Sitefinity offers many ways for developers to add custom features. Often we find ourselves asking, “What would work best”? Create custom controls or a custom module. From our experience working with the CMS on various client projects, the answer resolves to the question, “Native logic and custom controls or custom logic and native controls”? With a module there will be an entire configuration section that gets built for users to set global configuration. This may be a necessity, for example, when integrating Sitefinity to other applications such as SalesForce. Also, a Module’s native functions can be overridden to perform custom logic. This approach obviously involves more interface implementations, more coding and more resources. One might think the easier path would be to just create custom controls for content editors to drop into pages and create their own logic. Not so fast. The native Sitefinity controls extend the native Telerik controls. Those controls extend the native .NET 4.5 Toolbox controls. Many layers of polymorphism have already been applied, so adding another layer is not going to be a quick and trivial project. In fact if you were to look at extending any of the Sitefinity controls, they require over half a dozen supporting files to function properly. There are interfaces which must be implemented, there are JS files to manage the controls while in the browser, there are core references which must be set for everything to work on the platform. This in itself can be just as time consuming as creating a custom Module in C# and MVC.
Best practice for deciding how to create custom Sitefinity features is to first determine how much control over the logic flow content admins need.