Conclusion The Chain of Responsibility pattern is another great GoF pattern. It divides a large problem into smaller, cohesive units, each doing one job: handling its specific request(s).Now, let’s see how the Chain of Responsibility pattern can help us follow the SOLID principles: Next, let’s use the Template Method and Chain of Responsibility patterns to […]
Design – Behavioral Patterns-2
Each handler does two things: Let’s use Program.cs as the consumer of the Chain of Responsibility (the Client) and use a POST requests to interface with our REST API and build the message.Here is the first part of our REST API: var builder = WebApplication.CreateBuilder(args);builder.Services.AddSingleton<IMessageHandler>( new AlarmTriggeredHandler( new AlarmPausedHandler( new AlarmStoppedHandler()))); In the preceding code, […]
Design – Behavioral Patterns-1
The most basic Chain of Responsibility starts by defining an interface that handles a request (IHandler). Then we add classes that handle one or more scenarios (Handler1 and Handler2): Figure 12.2: Class diagram representing the Chain of Responsibility pattern A difference between the Chain of Responsibility pattern and many other patterns is that no central […]
Conclusion – Behavioral Patterns
The Template Method is a powerful and easy-to-implement design pattern allowing subclasses to reuse the algorithm’s skeleton while implementing (abstract) or overriding (virtual) subparts. It allows implementation-specific classes to extend the core algorithm. It can reduce the duplication of logic and improve maintainability while not cutting out any flexibility in the process. There are many […]
Project – Building a search machine – Behavioral Patterns-2
Now that we have defined the actors and explored the code, let’s see what is happening in our consumer (the Client): The Find method returns null when it does not find a value and, by extension, the IndexOf method.By running the program, we get the following output: =============================================Current search machine is LinearSearchMachineThe element ‘1’ was […]
Project – Building a search machine – Behavioral Patterns-1
Let’s start with a simple, classic example to demonstrate how the Template Method pattern works.Context: Depending on the collection, we want to use a different search algorithm. We want to use a binary search for sorted collections, but we want to use a linear search for unsorted collections.Let’s start with the consumer, a REST endpoint […]
Implementing the Template Method pattern – Behavioral Patterns
Before you begin: Join our book community on Discord Give your feedback straight to the author himself and chat to other early readers on our Discord server (find the “architecting-aspnet-core-apps-3e” channel under EARLY ACCESS SUBSCRIPTION). https://packt.link/EarlyAccess This chapter explores two new design patterns from the well-known Gang of Four (GoF). They are behavioral patterns, meaning […]
Conclusion – Structural Patterns
The Façade pattern is handy for simplifying consumers’ lives, allowing us to hide subsystems’ implementation details behind a wall. There are multiple flavors to it; the two most prominent ones are: Now, let’s see how the transparent façade pattern can help us follow the SOLID principles: Finally, let’s see how the opaque façade pattern can […]