Want to protect your cyber security and still get fast solutions? Ask a secure question today.Go Premium

x
?
Solved

C# Generic Messaging Pattern

Posted on 2011-09-08
1
Medium Priority
?
300 Views
Last Modified: 2012-05-12
I'm not sure if I can do this or not, but I am building the service layer of an application which needs to add one type of entity to another. An example might be adding an article to a category. It does this through a service class, for example:
 
 
public class ArticleService { 
     public IResponse AddArticleToCategory(IAddRelatedItemRequest<Category, Article> request) { 
     // do stuff with the request 
     } 
}

Open in new window


I would like the IAddRelatedItemRequest interface to be generic so it can be used for any addition request, similar to:

 
public interface IAddRelatedItemRequest<T, U> 
where T : class 
where U : class { 
    Object Key { get;set; } 
    List<Object> RelatedKey { get;set; } 
}

Open in new window


What is happening is that the request requires the primary key of the item (e.g. the category) and a list of the primary keys of the related items (e.g. the articles). The AddCommentToArticle class in the concrete ArticleService then retrieves the item by its key and then adds the related key items to it.   Note that the primary keys of the entities are not necessarily integers, they could be uniqueidentifiers.

I want to strongly type the request somehow, so instead of an object and a list of objects being supplied, the interface takes the types of the primary keys of the two entities.

The intereface would then look something like

 
public interface IAddRelatedItemRequest<T, U> 
where T : class 
where U : class { 
    TPrimaryKeyType Key { get;set; } 
    List<UPrimaryKeyType> RelatedKey { get;set; } 
}

Open in new window


Obviously this code is not correct but illustrates the end result.

Ideally I would like to somehow extract the type of the entity's Id from the generic type and include that in the interface. Is this possible?

Note:
What I don't want to happen is supply the actual entity and a list of related entities - it needs to be done through primitive primary keys.
I don't particularly want to supply the two types through Generics as it makes for less readable code and the keys of the objects could potentially change type.
0
Comment
Question by:pipelineconsulting
1 Comment
 
LVL 16

Accepted Solution

by:
SriVaddadi earned 2000 total points
ID: 36539443
Define an interface  
like
interface IPrimaryKey
{
    T Key {get;set;}
    List<T> RelatedKey {get;set;}
}

public interface IAddRelatedItemRequest<T, U>
where T : class
where U : IPrimaryKey

Means that your Article class has to implement IPrimaryKey interface and could specify the type

HTH
0

Featured Post

Keep up with what's happening at Experts Exchange!

Sign up to receive Decoded, a new monthly digest with product updates, feature release info, continuing education opportunities, and more.

Question has a verified solution.

If you are experiencing a similar issue, please ask a related question

Calculating holidays and working days is a function that is often needed yet it is not one found within the Framework. This article presents one approach to building a working-day calculator for use in .NET.
Hello there! As a developer I have modified and refactored the unit tests which was written by fellow developers in the past. On the course, I have gone through various misconceptions and technical challenges when it comes to implementation. I would…
In a question here at Experts Exchange (https://www.experts-exchange.com/questions/29062564/Adobe-acrobat-reader-DC.html), a member asked how to create a signature in Adobe Acrobat Reader DC (the free Reader product, not the paid, full Acrobat produ…
Screencast - Getting to Know the Pipeline

577 members asked questions and received personalized solutions in the past 7 days.

Join the community of 500,000 technology professionals and ask your questions.

Join & Ask a Question