Zakary  Goyette

Zakary Goyette

1596861600

Go: Debugging with Delve & Core Dumps

ℹ️ This article is based on Go Delve 1.4.1.

A core dump is a file containing the snapshot of a program’s memory that has terminated unexpectedly. It can be used for post-mortem debugging to understand why the crash occurred and the variables involved in it. With GOTRACEBACK, Go provides an environment variable that controls the output generated when a program crashes. This variable can also force a core dump to be generated, making the debugging possible.

GOTRACEBACK

GOTRACEBACK controls the verbosity of the output when the program crashes. It can take different values:

  • none does not display any goroutine stack traces.
  • single, the default option, displays the current goroutine stack traces.
  • all displays all the user-created goroutines stack traces.
  • system displays all the goroutines stack traces, even the one from the runtime.
  • crash similar to system, but also generates a core dump.

The last option gives us the ability to debug our program in case of crash. This can be a good option if you do not get enough logs, or the crash is not reproducible. Let’s take an example with the following program:

Image for post

#debug-instrumentation #golang #go

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Go: Debugging with Delve & Core Dumps
Einar  Hintz

Einar Hintz

1602560783

jQuery Ajax CRUD in ASP.NET Core MVC with Modal Popup

In this article, we’ll discuss how to use jQuery Ajax for ASP.NET Core MVC CRUD Operations using Bootstrap Modal. With jQuery Ajax, we can make HTTP request to controller action methods without reloading the entire page, like a single page application.

To demonstrate CRUD operations – insert, update, delete and retrieve, the project will be dealing with details of a normal bank transaction. GitHub repository for this demo project : https://bit.ly/33KTJAu.

Sub-topics discussed :

  • Form design for insert and update operation.
  • Display forms in modal popup dialog.
  • Form post using jQuery Ajax.
  • Implement MVC CRUD operations with jQuery Ajax.
  • Loading spinner in .NET Core MVC.
  • Prevent direct access to MVC action method.

Create ASP.NET Core MVC Project

In Visual Studio 2019, Go to File > New > Project (Ctrl + Shift + N).

From new project window, Select Asp.Net Core Web Application_._

Image showing how to create ASP.NET Core Web API project in Visual Studio.

Once you provide the project name and location. Select Web Application(Model-View-Controller) and uncheck HTTPS Configuration. Above steps will create a brand new ASP.NET Core MVC project.

Showing project template selection for .NET Core MVC.

Setup a Database

Let’s create a database for this application using Entity Framework Core. For that we’ve to install corresponding NuGet Packages. Right click on project from solution explorer, select Manage NuGet Packages_,_ From browse tab, install following 3 packages.

Showing list of NuGet Packages for Entity Framework Core

Now let’s define DB model class file – /Models/TransactionModel.cs.

public class TransactionModel
{
    [Key]
    public int TransactionId { get; set; }

    [Column(TypeName ="nvarchar(12)")]
    [DisplayName("Account Number")]
    [Required(ErrorMessage ="This Field is required.")]
    [MaxLength(12,ErrorMessage ="Maximum 12 characters only")]
    public string AccountNumber { get; set; }

    [Column(TypeName ="nvarchar(100)")]
    [DisplayName("Beneficiary Name")]
    [Required(ErrorMessage = "This Field is required.")]
    public string BeneficiaryName { get; set; }

    [Column(TypeName ="nvarchar(100)")]
    [DisplayName("Bank Name")]
    [Required(ErrorMessage = "This Field is required.")]
    public string BankName { get; set; }

    [Column(TypeName ="nvarchar(11)")]
    [DisplayName("SWIFT Code")]
    [Required(ErrorMessage = "This Field is required.")]
    [MaxLength(11)]
    public string SWIFTCode { get; set; }

    [DisplayName("Amount")]
    [Required(ErrorMessage = "This Field is required.")]
    public int Amount { get; set; }

    [DisplayFormat(DataFormatString = "{0:MM/dd/yyyy}")]
    public DateTime Date { get; set; }
}

C#Copy

Here we’ve defined model properties for the transaction with proper validation. Now let’s define  DbContextclass for EF Core.

#asp.net core article #asp.net core #add loading spinner in asp.net core #asp.net core crud without reloading #asp.net core jquery ajax form #asp.net core modal dialog #asp.net core mvc crud using jquery ajax #asp.net core mvc with jquery and ajax #asp.net core popup window #bootstrap modal popup in asp.net core mvc. bootstrap modal popup in asp.net core #delete and viewall in asp.net core #jquery ajax - insert #jquery ajax form post #modal popup dialog in asp.net core #no direct access action method #update #validation in modal popup

Fannie  Zemlak

Fannie Zemlak

1599854400

What's new in the go 1.15

Go announced Go 1.15 version on 11 Aug 2020. Highlighted updates and features include Substantial improvements to the Go linker, Improved allocation for small objects at high core counts, X.509 CommonName deprecation, GOPROXY supports skipping proxies that return errors, New embedded tzdata package, Several Core Library improvements and more.

