Some time ago, I had a requirement for an old application to be updated to support storing files in the Azure cloud service. The tool used to develop that application was pretty old, and didn’t provide good support for cloud services like Azure or Amazon.
Instead of trying to update all the old source code to support a more recent development tool, I opted to implement a COM component to interface to the cloud. The old tool (like many others) has supported COM interfaces for many years, and the changes to the older dropped significantly to implement cloud storage.
Rather than just writing an Azure component, I opted to implement a COM component capable of interfaceing to multiple back ends. It currently allows interaction with Azure, Amazon, FTP, and local file stores. It was written with Delphi, and implements an OOP approach to the back ends so that the same interface is presented to the caller regardless of the back end, and selection of the desired back end is done by a ‘connection string’ property.
You can get the source code from GitHub.
The code demonstrates creating a COM server in Delphi, as well as interacting with back ends like Azure or Amazon cloud in an OOP approach. The repositary has the source code as well as the pre-built DLL and basic documentation. Support will be through Github.
Note: If you’re new to Azure or Amazon, they can be intimidating. I suggest you sign up for trial accounts to give you a chance to play in your own sandbox to get an understanding how they work.