In software development, a framework is a pre-written code structure that provides a foundation for developing software applications. It includes a set of rules, protocols, and libraries that allow developers to build applications more easily and quickly by providing a pre-built structure and architecture.
Software developemnt frameworks can be used for different purposes, such as building web applications, desktop applications, mobile applications, or APIs. They often include pre-written code for common features and functionalities, such as user authentication, database integration, http request handle, and input validation.
Frameworks can also be designed to enforce certain coding conventions and patterns, making it easier for developers to work together and maintain consistency throughout a project.
Some popular examples of software development frameworks include Laravel, Ruby on Rails, AngularJS, React, Django and Flask.
The motivation behind building or using a software development framework can be explained by the following reasons:
Reusing software is not simple:
Developing software from scratch can be time-consuming, and reusing software components from previous projects is often difficult and not very efficient. Frameworks provide a solution to this problem by offering a pre-built architecture and structure that can be reused across multiple projects.
Majority of efforts result in only small component reuse:
Developers may spend a lot of time trying to reuse small components of code, but this can result in a fragmented and inconsistent codebase. Frameworks offer a more comprehensive solution by providing a set of pre-written code and conventions that ensure consistency and maintainability.
Increase reuse and decrease time for application development:
Using a framework can significantly increase the reuse of code and design, which in turn reduces the time required for building a family of applications. This is because the framework provides a reusable foundation that can be customized to fit the specific needs of each application.
Framework provides reuse of design and code:
Frameworks provide a set of pre-built design patterns and code components that can be used across multiple projects, resulting in more efficient and consistent development.
Frameworks enable large-scale reuse of code and design, as they are designed to be flexible and customizable. This means that developers can use a framework to build a variety of applications with different functionalities and requirements, while still maintaining consistency and efficiency across all projects.
A software development framework can be defined as follows:
A framework is a pre-built solution that provides a set of classes and interfaces to help developers decompose and solve a family of similar problems. It demonstrates how objects within these classes collaborate to fulfill their responsibilities. The set of classes must be flexible and extensible, allowing for the construction of multiple applications with minimal effort. Developers need only specify the unique features of each application, rather than building everything from scratch.
Some further explanation of the characteristics of frameworks are:
Frameworks provide a solution for a family of similar problems:
Frameworks are designed to solve a specific set of related problems, rather than addressing a single problem. By providing a pre-built solution for a family of similar problems, frameworks can save developers time and effort, as they do not need to build everything from scratch.
Frameworks use a set of classes and interfaces to decompose the family of problems:
Frameworks are built upon a set of classes and interfaces that define the structure and behavior of the application. This allows developers to decompose the problem into smaller, more manageable parts, which can then be addressed through the framework.
Frameworks demonstrate how objects collaborate to fulfill their responsibilities:
Frameworks provide a set of guidelines and best practices for how objects should interact with each other to fulfill their responsibilities. This ensures that the resulting application is cohesive and efficient, with minimal duplication of effort.
Frameworks must be flexible and extensible:
Frameworks must be flexible and extensible, meaning they can be adapted to meet the specific needs of each application. This allows developers to customize the framework to fit their unique requirements, rather than being limited by the pre-built solution.
Frameworks allow for the construction of multiple applications with minimal effort:
By providing a pre-built solution for a family of similar problems, frameworks enable developers to build multiple applications with minimal effort. This reduces the time and cost of development, while maintaining consistency and efficiency across all applications.
By using frameworks developers need only specify the unique features of each application:
Frameworks provide a foundation for building applications, but they are not complete solutions in themselves. Developers still need to specify the unique features and requirements of each application, but they can do so within the framework, rather than building everything from scratch. This results in faster and more efficient development, with fewer errors and inconsistencies.
These are formal definitions from software engineering scholars for software development frameworks:
“A framework is a set of classes that constitute an abstract design for solutions to a family of problems.”
Johnson and Foote (1988)
“A framework is a set of collaborating objects that collectively fulfill a set of responsibilities for an application or subsystem domain.”
“An architecture developed with the goal of achieving maximum reuse, represented as a set of abstract and concrete classes with great potential for specialization.”
Here is a list of some common types or classifications of software development frameworks:
System Infrastructure Frameworks: These frameworks provide a pre-built foundation for developing the infrastructure of a software system, including communication protocols, user interfaces, compilers, and middleware integration.
