state-management_skill

Overview

This skill implements a robust NgRx-based state layer for Angular apps, including actions, reducers, selectors, effects, entity adapters, and HTTP integration. It provides patterns for service-based stores, facades, signal mixing, caching, and testable effects so teams can manage normalized state and async flows consistently.

How this skill works

It defines typed actions and feature reducers to represent state transitions, then exposes selectors for efficient, memoized reads. Effects handle side effects and HTTP calls, returning success or error actions. Entity adapters normalize collections and provide common selectors; facades wrap store interactions for components and make testing easier.

When to use it

• When you need predictable, testable global state for complex UIs
• When managing collections that benefit from normalization and ID-based operations
• When coordinating HTTP requests, optimistic updates, or complex async flows
• When building reusable feature modules with lazy-loaded state
• When you want time-travel debugging and clear separation of side effects

Best practices

• Normalize state shape; prefer flat structures and entity adapters for collections
• Keep reducers focused on one feature and use actions for intent, not implementation
• Expose a facade per feature to simplify component code and decouple from NgRx APIs
• Memoize selectors and compose them to avoid unnecessary recalculations
• Always include loading and error state for async flows and handle errors in effects
• Register feature stores lazily when possible and use interceptors for cross-cutting HTTP concerns

Example use cases

• User management: load, add, update, delete users with adapter-backed reducers and selectors
• Product catalog: normalized product entities, filters via selectors, and cached HTTP requests
• Auth flow: interceptors attach tokens, effects handle login/logout flows and persistence
• Admin dashboards: combine facades from multiple features into a single AppFacade for composed views
• Offline caching: use a caching service with TTL for repeatable API calls inside effects