Asp.net core is a brand new, open source and cross
platform framework for building modern internet applications. Unlike its
predecessor Asp.net core is lightweight, robust, fast (Kestrel Web server), and
cloud ready.
Asp.net core
is designed to integrate seamlessly with varieties of client side frameworks like
AngularJS, ReactJS, KnockoutJS …
Modern
internet applications communication language is HTTP. So you will came across
many scenarios to intercept client’s HTTP request and process it. I will explain
a real scenario, “As part of application authentication, you have to make sure user\company
employee must be logged into their corporate network/global login before
accessing application.”
In Asp.net
core Middleware’s replaced IHTTPModule
and IHTTPHandler. Middleware is an application pipeline to
handle request and response .
I will
quickly walk through you the code snippets:
a
First create two class as below
using Microsoft.AspNetCore.Builder;
using Microsoft.AspNetCore.Http;
using System;
using System.Collections.Generic;
using System.Linq;
using System.Threading.Tasks;
namespace WebApplication5.Middleware
{
public class CustomMiddleware
{
private readonly RequestDelegate
_next;
public
CustomMiddleware(RequestDelegate next)
{
_next = next;
}
public async Task Invoke(HttpContext context)
{
string
companyAuthCookie = ApiHelper.GetConfigValue("companyAuthCookie");
bool securityEnabled = bool.Parse(ApiHelper.GetConfigValue("SecurityEnabled"));
if (securityEnabled)
{
var header = context.Request.Headers;
var cookies = context.Request.Cookies;
if
(cookies.ContainsKey(companyAuthCookie))
{
//allow other middle to process http request
await _next.Invoke(context);
}
else
{
//short circuit or terminate http process request because
user haven't logged in
context.Response.Redirect(ApiHelper.GetConfigValue("RedirectUrl"));
}
}
else
{
await _next.Invoke(context);
}
}
}
public static class CustomMiddlewareExtensions
{
public static IApplicationBuilder
UseCSPMiddleware(this IApplicationBuilder builder)
{
return
builder.UseMiddleware<CustomMiddleware>();
}
}
}
Then goto
Startup class (Startup.cs)
public void Configure(IApplicationBuilder app, IHostingEnvironment env, ILoggerFactory loggerFactory)
{
loggerFactory.AddConsole(Configuration.GetSection("Logging"));
loggerFactory.AddDebug();
//in asp.net core order is important. Make
sure you call it in early stage
app.UseCSPMiddleware();
app.UseMvc();
}
That’s it,
you have created code to intercept http request and process it inside asp.net
core.
Reference:
