () => `<script${nonce_attr}>${script}</script>`,
+				html: () => html,
+				head: () => `<noscript id='sapper-head-start'></noscript>${head}<noscript id='sapper-head-end'></noscript>`,
+				styles: () => styles
+			});
 
 			res.statusCode = status;
 			res.end(body);
@@ -356,6 +358,18 @@ export function get_page_handler(
 	};
 }
 
+function replace(
+    template: string,
+    replacers: Record<string, string | CallableFunction>
+) {
+    for (const key in replacers) {
+        if (replacers.hasOwnProperty(key)) {
+            template = template.replace(`%sapper.${key}%`, replacers[key] as any);
+        }
+    }
+    return template;
+}
+
 function read_template(dir = build_dir) {
 	return fs.readFileSync(`${dir}/template.html`, 'utf-8');
 }

From a87102f1e8e6a982afb6af59e38655e40778f663 Mon Sep 17 00:00:00 2001
From: "Fernando G. Vilar" <dev@polygonal.tech>
Date: Fri, 27 Dec 2019 13:05:20 +0700
Subject: [PATCH 2/2] feat(template): allow multiple substitutions

---
 runtime/src/server/middleware/get_page_handler.ts | 2 +-
 1 file changed, 1 insertion(+), 1 deletion(-)

diff --git a/runtime/src/server/middleware/get_page_handler.ts b/runtime/src/server/middleware/get_page_handler.ts
index db18c3c6c..32cd6e93d 100644
--- a/runtime/src/server/middleware/get_page_handler.ts
+++ b/runtime/src/server/middleware/get_page_handler.ts
@@ -364,7 +364,7 @@ function replace(
 ) {
     for (const key in replacers) {
         if (replacers.hasOwnProperty(key)) {
-            template = template.replace(`%sapper.${key}%`, replacers[key] as any);
+            template = template.replace(new RegExp(`%sapper.${key}%`, 'g'), replacers[key] as any);
         }
     }
     return template;