Add context registry

docs-site/src/content/docs/api/contextRegistry.md

@@ -0,0 +1,187 @@
+---
+title: contextRegistry
+---
+
+## Overview
+
+`ContextRegistry` is a utility class for explicit context sharing across
+component trees.
+
+It stores context instances by constructor and lets you resolve them by type.
+Lookup uses `instanceof`, so querying by a base class can return a subclass
+instance.
+
+## Usage
+
+```ts
+import { ContextRegistry } from 'regor'
+
+class AppServices {
+  readonly apiBase = '/v1'
+}
+
+const registry = new ContextRegistry()
+registry.register(new AppServices())
+
+const services = registry.require(AppServices)
+```
+
+## API
+
+### `register(context)`
+
+Registers an instance under its runtime constructor.
+
+- If another instance of the same constructor is already registered, it is
+  replaced.
+
+### `unregisterByClass(ContextClass)`
+
+Removes the entry for a constructor.
+
+- No-op when that constructor is not registered.
+
+### `unregister(context)`
+
+Removes an instance only if it is currently the registered value for its
+constructor.
+
+- This prevents deleting a newer replacement instance registered later.
+
+### `find(ContextClass)`
+
+Returns the first registered instance matching `instanceof ContextClass`, or
+`undefined`.
+
+### `require(ContextClass)`
+
+Returns the same result as `find`, but throws when not found.
+
+- Error message format: `ClassName is not registered in ContextRegistry.`
+
+## Example: parent provides registry, child resolves from `head.requireContext`
+
+```ts
+import { ComponentHead, ContextRegistry, defineComponent } from 'regor'
+
+class AppServices {
+  readonly apiBase = '/v1'
+}
+
+class Parent {
+  readonly registry = new ContextRegistry()
+
+  constructor() {
+    this.registry.register(new AppServices())
+  }
+}
+
+class Child {
+  readonly apiBase: string
+
+  constructor(head: ComponentHead<object>) {
+    // Parent can provide registry from any component context shape.
+    const parent = head.requireContext(Parent)
+    const services = parent.registry.require(AppServices)
+    this.apiBase = services.apiBase
+  }
+}
+
+const parent = defineComponent<Parent>('<div><slot></slot></div>', {
+  context: () => new Parent(),
+})
+
+const child = defineComponent<Child>('<p r-text="apiBase"></p>', {
+  context: (head) => {
+    return new Child(head)
+  },
+})
+```
+
+## Example: component ctx <=> component ctx communication through parent registry
+
+```ts
+import {
+  ComponentHead,
+  ContextRegistry,
+  createApp,
+  defineComponent,
+  html,
+  ref,
+} from 'regor'
+
+class Parent {
+  components = { producer, consumer }
+  registry = new ContextRegistry()
+}
+
+class Consumer {
+  message = ref('idle')
+  private readonly parent: Parent
+
+  constructor(head: ComponentHead<object>) {
+    this.parent = head.requireContext(Parent)
+    this.parent.registry.register(this)
+  }
+
+  receive = (next: string): void => {
+    this.message(next)
+  }
+}
+
+class Producer {
+  private readonly parent: Parent
+
+  constructor(head: ComponentHead<object>) {
+    this.parent = head.requireContext(Parent)
+    this.parent.registry.register(this)
+  }
+
+  send = (): void => {
+    // direct component-ctx -> component-ctx call through registry
+    const consumer = this.parent.registry.require(Consumer)
+    consumer.receive('message-from-producer')
+  }
+}
+
+const producer = defineComponent<Producer>(
+  html`<button class="send" @click="send">send</button>`,
+  {
+    context: (head) => new Producer(head),
+  },
+)
+
+const consumer = defineComponent<Consumer>(
+  html`<p class="value">{{ message }}</p>`,
+  {
+    context: (head) => new Consumer(head),
+  },
+)
+
+const parent = defineComponent<Parent>(
+  html`<section>
+    <Producer></Producer>
+    <Consumer></Consumer>
+  </section>`,
+  {
+    context: () => new Parent(),
+  },
+)
+
+createApp(
+  { components: { parent } },
+  {
+    element: document.querySelector('#app')!,
+    template: '<Parent></Parent>',
+  },
+)
+```
+
+## See Also
+
+- [`defineComponent`](/api/defineComponent)
+- [`useScope`](/api/useScope)
+- [Components Guide](/guide/components)
+- [TypeScript Guide](/guide/typescript)
+
+[Back to the API list](/api/)

docs-site/src/content/docs/api/index.md

@@ -51,6 +51,7 @@ Use this page as an index, then open each API page for signature details and exa
 1. [`useScope`](/api/useScope)
 2. [`onMounted`](/api/onMounted)
 3. [`onUnmounted`](/api/onUnmounted)
+4. [`contextRegistry`](/api/contextRegistry)
 
