Architecture/Design/Patterns

In one of my systems I’m using background process that hosts jobs that import and update some data and communicate with external services. These jobs are running after some interval or on specific moments. I generalized the common base part of these jobs so I can handle them as one in different background processes like Azure worker roles and Windows services. This blog post introduces my work and shows real-life implentation of jobs base.

Facade is known pattern for communication layer between system parts. Facades are classes that provide often simplified access to subsystems functionalities but they don’t set any limitations for using subsystem classes directly. Facades can be found from many API-s in different forms, This posting is quick introduction to Facade Pattern.

One problem related to composite pattern is how to implement operations over child collections. Composite classes have children and leaf classes not. There are many ways how to solve the problem of where and how to keep child nodes collection. In this posting I go through different options and analyze those solutions through different code examples.

This is one of the examples from my presentation about how to port existing ASP.NET applications to Windows Azure and how to build hybrid applications that work in multiple environments. One of important aspects is file storage that may have multiple implementations for different technical environments. In this posting I will introduce you my idea about generalized file access in web applications.

When building application that works both on WinRT and Window Phone you use Portable Class Libraries (PCL) for shared classes. As there are many application specific things that are not same on different platforms or that are not supported by PCL then you have to make some architectural decisions when creating shared functionalities. In this posting I will focus on persisting data for offline use.

Composite pattern is used in many applications. It helps to build hierarchies of similar objects and handle slices of hierarchy as one. Maybe one of the most popular implementation of this pattern in .NET world is Nodes collection of ASP.NET TreeView control. In this posting I will introduce you composite pattern and provide some implementation tips and samples about it.

Patterns of Enterprise Applications Architecture by Martin Fowler defines Transaction Script pattern that is one of domain logic patterns. In his book Martin Fowler also gives a hint how to use Command Pattern by Gang of Four with Transaction Script. In this posting I will show you some real-life code that makes use of both patterns.

Command pattern is object behavioral design pattern that helps you handle different activities in application using same interface. I’m Command pattern is object behavioral design pattern that helps you handle different activities in application using same interface. I’m using Command Pattern in some of my systems to handle similar actions together and to split more comples operations to smaller steps by example. In this posting I will give you overview of Command Pattern.

Transaction Script (TS) is the simplest domain logic pattern we can find. It needs less work to implement than other domain logic patterns and therefore it’s perfect fit for smaller applications that doesn’t need big architecture behind them. This posting focuses on TS pattern by illustrating and analysing it. Also some good hints for implementation are provided.

Enterprise applications need good architecture to survive ever-changing demands of customers. At same time these systems must be stable, convenient and easy to use which leads us to need of good architecting skills. Some customers need desktop applications while others need web-based and mobile applications. Making good architectural decisions is not easy and this is where brilliant book Microsoft .NET: Architecting Applications for the Enterprise by Dino Esposito and Andrea Saltarello comes in. (more…)