Angular 20 Upgrade Guide: Features, Use Cases & Best Practices

👋 Hello everyone,

Today, I’ll be highlighting the new features and improvements in Angular 20, a powerful web framework that empowers developers to build fast, scalable, and reliable applications.

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🔧 Upgrade Steps for Angular 20

To upgrade your project:

1. Install the latest CLI:
   npm install -g @angular/cli

2. Update Angular core and CLI:
   ng update @angular/core@20 @angular/cli@20

3. Upgrade TypeScript to version 5.x

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✨ Key Features in Angular 20

✅ Stable Signals API

• Signals are now officially stable.
• They help manage local component state without relying on RxJS for every change.

🧮 Computed Signals

• Read-only signals derived from other signals.
• Defined using the computed() function.
• Dynamically track dependencies.

⚡ Effects

• Run at least once and re-run when dependent signals change.
• Execute asynchronously during change detection.
• Track dependencies dynamically.

Use Cases for Effects:

• Logging data changes (analytics/debugging)
• Syncing with window.localStorage
• Custom DOM behavior
• Rendering with <canvas>, charts, or third-party libraries

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🚀 Zoneless Change Detection

• Removes the need for Zone.js
• Improves performance and reduces unnecessary re-renders
• Speeds up rendering by up to 30%

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🧩 Dynamic Component Creation with createComponent()

🔄 Why Use It?

To build flexible, modular UIs that respond to user interactions or app state without full page reloads.

💡 Key Benefits

• Dynamic UI Elements: Load modals, dialogs, charts, or widgets only when needed.
• Component Reusability: Reuse components with different data across contexts.
• Lazy Loading: Load components on demand to improve initial load performance.
• Customizable Views: Pass data at runtime for context-aware components.
• Flexible Layouts: Insert components dynamically based on user actions or system data.
• Reducing Complexity: Move logic to TypeScript, keeping templates clean and simple.

📌 Example Scenarios

• Modals and Popups: Show modal on user action without template clutter.
• Dynamic Forms: Build forms based on user roles or config files.
• Error Handling: Inject error notification components on failed API calls.
• Dashboard Widgets: Add charts/tables dynamically based on user configuration.

🛠️ Improvements in Angular 20

• Stabilized API for dynamic component creation
• Declarative, type-safe, and modern approach
• No need for ViewContainerRef or ComponentFactoryResolver
• Automatic handling of DI, lifecycle hooks, and content projection
• Works seamlessly with standalone components and signals

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📦 Resource API in Angular 20

🌐 What Is It?

A new API for managing external resources like REST APIs, WebSockets, and static assets.

✅ Why Use It?

• Declarative Resource Management: Cleaner, reusable logic
• Centralized Error Handling: Simplifies network error management
• Caching & State Management: Tracks fetch status and caches responses
• Improved Performance: Supports retries and parallel fetching
• Ease of Integration: Works with Angular’s HttpClient

🧩 Benefits

• Simplified HTTP requests with @Resource decorator
• Declarative syntax for API calls
• Centralized error handling
• Built-in caching support

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🧠 Extended Template Expression Syntax

🆕 New Syntax Features

• Optional Chaining (?.): Safely access nested properties
• Nullish Coalescing (??): Provide fallback values
• Robust Error Handling: Templates don’t break on missing data

Examples:

Interactivity on code previews is coming soon

{{ user().address?.city }}

{{ user().name ?? 'Name not provided' }}

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🗺️ Standalone Routing Improvements

🛠️ What’s New?

• No need for NgModule imports
• Cleaner code structure
• Full support for lazy loading and guards
• Uses inject() for DI instead of constructor injection
• Fully typed and declarative routing

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✅ Best Practices in Angular 20

🧾 TypeScript

• Use strict type checking
• Prefer type inference
• Avoid any; use unknown when uncertain

🅰️ Angular

• Prefer standalone components
• Avoid @HostBinding and @HostListener; use host object
• Use NgOptimizedImage for static images

🧱 Components

• Keep components small and focused
• Use input()/output() functions
• Use computed() for derived state
• Set ChangeDetectionStrategy.OnPush
• Prefer inline templates for small components
• Use reactive forms
• Avoid ngClass and ngStyle; use class and style bindings

📊 State Management

• Use signals for local state
• Use computed() for derived state
• Keep transformations pure
• Use update() or set() instead of mutate()

🧩 Templates

• Keep templates simple
• Use native control flow (@if, @for, @switch)
• Use async pipe for observables

🧰 Services

• Design around single responsibility
• Use providedIn: 'root' for singletons
• Prefer inject() over constructor injection