@barefootjs/twig

Twig (PHP) adapter for BarefootJS: compiles the BarefootJS IR (JSX → IR, see spec/compiler.md) into .twig template files plus the client JS bundle every other adapter produces, and ships a PHP rendering runtime (php/src/) that renders those templates through a plain Twig\Environment — no framework is required (Slim, plain PHP, etc. all work the same way).

Near-mechanical port of @barefootjs/jinja (the Jinja2 adapter) to Twig syntax. See src/adapter/twig-adapter.ts's header comment for the full Jinja↔Twig syntax-mapping table and the JS/PHP semantics divergences this port handles uniformly (truthiness, stringification, reserved-word identifier mangling, bf.eq/bf.neq for JS strict equality, and the evaluator-only higher-order-callback lowering since Twig has no lambda expression).

Template output shape

• name: 'twig', extension: '.twig', templatesPerComponent: true — one .twig file per component, named by snake-casing the PascalCase component name (UserCard → user_card.twig).
• Hydration markers (bf-s, bf-h/bf-m/bf-r, bf-p, slot/conditional comment markers, loop boundary comments) use the SAME runtime method names as every other adapter's bf.* calls (bf.scope_attr(), bf.hydration_attrs(), bf.text_start/text_end, bf.comment(...), …) — see spec/template-helpers.md for the shared helper contract.
• Every text/attribute interpolation of a possibly-non-string value is routed through bf.string(...) (or bf.bool_str(...) for boolean-shaped values); every non-comparison condition position is routed through bf.truthy(...); every JS ===/!== comparison routes through bf.eq(...)/bf.neq(...) (Twig's own ==/!= compile to PHP loose equality, which is wrong for JS strict-equality semantics). All are pure PHP-runtime helpers — see the PHP runtime pointer below.

PHP runtime

php/src/ is a self-contained PHP package (only dependency: twig/twig) implementing the engine-agnostic bf object every emitted template calls into: hydration markers, context propagation (provide_context/use_context), child-component rendering (render_child), script registration, and the JS-compatible helper library (string, bool_str, truthy, number, floor/ceil/round, array/string helpers, the *_eval evaluator helpers, spread_attrs, query, eq/neq, …). It mirrors the layering of packages/adapter-perl/lib/ (an engine-agnostic core plus a thin per-engine backend) — see spec/template-helpers.md for the semantic contract each helper must satisfy, and the package's own tests under php/tests/.

Usage

// barefoot.config.ts
import { createConfig } from '@barefootjs/twig/build'

export default createConfig({
  components: ['./src/components'],
  outDir: './dist',
})

bf build then emits .twig templates + client JS under outDir. A PHP host renders a component by constructing a Twig\Environment (with autoescape: 'html', strict_variables: false) over a FilesystemLoader pointed at the emitted templates, wiring in the PHP TwigBackend as the render backend. Twig's default escaper emits "/' for "/' where Perl/Go/markupsafe emit the numeric "/' forms — see the adapter header comment for how that byte-form difference is handled.