From 37dbd7898c9c0baf9aec5073b757e3205a6a0c3d Mon Sep 17 00:00:00 2001
From: Mischa POSLAWSKY <perl@shiar.org>
Date: Thu, 26 Apr 2018 23:05:19 +0200
Subject: [PATCH] page: replace placeholders dynamically

Instead of substituting known variables, search contents for placeholders
for identical results but allowing for additional options.
---
 page.php | 22 ++++++++++++++--------
 1 file changed, 14 insertions(+), 8 deletions(-)

diff --git a/page.php b/page.php
index 76a99b5..c6eee87 100644
--- a/page.php
+++ b/page.php
@@ -10,14 +10,8 @@ function abort($body, $status = NULL) {
 
 function getoutput($blocks = [])
 {
-	$rep = [];
-	foreach ($blocks as $name => $html) {
-		$rep["[[$name]]"] = sprintf('<!--BLOCK:%s-->%s<!--/-->',
-			is_numeric($name) ? '' : "[[$name]]",
-			preg_replace('{<!--[^-]*-->}', '', $html)
-		);
-	}
 	$doc = ob_get_clean();
+
 	if (!empty($blocks['warn'])) {
 		$warn = '<p class="warn">[[warn]]</p>';
 		if ($offset = strpos($doc, '</h2>')) {
@@ -27,7 +21,19 @@ function getoutput($blocks = [])
 			$doc = $warn . "\n\n" . $doc;
 		}
 	}
-	return str_replace(array_keys($rep), array_values($rep), $doc);
+
+	return preg_replace_callback(
+		'< \[\[ ([^]]*) \]\] >x',
+		function ($sub) use ($blocks) {
+			list ($placeholder, $name) = $sub;
+			$html = $blocks[$name];
+			return sprintf('<!--BLOCK:%s-->%s<!--/-->',
+				is_numeric($name) ? '' : $placeholder, # edit replacement
+				preg_replace('{<!--[^-]*-->}', '', $html) # contents
+			);
+		},
+		$doc
+	);
 }
 
 # custom error handling
-- 
2.30.0