using System;
namespace ConsoleApplication285
{
class Program
{
static void Main(string[] args)
{
Console.WriteLine("Hello, World!");
}
}
}
Console Template for .NET 6
// See https://aka.ms/new-console-template for more information
Console.WriteLine("Hello, World!");
CW 2021
Program.cs in ASP.NET Empty template for .NET 6
var builder = WebApplication.CreateBuilder(args);
var app = builder.Build();
if (app.Environment.IsDevelopment())
{
app.UseDeveloperExceptionPage();
}
app.MapGet("/", () => "Hello World!");
app.Run();
Minimal Application Example
var builder = WebApplication.CreateBuilder(args);
builder.Services.AddEndpointsApiExplorer();
builder.Services.AddSwaggerGen();
builder.Services.AddSingleton<IGameRepository, FakeGameRepository>();
var app = builder.Build();
if (app.Environment.IsDevelopment())
{
app.UseSwagger();
app.UseSwaggerUI();
}
app.UseHttpsRedirection();
app.MapPost("games", async (Game game, IGameRepository repo)
=>
{
await repo.CreateAsync(game);
return Results.Created($"games/{game.Id}", game);
}
);
app.MapGet("games/{id}", async (int id, IGameRepository repo)
=>
{
var game = await repo.GetAsync(id);
if (game is null)
{
return Results.NotFound();
}
return Results.Ok(game);
}
);
app.MapGet("games", async (string? likename, IGameRepository repo)
=>
{
if (likename is null)
{
var allgames = await repo.GetAll();
return Results.Ok(allgames);
}
var matchedGames = await repo.GetGameByLikeName(likename);
return Results.Ok(matchedGames);
}
);
app.MapPut("games", async (Game game, IGameRepository repo)
=>
{
await repo.UpdateAsync(game);
return Results.Ok(game);
}
);
app.Run();
CW 2021CW 2021CW 2021
Program.cs in ASP.NET Web template for .NET 6
var builder = WebApplication.CreateBuilder(args);
// Add services to the container.
builder.Services.AddControllersWithViews();
var app = builder.Build();
// Configure the HTTP request pipeline.
if (app.Environment.IsDevelopment())
{
app.UseDeveloperExceptionPage();
}
else
{
app.UseExceptionHandler("/Home/Error");
// The default HSTS value is 30 days.
app.UseHsts();
}
app.UseHttpsRedirection();
app.UseStaticFiles();
app.UseRouting();
app.UseAuthorization();
app.MapControllerRoute(
name: "default",
pattern: "{controller=Home}/{action=Index}/{id?}");
app.Run();
This is nothing new for other languages
NodeJs Hello World Example
// Import the top-level function of express
const express = require('express');
// Creates an Express application using the top-level function
const app = express();
// Define port number as 3000
const port = 3000;
// Routes HTTP GET requests to the specified path
// "/" with the specified callback function
app.get('/', function(request, response) {
response.send('Hello, World!');
});
// Make the app listen on port 3000
app.listen(port, function() {
console.log('Server listening on http://localhost:' + port);
});
Go REST API with gin
package main
import (
"net/http"
"github.com/gin-gonic/gin"
)
func main() {
router := gin.Default()
router.GET("/albums", getAlbums)
router.GET("/albums/:id", getAlbumByID)
router.POST("/albums", postAlbums)
router.Run("localhost:8080")
}
// album represents data about a record album.
type album struct {
ID string `json:"id"`
Title string `json:"title"`
Artist string `json:"artist"`
Price float64 `json:"price"`
}
// albums slice to seed record album data.
var albums = []album{
{ID: "1", Title: "Blue Train", Artist: "John Coltrane", Price: 56.99},
{ID: "2", Title: "Jeru", Artist: "Gerry Mulligan", Price: 17.99},
{ID: "3", Title: "Sarah Vaughan and Clifford Brown", Artist: "Sarah Vaughan", Price: 39.99},
}
// getAlbums responds with the list of all albums as JSON.
func getAlbums(c *gin.Context) {
c.IndentedJSON(http.StatusOK, albums)
}
// postAlbums adds an album from JSON received in the request body.
func postAlbums(c *gin.Context) {
var newAlbum album
// Call BindJSON to bind the received JSON to
// newAlbum.
if err := c.BindJSON(&newAlbum); err != nil {
return
}
// Add the new album to the slice.
albums = append(albums, newAlbum)
c.IndentedJSON(http.StatusCreated, newAlbum)
}
// getAlbumByID locates the album whose ID value matches the id
// parameter sent by the client, then returns that album as a response.
func getAlbumByID(c *gin.Context) {
id := c.Param("id")
// Loop through the list of albums, looking for
// an album whose ID value matches the parameter.