Enterprise Application Frameworks: These frameworks support the development of specific types of applications, such as telecommunications or financial systems. They are designed to handle complex business logic and are often related to a family of programs.
Web Application Frameworks: These frameworks are designed specifically for developing web applications and provide support for web-related features such as session management, security, and database integration.
Mobile Application Frameworks: These frameworks provide support for developing mobile applications and are optimized for the unique features of mobile devices, such as touchscreens and location-based services.
Testing Frameworks: These frameworks provide tools and utilities for automated testing of software applications. They can help developers identify and fix bugs and ensure that the application works as intended.
Game Development Frameworks: These frameworks provide support for developing video games and can handle features such as graphics rendering, physics simulation, and input handling.
UI Frameworks: These frameworks provide pre-built user interface components and libraries that can be used to develop desktop or mobile applications.
Data Science Frameworks: These frameworks provide tools and libraries for data analysis, machine learning, and statistical modeling.
Robotics Frameworks: These frameworks provide tools and libraries for developing robotic systems and control algorithms.
Software development frameworks have several characteristics that make them useful and effective for building software applications. These characteristics are important because they help to ensure that the resulting applications are reusable, well-documented, easy to use, extensible, secure, efficient, and complete.
Reusability: The purpose of a software development framework is to provide a reusable solution to a family of problems. This means that a good framework must be designed with reusability in mind, and should be usable across multiple applications and domains. To achieve this, the framework must first be usable, meaning that it is easy to understand and use.
Well-documented: A well-documented framework provides clear and concise documentation that explains how to use the framework, its features, and its APIs. This documentation should be readily available and easy to understand, to facilitate the adoption and use of the framework.
Easy to use: A good framework should be easy to use, even for developers who are not experts in the underlying technologies. This means that the framework should have a simple and intuitive API, with clear and concise documentation that explains how to use it.
Extensibility: A framework should be extensible, meaning that it should provide a set of abstract functionality that can be extended and implemented by developers. This allows developers to customize the framework to meet their specific needs and requirements.
Safety: A framework should be safe, meaning that developers should not be able to inadvertently destroy or break the framework. This requires careful design and implementation of the framework’s APIs and features.
Efficiency: A framework should be efficient, meaning that it should be optimized for performance and resource usage. This is important because frameworks are used in many different situations, some of which may require high levels of efficiency.
Completeness: A good framework should be complete, meaning that it should provide a comprehensive solution to the intended problem domain. This requires careful consideration of the features and capabilities that are needed to address the problem domain effectively.
Inversion-of-Control (IoC): Inversion-of-Control is a key principle in software development frameworks, and refers to the idea that the framework is responsible for controlling the flow of execution in the application, rather than the application code itself. This allows the framework to provide a consistent and predictable programming model, and can simplify the development process.
Overall, these characteristics are essential for designing and implementing effective software development frameworks that can help developers to build high-quality and reliable software applications. There are many research articles on software development frameworks that provide further insights and best practices for designing and implementing effective frameworks, including “Software Frameworks: A Comprehensive Survey” by F. Buschmann et al., and “A Taxonomy of Software Development Frameworks” by M. Alshayeb et al.
The properties of a software development framework are essential for creating a reusable, scalable, and extensible solution to a family of problems. These properties help to ensure that the framework is flexible enough to meet the needs of different applications and domains, while also providing a consistent and predictable programming model.
Core of the framework: The core of a software development framework is a set of classes that work together to implement a family of systems. This core provides the foundation for the framework and includes the fundamental architecture and design patterns that define its behavior.
Extension points: Extension points are classes or interfaces that provide a way to extend the functionality of the framework. They are defined in the form of abstract classes or interfaces, and can be implemented by developers to customize the behavior of the framework.
Application flow control: A software development framework defines the control flow of an application, which is determined by the behavior of the classes that represent its core. These classes are responsible for invoking the classes that extend the extension points, which allows the framework to provide a consistent and predictable programming model.
Hot spots: Hot spots are parts of the framework that are flexible and extensible, and represent aspects of the domain that cannot be anticipated. They are discovered during the analysis of the domain and are instantiated by domain experts in the application. Hot spots are crucial for ensuring that the framework is customizable and can be adapted to meet the specific needs of different applications.
