From 7b955ef26a539c9c6155f4c8e38a172703bcaba3 Mon Sep 17 00:00:00 2001
From: =?UTF-8?q?Marek=20S=2E=20=C5=81ukasiewicz?= <marek@lukasiewicz.tech>
Date: Fri, 11 Oct 2024 15:39:14 +0200
Subject: [PATCH] Index wikilinks in frontmatter strings (#1000) (#1066)

---
 plugs/index/page_links.ts | 37 +++++++++++++++++++++++++++++++++++++
 website/YAML.md           | 24 +++++++++++++++++++++++-
 2 files changed, 60 insertions(+), 1 deletion(-)

diff --git a/plugs/index/page_links.ts b/plugs/index/page_links.ts
index bba0f6f4f..1d177bf6b 100644
--- a/plugs/index/page_links.ts
+++ b/plugs/index/page_links.ts
@@ -1,4 +1,5 @@
 import {
+  collectNodesOfType,
   findNodeOfType,
   renderToText,
   traverseTree,
@@ -206,6 +207,42 @@ export async function indexLinks({ name, tree }: IndexTreeEvent) {
         }
       }
     }
+
+    // Also index links used inside quoted frontmatter strings like "[[Page]]"
+    // must match the full string node, only allowing for quotes and whitespace around it
+    if (n.type === "FrontMatter") {
+      // The YAML in frontmatter is parsed by CodeMirror itself
+      for (const textNode of collectNodesOfType(n, "string")) {
+        const text = textNode.children![0].text!;
+        const trimmed = text.replace(/^["'\s]*/, "").replace(/["'\s]*$/, "");
+        // Make sure we search from the beginning, when reusing a Regex object with global flag
+        wikiLinkRegex.lastIndex = 0;
+        const match = wikiLinkRegex.exec(text);
+        // Search in entire node text to get correct position, but check for full match against trimmed
+        if (match && match[0] === trimmed) {
+          const [_fullMatch, firstMark, url, alias, _lastMark] = match;
+          const pos = textNode.from! + match.index! + firstMark.length;
+          const link: any = {
+            ref: `${name}@${pos}`,
+            tag: "link",
+            page: name,
+            snippet: extractSnippetAroundIndex(pageText, pos),
+            pos: pos,
+            asTemplate: false,
+          };
+          if (looksLikePathWithExtension(url)) {
+            link.toFile = resolvePath(name, url);
+          } else {
+            link.toPage = resolvePath(name, parsePageRef(url).page);
+          }
+          if (alias) {
+            link.alias = alias;
+          }
+          updateITags(link, frontmatter);
+          links.push(link);
+        }
+      }
+    }
     return false;
   });
 
diff --git a/website/YAML.md b/website/YAML.md
index 12f575c71..88ddedbc7 100644
--- a/website/YAML.md
+++ b/website/YAML.md
@@ -1,3 +1,25 @@
 YAML stands for “YAML Ain’t Markup Language.” More information can be found at [the YAML website](https://yaml.org/).
 
-SilverBullet uses YAML in various contexts, specifically [[Frontmatter]].
\ No newline at end of file
+SilverBullet uses YAML in various contexts, specifically [[Frontmatter]] and [[Space Config]]
+
+# Internal links
+Many string values can be written directly in YAML without any quoting, like:
+```yaml
+property: value
+```
+
+However when you want to reference [[Links|a page]] or [[Command links|command]] you will need to quote the full link:
+```yaml
+some page: "[[Pages]]"
+list of pages:
+  - "[[Pages]]"
+  - "[[Links]]"
+```
+
+This is because the square brackets used in the internal link format have a meaning in YAML as well. So an unquoted link is parsed as list inside a list:
+```yaml
+some page: [[Pages]]
+equivalent yaml: [
+    [ "Pages" ]
+]
+```