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Query Objects with a Mediator

In my previous blog Query Objects instead of Repositories, I demonstrated creating query objects and handlers to encapsulate and execute query logic instead of polluting a repository with both read and write methods.  Since we have moved away from repositories and are now using query objects, we will introduce the Mediator pattern. It will allows have a common interface that can be injected into our controller or various parts of our application. The mediator will delegate our query objects to the appropriate handler that will perform the query and return the results. First we will create an interface that will… Read More »Query Objects with a Mediator

Query Objects instead of Repositories

The repository pattern is often used to encapsulate simple and sometimes rather complex query logic.   However, it has also been morphed into handling persistence and is often used as another layer of abstraction from your data mapping layer.   This blog post show you how to slim down and simplify your repositories or possibly eliminate them all together by using query objects. A typical repository will look something like this: public interface IProductRepository { void Insert(Product product); void Delete(Product product); IEnumerable<Product> GetById(Guid id); IEnumerable<Product> GetAllActive(); IEnumerable<Product> FindByName(string name); IEnumerable<Product> FindBySku(string name); IEnumerable<Product> Find(string keyword, int limit, int page); IEnumerable<Product> GetRelated(Guid id); } Each… Read More »Query Objects instead of Repositories

Throw Out Your Dependency Injection Container

Dependency injection containers (aka inversion of control containers) seem to be common in most modern applications.  There is no argument against the value dependency injection, but I do have a couple arguments against using a dependency injection container.  Like many other design patterns and practices, over time the development community seems to forget the original problem the pattern or practice was solving. Constructor & Setter Injection Passing your dependencies via the constructor is generally a better way of injecting dependencies instead of  setters. Constructor injection gives you a much clearer definition of what dependencies are needed in order to construct the object into a valid… Read More »Throw Out Your Dependency Injection Container