Frozen spots: Frozen spots are parts of the framework that are fixed and cannot be customized. They include the core of the framework and the parts of the code that have already been implemented. Frozen spots are important for ensuring that the framework is stable and reliable, and that it provides a consistent programming model.
Software development frameworks are abstractions that provide a set of pre-built components and design patterns, you already know, they are used to address a family of problems.
It’s important to understand that these frameworks are not themselves executable applications, but rather provide a foundation on which applications can be built. To produce a complete and executable application using a framework, developers must instantiate the framework by implementing specific code for each hot spot in the framework. This allows the framework to be customized and adapted to meet the specific needs of the application.
To use and customize frameworks for software development, there are several techniques that developers can employ, including extension of abstract classes, implementation of interfaces, configuration/composition of existing classes, and parametrization.
Extension of abstract classes: One technique for customizing a framework is to extend the abstract classes provided by the framework. Extension points in the framework provide a way to extend the functionality of the framework, and can be implemented by extending the abstract classes provided by the framework. By extending these classes, developers can customize the behavior of the framework to meet the specific needs of the application.
Implementation of interfaces: Another technique for customizing a framework is to implement the interfaces provided by the framework. Interfaces define a set of methods that must be implemented by the application code, and can be used to customize the behavior of the framework. By implementing the interfaces provided by the framework, developers can add new functionality to the framework or customize existing functionality.
Configuration/composition of existing classes: A third technique for customizing a framework is to configure or compose existing classes provided by the framework. Frozen spots in the framework represent parts of the framework that are fixed and cannot be customized, but these classes can still be used to build the application. By configuring or composing these classes, developers can create custom functionality that leverages the existing functionality provided by the framework.
Parametrization: Finally, parametrization is a technique for customizing a framework by providing configurable parameters that can be used to customize the behavior of the framework. These parameters can be used to change the behavior of the framework at runtime, without requiring changes to the underlying code. Parametrization is a powerful technique for customizing frameworks, as it allows developers to create highly flexible and customizable applications that can be adapted to meet a wide range of needs.
Overall, these techniques allow developers to customize and extend the functionality of software development frameworks to meet the specific needs of their applications. By leveraging the extension points, hot spots, and frozen spots provided by the framework, developers can create high-quality and reliable applications that leverage the underlying functionality of the framework, while also addressing the specific needs of the application.
Frameworks can be classified based on the strategy they use to implement hot spots. The three main types of frameworks are white box, black box, and gray box frameworks.
White box frameworks: are strongly linked to the features of object-oriented languages, and rely on inheritance and abstract classes to instantiate hot spots. This type of framework requires a good understanding of the framework to create an instance, and typically uses design patterns such as template method and abstract factory. White box frameworks provide a high degree of customization, but require a significant investment of time and effort to implement.
Black box frameworks: are instantiated from scripts or some form of configuration, such as XML or a graphical wizard. This type of framework is based on the mechanism of composition, and does not require an in-depth understanding of the internal details to create an instance. Black box frameworks are easy to use and provide a high level of abstraction, but may lack flexibility and extensibility.
Gray box frameworks: are a mix of customization by inheritance and composition/configuration, and aim to avoid the disadvantages of both white box and black box frameworks. This type of framework provides a high degree of flexibility and extensibility, while also allowing developers to hide unnecessary information from the application developers. Gray box frameworks are highly customizable and can be adapted to meet the specific needs of a wide range of applications.
In summary, software development frameworks are a powerful tool for building scalable, flexible, and extensible software applications. These frameworks provide a set of pre-built solutions to common problems, allowing developers to focus on the specific requirements of the application rather than the underlying implementation details.
There are several types of software development frameworks, including system infrastructure frameworks, enterprise application frameworks, and web application frameworks, each with its own set of benefits and use cases.
To effectively use and customize a framework, developers must understand its core set of classes, extension points, hot spots, and frozen spots, and employ techniques such as extension of abstract classes, implementation of interfaces, configuration/composition of existing classes, and parametrization.
Finally, the type of framework chosen will depend on the specific needs of the application and the expertise of the development team, with white box frameworks providing high customization, black box frameworks providing quick solutions, and gray box frameworks providing a balance between flexibility and simplicity. By leveraging the power of software development frameworks, developers can create high-quality and reliable applications that meet the needs of users and stakeholders, while also delivering value to the business.