How best to add Plugin Capability to a Delphi program

Question

I am looking to add the capability for users to write plugins to the program I have developed in Delphi. The program is a single executable with no DLLs used.

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Answer 1

If plugins will be developed in Delphi or C++ builder, use packages + interfaces. Delphi OTA is a good example for that. If plugins will be language independent, COM is a good way to go.

Addition: If you won't use COM, u may need to provide SDKs for each language. And datatype handling between different languages can be pain(for example delphi string type). Delphi COM support is excellent, u don't need to worry about kind of details. Those are mostly impilicit with Delphi COM support. Don't try to invent the wheel again. I'm surprised why people doesn't tend to mention about it.

Answer 2

You could have a look at Hydra from Remobjects. Not only will this allow you to add plugins, but also to mix win32 and .net.

Answer 3

I'm using plug-ins to implement most of the functionality in the game engine I'm building. The main EXE is made up of a script engine, a plug-in manager, some basic graphics routines and not much else. I'm using TJvPluginManager from the JEDI VCL library. It's a very good manager, and it can add just about anything you want to your program. Check out the demos included with the package to see how it works. The only downside is that it adds a lot of JCL/JVCL code to your program, but that's not really an issue if you're already using other JVCL components.