Technical posts regarding DotNet

Dependency Injection

Dependency injection is a software design pattern that allows the removal of hard-coded dependencies and makes it possible to change them, whether at run-time or compile-time. It promotes loose coupling of components by passing dependencies to an object, rather than having an object instantiate its own dependencies.

What is Dependency Injection and Implementation of Dependency Injection Pattern in C#?

Sometime Classes in Object-oriented design have some dependent classes and sometime we have to the create structure containing components that are dependent upon other classes, known as dependencies. In such situations, you may decide to instantiate a class's dependencies from within the dependent class, using the new keyword.

There are many useful Dependency Injection Container tools as below.

Castle Windsor

StructureMap

Spring.NET

Autofac

Unity

MEF

Some more DI container frameworks are Ninject, Hiro, Funq and LinFu,OCInject. We will conver these in step by step in next posts

As an example, consider the code below. This defines a class, named "RechargeClient", that holds the details of recharge for any mobile and we can recharge any mobile no. We can set PhoneNo, Amount of recharge and provider name which we want to recharge and call methode “Rechage”. “Recharge” Method recharge phone number using “PayIntegra” object.

PayIntegra is class that call a third party web service to recharge phone number. Operation of PayIntegra class is out of scope in this post.

If we see in below code than we can see that “RechargeClient” is having dependency on “PayIntegra” object. This “objRecharge” is a dependency of “RechargeClient” and is initialised when an object is instantiated.

Public class PayIntegra { public string DoRecharge(string phoneNo,double amount,string providor) { return "Result for Recharge api based on parameters"; } } public class RechargeClient { PayIntegra objRecharge=new PayIntegra(); public string PhoneNo{get;set;} public double Amount{get;set;} public string Provider{get;set;} public string Recharge() { return objRecharge.DoRecharge(this.PhoneNo,this.Amount,this.Provider); } }

One of the key problems with the above code is the instantiation of the PayIntegra object from within the RechargeClient class. As the dependency is initialised within the containing class, the two classes are tightly coupled and we are doing all recharges from PayIntegra. But now we have to add a new API to recharge in project named “LapuOne”.

Public class LapuOne { public string DoRecharge(string phoneNo,double amount,string providor) { return"Result for Recharge api based on parameters"; } }

As object of PayIntegra is initiated inside RechargeClient so we have to change code if we want to use LapuOne class inside RechargeClient.

Dependency injection reduces the problem of tight coupling by removing the instantiation of dependencies from a dependent class. Instead, pre-constructed objects are passed to a dependent object at some time before they are required.

In this post we will show solution for above problem using dependency injection and we will consider below type of dependencyInjection.

Constructor Injection

Property Injection

Method Injection

Each provides a solution to class's dependencies using a different manner.

Recently I got a task to upload heavy data to sql server database. Data was in xml files and I am to upload that files in database. Size xml file was big. First I tried to fetch data and pull into my Data Base one by one. I faced performance issue due to continues inserting process. So decided to read xml file in data table and upload this data table to sql server database using SqlBulkCopy class. It was much batter to copy data table to database  using bulk copy operation in c sharp.

Data table is being used to store sql server data in memory for local use. So we can hold xml file data in Data table and bulk copy complete data of data table in database with in seconds.

In last post of jquery we learn how to create a genric jquery code to validation complete site. Now will will learn how to Delay function or Method execution for sometime with SetTimOut Function after Jquery ready method.

Some time we have to delay execution of method for some time or want to execute method continuously after a fix time interval using java script. i.e. want to create clock or do a service call. In any of these situation we will user java script setTimeOut function.

Error Message: The property is part of the object's key information and cannot be modified

Introduction: Sometime we get an error “The property is part of the object's key information and cannot be modified “ while try to change value of model class with entity framework whether you use MVC or ASP.NET. This issue comes when property you are trying to update is in list of object key collection of Entity model. To Resolve this we can follow below steps.

error CS0117: NamespaceOuter does not contain a definition for NamespaceInner or The namespace in dll conflicts with the type in dll

In last post regarding error will see how to resolve issue of Error Message: The property is part of the object's key information and cannot be modified

Some time we receive above error when try to run our web site but does not show any error on build and show build success. It is a strange situation when your solution build successfully but show error when try to run website and if you try to see namespace name in intelligence than we can see name of namespace.

If we see in error message than we can see “The namespace in dll conflicts with the type in ddl” that bold letters show that there are two object with same name in our solution, one is namespace and other is a type(type could be class name, structure or any other dotnet type).

In Previous post we learnt about Validation with Jquery. In Current post we will learn new feature of C sharp in .net framework 4.5. 

Introduction to Async and Await

Async and await are two new keyword that is introduce with .net framework 4.5 for supporting asynchronous programming. We can use Async feature which makes asynchronous programming straightforward as synchronous programming.

Async modifier specifies that method is async method and returns a Task or Task. Task or Task return type hold information regarding ongoing work of methods i.e. Task contains information that the caller of the method can use status of Task, its unique ID and method's result.

async Task<int> DoSomeTasksAsync()

Await operator is use with return task in a await expression. This expression suspends execution of method that contains it until the awaited task is complete. In mean time controls is returned to the caller of the suspended method.

Task<int> taskobject= DoSomeTasksAsync() int taskResult = await taskobject;

Introduction: In Today's Post I will explain how to do Validation with Jquery for Emailid, Phone number, numbers, Decimal and Required in single generic code. 

Post:

Client side validation is most common process in any web site. Even though we have jQuery form validation plug in also. But issue we faced with this plug in is that We have to write separate code to validate every form. So I decided to write something generic that I can write once and not need to think about client side validation part in complete site. Luckily jQuery provide us option to do this easily.

One single code will validate complete site. In current post I will do validation only for required, emailid, phone number and decimal values. With a little code of jQuery and some css we can do it.