What are Singletons?
A singleton is a unique, purpose-driven object within a digital system that acts as a global manager and access point for functionality and variables.
Origin
Singletons originated from Erich Gamma, Richard Helm, Ralph Johnson and John Vlissides's Design Patterns: Elements of Reusable Object-Orientated Software in 1994 and are referred to as a creational digital design pattern that creates a unique object (or "instance") with a specific purpose within a technology system.
Benefits
The benefits of singletons revolve around the idea of centralized access points for variables and/or functionality; consistent system-wide state and property management as well as providing a structured way to manage events within apps, websites or other digital experiences (i.e. AR/VR/AI).
Central Access Point
Singletons provide a unique object that holds purpose specific functionality and variables which can be accessed by an entire system.
For example: All bluetooth events, from connection management to processing messages can be boxed within a singleton.
State Management
Singleton's provide a central point of truth which enables effective state management and communication between an entire system.
For example: A singleton for data can manage how the data is gathered and stored and can use a notification singleton to inform the system when data has been downloaded and updated, allowing elements within a digital system to sync to that data and reliable update across the entire system.
Reduced Redundancy & Confusion
Singleton's reduce duplicate or unnecessary code and confusions by providing a centralized object for variables and functionality to be accessed by an entire system (i.e. app, website or digital experience).
For example, someone can buy a product or good within multiple points of a website, app or digital experience - but the functionality that is required for errors to be managed or for successful purchases to be completed remains centralized and should work equally across the system.
Augmented Development Speed
Singletons increase development speed by providing tested, central, proven development paradigms.
They help engineers reliably scale functionality, give clear directions as to where evolutions within a system should take place and act as well as to help teams quickly identify where bug-fixes need to be applied as unforced errors occur.
For example, if the typography of a website doesn't produce the adequate result, they can alter the typography and colors through a Styleguide singleton.
Enhanced System Analysis
As singletons have a specific purpose, they allow organizations to break apart functionality into specific silos.
This enhances system analysis and organizations can more effectively measure performance and results for specific purposes.
Use Cases
We recommend that you check out our article on Coordinators to learn more about use cases for Singletons.