Add TOML metadata parsing.

src/lib.rs

@@ -31,6 +31,8 @@ use pathdiff::diff_paths;
 
 use chrono::{DateTime, MappedLocalTime, TimeZone, Local};
 
+use pulldown_cmark::{Event, Tag, TagEnd};
+
 pub struct Historian {
     source_root: PathBuf,
     index_filename: String,
@@ -368,11 +370,47 @@ pub struct PageRenderer {
     tera: Tera
 }
 
-fn render_markdown (content: &tera::Value, args: &HashMap<String, tera::Value>) -> tera::Result<tera::Value> {
-    let parser = pulldown_cmark::Parser::new(content.as_str().unwrap());
+fn parse_markdown (content: &str, metadata: &mut Table) -> String {
+    let mut metadata_str = String::new();
+    let mut in_metadata = false;
+    let parser = pulldown_cmark::Parser::new_ext(content, pulldown_cmark::Options::ENABLE_YAML_STYLE_METADATA_BLOCKS).map(|event| {
+        match &event {
+            Event::Start(tag) => {
+                if let Tag::MetadataBlock(_) = tag {
+                    in_metadata = true;
+                }
+            }
+            Event::Text(text) => {
+                if in_metadata {
+                    metadata_str.push_str(text);
+                }
+            }
+            Event::End(tag) => {
+                if let TagEnd::MetadataBlock(_) = tag {
+                    if in_metadata {
+                        if let Ok(parsed_metadata) = toml::de::from_str::<Table>(&metadata_str) {
+                            println!("{:?}", parsed_metadata);
+                            for (key, value) in parsed_metadata {
+                                metadata.insert(key, value);
+                            }
+                        }
+                    }
+
+                    metadata_str.clear();
+                    in_metadata = false;
+                }                
+            }
+            _ => {}
+        }
+        event
+    });
     let mut html_output = String::new();
     pulldown_cmark::html::push_html(&mut html_output, parser);
-    Ok(tera::Value::String(html_output))
+    html_output
+}
+
+fn render_markdown (content: &tera::Value, args: &HashMap<String, tera::Value>) -> tera::Result<tera::Value> {
+    Ok(tera::Value::String(parse_markdown(content.as_str().unwrap(), &mut Table::new())))
 }
 
 impl PageRenderer {
@@ -506,6 +544,11 @@ impl<'a> Render<'a> {
         }
         self.context.insert("content", &content);
 
+        let mut metadata = Table::new();
+        let html_content = parse_markdown(&content, &mut metadata);
+        self.context.insert("html_content", &html_content);
+        self.context.insert("metadata", &metadata);
+
         let mut ancestors: VecDeque<&Page> = VecDeque::new();
         let mut ancestor = page.parent.as_ref();
         while ancestor.is_some() {