Mastering-ASPNET-Web-API-and-RESTful-Patterns.pptx

Mastering-ASPNET-Web-API-and-RESTful-Patterns.pptx

• 1.
  Mastering ASP.NET Web API& RESTful Patterns Welcome to this deep dive into ASP.NET Web API and RESTful principles, tailored for software developers. We'll explore how to build robust, scalable, and maintainable web services.
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  Introduction to ASP.NETWeb API What is ASP.NET Web API? A framework for building HTTP services that can be consumed by a broad range of clients, including browsers, mobile devices, and other applications. Use Cases • Building backend services for single-page applications (SPAs) • Creating mobile application backends • Exposing data for public APIs Web API vs. MVC Web API Focuses on data, returns various formats (JSON, XML), no view engine. MVC Focuses on views, returns HTML, includes a view engine for rendering UI.
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  REST Basics: TheFoundation of Modern APIs Representational State Transfer (REST) An architectural style for distributed hypermedia systems. It leverages existing protocols, primarily HTTP. Key Principles Client-Server, Stateless, Cacheable, Layered System, Uniform Interface, Code-On-Demand (optional). Why REST for Web APIs? Simplicity, scalability, and broad interoperability with various clients. It's lightweight and widely adopted.
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  RESTful API DesignPrinciples 1 Resource-based URLs Identify resources with unique URIs, treating them as nouns (e.g., /products, /users). 2 Stateless Communication Each request from a client to server contains all information needed to understand the request. No session state on the server. 3 Standard HTTP Methods Utilize HTTP verbs (GET, POST, PUT, DELETE, PATCH) to perform actions on resources. 4 Hypermedia as the Engine of Application State (HATEOAS) Responses include links to related resources, guiding the client on available actions.
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  HTTP Verbs andTheir Usage GET Retrieve a resource or a collection of resources. Idempotent & Safe. POST Create a new resource. Not idempotent. PUT Update an existing resource, replacing it entirely. Idempotent. DELETE Remove a resource. Idempotent. PATCH Apply partial modifications to a resource. Not necessarily idempotent.
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  URI Design BestPractices Plural Nouns for Resources Use plural forms to represent collections: /products, /users. Nesting for Relationships Show relationships clearly: /users/10/orders, /products/5/reviews. Avoid Verbs in URIs URIs should identify resources, not actions. Actions are handled by HTTP methods. Bad: /getAllProducts. Good: /products. Use Lowercase and Hyphens Maintain consistency with lowercase letters and hyphens for readability.
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  Understanding HTTP StatusCodes HTTP status codes communicate the result of an API request, providing crucial feedback to the client. 200 OK Standard success response for GET, PUT, PATCH. 201 Created Resource successfully created, typically for POST requests. 204 No Content Request successful, but no content to return (e.g., DELETE). 400 Bad Request Client-side error, e.g., invalid input. 404 Not Found Resource does not exist. 500 Internal Server Error Generic server-side error.
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  Designing Controllers inASP.NET Web API Convention-based Routing Default routing based on controller and action names (e.g., /api/{controller}/{id}). Attribute Routing More flexible and explicit routing using attributes like [HttpGet], [HttpPost], and [Route("api/products")] directly on methods and controllers. Controller Example: ProductController [RoutePrefix("api/products")]public class ProductController : ApiController{ [HttpGet] [Route("")] public IHttpActionResult GetProducts() { ... } [HttpGet] [Route("{id}")] public IHttpActionResult GetProduct(int id) { ... } [HttpPost] [Route("")] public IHttpActionResult CreateProduct([FromBody]Product product) { ... }}
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  Content Negotiation andAPI Versioning Content Negotiation APIs can serve different data formats (e.g., JSON, XML) based on the client's Accept header. Accept Headers Clients specify preferred formats (e.g., Accept: application/json). Default Format ASP.NET Web API defaults to JSON. Custom Formatters Extend API to support additional formats (e.g., CSV, Protobuf). API Versioning Manage changes to your API over time without breaking existing client applications. URI Versioning Include version in the URI: /api/v1/products. Simple, but can make URIs longer. Query String Versioning Add version as a query parameter: /api/products?v=2. Less RESTful. Header-based Versioning Custom header for version: X-API-Version: 2. Clean URIs, but less discoverable.
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  Security in WebAPI Authentication Verify user identity: JSON Web Tokens (JWT), OAuth2, API Keys. Crucial for secure access. Authorization Determine user permissions: Role- based, Claim-based. Control what actions authenticated users can perform. CORS (Cross-Origin Resource Sharing) Enable secure cross-domain requests, specifying which origins are allowed to access your API. Thank you for joining this session on ASP.NET Web API and RESTful patterns. Embrace these principles to build powerful and secure web services.