javascript / expert
Snippet
Proxy-driven Property Access Tracking
Advanced state management libraries use Proxies to track which properties of a state object are accessed during a component's render. This allows the system to trigger re-renders only when those specific properties change, rather than on any object update.
snippet.js
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function createTrackedProxy(obj, onAccess) {return new Proxy(obj, {get(target, prop) {onAccess(prop);const value = Reflect.get(target, prop);return (value && typeof value === 'object')? createTrackedProxy(value, onAccess): value;}});}
react
Breakdown
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get(target, prop) { onAccess(prop); ... }
Intercepts property access to register a dependency for the current rendering context.
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return (value && typeof value === 'object') ? ...
Recursively wraps nested objects to ensure deep tracking.