Working with DLL in Servoy?

[felipebortoli017]

Working with DLL in Servoy?

Help!!!

[ROCLASI]

Hi Felipe,

I have never used Servoy with DLL's but I think the closest you can get is via https://www.servoyforge.net/projects/servoy-com .

Hope this helps.

[felipebortoli017]

Much thanks ROCLASI

[tparry]

What do you want to do with a DLL?

[felipebortoli017]

I need to call a dll in Servoy

[tparry]

Does the DLL do only processing or does it have a UI function?

There is a way to call a DLL from Java code (via JNI - Java Native Interface) and therefore from Javascript. But this is a lot of an effort.
For example see:
http://www.java-forums.org/advanced-java/2064-how-call-dll-java.html
Perhaps the functionality can be duplicated in a plugin (Java code)?

[ptalbot]

Calling JNI from JavaScript? Oh man. This sounds like a mad plan to me!
Better encapsulate this kind of stuff inside a plugin, yes.
Or use the COM plugin, it's using Jacob which is making it easier...

[tparry]

Of course from a plugin! Javascript in Servoy to invoke it!

I wonder about JNA (Java Native Access project) - maybe a better choice.

[ptalbot]

JNA is easier. It's the lib used in the BrowserSuite for various Native access.
But still you need a good understanding of how Native objects works, and it can be tricky with C++ Struct

For simple COM usage, Jacob is the way to go.

[tparry]

@Patrick:
Glad to hear you have used JNA. I have used JNI quite a lot over a several years now to interface MATLAB code that was compiled to Java then I interfaced to several c++ dlls using JNI for some complex (READ MATLAB complex) structures. Not easy to do and quite a lot of effort, iterations and testing.

If JNA can be a production quality tool then it would be a way to go.

In either case one needs to know the dll functions in order to provide a way to call them. I have not seen a generic way to extract the function names return values, types etc yet (e.g. likehttp://www.dependencywalker.com/). Therefore the dll to be used must have some information for the user to "use" (properly and legally of course).

Is there a real need to use dlls in Servoy (encapsulated within plugins) by users or is the feeling that duplicating the functionality in Javascript/Servoy is better for the long maintenance support? I understand that "common" well maintained dlls appear to save development time.

@Felipe
Does this help or or you convinces not to use the dll by now?