rendering md with layouts

Cargo.lock

@@ -1056,8 +1056,11 @@ version = "0.1.0"
 dependencies = [
  "eframe",
  "egui_ltreeview",
+ "markdown",
  "rfd",
+ "serde",
  "thiserror 2.0.16",
+ "toml",
 ]
 
 [[package]]
@@ -1652,6 +1655,15 @@ dependencies = [
  "libc",
 ]
 
+[[package]]
+name = "markdown"
+version = "1.0.0"
+source = "registry+https://github.com/rust-lang/crates.io-index"
+checksum = "a5cab8f2cadc416a82d2e783a1946388b31654d391d1c7d92cc1f03e295b1deb"
+dependencies = [
+ "unicode-id",
+]
+
 [[package]]
 name = "memchr"
 version = "2.7.5"
@@ -2549,6 +2561,15 @@ dependencies = [
  "syn",
 ]
 
+[[package]]
+name = "serde_spanned"
+version = "1.0.0"
+source = "registry+https://github.com/rust-lang/crates.io-index"
+checksum = "40734c41988f7306bb04f0ecf60ec0f3f1caa34290e4e8ea471dcd3346483b83"
+dependencies = [
+ "serde",
+]
+
 [[package]]
 name = "shlex"
 version = "1.3.0"
@@ -2815,12 +2836,36 @@ dependencies = [
  "zerovec",
 ]
 
+[[package]]
+name = "toml"
+version = "0.9.5"
+source = "registry+https://github.com/rust-lang/crates.io-index"
+checksum = "75129e1dc5000bfbaa9fee9d1b21f974f9fbad9daec557a521ee6e080825f6e8"
+dependencies = [
+ "indexmap",
+ "serde",
+ "serde_spanned",
+ "toml_datetime 0.7.0",
+ "toml_parser",
+ "toml_writer",
+ "winnow",
+]
+
 [[package]]
 name = "toml_datetime"
 version = "0.6.11"
 source = "registry+https://github.com/rust-lang/crates.io-index"
 checksum = "22cddaf88f4fbc13c51aebbf5f8eceb5c7c5a9da2ac40a13519eb5b0a0e8f11c"
 
+[[package]]
+name = "toml_datetime"
+version = "0.7.0"
+source = "registry+https://github.com/rust-lang/crates.io-index"
+checksum = "bade1c3e902f58d73d3f294cd7f20391c1cb2fbcb643b73566bc773971df91e3"
+dependencies = [
+ "serde",
+]
+
 [[package]]
 name = "toml_edit"
 version = "0.22.27"
@@ -2828,10 +2873,25 @@ source = "registry+https://github.com/rust-lang/crates.io-index"
 checksum = "41fe8c660ae4257887cf66394862d21dbca4a6ddd26f04a3560410406a2f819a"
 dependencies = [
  "indexmap",
- "toml_datetime",
+ "toml_datetime 0.6.11",
  "winnow",
 ]
 
+[[package]]
+name = "toml_parser"
+version = "1.0.2"
+source = "registry+https://github.com/rust-lang/crates.io-index"
+checksum = "b551886f449aa90d4fe2bdaa9f4a2577ad2dde302c61ecf262d80b116db95c10"
+dependencies = [
+ "winnow",
+]
+
+[[package]]
+name = "toml_writer"
+version = "1.0.2"
+source = "registry+https://github.com/rust-lang/crates.io-index"
+checksum = "fcc842091f2def52017664b53082ecbbeb5c7731092bad69d2c63050401dfd64"
+
 [[package]]
 name = "tracing"
 version = "0.1.41"
@@ -2889,6 +2949,12 @@ dependencies = [
  "winapi",
 ]
 
+[[package]]
+name = "unicode-id"
+version = "0.3.5"
+source = "registry+https://github.com/rust-lang/crates.io-index"
+checksum = "10103c57044730945224467c09f71a4db0071c123a0648cc3e818913bde6b561"
+
 [[package]]
 name = "unicode-ident"
 version = "1.0.18"

