UCE Docs / Coming from React, Next, or Remix

UCE is server-first C++ with a small template preprocessor. It does not try to be React, but several concepts map cleanly.

Concept Map

• RENDER(Request& context) is the page/server-render entrypoint.

• COMPONENT(Request& context) and COMPONENT:NAME(Request& context) are server-rendered components.

• context.props is the component invocation payload, similar to props.

• context.call is request-local scratch state shared across units during one request.

• context.cfg is structured app/config data.

• ONCE(Request& context) is per-request setup for a unit before its first render/component entry.

• INIT(Request& context) is worker-local setup when a unit is loaded.

• <?= expression ?> is escaped interpolation; prefer it for user-visible text.

• <?: expression ?> writes trusted raw markup, similar to dangerouslySetInnerHTML in React.

• unit_render() renders another page unit; component() returns component HTML as a string.

Routes and Layouts

UCE does not require a framework-level router. A front controller can keep routing explicit and app-local. The starter example demonstrates this in site/examples/uce-starter/index.uce: it resolves a request path by checking:

1. views/<path>.uce

2. views/<path>/index.uce

3. parent index handlers such as views/workspace/index.uce with the last segment as a route parameter

That keeps file-based and hierarchical routing in normal UCE code instead of hiding it in the runtime.

Data Shaping Near Render Code

The function library includes small collection helpers for common route/menu/card transformations:

Use these when a short transformation is clearer than a loop. Prefer explicit loops for side effects or multi-step validation.

Assets and Islands

UCE core does not provide a global asset or island registry. The starter emits CSS and JavaScript from the owning unit's ONCE(Request& context) hook, with a few shared sibling asset components when multiple components need the same files. The starter's COMPONENT:island helper in components/theme/web_affordances.uce covers small progressive-enhancement modules while keeping app policy in the app.

Debugging

When a unit fails to compile, UCE reports the source path, generated C++ path, compile-output artifact, a source/generated excerpt when it can identify a line, and the raw compiler output. The generated C++ under BIN_DIRECTORY is the source of truth for what the configured compiler actually saw.

What Not To Expect

• No client-side virtual DOM is built into UCE.

• No global file-router is imposed by the runtime.

• No JSX-like component tags are required for this workflow.

• Component children/slot syntax is not part of UCE yet; use explicit props and component calls for now.