gistfile1.txt

using Microsoft.AspNetCore.Mvc;
using Newtonsoft.Json;
using ShoppingCartApp.ExtensionMethod;
using ShoppingCartApp.Models;

namespace ShoppingCartApp.Controllers
{
    public class ShoppingCartController : Controller
    {

        public IActionResult Index()
        {
            return View();
        }
        public IActionResult Create(CartItem item)
        {
            AddToCart(item);

            return View("Index");
        }

        public IActionResult Remove(CartItem item)
        {
            if (item == null)
            {
                return View("Index");
            }
            //Calling Item Remove Method and passing cart item
            RemoveItemFromCart(item);

            return View("Index");
        }
        public IActionResult RemoveAllItems()
        {

            //Calling Item Remove Method and passing cart item
            RemoveAllItemFromCart();

            return View("Index");
        }
        public IActionResult CheckOut()
        {
            //Do Check out stuff here


            //Clear your shopping cart once checkout stuff done
            RemoveAllItemFromCart();

            return View("Index");
        }
        public void AddToCart(CartItem item)
        {

            var cart = HttpContext.Session.GetComplexObjectSession<ShoppingCartObject>("ShoppingCart");
            if (cart != null)
            {
                cart!.CartItems!.Add(item);
                HttpContext.Session.SetComplexObjectSession("ShoppingCart", cart);
            }
            else
            {
                cart = new ShoppingCartObject();
                cart!.CartItems!.Add(item);
                HttpContext.Session.SetComplexObjectSession("ShoppingCart", cart);
            }

        }
        public void RemoveAllItemFromCart()
        {
            var cart = HttpContext.Session.GetComplexObjectSession<ShoppingCartObject>("ShoppingCart");
            if (cart != null)
            {
                foreach (var item in new List<CartItem>(cart.CartItems))
                {
                    cart!.CartItems!.Remove(item);
                    HttpContext.Session.SetComplexObjectSession("ShoppingCart", item);
                }
            }
           
            
            
        }
        public void RemoveItemFromCart(CartItem item)
        {
            var cart = HttpContext.Session.GetComplexObjectSession<ShoppingCartObject>("ShoppingCart");
            cart!.CartItems!.Remove(cart.CartItems.Find(cartItem => cartItem.ItemName == item.ItemName));
            HttpContext.Session.SetComplexObjectSession("ShoppingCart", cart);
        }
    }

    
}

namespace ShoppingCartApp.Models
{
    public class ShoppingCartObject
    {
        public List<CartItem>? CartItems { get; set; } = new List<CartItem>();

    }
}

using ShoppingCartApp.ExtensionMethod;

namespace ShoppingCartApp.Models
{
    public class CartItem
    {
        public int CartId { get; set; }
        public string? ItemName { get; set; }
        public decimal Price { get; set; }
        public decimal Total { get; set; } = decimal.Zero;
        
    }
}

using Microsoft.AspNetCore.Mvc;
using ShoppingCartApp.ExtensionMethod;
using ShoppingCartApp.Models;
using System.Diagnostics;

namespace ShoppingCartApp.Controllers
{
    public class HomeController : Controller
    {
        private readonly ILogger<HomeController> _logger;

        public HomeController(ILogger<HomeController> logger)
        {
            _logger = logger;
        }

        public IActionResult Index()
        {
            return View();
        }
        public IActionResult Remove(CartItem item)
        {
            if (item == null)
            {
                return View("Index");
            }
            //Calling Item Remove Method and passing cart item
            RemoveItemFromCart(item);

            return View("Index");
        }
        public void RemoveItemFromCart(CartItem item)
        {
            Console.WriteLine($"Your function has executed item: {item.ItemName}");
        }

        public IActionResult Privacy()
        {
            return View();
        }

        [ResponseCache(Duration = 0, Location = ResponseCacheLocation.None, NoStore = true)]
        public IActionResult Error()
        {
            return View(new ErrorViewModel { RequestId = Activity.Current?.Id ?? HttpContext.TraceIdentifier });
        }
    }
}

using Newtonsoft.Json;

namespace ShoppingCartApp.ExtensionMethod
{
    public static class SessionExtension
    {
        //setting session
        public static void SetComplexObjectSession(this ISession session, string key, object value)
        {
            session.SetString(key, JsonConvert.SerializeObject(value));
        }

        //getting session
        public static T? GetComplexObjectSession<T>(this ISession session, string key)
        {
            var value = session.GetString(key);
            return value == null ? default(T) : JsonConvert.DeserializeObject<T>(value);
        }
    }
}

var builder = WebApplication.CreateBuilder(args);

// Add services to the container.
builder.Services.AddControllersWithViews();

builder.Services.AddHttpContextAccessor();

builder.Services.AddSession(options =>
{
    options.Cookie.Name = "shoppingCart";
    options.IdleTimeout = TimeSpan.FromMinutes(5);
    options.Cookie.IsEssential = true;
});

var app = builder.Build();

