Renderer and block registry

This page describes the shipped surface of @nubbin/react: the Renderer server component, defineRegistry, loadBlocks, and the BlockComponent, BlockRegistry, RendererProps, HoleContext and HoleResolver types — every one of them declared where it is defined, and generated from there. The package renders an artifact tree against a registry of blocks and evaluates nothing the artifact carries — why that boundary exists is Artifacts contain data, never code.

What a render does

Renderer loads the blocks the artifact names — Object.keys(artifact.blockVersions) — then walks artifact.tree, rendering each node, and wraps the results in a Fragment. A block is invoked and its root element cloned rather than wrapped, which is what obliges it to be a server component: Blocks are server components.

A node fills its holes before its block is invoked, because a block reads a hole as an ordinary prop. A node that declares holes and was given no resolveHole refuses, naming the node — rendering the placeholder instead would put a compile-time artefact in front of a visitor with nothing to notice it.

Holes

The renderer decides where a resolved value lands; the resolver the consumer supplies decides what it is. It receives the hole's spec and never a value, and mapping a declared lifecycle onto a caching layer belongs to the framework binding — @nubbin/next's holeFetchOptions is that mapping for Next.