Using TopShelf for windows service

Windows service runs continuously in the background and more often used as a back-end job. Its a pain if you want to debug it,even though you use logger to capture all events.we either attach the service as a process and debug it. But TopShelf lets you eliminate all of these and allows you to debug like console application.

Topshelf has a start and stop method just like a service and also an separate command to install windows service with ease.

DocLink : https://topshelf.readthedocs.io/en/latest/installation/index.html

Object Comparisons — Difference between Equals method and ==

When we compare two objects with same content,there is a difference between “Equals and == “.

Equals :

The Equals method does the content based comparison between two objects.

== :

“==” compares only object references.

Scenarios :


Sample s = new Sample () { a = "Hey" };
Sample s1 = s;
Sample s4 = new Sample () { a = "Hey" };

 Console.WriteLine(s1==s); &amp;nbsp;// True --Compares the instances&amp;nbsp;

Console.WriteLine(s==s4); // False ---Eventhough content is same,still == looks only for reference.

Console.WriteLine(s.Equals(s4)); // True --- Compares the value in field "a" &amp;nbsp;in both object and returns true.

String is an exceptional case and its immutable. It behaves with == as Equals.

GC Triggers :When does Garbage Collection Occurs ?

CLR triggers the garbage collection when one of the following event occurs :

GC.Collect() Method is called explicitly by code.
Windows reporting low memory condition via Win32 notification.
When CLR Unloads the AppDomain.
When CLR is shutting down.

Parse JSON Data in Sql Server 2016

Sql server allows you to parse Json data with OpenJson .

Sample Json data : [{“MinValue”:”1″,”MaxValue”:”6″}]

Parsing Json to map into Tables:


declare @metadata="[{"MinValue":"1","MaxValue":"6"}]"
select Minvalue,MaxValue from openjson(@metadata)
with (MinValue nvarchar(2),MaxValue nvarchar(2));

WebHook in .NET

What is WebHook ?

A webhook is a provider that helps you to get data from external system as and whenit flows into the system.These are real time data that is exposed over HTTP as and when data flows into system.

Components in WebHook :

Receiver : This type of webhook pulls the data from external system to your server.

Sender : This type of webhook is responsible for exposing your data to external system.

WebHook with .NET :

.NET does support web hook and there are various type of web hook that is customized according to business need.

Types of WebHook Libraries provided by .NET :

GitHubWebHook.
SlackWebHook.
GenericWebHook (This is the one which you use at custom level,the webhook is not tied to any providers like github,stripe instead you can define/customize to your needs)

References :

https://github.com/aspnet/WebHooks

Return Type of Controller Action in Web-API

Web API controller action can return any of the following

1.Void

2.HttpResponse Message.

3.IHttpActionResult.

4.Customtypes (Json,xml,text etc…)

SetInterval and ClearInterval -Javascript

I had been developing a real time chat system at my work and the chat system takes some time to load(makes an ajax call to the backend that fetches users details,chat message,chat room id ,chat user role id etc..).and also there are multiple chat rooms based on user roles. The challenge was to wait for all of data to load and then enable the chat system.

Solution :

The solution is to wait for x interval of time and then make a call x time to check if the data we require is loaded.


var intialloading=false;
waitoperation();
var someinterval =setInterval(function(){

if(intialloading)

{

//clear the interval.

ClearInterval(someinterval);

}

},2000) // call function every 2 secs

function waitoperation()

{

//some call

intialloading=true;

}