for _, a := range albums {
if a.ID == id {
c.IndentedJSON(http.StatusOK, a)
return
}
}
c.IndentedJSON(http.StatusNotFound, gin.H{"message": "album not found"})
}
REST API : Python FastApi
# main.py
from fastapi import FastAPI
app = FastAPI()
@app.get("/users/me")
async def read_user_me():
return {"user_id": "the current user"}
@app.get("/users/{user_id}")
async def read_user(user_id: str):
return {"user_id": user_id}
CW 2021
NancyFX is a lightweight, low-ceremony, framework for building HTTP based services on .NET Framework/Core
public class Module : NancyModule
{
public Module()
{
Get("/greet/{name}", x => {
return string.Concat("Hello ", x.name);
});
}
}
You mean people didn't like controllers in the past in .NET 😲
How is this possible in C#? 👓
CW 2021CW 2021C# 9 Top Level Statements
C# 9.0 : Console Top Level Calls
using System;
if (args.Length == 0)
{
System.Console.WriteLine("Please enter a numeric argument.");
}
using System;
using System.Collections.Generic;
using System.Threading.Tasks;
Console.WriteLine("Daj pozytwna ocene");
await Task.Delay(2000);
List<string> list = new List<string>();
list.Add("Tej prelekcj");
// <auto-generated/>
global using global::System;
global using global::System.Collections.Generic;
global using global::System.IO;
global using global::System.Linq;
global using global::System.Net.Http;
global using global::System.Threading;
global using global::System.Threading.Tasks;
For web application
// <autogenerated />
global using global::System;
global using global::System.Collections.Generic;
global using global::System.IO;
global using global::System.Linq;
global using global::System.Net.Http;
global using global::System.Threading;
global using global::System.Threading.Tasks;
global using global::System.Net.Http.Json;
global using global::Microsoft.AspNetCore.Builder;
global using global::Microsoft.AspNetCore.Hosting;
global using global::Microsoft.AspNetCore.Http;
global using global::Microsoft.AspNetCore.Routing;
global using global::Microsoft.Extensions.Configuration;
global using global::Microsoft.Extensions.DependencyInjection;
global using global::Microsoft.Extensions.Hosting;
global using global::Microsoft.Extensions.Logging;
// C# 9
Func getUserInput = Console.ReadLine;
Action tellUser = (string s) => Console.WriteLine(s);
Func waitForEnter = Console.ReadLine;
tellUser("Please enter name");
var name = getUserInput();
tellUser($"Your name is {name}");
waitForEnter();
C# 10 Inferred lambda types
// C# 10
var getUserInput = Console.ReadLine;
var tellUser = (string s) => Console.WriteLine(s);
var waitForEnter = Console.ReadLine;
tellUser("Please enter name");
var name = getUserInput();
tellUser($"Your name is {name}");
waitForEnter();
Explicit return types in lambdas
var a1 = string () => string.Empty;
var a2 = int () => int.MaxValue;
var a3 = static void () => { };
var a4 = string? () => null;
public static void Example<T>()
{
var a5 = T () => default;
}
Maybe in the future this will be great for interactive notebooks (Jupyter Notebooks)
Good for source generators
But seriously why?
What minimal APIs are not?
One-file API's
Just for demos
Just for beginners
Going to kill Controllers
Minimal APIs maybe would perform much better than controller-based APIs ? 🤔
Yes, kinda 😅
What is not supported
No support for filters (IAsyncActionFilter, IAsyncResultFilter, IAsyncExceptionFilter)
No build-in support for validation (IModelValidator)
What is not supported
No support for JsonPatch
No support for OData
No support for ApiVersioning (yet :))
What is wrong with Controllers? 😨
How many Controllers you created that return a View 🤔
What is wrong with Controllers for APIs? 😨
What is wrong with Controllers for APIs?
Controllers have methods that never call one another
Controllers kinda break Single Responsibility
You can create BIG FAT Controllers
What is wrong with Controllers for APIs?
They can have services inejected that aren't used by all Actions
They never share state between Actions
They invoke Middleware and Filters you might not need
What about DDD, Clean Architecture, CQRS You know buzzwords
CW 2021CW 2021
In this context the most important thing in controller is?
Information about which URL path is supported by which controller. Is that clear enough?
Other important things in controller are?
What HTTP Status should be returned when
Maybe translation between client object and Commands and Queries
CW 2021CW 2021CW 2021Code Example of Clean Architecture
Return to Minimal Application
Minimal Application Example
var builder = WebApplication.CreateBuilder(args);
builder.Services.AddSingleton<IEmployeeService, EmployeeService>();
builder.Services.AddSingleton<IHelloWorldService, HelloWorldService>();
var app = builder.Build();
app.MapGet("/", () => "Daj Like");
app.MapGet("/quote/", async () =>
await new HttpClient().GetStringAsync
("https://ron-swanson-quotes.herokuapp.com/v2/quotes"));
app.MapPost("/employee",
(Employee e, IEmployeeService ser) =>
{
return ser.ShowEmployee(e);
});
app.MapGet("/hello",
(HttpContext context, IHelloWorldService service)
=>
{
return service.SayHello
(context.Request.Query["name"].ToString());
});
app.Run();
public class HelloWorldService : IHelloWorldService
{
public string SayHello(string user)
{
return $"Hello {user}";
}
}
public interface IHelloWorldService
{
public string SayHello(string user);
}
public record Employee(string FirstName, [Required] string LastName);
public interface IEmployeeService
{
public string ShowEmployee(Employee employee);
}
public class EmployeeService : IEmployeeService
{
public string ShowEmployee(Employee e)
{
return "We have a new employee:" +
$" {e.FirstName} {e.LastName}";
}
}
Show me example of CQRS with minimal application
You: OK...
You: OK, so you created one big file instead of controllers
You: This is lame 😟
Nah...Man You don't see everything 😎
CW 2021You are forced to always make a castle
CW 2021But maybe you want more control
without IControllerFactory or other hacks
Show me a system for minimal application
Let's end this with this slide
CW 2021
