Verified against Semitexa Ultimate 2026.09.19.1020

Slot Resources

A slot is not a fragment hack. It is a real resource with its own handler pipeline, template, and lifecycle. Slot resources turn page regions into first-class response pipelines instead of informal partial includes.

The problem

Traditional page composition often leaves nav, sidebar, widgets, and footers as special-case includes with hidden data dependencies. Frontend and backend fragments drift apart because each region gets wired by a different mechanism. When regions are not first-class resources, no one can tell where their data really comes from or how they are refreshed.

How it works

Each region is a resource with its own handler flow, render context, asset collection, and optional deferred or live lifecycle. The same template system renders the page, the sidebar, the nav, and reactive slots.

layout_slot() composes the shell declaratively while the data flow stays explicit and reviewable.

The rules

• A slot is a real response object, not a string include or a magical template fragment.
• Slots use the same Twig system and rendering model as the page itself, so frontend and backend stop speaking different dialects.
• Each region can evolve independently: own handler, own template, own assets, own deferred or reactive lifecycle.
• layout_slot() composes the shell declaratively while the data flow stays explicit and reviewable.

Key mechanisms

• #[AsSlotResource] — registers a named page region as a first-class resource for one layout handle.
• SlotHandlerPipeline — runs the region through typed slot handlers before it renders.
• Shared Twig — the page template and the slot template use the same rendering engine and conventions.