withView.ts

Purpose

This module implements the withView() extension and the provideView() provider used to pass a ViewBinding into controller creation.

Overview

The file connects the controller runtime to the UI layer. It defines ViewControllerContext, can infer view props from controller context, and ensures that a view binding is actually present in extension params.

Conceptual Architecture

The module is built around the extension mechanism from controller.ts:

1. withView<TProps>() returns an ExtensionFn that extracts ViewBinding through the service key NRGY_EXTENSION_VIEW_KEY.
2. If the view is missing, ControllerConstructorError is thrown.
3. provideView(view) packages the view object into an ExtensionParamsProvider.
4. The types ViewControllerContext<TProps> and InferViewPropsFromControllerContext<TContext, ElseType> form a type-safe bridge between a controller and its view props.

Public API Description

NRGY_EXTENSION_VIEW_KEY

• Service key used to store ViewBinding inside extension params.

ViewControllerContext<TProps>

• Controller context extended with the view field.

InferViewPropsFromControllerContext<TContext, ElseType>

• Extracts the view prop type from a controller context.

withView<TProps>(): ExtensionFn<BaseControllerContext, ViewControllerContext<TProps>>

• Returns an extension that adds view to the controller context.

provideView(view): ExtensionParamsProvider

• Wraps a ViewBinding into a provider for controller creation.

Usage Examples

import { declareController, provideView, withView, createViewProxy } from '@nrgyjs/core';

const GreetingController = declareController()
  .extend(withView<{ name: string }>())
  .apply(({ view }) => ({
    greet: () => `Hello, ${view.props.name()}!`,
  }));

const view = createViewProxy({ name: 'Ada' });
const controller = new GreetingController([provideView(view)]);