As Go promise for maintaining backward compatibility. After upgrading to the latest Go 1.15 version, almost all existing Golang applications or programs continue to compile and run as older Golang version.

#go #golang #go 1.15 #go features #go improvement #go package #go new features

Go (Golang) Debugging with Delve

Delve is a third-party debugger for the Go programming language and it’s available on github https://github.com/go-delve/delve. It’s a valid alternative to the GDB golang debugger (https://golang.org/doc/gdb) as it’s more feature rich as mentioned in the official Go GDB website

By the end of this video you are going to be able to easily debug and inspect Go programs using the delve debugger command line tool. We are going to see how to view, add and change breakpoints in a Go program, navigate the program line by line or through breakpoints, inspect variables, functions and expressions values and finally analyse all our programs in detail.

Go Delve can be downloaded and installed by just using the go get command
Linux, Windows, OSX
$ go get github.com/go-delve/delve/cmd/dlv

If you are using Go modules you might want to execute this command outside your project directory to avoid delve being added as a dependency in your go.mod file

Once installed check your installation by typing
$ dlv version
Delve Debugger
Version: 1.5.1
Build: $Id: bca418ea7ae2a4dcda985e623625da727d4525b5 $

Golang Debugging with Delve - https://golang.cafe/blog/golang-debugging-with-delve.html

Source Code - https://play.golang.org/p/PZ5b_-_K1b5

💼 Golang Cafe - https://golang.cafe
📬 Golang Cafe Jobs Newsletter - https://golang.cafe/newsletter
🐦 Golang Cafe Twitter - https://twitter.com/golangcafe
📣 Telegram Channel - https://t.me/golangcafe

#golang #go #delve #debugging

Zakary  Goyette

Zakary Goyette

1596861600

Go: Debugging with Delve & Core Dumps

ℹ️ This article is based on Go Delve 1.4.1.

A core dump is a file containing the snapshot of a program’s memory that has terminated unexpectedly. It can be used for post-mortem debugging to understand why the crash occurred and the variables involved in it. With GOTRACEBACK, Go provides an environment variable that controls the output generated when a program crashes. This variable can also force a core dump to be generated, making the debugging possible.

GOTRACEBACK

GOTRACEBACK controls the verbosity of the output when the program crashes. It can take different values:

  • none does not display any goroutine stack traces.
  • single, the default option, displays the current goroutine stack traces.
  • all displays all the user-created goroutines stack traces.
  • system displays all the goroutines stack traces, even the one from the runtime.
  • crash similar to system, but also generates a core dump.

The last option gives us the ability to debug our program in case of crash. This can be a good option if you do not get enough logs, or the crash is not reproducible. Let’s take an example with the following program:

Image for post

#debug-instrumentation #golang #go

Einar  Hintz

Einar Hintz

1602564619

MVC User Registration & Login with ASP.NET Core Identity

User registration and authentication are mandatory in any application when you have little concern about privacy. Hence all most all application development starts with an authentication module. In this article, we will discuss the quickest way to use **ASP.NET Core Identity for User Login and Registration **in a new or existing MVC application.

Sub-topics discussed :

  • How to add ASP.NET Core Identity to MVC application.
  • Customize ASP.NET Core Identity.
  • Identity.UI Design Customization.
  • Next step.

Background

ASP.NET Core Identity is an API, which provides both user interface(UI) and functions for user authentication, registration, authorization, etc. Modules/ APIs like this will really be helpful and fasten the development process. It comes with ASP.NET Core Framework and used in many applications before. Which makes the API more dependable and trustworthy.

ASP.NET Core MVC with user authentication can easily be accomplished using Identity.UI. While creating the MVC project, you just need to select Authentication as Individual User Accounts.

Showing how to create an MVC application with ASP.NET Core Identity API

The rest will be handled by ASP.NET Core Identity UI. It already contains razor view pages and backend codes for an authentication system. But that’s not what we want in most of the cases. we want to customize ASP.NET Core Identity as per our requirement. That’s what we do here.

Create an ASP.NET Core MVC Project

First of all, I will create a brand new ASP.NET Core MVC application without any authentication selected. We could add ASP.NET Core Identity later into the project.

In Visual Studio 2019, Go to File > New > Project (Ctrl + Shift + N). From new project window, select ASP.NET Core Web Application.

Create an ASP.NET Core Web application

Once you provide the project name and location. A new window will be opened as follows, Select _Web Application(Model-View-Controller), _uncheck _HTTPS Configuration _and DO NOT select any authentication method. Above steps will create a brand new ASP.NET Core MVC project.

Select Model View Controller templet under .NET Core

#asp.net core article #asp.net core #add asp.net core identity to existing project #asp.net core identity in mvc #asp.net core mvc login and registration #login and logout in asp.net core