The app would provide a user with a way to keep a record of expenses.

NOTE: This tutorial uses .NET 6.0 (Long Term Support) and may not work the same for other versions.

Things you'll need (Prerequisites)

• Visual Studio Installed

• SQL Server Express Installed

• Working knowledge of C#

GitHub Link

https://github.com/MarvinBotchway/BlazorExpenseTracker

Create New Project

• Open Visual Studio and click Create New Project

• Search and select Blazor Webassembly App -> press next

  • NOTE: Make sure its the option for C# and not F#

• Name both the project and solution BlazorExpenseTracker -> press next.

• Select .NET 6.0 (Long Term Support).

  • Authentication type None.

  • Make sure the ASP.NET Core Hosted option is ticked (This would add a Web API and Shared Project to the solution).

  • Click Create.

• Run the application to test if everything worked well.

• If you see the default app without any error you are fine.

Add Swagger

Installing Swagger

• Right-click on BlazorExpenseTracker.Server -> Manage Nuget Packages...

• Make sure Browse is selected and search Swagger.

  • Select the package shown in the picture below Swashbuckle.AspNetCore and install.

    NOTE: Select a version starting with 6 like 6.4.0

Add and Configure Swagger Middleware.

• In BlazorExpenseTracker.Server/Program.cs add the Swagger generator to the services collection.

• Enable the middleware for serving the generated JSON document and also the Swagger UI.

Full BlazorExpenseTracker.Server/Program.cs File Below.

using Microsoft.AspNetCore.ResponseCompression;
using Microsoft.OpenApi.Models;

var builder = WebApplication.CreateBuilder(args);

// Add services to the container.

builder.Services.AddControllersWithViews();
builder.Services.AddRazorPages();

// Swagger - Add the Swagger generator to the services collection
builder.Services.AddSwaggerGen(option =>
{
    option.SwaggerDoc("v1", new OpenApiInfo { Title = "ExpenseNerd API", Version = "v1" });

});

var app = builder.Build();

// Configure the HTTP request pipeline.
if (app.Environment.IsDevelopment())
{
    app.UseWebAssemblyDebugging();

    // Swagger - Enable the middleware
    app.UseSwagger();
    app.UseSwaggerUI();
}
else
{
    app.UseExceptionHandler("/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.UseBlazorFrameworkFiles();
app.UseStaticFiles();

app.UseRouting();


app.MapRazorPages();
app.MapControllers();
app.MapFallbackToFile("index.html");

app.Run();

• Save and run the app.

• Add /swagger/index.html to the URL and press enter.

• You can see the default API endpoint WeatherForcast showing.

Add ExpenseModel

• In BlazorExpenseTracker.Shared add a new folder named Models.

• In BlazorExpenseTracker.Shared/Models add a class and name it Expense.cs

  • Change the class modifier from internal to public.

  • Add the properties below.

using System;
using System.Collections.Generic;
using System.Linq;
using System.Text;
using System.Threading.Tasks;

namespace BlazorExpenseTracker.Shared.Models
{
    public class ExpenseModel
    {
        public int Id { get; set; }
        public decimal Amount { get; set; } = 0;
        public DateTime CreatedAt { get; set; }
    }
}

Add Database

Add Database Connection String

In BlazorExpenseTracker.Server/appsettings.json add "ConnectionStrings".

{
  // Database Connection String
  "ConnectionStrings": {
    "DefaultConnection": "server =localhost\\sqlexpress; database = BlazorExpenseTrackerDb; trusted_connection = true"
  },
  "Logging": {
    "LogLevel": {
      "Default": "Information",
      "Microsoft.AspNetCore": "Warning"
    }
  },
  "AllowedHosts": "*"
}

Install EF Core

• Right-click on BlazorExpenseTracker.Server and Select Manage Nuget Packages...

• Make sure Browse is selected and search EntityFrameworkCore.

• Install the 4 EntityFrameworkCore packages shown below.

  NOTE: Instal version 6.0.11 or it may not work well.

