Block dependencies

The engine loads blocks listed in bundle dependency declarations (deps): it finds their .nu.ts files and invokes them without a manual registerBlock. The bundle's block list is explicit; page content does not update it automatically.

bemdecl — the entry point

The entry point of the dependencies is the file blocks/<bundle>/<bundle>.bemdecl.js (the BEM standard). It lists which blocks the bundle needs:

// blocks/docs-layout/docs-layout.bemdecl.js — CommonJS
module.exports = {
    mustDeps: [
        'root',          // Standard document wrapper
        'docs-layout',   // the frame itself
    ],
    shouldDeps: [
        'menu',          // navigation
        'article',       // content
    ],
};

The file is read as CommonJS. An entry is a string ('menu') or an object ({ block: 'menu' }); a flat array (module.exports = ['root', 'docs-layout', 'menu']) and an object with mustDeps/shouldDeps are both valid — the two lists are merged into one.

The list is flat, with no transitivity

The declaration does not traverse nested dependencies: if the menu block needs button, button is also written into the bundle's bemdecl. The list is read in full:

docs-layout.bemdecl.js → root, docs-layout, menu, article, button, icon

Each block is loaded from its own .nu.ts. A flat list is easier to verify: what is written is what gets into the build.

Where bundles come from

Bundles are listed in config/site.json → bundles (an empty list by default; configure each required bundle explicitly). For each one, the engine reads its bemdecl and builds a CSS and a JS bundle — for details, see assets in the output.

CSS and JS via dependencies

The same list defines the style and script bundles. If a block is in the dependencies, its block.css and block.js are included in the page bundle.

One declaration for templates and assets

The declaration is an explicit bundle block list. It selects templates, CSS, and JavaScript together; adding a block to content does not update it automatically. The loader does not traverse .deps.js files. See block levels for file lookup.

In a project with "type":"module", add blocks/package.json containing {"type":"commonjs"} so .bemdecl.js remains CommonJS. A later-level declaration replaces the earlier declaration in full.