Sunday, November 24, 2019

ContactForm.Sample project on GitHub

I added a new demo project called ContactForm.Sample at It's just a sample solution with 2 projects, one to show a contact form with both C# and JS / AJAX, which then uses HTTP POST to a web API project, which saves data to a Postgres database. The web API (Contactform.Sample.Postgres) is build as a separate infrastructure project because I intend to add some more API projects for other databases, SQL and no-SQL.

Here's a simple diagram of the projects:

And the regular C# web form with Google reCAPTCHA (demo) enabled:

More technical details are added to readme files in the project source code, including details to run it with Docker compose from Docker containers.

By the way, the project Docker images are also available on Docker Hub here and here.

Comments are welcome. Thanks.

Monday, November 18, 2019

Seagate external hard drive

Black Friday came earlier this year for me with a new Seagate 6TB external hard drive, for all videos and books scattered of different computers and laptops I use, at home and at work. All good with it so far but it's formatted with NTFS which doesn't quite work on Mac OS. After a bit of digging I found out that Seagate offers a free version of Paragon NTFS for Mac. Installed and tested. Nice.

Thursday, November 7, 2019

ContactForm github project

It's been a while since I wanted to post a personal project on GitHub, with few features I'm interested in: ASP.NET Core MVC and APIs, Azure DevOps, Azure Functions & AWS Lambda, as well as Docker images. Some other features will be covered in another project I'm working on, but let's keep that as a secret until available.

The project I'm presenting now it's called ContactForm and is available at (see the link on the right side bar). It's meant for a simple contact form processing page, which works with both HTTP POST form data as well as REST API JSON, on the same endpoint (the root of deployed URL). There is more in the files from the project, with this diagram trying to explain different components:

The core of it is a .NET Standard 2.0 library deployed to (, which then is used in ContactForm.Web (web app  + web API), ContactForm.AzFunc (Azure Function) and ContactForm.AWSLambda (AWS Lambda function). Some libraries are using older versions just because AWS Lambda uses .NET Core 2.1, and also at the time of writing this Azure Functions 3.0 are in 'preview' mode.

Depending on the settings in the config file or environment variables it enables email notification and/or webhook posting or REST API call. Also, optionally, you can enable Google reCAPTCHA v2 with visible checkbox. For this last option you need to register your own set of keys or use for testing Google provided samples, which you can find in the readme files in the project.

The web application is also deployed as a Docker image at, read more here.

The core library and web app have some unit testing projects, but very minimal (using XUnit). Also provided Azure DevOps YAML file for core library continuous integration. Some other additions will be added soon.

Comments, suggestions and bugs reporting are welcome. Thanks in advance.

Wednesday, November 6, 2019

PostgreSQL 12 on Windows 10

I used previous versions of PostgreSQL, but I installed them with default Windows installer from the website which came with a Windows Service easy to start / stop. This last version 12 I installed with Chocolatey and I couldn't find any Windows Service to start.

So, back to documentation and googling. First I create environment variable PGDATA pointing to a newly created data folder, like C:\pgdata (easier than specify that folder in parameters). Then from C:\Program Files\PostgreSQL\12\bin I ran:

.\initdb C:\pgdata
.\pg_ctl start
.\createuser --interactive
.\createdb test1

Newly created user 'postgres' has the superuser role.

Additionally, you can create other users with passwords to be used by the applications.

Then, I prefer to use Valentina Studio which integrates nicely with Postgres.

Monday, November 4, 2019

Big Azure update today

There are a lot of announcements today from Microsoft Azure specially for Ignite event, some of most important ones in my opinion:

Thursday, September 26, 2019

Conditionally added XML element

On a project I'm working on we have to generate some XML documents with a pretty complex structure. In previous version we used XmlDocument, but the code is pretty verbose, so I checked XDocument alternative from Linq to XML.

This new solution works better (looks like is even faster), but I was looking for a simple solution to skip empty nodes. We didn't want <node></node> or <node />.

So in the end I tried something like this:
using System;
using System.Linq;
using System.Xml.Linq;
namespace ConsoleApp1
    class Program
        static void Main(string[] args)
            var b3 = string.Empty; // "3"
            XDocument x = new XDocument(
                new XDeclaration("1.0", "utf-8", null),
                new XElement("a",
                    new XElement("b1", "1"),
                    ElemString("b2", "2"),
                    ElemString("b3", b3),
                    new XElement("b4", string.Empty),
                    new XElement("b5", null),
                    ElemChildren("c", ElemString("c1", "11"), ElemString("c2", string.Empty)),
                    ElemChildren("d", ElemString("d1", string.Empty), ElemString("d2", string.Empty))
        static XElement ElemChildren(string name, params object[] children) {
            return children.Where( obj => obj != null).Any() ? new XElement(name, children) : null;
        static XElement ElemString(string name, string val) {
            return string.IsNullOrEmpty(val) ? null : new XElement(name, val);
which produces:
<?xml version="1.0" encoding="utf-8"?>
  <b5 />
ElemChildren() was used to exclude a node having all children Null, while ElemString() is a simple ternary function (here's only for strings, most important part).
Notice the difference between <b4></b4> and <b5 />. Also notice that node <d> is missing completely because of all Null children nodes.

Monday, September 23, 2019

.NET Core 3.0 and .NET Core 3.1 LTS

New .NET Core 3.0 was just launched today at .NET Conf but I also see that new LTS version is announced:

.NET Core 3.0 is a ‘current’ release and will be superseded by .NET Core 3.1, targeted for November 2019. .NET Core 3.1 will be a long-term supported (LTS) release (supported for at least 3 years). We recommend that you adopt .NET Core 3.0 and then adopt 3.1. It’ll be very easy to upgrade.
Nice. Moving very fast, hard to catch up with all the new announced features.

Also don't forget that .NET 2.2 will be retired at the end of this year: ".NET Core 2.2 will go EOL on 12/23"