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

Contracts in WCF Service

 Contracts in WCF Service 

Contracts are useful for building WCF service applications. They define what the protocol (binding) the service uses, how the communication will be done, what message exchange format to use and so on.

 

The following are the contracts are available in WCF:

• Service contracts
• Data Contracts
• Message contracts
• Fault Contract
• Operation Contract

Service contracts

 

Service contracts define the Interface for the service. It can be defined as follows.

 

Syntax

1. [ServiceContract]  
2. public interface IService1  
3. {  
4.  
5.     // TODO: Add your service operations here  
6. } 
   

Key Points

• Any WCF service can have more than one service contract.
• Declare at least one service contract in a service.
• A service contract can be declared using the [ServiceContract] attribute.
• It allows defining an Operation Contract under it to expose the service outside the world.
• It maps the interface and methods of your service to a platform-independent description.
• It describes message exchange patterns that the service can have with another party. Some service operations might be one-way, others might require a request-reply pattern.

The service contract attribute has the following properties:

• CallbackContract
• ConfigurationName
• HasProtectionLevel
• Name
• Namespace
• ProtectionLevel
• SessionMode
• TypeId

Operation Contract

 

An Operation Contract defines the method exposed to the client to exchange the information between the client and server. An Operation Contract describes what functionality is to be given to the client, such as addition, subtraction and so on.

 

It can be defined as in the following:

1. public interface IService1  
2. {  
3.     [OperationContract]  
4.     string GetData(int value);  
5.   
6.     [OperationContract]  
7.     CompositeType GetDataUsingDataContract(CompositeType composite);  
8.     
9. } 
   

The Operation Contract attribute has the following properties:

• CallbackContract: Gets or sets the type of callback contract when the contract is a duplex contract.
  
• ConfigurationName: Gets or sets the name used to locate the service in an application configuration file.
  
• HasProtectionLevel: Gets a value that indicates whether the member has a protection level assigned.
  
• Name: Gets or sets the name of the <portType> element in the Web Services Description Language (WSDL).
  
• Namespace: Gets or sets the namespace of the <portType> element in the Web Services Description Language (WSDL).
  
• ProtectionLevel: Specifies whether the binding for the contract must support the value of the ProtectionLevel property.
  
• SessionMode: Gets or sets whether sessions are allowed, not allowed or required.
  
• TypeId: When implemented in a derived class, gets a unique identifier for this Attribute.

Data Contract

 

Data Contracts define the data type for variables that are the same as get and set properties but the difference is that a Data Contract in WCF is used to serialize and deserialize the complex data. It defines how data types are serialized and deserialized. Using serialization, you can convert an object into a sequence of bytes that can be transmitted over a network. Using de-serialization, you reassemble an object from a sequence of bytes that you receive from a calling application.

 

It can be defined as follows:

1. [DataContract]  
2. public class Student  
3. {  
4.     private string _Name;  
5.   
6.     private string _City;  
7.   
8.   
9.     [DataMember]  
10.     public string Name  
11.     {  
12.         get { return _Name; }  
13.         set { _Name = value; }  
14.     }  
15. } 
    

Fault Contract

 

A Fault Contract handles the exception and understands the cause of the error that occurs in the WCF service. When we develop a managed application or service, we will handle the exception using a try- catch block, but these exceptions handlers are technology-specific.

 

The following is the syntax to raise the custom error in WCF:

1. [ServiceContract]  
2. public interface IGetDetailsService  
3. {  
4.      [OperationContract]  
5.      [FaultContract(typeof(Student))]  
6.      Student GetDetails(string Name);  
7. }  
8.   
9. [DataContract]  
10. public class Student  
11. {  
12.      private string _Name;  
13.   
14.      private string _City;  
15.   
16.      [DataMember]  
17.      public string Name  
18.      {  
19.          get { return _Name; }  
20.          set { _Name = value; }  
21.      }  
22.   
23.      [DataMember]  
24.      public string City  
25.      {  
26.          get { return _City; }  
27.          set { _City = value; }  
28.      }  
29. } 
    

Message contracts

 

The default SOAP message format is provided by the WCF runtime for communication between the client and the service. If it does not meet your requirements then we can create our own message format. This can be done using the Message Contract attribute.

 

It can be defined as:

1. [MessageContract]  
2. public class Person  
3. {  
4.    [MessageHeader] public Operation Name;  
5.    [MessageHeader] public string city;  
6.    [MessageBodyMember] private Home Address;  
7.    [MessageBodyMember] private Home Streat;  
8.    [MessageBodyMember] public int age;  
9. } 
   

Note

 

Please refer to the following articles for a complete understanding:

• Introduction to WCF Service
• Creating WCF Service
• End Points in WCF
• Ajax Enabled WCF Service
• Binding In WCF Service
• Consuming WCF Service in Web Application

Summary

 

I hope this article is useful for all students and beginners. Happy Learning , i have refer this Article from Mr Vithal Wadje