feat: allow adding CSS URLs to HTML output

This is in the meta data field "css_urls".

Signed-off-by: Lars Wirzenius <liw@liw.fi>
Sponsored-by: author

3 files changed, 56 insertions, 0 deletions

diff --git a/src/doc.rs b/src/doc.rs
index 83b5ec2..7e80deb 100644
--- a/src/doc.rs
+++ b/src/doc.rs
@@ -160,6 +160,14 @@ impl Document {
         }
         head.push_child(Content::Elt(css));
 
+        for css_url in self.meta.css_urls() {
+            let mut link = Element::new(ElementTag::Link);
+            link.push_attribute(Attribute::new("rel", "stylesheet"));
+            link.push_attribute(Attribute::new("type", "text/css"));
+            link.push_attribute(Attribute::new("href", css_url));
+            head.push_child(Content::Elt(link));
+        }
+
         self.meta.set_date(date.into());
 
         let mut body_content = Element::new(crate::html::ElementTag::Div);
diff --git a/src/metadata.rs b/src/metadata.rs
index dc28ac4..e382840 100644
--- a/src/metadata.rs
+++ b/src/metadata.rs
@@ -51,6 +51,7 @@ pub struct YamlMetadata {
     #[serde(default)]
     impls: BTreeMap<String, Vec<PathBuf>>,
     css_embed: Option<Vec<PathBuf>>,
+    css_urls: Option<Vec<String>>,
 }
 
 impl YamlMetadata {
@@ -169,6 +170,7 @@ pub struct Metadata {
     /// Extra class names which should be considered 'correct' for this document
     classes: Vec<String>,
     css_embed: Vec<String>,
+    css_urls: Vec<String>,
 }
 
 #[derive(Debug)]
@@ -221,6 +223,12 @@ impl Metadata {
             }
         }
 
+        let css_urls = if let Some(urls) = &yaml.css_urls {
+            urls.clone()
+        } else {
+            vec![]
+        };
+
         let meta = Self {
             basedir: basedir.as_ref().to_path_buf(),
             title: yaml.title().into(),
@@ -232,6 +240,7 @@ impl Metadata {
             impls,
             classes,
             css_embed,
+            css_urls,
         };
         trace!("metadata: {:#?}", meta);
 
@@ -297,6 +306,11 @@ impl Metadata {
     pub fn css_embed(&self) -> impl Iterator<Item = &str> {
         self.css_embed.iter().map(Deref::deref)
     }
+
+    /// List of CSS urls to add to the HTML output.
+    pub fn css_urls(&self) -> impl Iterator<Item = &str> {
+        self.css_urls.iter().map(Deref::deref)
+    }
 }
 
 impl DocumentImpl {
diff --git a/subplot.md b/subplot.md
index 6532614..432b571 100644
--- a/subplot.md
+++ b/subplot.md
@@ -3683,6 +3683,40 @@ html {
 }
 ~~~
 
+### CSS URLs
+
+_Requirement:_ The user can specify CSS URLs to add in the HTML
+output.
+
+Justification: We want to allow users to specify non-embedded CSS.
+
+~~~scenario
+given file css-urls.subplot
+given file css-urls.md
+given file b.yaml
+given an installed subplot
+when I run subplot docgen css-urls.subplot -o foo.html
+then file foo.html contains "https://example.com/flushing.css"
+~~~
+
+~~~{#css-urls.subplot .file .yaml .numberLines}
+title: Embedded CSS
+markdowns:
+  - css-urls.md
+bindings:
+  - b.yaml
+css_urls:
+  - https://example.com/flushing.css
+~~~
+
+~~~~~~{#css-urls.md .file .markdown .numberLines}
+# This is a title
+
+~~~scenario
+given precondition
+~~~
+~~~~~~
+
 
 ## Running Subplot