Add DbContext (DataContext)

• Right-click on BlazorExpenseTracker.Server -> Add a new folder Data .

• Right-Click on the new folder Data you just created and add a class DataContext.cs .

• Let DataContext Inherit from DbContext as shown below.

using Microsoft.EntityFrameworkCore;

namespace BlazorExpenseTracker.Server.Data
{
    public class DataContext : DbContext
    {
    }
}

Register DataContext

In BlazorExpenseTracker.Server/Program.cs register DataContext

using BlazorExpenseTracker.Server.Data;
using Microsoft.AspNetCore.ResponseCompression;
using Microsoft.EntityFrameworkCore;
using Microsoft.OpenApi.Models;

var builder = WebApplication.CreateBuilder(args);

// Add services to the container.

builder.Services.AddControllersWithViews();
builder.Services.AddRazorPages();

// Register DataContext
builder.Services.AddDbContext<DataContext>(options =>
{
    options.UseSqlServer(builder.Configuration.GetConnectionString("DefaultConnection"));
});

// Swagger - Add the Swagger generator to the services collection
builder.Services.AddSwaggerGen(option =>
{
    option.SwaggerDoc("v1", new OpenApiInfo { Title = "ExpenseNerd API", Version = "v1" });

});

var app = builder.Build();

// Configure the HTTP request pipeline.
if (app.Environment.IsDevelopment())
{
    app.UseWebAssemblyDebugging();

    // Swagger - Enable the middleware
    app.UseSwagger();
    app.UseSwaggerUI();
}
else
{
    app.UseExceptionHandler("/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.UseBlazorFrameworkFiles();
app.UseStaticFiles();

app.UseRouting();


app.MapRazorPages();
app.MapControllers();
app.MapFallbackToFile("index.html");

app.Run();

Add Seed Data

In BlazorExpenseTracker.Server/Data/DataContext

using BlazorExpenseTracker.Shared.Models;
using Microsoft.EntityFrameworkCore;

namespace BlazorExpenseTracker.Server.Data
{
    public class DataContext : DbContext
    {
        public DataContext(DbContextOptions<DataContext> options) : base(options)
        {

        }

        protected override void OnModelCreating(ModelBuilder modelBuilder)
        {
            modelBuilder.Entity<ExpenseModel>().HasData
            (
                new ExpenseModel()
                {
                    Id = 1,
                    Amount = 10.0M,
                    CreatedAt = DateTime.UtcNow
                },
                new ExpenseModel()
                {
                    Id = 2,
                    Amount = 100.0M,
                    CreatedAt = DateTime.UtcNow.AddHours(1)
                }
                , new ExpenseModel()
                {
                    Id = 3,
                    Amount = 0.0M,
                    CreatedAt = DateTime.UtcNow.AddHours(2)
                }

            );


        }

        public DbSet<ExpenseModel> Expenses { get; set; }
    }
}

Add Migrations

• Open Package Manager Console

• Enter the following commands

cd .\BlazorExpenseTracker\Server

• Change current folder to .\BlazorExpenseTracker\Server with the command above.

Add-Migration InitialSeedData

• Add the first migration and name it InitialSeedData as above.

Update-Database

• Create/Update the Database.

Update ExpenseModel.cs

In BlazorExpenseTracker.Shared/models/ExpenseModel.cs

• Add 2 properties Title and Description

• Add an attribute to Amount to remove the warning when adding migration.

using System;
using System.Collections.Generic;
using System.ComponentModel.DataAnnotations;
using System.ComponentModel.DataAnnotations.Schema;
using System.Linq;
using System.Text;
using System.Threading.Tasks;

namespace BlazorExpenseTracker.Shared.Models
{
    public class ExpenseModel
    {
        public int Id { get; set; }
        public string Title { get; set; } = string.Empty;
        public string Description { get; set; } = string.Empty;

        [Column(TypeName = "decimal(18,4)")]
        public decimal Amount { get; set; } = 0.0M;
        public DateTime CreatedAt { get; set; } 
    }
}

Using the package manager Add a Migration to make the change in the database

Add-Migration AddPresisonToAmount

Update-Database

Add Controller.

