Go net/http Starter

In this edition of Stripe Developer Office Hours, follow along as CJ Avilla walks through the fundamentals of setting up a basic web application with the net/http go lang package.

#net/http starter #net/http #http #net

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   Go net/http Starter

Go net/http Starter

In this edition of Stripe Developer Office Hours, follow along as CJ Avilla walks through the fundamentals of setting up a basic web application with the net/http go lang package.

#net/http starter #net/http #http #net

Einar  Hintz

Einar Hintz


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
    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.")]
    public string SWIFTCode { get; set; }

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

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


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


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

Nigel  Uys

Nigel Uys


CORS: Go Net/http Configurable Handler to Handle CORS Requests

Go CORS handler 

CORS is a net/http handler implementing Cross Origin Resource Sharing W3 specification in Golang.

Getting Started

After installing Go and setting up your GOPATH, create your first .go file. We'll call it server.go.

package main

import (


func main() {
    mux := http.NewServeMux()
    mux.HandleFunc("/", func(w http.ResponseWriter, r *http.Request) {
        w.Header().Set("Content-Type", "application/json")
        w.Write([]byte("{\"hello\": \"world\"}"))

    // cors.Default() setup the middleware with default options being
    // all origins accepted with simple methods (GET, POST). See
    // documentation below for more options.
    handler := cors.Default().Handler(mux)
    http.ListenAndServe(":8080", handler)

Install cors:

go get github.com/rs/cors

Then run your server:

go run server.go

The server now runs on localhost:8080:

$ curl -D - -H 'Origin: http://foo.com' http://localhost:8080/
HTTP/1.1 200 OK
Access-Control-Allow-Origin: foo.com
Content-Type: application/json
Date: Sat, 25 Oct 2014 03:43:57 GMT
Content-Length: 18

{"hello": "world"}

Allow * With Credentials Security Protection

This library has been modified to avoid a well known security issue when configured with AllowedOrigins to * and AllowCredentials to true. Such setup used to make the library reflects the request Origin header value, working around a security protection embedded into the standard that makes clients to refuse such configuration. This behavior has been removed with #55 and #57.

If you depend on this behavior and understand the implications, you can restore it using the AllowOriginFunc with func(origin string) {return true}.

Please refer to #55 for more information about the security implications.

More Examples


Parameters are passed to the middleware thru the cors.New method as follow:

c := cors.New(cors.Options{
    AllowedOrigins: []string{"http://foo.com", "http://foo.com:8080"},
    AllowCredentials: true,
    // Enable Debugging for testing, consider disabling in production
    Debug: true,

// Insert the middleware
handler = c.Handler(handler)
  • AllowedOrigins []string: A list of origins a cross-domain request can be executed from. If the special * value is present in the list, all origins will be allowed. An origin may contain a wildcard (*) to replace 0 or more characters (i.e.: http://*.domain.com). Usage of wildcards implies a small performance penality. Only one wildcard can be used per origin. The default value is *.
  • AllowOriginFunc func (origin string) bool: A custom function to validate the origin. It takes the origin as an argument and returns true if allowed, or false otherwise. If this option is set, the content of AllowedOrigins is ignored.
  • AllowOriginRequestFunc func (r *http.Request, origin string) bool: A custom function to validate the origin. It takes the HTTP Request object and the origin as argument and returns true if allowed or false otherwise. If this option is set, the content of AllowedOrigins and AllowOriginFunc is ignored
  • AllowedMethods []string: A list of methods the client is allowed to use with cross-domain requests. Default value is simple methods (GET and POST).
  • AllowedHeaders []string: A list of non simple headers the client is allowed to use with cross-domain requests.
  • ExposedHeaders []string: Indicates which headers are safe to expose to the API of a CORS API specification
  • AllowCredentials bool: Indicates whether the request can include user credentials like cookies, HTTP authentication or client side SSL certificates. The default is false.
  • MaxAge int: Indicates how long (in seconds) the results of a preflight request can be cached. The default is 0 which stands for no max age.
  • OptionsPassthrough bool: Instructs preflight to let other potential next handlers to process the OPTIONS method. Turn this on if your application handles OPTIONS.
  • OptionsSuccessStatus int: Provides a status code to use for successful OPTIONS requests. Default value is http.StatusNoContent (204).
  • Debug bool: Debugging flag adds additional output to debug server side CORS issues.

See API documentation for more info.


BenchmarkWithout          20000000    64.6 ns/op      8 B/op    1 allocs/op
BenchmarkDefault          3000000      469 ns/op    114 B/op    2 allocs/op
BenchmarkAllowedOrigin    3000000      608 ns/op    114 B/op    2 allocs/op
BenchmarkPreflight        20000000    73.2 ns/op      0 B/op    0 allocs/op
BenchmarkPreflightHeader  20000000    73.6 ns/op      0 B/op    0 allocs/op
BenchmarkParseHeaderList  2000000      847 ns/op    184 B/op    6 allocs/op
BenchmarkParse…Single     5000000      290 ns/op     32 B/op    3 allocs/op
BenchmarkParse…Normalized 2000000      776 ns/op    160 B/op    6 allocs/op

Author: RS
Source Code: https://github.com/rs/cors 
License: MIT license

#go #golang #http #net 

Eric  Bukenya

Eric Bukenya


.NET Conf 2020 Demos & Sessions for .NET 5 + Virtual Events!

This year’s .NET Conf was the largest one yet, with over 80 live sessions across three days that were co-organized and presented by the .NET community and Microsoft. On top of all of that, it also marked the release of .NET 5.0  that brings a full set of new capabilities, performance gains, and new languages features for developers to create amazing apps. If you missed this year’s .NET Conf live stream, don’t worry because we have you covered!

#.net #.net core #asp.net #c# #.net conf #.net foundation #community #demos