// Configure the HTTP request pipeline.
if (!app.Environment.IsDevelopment())
{
    app.UseExceptionHandler("/Home/Error");
    // The default HSTS value is 30 days. You may want to change this for production scenarios, see https://aka.ms/aspnetcore-hsts.
    app.UseHsts();
}

app.UseHttpsRedirection();
app.UseStaticFiles();

app.UseRouting();
app.UseSession();

app.UseAuthorization();

app.MapControllerRoute(
    name: "default",
    pattern: "{controller=Home}/{action=Index}/{id?}");

app.Run();

@model ShoppingCartApp.Models.CartItem

@{
    ViewData["Title"] = "Home Page";
}

<div class="text-center">
    <h1 class="display-4">Welcome</h1>
    <p>Learn about <a href="https://docs.microsoft.com/aspnet/core">building Web apps with ASP.NET Core</a>.</p>
</div>


<div>
    <form asp-action="Remove">
        <input asp-for="@Model.ItemName" class="form-control" value="MyValue" hidden />
        <input type="submit" value="Call Controller Method" class="btn btn-warning" />
    </form>
</div>

@model ShoppingCartApp.Models.CartItem
@inject IHttpContextAccessor httpContextAccessor
@using ShoppingCartApp.ExtensionMethod


<div class="row">
    <div class="col-sm-3">
        <form method="post" asp-action="Create">
            <div class="card" style="width: 18rem; margin-bottom:20px;box-shadow: rgba(0, 0, 0, 0.35) 0px 5px 15px;">
                <div class="card-body">
                    <h5 class="card-title">C# Fundamental</h5>
                    <p class="card-text">A-Z of csharp</p>
                    <p class="card-text">$10.00</p>
                    <input asp-for="@Model.ItemName" class="form-control" value="C# Fundamental" hidden />
                    <input asp-for="@Model.Price" class="form-control" value="10" hidden />
                    <input type="submit" value="Add to cart" class="btn btn-primary" />
                </div>
            </div>
        </form>
    </div>
    <div class="col-sm-3">
        <form method="post" asp-action="Create">
            <div class="card" style="width: 18rem; margin-bottom:20px;box-shadow: rgba(0, 0, 0, 0.35) 0px 5px 15px;">
                <div class="card-body">
                    <h5 class="card-title">Asp.net core</h5>
                    <p class="card-text">A-Z of Asp.net core</p>
                    <p class="card-text">$15.00</p>
                    <input asp-for="@Model.ItemName" class="form-control" value="Asp.Net Core" hidden />
                    <input asp-for="@Model.Price" class="form-control" value="15" hidden />
                    <input type="submit" value="Add to cart" class="btn btn-primary" />
                </div>
            </div>
        </form>
    </div>
    <div class="col-sm-3">
        <form method="post" asp-action="Create">
            <div class="card" style="width: 18rem; margin-bottom:20px;box-shadow: rgba(0, 0, 0, 0.35) 0px 5px 15px;">
                <div class="card-body">
                    <h5 class="card-title">Asp.net Core Razor</h5>
                    <p class="card-text">A-Z of Razor</p>
                    <p class="card-text">$18.00</p>
                    <input asp-for="@Model.ItemName" class="form-control" value="Asp.net Core Razor" hidden />
                    <input asp-for="@Model.Price" class="form-control" value="18" hidden />
                    <input type="submit" value="Add to cart" class="btn btn-primary" />
                </div>
            </div>
        </form>
    </div>
    @{

        var shoppingCart = httpContextAccessor.HttpContext!.Session.GetComplexObjectSession<ShoppingCartObject>("ShoppingCart");
        decimal totalPrice = 0;
        if (shoppingCart != null)
        {
            <div class="col-sm-2">
                <div class="card" style="width: 18rem; margin-bottom:20px;box-shadow: rgba(0, 0, 0, 0.35) 0px 5px 15px;">
                    <div class="card-body">
                        <h5 class="card-title">Shopping Cart</h5>
                        <table class="table">
                            <thead>
                                <tr>
                                    <th>
                                        Item
                                    </th>
                                    <th>
                                        Price
                                    </th>
                                </tr>
                            </thead>
                            <tbody>

                                @foreach (var item in shoppingCart!.CartItems!)
                                {
                                    <tr>
                                        <td>
                                            @Html.DisplayFor(modelItem => item.ItemName)
                                        </td>
                                        <td>
                                            @Html.DisplayFor(modelItem => item.Price)
                                        </td>
                                        <td>
                                            <form asp-action="Remove">
                                                <input asp-for="@Model.ItemName" class="form-control" value="@item.ItemName" hidden />
                                                <input type="submit" value="Remove" class="btn btn-warning" />
                                            </form>

                                        </td>
                                    </tr>
                                    totalPrice += item.Price;
                                }
                            </tbody>
                        </table>
                        <strong style="margin-right:153px">Total</strong> <strong><i>$ @totalPrice</i></strong>
                        <div class="row" style="margin-top:20px">
                            <div class="col-md-6">
                                <form asp-action="RemoveAllItems">
                                    <input type="submit" value="Clear All Item" class="btn btn-danger"/>
                                </form>
                            </div>
                            <div class="col-md-6">
                                <form asp-action="CheckOut">
                                    <input type="submit" value="Check Out" class="btn btn-success" />
                                </form>

                            </div>
                        </div>
                    </div>
                </div>
            </div>

        }


    }
</div>