• Right-Click on BlazorExpenseTracker.Server/Controllers

• Click Add -> Controller...

• At the left side of the dialogue click API.

• Select API Controller - Empty.

• Click Add and name the controller ExpenseController.cs.

• Add a constructor with the DataContext context as a parameter

• Add the field _context

• Add functions for different API calls.

• Run the app and go to swagger to view and test the API endpoints.

using BlazorExpenseTracker.Server.Data;
using BlazorExpenseTracker.Shared.Models;
using Microsoft.AspNetCore.Http;
using Microsoft.AspNetCore.Mvc;
using Microsoft.EntityFrameworkCore;

namespace BlazorExpenseTracker.Server.Controllers
{
    [Route("api/[controller]")]
    [ApiController]
    public class ExpenseController : ControllerBase
    {
        private readonly DataContext _context;

        public ExpenseController(DataContext context)
        {
            _context = context;
        }
        [HttpGet]
        public async Task<ActionResult<List<ExpenseModel>>> GetAllExpensesAsync()
        {
            var response = await _context.Expenses.ToListAsync();
            return Ok(response);
        }
        [HttpPost]
        public async Task<ActionResult<ExpenseModel>> CreateExpenseAsync(ExpenseModel expense)
        {
            var response = await _context.Expenses.AddAsync(expense);
            await _context.SaveChangesAsync();
            return Ok(response.Entity);

        }

        [HttpPut]
        [Route("{id}")]
        public async Task<ActionResult<ExpenseModel>> EditExpenseAsync(ExpenseModel expense, int id)
        {
            ExpenseModel? response = null;

            var DbExpense = await _context.Expenses.FirstOrDefaultAsync(e => e.Id == id);

            if (DbExpense != null)
            {
                DbExpense.Title = expense.Title;
                DbExpense.Description = expense.Description;
                DbExpense.Amount = expense.Amount;
                DbExpense.CreatedAt = expense.CreatedAt;


                await _context.SaveChangesAsync();

                response = DbExpense;
            }

            return Ok(response);

        }

        [HttpDelete]
        [Route("{id}")]
        public async Task RemoveExpense(int id)
        {
            var DbTransaction = await _context.Expenses.FirstOrDefaultAsync(e => e.Id == id);

            if (DbTransaction != null)
            {
                _context.Expenses.Remove(DbTransaction);

            }


            await _context.SaveChangesAsync();

        }
    }
}

Update SeedData

In BlazorExpenseTracker.Server/Data/DataContext Edit the seed data as below.

using BlazorExpenseTracker.Shared.Models;
using Microsoft.EntityFrameworkCore;

namespace BlazorExpenseTracker.Server.Data
{
    public class DataContext : DbContext
    {
        public DataContext(DbContextOptions<DataContext> options) : base(options)
        {

        }

        protected override void OnModelCreating(ModelBuilder modelBuilder)
        {
            modelBuilder.Entity<ExpenseModel>().HasData
            (
                new ExpenseModel()
                {
                    Id = 1,
                    Title= "Bought a Snack",
                    Description = "",
                    Amount = 10.0M,
                    CreatedAt = DateTime.UtcNow
                },
                new ExpenseModel()
                {
                    Id = 2,
                    Title = "Bought a phone",
                    Description = "",
                    Amount = 100.0M,
                    CreatedAt = DateTime.UtcNow.AddHours(1)
                }
                , new ExpenseModel()
                {
                    Id = 3,
                    Title = "Bought Lunch",
                    Description = "",
                    Amount = 20.0M,
                    CreatedAt = DateTime.UtcNow.AddHours(2)
                }

            );


        }

        public DbSet<ExpenseModel> Expenses { get; set; }
    }
}

Using the package manager Add a Migration to make the change in the database

Add-Migration AddTitleAndDescriptionToSeedData

Update-Database

Conclusion

We now have a working API capable of creating, reading and writing. Part 2 Continues from where we left off by adding services to the server project.