viewProxy.ts

Purpose

This module implements ViewProxy and createViewProxy(), representing a view binding as a programmatically controlled object.

Overview

ViewProxy is especially useful in tests and adapter layers. It simulates a view by storing props as atoms, tracking mount/update/unmount status, and broadcasting lifecycle events to listeners.

Conceptual Architecture

The implementation consists of several parts:

1. A status atom stores the current view state.
2. For each initial prop, a source atom is created while a read-only version is exposed publicly.
3. Three Emitter instances handle mount, update, and unmount events.
4. A local Scope owns the prop atoms and is destroyed in destroy().

Methods mount(), update(), unmount(), and destroy() synchronize the internal state and notify subscribers.

Public API Description

type ViewProxy<TProps>

• Extends ViewBinding<TProps>.
• Adds mount(), update(props?), unmount(), and destroy().

createViewProxy(): ViewProxy<Record<string, never>>

• Creates a proxy without initial props.

createViewProxy<TProps>(initialProps: TProps): ViewProxy<TProps>

• initialProps: initial props of the view.
• Returns a ViewProxy<TProps> instance.

Usage Examples

import { createViewProxy } from '@nrgyjs/core';

const view = createViewProxy({ id: '42' });

view.onMount(() => {
  console.log(view.props.id());
});

view.mount();
view.update({ id: '43' });
view.destroy();