Cargo.toml

@@ -8,3 +8,6 @@ eframe = "0.32.1"
 egui_ltreeview = "0.5.3"
 rfd = "0.15.4"
 thiserror = "2.0.16"
+toml = "0.9.5"
+markdown = "1.0.0"
+serde = "1.0.219"

src/main.rs

@@ -1,4 +1,5 @@
 mod fleen_app;
+mod renderer;
 
 use std::path::{Path, PathBuf};
 use eframe::egui::{Color32, Context, Id, RichText};

src/renderer.rs

@@ -0,0 +1,104 @@
+use std::{default, fs};
+use std::io::Error;
+use std::path::PathBuf;
+use eframe::egui::TextBuffer;
+use markdown::message::Message;
+use markdown::{CompileOptions, Constructs, ParseOptions};
+use markdown::mdast::Node;
+use serde::Deserialize;
+use thiserror::Error;
+
+pub struct RenderOutput {
+    pub filename: PathBuf,
+    pub contents: String
+}
+
+#[derive(Deserialize)]
+pub struct Frontmatter {
+    layout: Option<String>,
+    title: Option<String>
+}
+
+impl Frontmatter {
+    fn apply_layout(self, content: String, root: PathBuf) -> Result<String, RenderError> {
+        let title = self.title.unwrap_or(String::new());
+        if let Some(layout) = self.layout {
+            let absolute_layout = root.join(layout);
+            let layout = fs::read_to_string(absolute_layout.clone()).map_err(|e| RenderError::FileReadError(e, absolute_layout))?;
+            Ok(layout.replace("$title", title.as_str()).replace("$content", content.as_str()))
+        } else {
+            Ok(content)
+        }
+    }
+}
+
+#[derive(Error, Debug)]
+pub enum RenderError {
+    #[error("Error reading {1}: {0}")]
+    FileReadError(Error, PathBuf),
+    #[error("Error parsing Markdown {1}: {0}")]
+    MarkdownParseError(Message, PathBuf),
+    #[error("Error parsing frontmatter in {1}: {0}")]
+    FrontmatterParseError(toml::de::Error, PathBuf)
+}
+
+pub fn render(source: PathBuf, root: PathBuf) -> Result<RenderOutput, RenderError> {
+    let contents = match source.extension().map(|o| o.to_str().unwrap()) {
+        Some("md") => render_as_markdown(source.clone(), root),
+        _ => todo!()
+    }?;
+    let filename = source.with_extension("html");
+    Ok(RenderOutput { filename, contents })
+}
+
+fn render_as_markdown(source: PathBuf, root: PathBuf) -> Result<String, RenderError> {
+    let absolute_source = root.join(source.clone());
+    let contents = fs::read_to_string(absolute_source.clone()).map_err(|e| RenderError::FileReadError(e, source.clone()))?;
+    let options = markdown::Options {
+        parse: ParseOptions {
+            constructs: Constructs {
+                frontmatter: true,
+                gfm_table: true,
+                ..Default::default()
+            },
+            ..Default::default()
+        },
+        ..Default::default()
+    };
+    let html = markdown::to_html_with_options(contents.as_str(), &options).map_err(|e| RenderError::MarkdownParseError(e, source.clone()))?;
+    let ast = markdown::to_mdast(contents.as_str(), &options.parse).map_err(|e| RenderError::MarkdownParseError(e, source.clone()))?;
+
+    if let Some(frontmatter) = find_frontmatter(ast, source.clone())? {
+        frontmatter.apply_layout(html, root)
+    } else {
+        Ok(html)
+    }
+}
+
+fn find_frontmatter(node: Node, source: PathBuf) -> Result<Option<Frontmatter>, RenderError> {
+    if let Some(children) = node.children() {
+        for child in children.into_iter() {
+            if let Node::Toml(toml_str) = child {
+                let fmatter: Frontmatter = toml::from_str(toml_str.value.as_str()).map_err(|e| RenderError::FrontmatterParseError(e, source))?;
+                return Ok(Some(fmatter))
+            }
+        }
+        Ok(None)
+    } else { Ok(None) }
+}
+
+#[cfg(test)]
+mod tests {
+    use super::*;
+
+    #[test]
+    fn test_rendering_markdown() {
+        match render("index.md".into(), "./testdata".into()) {
+            Err(e) => println!("{}", e),
+            Ok(ro) => {
+                println!("File: {}", ro.filename.to_str().unwrap());
+                println!("Contents:\n\n{}", ro.contents);
+            }
+        }
+    }
+}

testdata/index.md

@@ -0,0 +1,18 @@
++++
+layout = "layouts/post.html"
+title = "Pest Toast"
++++
+Test
+===
+
+This is a test. This is only a test.
+~~~rust
+fn main() {
+    println!("Here is some Rust")
+}
+~~~
+
+|This|is|
+|----|--|
+|a|table|
+

testdata/layouts/post.html

@@ -0,0 +1,9 @@
+<!DOCTYPE html>
+<html>
+<head>
+  <title>blog - $title</title>
+</head>
+<body>
+$content
+</body>
+</html>