Declarative Inversion of Control Configuration in Modern .NET8 Applications

Abstract

As software systems continue to evolve in complexity and scale, the importance of adopting componentbased architectural paradigms becomes increasingly evident. Inversion of Control (IoC) and Dependency Injection (DI) patterns play important role in managing OO-components dependencies, reduce coupling and enable seamless integration of components. This article explores the theoretical foundations of IoC and DI, shedding light on their practical implementation in modern .NET applications.Standard .NET DI-container has a number of technical limitations: properties injection is not supported, dependencies definitions from keyed services partially breaks IoC principle, and finally lack of declarative way to define components and their dependencies. To address these limitations, it is proposed to implement a special extension for standard DI-container in the form of a component factory. This factory would register components within the container and define their dependencies based on declarative configuration. The configuration can be stored either in a standard (for .NET Core apps) appsettings.json file or loaded from a separate JSON file. In fact, this JSON could be even dynamically generated in specific usage scenarios.The capability to use a declarative configuration for standard DI-container opens up broad possibilities for generative programming. It becomes technically feasible to implement a model-driven development, particularly an approach that leverages the DI-container configuration as the final (execution) model in a chain of transformations of domain-specific models.Modern .NET8 platform assumes that software is assembled from libraries of pre-existing components that are hosted in a standard DI-container that provides suitable runtime environment for them. Practical aspects of applying the Inversion of Control pattern are examined, considering the use of a standard Dependency Injection (DI) container implementation. Existing technological limitations are defined, and a solution is proposed: implementation of declarative configuration of dependencies between components. This approach contributes to a reduced level of coupling between components and facilitates the decomposition of the program into more granular and abstract components – which increases their reusability in consequence.