Live demo

Send something to the server Every keystroke is dispatched to POST /__ui/dispatch and the server patches its reply below.

UiOn Signed event manifest POST /__ui/dispatch

Interactive HTML

The moment a page needs to do something — validate a field, toggle a state, submit an action — most teams escape into per-feature endpoints and hand-written fetch glue. That glue is a second interaction architecture, and it grows without a contract.

Semitexa keeps interaction inside the component model. A component declares its backend events with #[UiOn(part, event)], and the framework wires the whole round-trip.

The signed round-trip

On render, the server emits a signed, inert event manifest into the DOM — the handler method name and class never leave the server. One tiny capture-only runtime watches for matching events and posts exactly { ctx, dispatchId, payload } to POST /__ui/dispatch. The dispatcher verifies the signature, guards replays, runs the handler, and returns DOM patches scoped to the firing instance.

The result is interactivity with no escape hatch: no per-feature endpoint to secure, no client-held routing table to tamper with, no second framework owning interaction. The only thing a browser can do is ask the server — over one signed, replay-guarded channel — to run the handler the server already chose. Type in the field above and watch the server's reply patch back in.

1#[UiOn(part: 'input', event: 'change')]2public function onInputChanged(UiInteractionEvent $event): UiInteractionResult3{4    return UiInteractionResult::patch(patches: [5        new UiResponsePatch(6            op: UiResponsePatch::OP_SET_TEXT,7            targetInstance: $event->instanceId,8            targetName: 'server-ack',9            value: 'Server received: ' . (string) $event->value(),10        ),11    ]);12}

#[UiOn(part: 'input', event: 'change')]
public function onInputChanged(UiInteractionEvent $event): UiInteractionResult
{
    return UiInteractionResult::patch(patches: [
        new UiResponsePatch(
            op: UiResponsePatch::OP_SET_TEXT,
            targetInstance: $event->instanceId,
            targetName: 'server-ack',
            value: 'Server received: ' . (string) $event->value(),
        ),
    ]);
}

How it works

A #[UiOn(part, event)] method is the handler for an event. The server emits a signed, inert event manifest into the DOM; one tiny capture-only runtime posts matches to POST /__ui/dispatch; the dispatcher verifies the signature, runs the handler, and returns DOM patches scoped to the firing instance. Type in the field below — each keystroke round-trips to the server and back.

Why it matters

Interactivity with no escape hatch: no per-feature endpoint to secure, no client-held routing to tamper with, no second framework owning interaction — just signed requests to run the handler the server already chose.