extension-rendering

name	Extension: Rendering
description	ComponentRenderer, TemplateProvider, TemplateDataExtender, and PagePrerenderer trait implementations

Extension: Rendering

Rendering traits control how pages are composed, how templates are provided, how template context is extended, and how static pages are pre-generated. All traits live in crates/shared/provider-contracts/src/.

---

1. ComponentRenderer

Renders reusable UI components (header, footer, sidebar, partials) into page templates.

Trait

#[async_trait]
pub trait ComponentRenderer: Send + Sync {
    fn component_id(&self) -> &str;
    fn applies_to(&self) -> Vec<String>;
    fn partial_template(&self) -> Option<PartialTemplate>;
    async fn render(&self, ctx: &dyn ComponentRenderContext) -> Result<RenderedComponent>;
}

Existing Components

Component	Renderer	Pages
Head assets	HeadAssetsPartialRenderer	All
Header	HeaderPartialRenderer	All
Footer	FooterPartialRenderer	All
Scripts	ScriptsPartialRenderer	All
CLI animation	CliRemoteAnimationPartialRenderer	Homepage

Registration

impl Extension for MyExtension {
    fn component_renderers(&self) -> Vec<Arc<dyn ComponentRenderer>> {
        vec![Arc::new(MyComponent)]
    }
}

---

2. TemplateProvider

Supplies page templates (embedded or file-based) for rendering.

Trait

pub trait TemplateProvider: Send + Sync {
    fn templates(&self) -> Vec<TemplateDefinition>;
    fn provider_id(&self) -> &'static str;
    fn priority(&self) -> u32;
}

Priority System

Priority	Source
100	Extension templates (override core)
1000	Core default templates (fallback)

Lower priority wins. Extension templates override core.

---

3. TemplateDataExtender

Injects variables into template rendering context. Runs before template compilation.

Trait

#[async_trait]
pub trait TemplateDataExtender: Send + Sync {
    fn applies_to(&self) -> Vec<String>;
    async fn extend(&self, ctx: &dyn ExtenderContext, data: &mut Value) -> Result<()>;
    fn priority(&self) -> u32;
}

Standard Template Variables

Variable	Type	Source
site	Object	Full site configuration
title	String	Page title
CONTENT_HTML	String	Rendered markdown
ORG_NAME	String	Organization name
JS_BASE_PATH	String	JavaScript directory
CSS_BASE_PATH	String	CSS directory
FOOTER_NAV	String	Footer navigation HTML

---

4. PagePrerenderer

Generates static HTML pages at build time. Runs during content_prerender job.

Trait

#[async_trait]
pub trait PagePrerenderer: Send + Sync {
    fn page_type(&self) -> &str;
    async fn prepare(&self, ctx: &dyn PrerendererContext) -> Result<Option<PageRenderSpec>>;
    fn priority(&self) -> u32;
}

Existing Prerenderers

Prerenderer	Output
HomepagePrerenderer	/index.html
FeaturePagePrerenderer	/features/*.html

---

5. Rules

Rule	Rationale
Templates use Handlebars syntax	{{variable}}, {{#if}}, {{> partial}}
Partials embedded via include_str!()	Compile-time inclusion
Extension priority starts at 100	Core uses 1-50
Escape all user content	{{variable}} auto-escapes. {{{raw}}} only for trusted HTML.
CSS/JS paths via template variables	Never hardcode paths
All renderers are Send + Sync	Multi-threaded async context