`, a nav bar, and the body. /// Minimal but real — a single `base` template, no partials yet. const BASE_TEMPLATE: &str = r#"<!DOCTYPE html> <html lang="en"> <head> <meta charset="utf-8"> <title>{{ title }}

//! TEMPLATE stage (spec §2.1, §2.4, §3.3): rendered fragment + page metadata → full HTML. //! //! minijinja (Jinja2 semantics, runtime templates: edit-and-rebuild, no recompile). //! Templates are a hashing input for incrementality (spec §4.1): a base-layout edit //! invalidates every page that transitively uses it. Keep the fragment/template //! boundary sharp so content HTML can be snapshot-tested independently of chrome. use minijinja::{context, Environment}; use serde::Serialize; /// A navigation entry: a page title and the URL to reach it from the current page. #[derive(Debug, Clone, Serialize)] pub struct NavItem { pub title: String, pub url: String, } /// The base layout applied to every page: ``, a nav bar, and the body. /// Minimal but real — a single `base` template, no partials yet. const BASE_TEMPLATE: &str = r#"<!DOCTYPE html> <html lang="en"> <head> <meta charset="utf-8"> <title>{{ title }}

"#; /// The source text of every template that participates in the page layout. Hashed by /// the incremental layer (spec §4.1): a base-layout edit invalidates every page that /// uses it. There is a single `base` template today; when partials arrive this returns /// the transitive closure so a single-partial edit invalidates only its users. pub fn template_sources() -> &'static [(&'static str, &'static str)] { &[("base", BASE_TEMPLATE)] } #[derive(Debug, thiserror::Error)] pub enum TemplateError { #[error("template error: {0}")] Render(String), } /// Wraps a rendered fragment in its page template. pub struct Templater { env: Environment<'static>, } impl Templater { pub fn new() -> Self { let mut env = Environment::new(); env.add_template("base", BASE_TEMPLATE) .expect("base template compiles"); Templater { env } } /// fragment + page metadata → full HTML page. pub fn render_page( &self, title: &str, body: &str, nav: &[NavItem], ) -> Result { let tmpl = self .env .get_template("base") .map_err(|e| TemplateError::Render(e.to_string()))?; tmpl.render(context! { title => title, body => body, nav => nav }) .map_err(|e| TemplateError::Render(e.to_string())) } } impl Default for Templater { fn default() -> Self { Self::new() } }