in this article, I will show how to take a medium-small demo app written using Visual Studio 2013, ASP.NET 4.5, VC 5, and Entity Framework 6 and turn it into a working ASP.NET 5 app employing Visual Studio 2015, MVC 6 and Entity Framework 7. And the new app will happily run on either the .NET 4.6 CLR or the .NET Core CLR. Let's get started.
using System.Collections.Generic;
namespace Refactoring.Day2.ExtractMethod.Before
{
public class Receipt
{
private IList<decimal> Discounts { get; set; }
private IList<decimal> ItemTotals { get; set; }
public decimal CalculateGrandTotal()
{
// Calculate SubTotal
decimal subTotal = 0m;
foreach (decimal itemTotal in ItemTotals)
subTotal += itemTotal;
// Calculate Discounts
if (Discounts.Count > 0)
{
foreach (decimal discount in Discounts)
subTotal -= discount;
}
// Calculate Tax
decimal tax = subTotal * 0.065m;
subTotal += tax;
return subTotal;
}
}
}
using System.Collections.Generic;
namespace Refactoring.Day2.ExtractMethod.After
{
public class Receipt
{
private IList<decimal> Discounts { get; set; }
private IList<decimal> ItemTotals { get; set; }
public decimal CalculateGrandTotal()
{
decimal subTotal = CalculateSubTotal();
subTotal = CalculateDiscounts(subTotal);
subTotal = CalculateTax(subTotal);
return subTotal;
}
private decimal CalculateTax(decimal subTotal)
{
decimal tax = subTotal * 0.065m;
subTotal += tax;
return subTotal;
}
private decimal CalculateDiscounts(decimal subTotal)
{
if (Discounts.Count > 0)
{
foreach (decimal discount in Discounts)
subTotal -= discount;
}
return subTotal;
}
private decimal CalculateSubTotal()
{
decimal subTotal = 0m;
foreach (decimal itemTotal in ItemTotals)
subTotal += itemTotal;
return subTotal;
}
}
}
On over-engineering; finding the right balance
A big debate among developers is whether to write code for today’s problem or to build a general-purpose solution for future needs. Both approaches have their pros and cons. Specific-purpose code can quickly become messy. But overly general code can add unnecessary complexity. This post, obviously opinionated, argues for a middle ground. That’s the sweet spot, as always.
Visual Studio Code doesn't support solution files, whereas Visual Studio does. In Visual Studio we use solution files to link multiple projects together, and at first I thought that this was going to be a deal breaker for Visual Studio Code - but it's not at all. Many people aren't aware that Visual Studio Code, although lightweight, is a powerful editor that can do most of the things you need.
I am so excited about using Plotly packages in Power BI.
So What is Plotly: is an R package for creating interactive web-based graphs via the open source JavaScript graphing library :https://plot.ly/r/getting-started/
Is OOP a failure? Well, what is it? I've heard OOP given about 12 definitions, all credible in some core way, but many conflicting. Like "Scrum", it's too all over the place to justify a closed-form, final opinion.
Here’s the list of what’s new in this preview:
@using 
A function for loading CSS asynchronously
Referencing CSS stylesheets with link[rel=stylesheet] or @import causes browsers to delay page rendering while a stylesheet loads. When loading stylesheets that are not critical to the initial rendering of a page, this blocking behavior is undesirable. The new <link rel="preload"> standard enables us to load stylesheets asynchronously, without blocking rendering, and loadCSS provides a JavaScript polyfill for that feature to allow it to work across browsers. Additionally, loadCSS offers a separate (and optional) JavaScript function for loading stylesheets dynamically.
npm install fg-loadcss --save
یک نکته‌ی تکمیلی: روش استفاده از خواص راهبری، در به‌روزسانی‌های دسته‌ای
در همین مثال مطلب جاری، فرض کنید موجودیت کاربر، به همراه خاصیت محاسباتی تعداد کتاب‌ها (NumberOfBooks) هم هست:
public class User
{
// ...
public virtual List<Book> Books { get; set; } = new();
public int NumberOfBooks { get; set; }
}اگر سعی کنیم این خاصیت را به صورت زیر به‌روز رسانی کنیم که در آن مقدار تعداد کتاب‌ها به کمک خاصیت راهبری Books محاسبه شود:
await context.Users.Where(x=> x.Id == 1).ExecuteUpdateAsync(s => s.SetProperty(user => user.NumberOfBooks,
user => user.Books.Count()));به خطای زیر می‌رسیم:
... could not be translated. Additional information: Translation of member 'Books' on entity type 'User' failed. This commonly occurs when the specified member is unmapped.
عنوان می‌کند که این خاصیت راهبری، نگاشت نشده‌است. برای رفع این مشکل باید به صورت زیر عمل کرد:
await context.Users
.Where(user => user.Id == 1)
.Select(user => new
{
user.NumberOfBooks,
BooksCount = user.Books.Count()
})
.ExecuteUpdateAsync(s => s.SetProperty(arg => arg.NumberOfBooks, arg => arg.BooksCount));در اینجا تنها کاری که انجام شده، انجام محاسبات و نگاشت‌های لازم، پیش از فراخوانی متد ExecuteUpdateAsync است.
AutoMapper has been a popular library in the .NET open source community for a long time. As their site says:
AutoMapper is a simple little library built to solve a deceptively complex problem - getting rid of code that mapped one object to another. This type of code is rather dreary and boring to write, so why not invent a tool to do it for us?
