MVVM: Understanding the Model–View–ViewModel Software Design Pattern

MVVM, which stands for Model-View-ViewModel provides flexibility, reusable components, and facilitates near-simultaneous collaboration. That’s only a few of the reasons developers enjoy working with the MVVM software design pattern. In this article, learn about patterns and MVVM. 

What are software design patterns?

Software design patterns offer tested designs for recurring problems so that users don’t have to create a new one from scratch. Patterns can be reused, saving time and effort and making it more straightforward for developers to structure software. 

Each pattern describes a common problem and how to address it, allowing developers to adopt a solution efficiently. The pattern shares not only the solution but also design decisions, options considered, and trade-offs. 

The idea is to leverage the design pattern as a jumping-off point for new approaches. Patterns make it easier for developers to solve general problems and customize a fix for their issues with agility. By enabling developers to focus on specific classes or objects, these patterns make it possible to test and maintain code without risk to the entire system.

What is Model-View-ViewModel?

Software development uses the model-view-view model (MVVM) design pattern. This pattern helps developers and architects separate objects to improve and maintain their architecture.

Microsoft first developed MVVM to use with its Windows Presentation Foundation (WPF) framework, but it has since gained popularity across various platforms and frameworks.

To better understand MVVM, you’ll need to know the distinctions between its three key components:

• The Model constitutes the application data and business logic. It encapsulates the application's data structures, operations, and rules. This can include data access, validation, calculations, and other domain-specific logic.

• The View provides the application’s user interface (UI). It presents the application data to the user and captures their inputs. The View takes an active role in making the layout and structure more presentable. It determines the placement of visual elements such as buttons, labels, and input fields.

• The ViewModel acts as a go-between. It provides data and behavior to the View and notifies the Model to retrieve or update data. The ViewModel also provides properties and commands to transform the Model’s raw data into a presentable View form.

The separation of Model and View makes the MVVM pattern appealing to developers because it allows them to focus on the specific responsibilities of each component. A developer might work on business logic and data manipulation, while a UI designer can focus on creating a visually appealing view. This ability to work almost simultaneously, without the risk of derailing others’ efforts, makes MVVM a common design pattern for modern graphical user interface (GUI) applications.

MVVM, MVP, and MVC

The MVVM model joins the Model View Presenter (MVP) design pattern as newer variants of the original Model View Controller (MVC) pattern. In the MVC pattern, the Model or Controller can update the View by sending notification updates. In the MVP pattern, the Presenter communicates with the View and the Model, but these two remain separate from one another.

Business vs. presentation logic 

Consider the Model and View components separate from business and presentation logic: 

• Business logic represents the core functionality and rules of the application. It typically includes operations such as data validation, calculations, and interaction with data sources. Business logic handles the application's domain-specific operations and implements the desired behavior.

• Presentation logic focuses on UI and how data looks for the user. It includes tasks such as data binding, event handling, and updating the UI based on changes in the underlying data. Presentation logic provides a user-friendly and interactive experience, often through the use of visual elements and controls.

Who uses MVVM?

Typically software developers, front-end developers, full stack developers, and related roles may need expertise in MVVM. For example, Javascript frameworks, Windows Presentation Foundation, Windows phone, and Silverlight all use MVVM. This architecture proves useful when the framework has two-way data binding as MVVM requires less code to develop a full-featured application. MVVM also appeals to apps that require real-time, up-to-date data, such as stock ticker apps. 

Benefits of MVVM pattern

Here are several advantages to using the MVVM model. 

Flexibility

MVVM helps developers and software architects create flexible solutions. The pattern describes solutions to common design problems, allowing developers to make decisions quicker to expedite design deliveries. Plus, with MVVM, you can change your user interface without the risk of it impacting other code base logic.

Reusability

MVVM provides reusable components that let developers within a company use each other’s work. Likewise, an individual developer can simplify work across projects with the design pattern.

Component independence 

MVVM lets you conduct thorough unit testing and maintenance for View or Model solutions separately, leading to more robust and scalable applications.

Designer and developer independence

MVVM allows designers and developers to collaborate almost simultaneously. The codebase is separately organized between presentation and business logic so that different team members can understand and modify only their responsibilities.

Next steps

Studying design patterns can help you design more efficiently and effectively. Having the vocabulary to communicate about patterns such as MVVM can also support your collaboration with designers and other teams. Get an introduction to in computational thinking with the University of Alberta on Coursera. You might also begin with an overall overview of with the University of Minnesota. Upon completing either program, receive a shareable certificate to include in your resume, CV, or LinkedIn profile.