Andiswa Ndlovu

Have you ever been involved in a project’s design phase on its development life cycle? Building a design structure might seem intimidating if you don’t know where to begin. By understanding design patterns, we can improve the scalability and functionality of our software according to how scalable we want it to be.

Numerous problems occur in web development that can be solved using a design pattern. A pattern typically demonstrates how classes or objects interact and relate to each other. They are not programming language-dependent; therefore, they illustrate an idea, not the implementation itself. Let’s discuss different design patterns in web development, and how they can help you become a better developer.

Types of Design Patterns

Creational Design Patterns

Creational patterns provide various object creation mechanisms, increasing flexibility and reusing existing code. Some of the main types of creational patterns are:

• Singleton – A singleton pattern allows one class instance to exist at any given time, whereas a global access point allows worldwide access to the singleton instance.
• Prototype – With the prototype pattern, you can copy existing objects without having to depend on their classes.
• Builder – This pattern allows you to construct objects step by step. You can build multiple types and representations of an object with the same code through this pattern. 
• Factory Method- In a factory method, a superclass presents an interface for creating objects in a subclass that subclasses can manipulate. 
• Abstract Factory – An abstract factory allows for the creation of families of related objects without specifying their concrete classes.   

An example of when you might use creational design patterns:

In the case of creating an object for a class, these design patterns are used to decide during class instantiation (i.e., at the creation of the object of the class). For example, a developer will generally create an instance of the Data Base Connection class and use it for all database operations wherever they are required when creating a simple Data Base Connection class to connect to a database.

If the developer wishes to access a database from code at multiple locations, he/she will use an instance of the class. Since each instance of the Data Base Connection class has its own database connection, multiple connections will be created from the database. Our solution is to create Data Base Connection as a singleton class to handle this issue so that we only need to create one instance. One instance allows us to manage several DB connections, thus controlling load balancing, unnecessary connections, etc.

Behavioural Design Patterns

A behavioural design pattern deals with algorithms and the assignment of responsibilities among objects. Some of the key main types of behavioural patterns are:

• Observer – Observers are behavioural patterns that allow multiple objects to be notified about events occurring to the object they’re observing.
• Chain of Responsibility – The Chain of Responsibility pattern allows you to pass requests along a chain of handlers. After receiving a request, each handler determines whether to process it or pass it along to the next handler.
• Mediator – It allows you to reduce chaos between objects by reducing chaotic dependencies between objects. Objects are not allowed to communicate directly with one another and must collaborate using a mediator object. 
• State – A state pattern allows an object’s behaviour to be altered as its internal state changes.
• Template method – In a template method, the superclass defines the structure of an algorithm without changing the steps, but subclasses can override specific actions. 

An example of when you might use behavioural design patterns:

Template patterns define algorithms as templates, with some steps deferred to subclasses. The template method allows subclasses to make changes to an algorithm structure without affecting the algorithm itself. For example, if the requirements of the application change, or if new applications are developed, you want the module’s behaviour to also adapt. There is one exception, however, in those scenarios where developers can implement template design patterns.  Source code can only be added rather than modified, i.e., adding but not modifying the structure.

Structural Design Patterns

The principles of structural design patterns explain how to assemble objects and classes into larger structures while maintaining flexibility and efficiency. Some of the key main types of structural patterns are:

• Adapter – Adapters are structural patterns that allow objects with different interfaces to interact.
• Decorator – The Decorator pattern allows you to attach new behaviours to objects by encapsulating them within special wrapper objects.
• Bridge – The bridge method allows you to create independent classes by dividing a large class or a group of closely related classes into abstractions and implementations.
• Façade – As a structural design pattern, facades simplify the interface of a library, a framework, or any other set of complex classes.
• Proxy – In a structural design, a proxy replaces or serves as a placeholder for another object. In addition to controlling access to the original object, proxies also allow you to perform other actions before or after the request arrives at the original object.  

An example of when you might use structural design patterns:

Adapter designs are used when two interfaces are incompatible and want to establish a relationship through an adapter. Adopting a class’s interface to another, allows classes to work together even if their interfaces are incompatible. We can therefore use the adapter pattern in scenarios in which the two are incompatible.

Design patterns provide simple solutions to everyday problems encountered by software developers. Whenever a need arises, a suitable pattern can be implemented to prevent future issues. Understanding design patterns and their purposes will help you decide which pattern to use. By doing that, you will be able to find the one that is the most suitable for your project.

Web Development at Integrove

At Integrove we work side by side with businesses to build modern user-centric digital solutions, taking advantage of modern technologies and software engineering practices to innovate, automate and modernize. Our software developers are experts at their craft, and our technology-agnostic approach allows us to tailor our solutions to your needs.