 ## Cleanup and Unbind
 

docs-site/src/content/docs/guide/components.md

@@ -231,3 +231,4 @@ Unmount cleans child component bindings and observers.
 3. [Directive: :context](/directives/context)
 4. [TypeScript Guide](/guide/typescript)
 5. [Directive: r-for](/directives/r-for)
+6. [contextRegistry API](/api/contextRegistry)

docs-site/src/content/docs/guide/typescript.md

@@ -127,3 +127,4 @@ class ChildContext {
 1. [Components](/guide/components)
 2. [defineComponent API](/api/defineComponent)
 3. [createApp API](/api/createApp)
+4. [contextRegistry API](/api/contextRegistry)

package.json

@@ -1,6 +1,6 @@
 {
   "name": "regor",
-  "version": "1.3.8",
+  "version": "1.3.9",
   "description": "A modern UI framework for web and desktop applications, inspired by Vue's concepts and powered by simplicity and flexibility.",
   "author": "Ahmed Yasin Koculu",
   "license": "MIT",

src/app/ComponentHead.ts

@@ -2,7 +2,9 @@ import { type IRegorContext } from '../api/types'
 import { removeNode } from '../cleanup/removeNode'
 import { callUnmounted } from '../composition/callUnmounted'
 
-export type ContextClass<TValue> = abstract new (...args: never[]) => TValue
+export type ContextClass<TValue extends object> = abstract new (
+  ...args: never[]
+) => TValue
 
 /**
  * Runtime metadata passed to a component's `context(head)` factory.
@@ -185,7 +187,7 @@ export class ComponentHead<
    * @param occurrence - Zero-based index of the matching instance to return.
    * @returns The matching parent context instance, or `undefined` when not found.
    */
-  findContext<TValue>(
+  findContext<TValue extends object>(
     constructor: ContextClass<TValue>,
     occurrence = 0,
   ): TValue | undefined {
@@ -218,7 +220,7 @@ export class ComponentHead<
    * @returns The parent context instance at the requested occurrence.
    * @throws Error when no matching instance exists at the requested occurrence.
    */
-  requireContext<TValue>(
+  requireContext<TValue extends object>(
     constructor: ContextClass<TValue>,
     occurrence = 0,
   ): TValue {

src/composition/ContextRegistry.ts

@@ -0,0 +1,89 @@
+import { type ContextClass } from '../app/ComponentHead'
+
+/**
+ * Registry for sharing typed context instances across component boundaries.
+ *
+ * Entries are keyed by the runtime constructor of each registered instance:
+ * - one active entry per concrete constructor
+ * - registering another instance of the same constructor replaces the previous
+ *
+ * Lookup is type-based and uses `instanceof`, so querying a base class can
+ * resolve a registered subclass instance.
+ */
+export class ContextRegistry {
+  private readonly byConstructor = new Map<ContextClass<object>, object>()
+
+  /**
+   * Registers a context instance under its concrete runtime constructor.
+   *
+   * If an instance with the same constructor already exists, it is replaced.
+   *
+   * @param context - Context instance to register.
+   */
+  register<TContext extends object>(context: TContext): void {
+    this.byConstructor.set(context.constructor as ContextClass<object>, context)
+  }
+
+  /**
+   * Removes the entry for a constructor.
+   *
+   * No-op when the constructor is not registered.
+   *
+   * @param contextClass - Constructor key to remove.
+   */
+  unregisterByClass<TContext extends object>(
+    contextClass: ContextClass<TContext>,
+  ): void {
+    this.byConstructor.delete(contextClass)
+  }
+
+  /**
+   * Removes a specific context instance if it is currently registered for its
+   * constructor.
+   *
+   * This prevents deleting a newer replacement instance of the same class.
+   *
+   * @param context - Context instance to remove.
+   */
+  unregister<TContext extends object>(context: TContext): void {
+    const key = context.constructor as ContextClass<object>
+    if (this.byConstructor.get(key) === context) {
+      this.byConstructor.delete(key)
+    }
+  }
+
+  /**
+   * Finds a context instance by constructor type.
+   *
+   * The registry is scanned in insertion order and each entry is checked with
+   * `instanceof contextClass`.
+   *
+   * @param contextClass - Class to match via `instanceof`.
+   * @returns Matching instance, or `undefined` when not found.
+   */
+  find<TContext extends object>(
+    contextClass: ContextClass<TContext>,
+  ): TContext | undefined {
+    for (const value of this.byConstructor.values()) {
+      if (value instanceof contextClass) return value
+    }
+    return undefined
+  }
+
+  /**
+   * Resolves a context instance by constructor type and guarantees a value.
+   *
+   * @param contextClass - Class to match via `instanceof`.
+   * @returns Matching context instance.
+   * @throws Error when no matching context is registered.
+   */
+  require<TContext extends object>(
+    contextClass: ContextClass<TContext>,
+  ): TContext {
+    const value = this.find(contextClass)
+    if (value) return value
+    throw new Error(
+      `${contextClass.name} is not registered in ContextRegistry.`,
+    )
+  }
+}

src/index.ts

@@ -33,6 +33,7 @@ export { getBindData } from './cleanup/getBindData'
 export { drainUnbind } from './cleanup/removeNode'
 export { removeNode } from './cleanup/removeNode'
 export { unbind } from './cleanup/unbind'
+export { ContextRegistry } from './composition/ContextRegistry'
 export { onMounted } from './composition/onMounted'
 export { onUnmounted } from './composition/onUnmounted'
 export { useScope } from './composition/useScope'