From c1bc529986f723f8bb06feedfbdc98520763ceb9 Mon Sep 17 00:00:00 2001
From: Laurenz <laurmaedje@gmail.com>
Date: Mon, 20 Nov 2023 18:31:23 +0100
Subject: [PATCH] Support arbitrary content for document title

For PDF, they will be immediately turned into plain text. However, it's still useful because templates can now accept content titles (with math or such things) instead of forcing strings because of set document. Moreover, it will be useful with "get rules" in the future.
---
 crates/typst-library/src/meta/document.rs | 9 ++++++---
 tests/typ/meta/document.typ               | 6 +++---
 2 files changed, 9 insertions(+), 6 deletions(-)

diff --git a/crates/typst-library/src/meta/document.rs b/crates/typst-library/src/meta/document.rs
index f6ff6812e..581be60c2 100644
--- a/crates/typst-library/src/meta/document.rs
+++ b/crates/typst-library/src/meta/document.rs
@@ -13,7 +13,7 @@ use crate::prelude::*;
 /// rule must appear before any of the document's contents.
 ///
 /// ```example
-/// #set document(title: "Hello")
+/// #set document(title: [Hello])
 ///
 /// This has no visible output, but
 /// embeds metadata into the PDF!
@@ -25,7 +25,10 @@ use crate::prelude::*;
 pub struct DocumentElem {
     /// The document's title. This is often rendered as the title of the
     /// PDF viewer window.
-    pub title: Option<EcoString>,
+    ///
+    /// While this can be arbitrary content, PDF viewers only support plain text
+    /// titles, so the conversion might be lossy.
+    pub title: Option<Content>,
 
     /// The document's authors.
     pub author: Author,
@@ -90,7 +93,7 @@ impl LayoutRoot for DocumentElem {
 
         Ok(Document {
             pages,
-            title: self.title(styles),
+            title: self.title(styles).map(|content| content.plain_text()),
             author: self.author(styles).0,
             keywords: self.keywords(styles).0,
             date: self.date(styles),
diff --git a/tests/typ/meta/document.typ b/tests/typ/meta/document.typ
index 43e4ca399..33c15dbce 100644
--- a/tests/typ/meta/document.typ
+++ b/tests/typ/meta/document.typ
@@ -2,7 +2,7 @@
 
 ---
 // This is okay.
-#set document(title: "Hello")
+#set document(title: [Hello])
 What's up?
 
 ---
@@ -24,7 +24,7 @@ What's up?
 Hello
 
 // Error: 2-30 document set rules must appear before any content
-#set document(title: "Hello")
+#set document(title: [Hello])
 
 ---
 // Error: 10-12 can only be used in set rules
@@ -33,7 +33,7 @@ Hello
 ---
 #box[
   // Error: 4-32 document set rules are not allowed inside of containers
-  #set document(title: "Hello")
+  #set document(title: [Hello])
 ]
 
 ---