Enhancing Code Flexibility with Dependency Injection in DNN

DNN Dependency Injection A Step to Modernization

Why Dependency Injection Development is completed using interfaces allowing code to be swapped for implementations Code can be better unit tested for ongoing functionality Code can be validated BEFORE being executed Following SOLID principles results in code that is less complex and easier to understand.

Introduction of Dependency Injection in DNN Current implementation was added in DNN 9.4.0 Enhancements came in 9.5.0 with a final change coming in 9.5.1 Older Service Locator pattern has existed for a while Current implementation follows .NET Core Standards

What Code Used to Look Like

Usage

But That Works Right? Yes, it does, until changes happen What happens if you change MessageService to be CloudMessageService or TextMessageService? You edit EVERYWHERE

Introduce Dependency Injection

Traditional Dependency Injection Usage

Traditional .NET Core DI Registration (Startup.cs)

Support for Dependency Injection All major module development paradiggms WebForms MVC Spa Similar to .NET Core Implementation but configured for DNN

Introducing IDnnStartup Base class allowing Dependency Injection to be Discovered Anything that would be done in .NET Core using Startup.cs would be done in this class Executed at startup

Example

Implementation Rules Aside from the IDnnStartup base class, all rules follow .NET Core Standards Constructor Injection for all except WebForms WebForms require a ServiceLocator process due to limitations in implementation ability

Module Implementation Examples Special thanks to Andrew Hoefling for the samples https://github.com/ahoefling/DNN.DependencyInjection.Samples

NuGet Package Install-Package DotNetNuke.DependencyInjection

WebForms Service Locator

MVC Just like everyone else

Samples & Detail https://www.andrewhoefling.com/Blog/Post/dnn-dependency- injection Thanks Andrew!