Entity Framework: (anti)pattern Repository

Entity Framework: (anti)pattern Repository
4.7 (93.33%) 3 vote[s]

A Repository mediates between the domain and data mapping layers, acting like an in-memory domain object collection. Client objects construct query specifications declaratively and submit them to Repository for satisfaction.

Entity Framework provides us with the actual implementation of the Repository patterns: DbSet<T> and UnitOfWork: DbContext. I often see colleagues using in projects their own implementation of repositories on top of the ones existing in Entity Framework.

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Modular WPF application using Caliburn.Micro and Castle.Windsor

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To start with, I want to specify what is meant by a modular application in this article. So, a modular application will be considered an application, which consists of the so-called shell and a set of plug-in modules. There is no direct dependence between them, only via contracts. This allows independently modify each of the components, change their contents, etc. I think everyone knows the advantages of modular architecture.

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Synchronizing database structure between applications

Synchronizing database structure between applications
2.5 (50%) 2 vote[s]

Anyone who has ever developed applications that use a database has probably faced the problem of updating the database structure when the application is deployed and updated.

The most common approach is to create a set of SQL scripts to modify the database structure from version to version. Of course, there are paid tools, but they do not always solve the problem of full automation of the update.

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Drilling Down the Visitor Pattern

Drilling Down the Visitor Pattern
4 (80%) 4 vote[s]


Recently, I have often had to use the well-known Visitor pattern. I used to ignore this pattern and thought that it simply complicates the code. In this article, I will share my thoughts about this pattern. We will talk about pros and cons, as well as what tasks it helps to solve and how to simplify its use. The code will be in C#.

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Replacement of Algorithm Testing with Testing of Effects Being Inserted

Replacement of Algorithm Testing with Testing of Effects Being Inserted
4.5 (90%) 2 vote[s]

As I expected, Rule 8 from the article “Rules for Implementing TDD in Old Project” stating that we don’t need to test the algorithm of methods raised many “how” and “why” questions. When writing the previous article, it seemed obvious to me, so I did not go into much details on the matter. In this article, I provide a small sample code and two examples of how it could be tested.

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Rules for Implementing TDD in Old Project

Rules for Implementing TDD in Old Project
3.4 (68%) 5 vote[s]

The article “Sliding Responsibility of the Repository Pattern” raised several questions, which are very difficult to answer. Do we need a repository if the complete disregard of technical details is impossible? How complex must the repository be so that its addition can be regarded worth-while? The answer to these questions varies depending on the emphasis placed in the development of systems. Probably the most difficult question is the following: do you even need a repository? The problem of “flowing abstraction” and the growing complexity of coding with an increase in the level of abstraction do not allow to find a solution that would satisfy both sides of the fence. For example, in reporting, intention design leads to the creation of a large number of methods for each filter and sorting, and a generic solution creates a large coding overhead.

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Steps to Reduce Code Size after Use of Strategy Pattern

Steps to Reduce Code Size after Use of Strategy Pattern
3 (60%) 2 vote[s]

This article features a few tricks to reduce the size of the code resulting from the use of the ‘strategy’ pattern. As you can deduce from the title, all these tricks will be related to the usage of generic types.

1. Hierarchy of classes involved in magic rituals

Suppose we have an abstract ‘vehicle’ class that can move (the Move method). This class has 3 descendants: a car, a plane, and a rickshaw. Each of them implements the method in its own way: Read More

Indicators of Problem Design

Indicators of Problem Design
3 (60%) 6 vote[s]

The concept of good or bad design is relative. At the same time, there are some programming standards, which in most cases guarantee effectiveness, maintainability, and testability. For example, in object-oriented languages, this is the use of encapsulation, inheritance, and polymorphism. There is a set of design patterns that in a number of cases have a positive or negative effect on the application design depending on the situation. On the other hand, there are opposites, following which sometimes leads to the problem design.

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