[aur-dev] [PATCH 1/4] Convert markdown codeblocks to HTML code blocks

[Marcel Korpel]

Only codeblocks delimited with ```<newline> are supported.

Signed-off-by: Marcel Korpel <marcel.korpel at gmail.com>
---
 web/lib/aur.inc.php | 49 +++++++++++++++++++++++++++++++++++++++----------
 1 file changed, 39 insertions(+), 10 deletions(-)

diff --git a/web/lib/aur.inc.php b/web/lib/aur.inc.php
index 411d5ee..4b1850f 100644
--- a/web/lib/aur.inc.php
+++ b/web/lib/aur.inc.php
@@ -596,7 +596,8 @@ function comment_by_id($comment_id) {
 }
 
 /**
- * Process submitted comments so any links can be followed
+ * Process submitted comments so any links can be followed and
+ * parse markdown code blocks (within ```<newline>)
  *
  * @param string $comment Raw user submitted package comment
  *
@@ -605,23 +606,51 @@ function comment_by_id($comment_id) {
 function parse_comment($comment) {
 	$url_pattern = '/(\b(?:https?|ftp):\/\/[\w\/\#~:.?+=&%@!\-;,]+?' .
 		'(?=[.:?\-;,]*(?:[^\w\/\#~:.?+=&%@!\-;,]|$)))/iS';
+	$md_codeblock_delimiter = '/(```)\R/';
+	$md_codeblock_active = false;
 
-	$matches = preg_split($url_pattern, $comment, -1,
+	$blocks = preg_split($md_codeblock_delimiter, $comment, -1,
 		PREG_SPLIT_DELIM_CAPTURE);
 
 	$html = '';
-	for ($i = 0; $i < count($matches); $i++) {
+	for ($i = 0; $i < count($blocks); $i++) {
 		if ($i % 2) {
-			# convert links
-			$html .= '<a href="' . htmlspecialchars($matches[$i]) .
-				'">' .	htmlspecialchars($matches[$i]) . '</a>';
-		}
-		else {
-			# convert everything else
-			$html .= nl2br(htmlspecialchars($matches[$i]));
+			// add start/end of code block
+			if ($md_codeblock_active) {
+				$html .= '</code></pre><p>';
+				$md_codeblock_active = false;
+			} else {
+				$html .= '</p><pre><code>';
+				$md_codeblock_active = true;
+			}
+		} else {
+			if ($md_codeblock_active) {
+				// do not convert code blocks (white-space and newlines are
+				// preserved)
+				$html .= htmlspecialchars($blocks[$i]);
+			} else {
+				$matches = preg_split($url_pattern, $blocks[$i], -1,
+					PREG_SPLIT_DELIM_CAPTURE);
+
+				for ($j = 0; $j < count($matches); $j++) {
+					if ($j % 2) {
+						// convert links
+						$html .= '<a href="' . htmlspecialchars($matches[$j]) .
+							'">' .	htmlspecialchars($matches[$j]) . '</a>';
+					} else {
+						// convert everything else
+						$html .= nl2br(htmlspecialchars($matches[$j]));
+					}
+				}
+			}
 		}
 	}
 
+	// close possible open code block
+	if ($md_codeblock_active) {
+		$html .= '</code></pre><p>';
+	}
+
 	return $html;
 }
 
-- 
2.4.5