[fpc-devel] Dnamic packages support

[Michael Van Canneyt]

On Sat, 3 Nov 2007, Daniël Mantione wrote:

> 
> 
> Op Sat, 3 Nov 2007, schreef Michael Van Canneyt:
> 
> > 
> > 
> > On Sat, 3 Nov 2007, Florian Klaempfl wrote:
> > 
> > > Leonardo M. Ramé schrieb:
> > > > Reading a post in "public.mseide-msegui.talk", the mseide discussion
> > > >  list, I found this:
> > > > 
> > > > "Florian has committed the beginning of dynamic packages support".
> > > > 
> > > > With "Dynamic Packages" you mean a platform independent way of
> > > >  implementing something similar to
> > > > .Dlls (or .bpl)? without creating each library its own memory manager?,
> > > >  where objects can flow
> > > > across all libraries without problems?
> > > > 
> > > 
> > > If it is finished, it would be something like this yes. However, I'am
> > > not convinced of the use of dyn. loaded packages for an OSS project so I
> > > played only with it.
> > 
> > Hm. I don't see what OSS or not OSS has to do with it ?
> > 
> > Packages are IMHO a pre-requisite for any good plugin system.
> 
> The reason is that the "library" construction requires you to write down 
> your binary interface, and therefore design it properly. If the 
> interfacing between application and plugin is automatic, it can also 
> change automatically without you knowing.
> 
> I believe such a system is only useable in contolled environments. If 
> plug-ins are to be developed by a third party, runtime-packages aren't 
> a feasible mechanism.

Indeed.

It is exactly because I wish to control the plugins that I require packages.
The single identifier space is a huge advantage, which make it almost automatic.

If you don't have packages, then you must revert to COM interfaces, refcounted
stuff, explicitly sharing memory managers to be able to use ansistrings properly etc.

Packages solve all problems in 1 fell swoop. There is only 1 disadvantage to
packages, this is the versioning of the base packages, which is IMHO very 
controllable. All other things are advantages.

In my opinion, Packages are the second best thing Borland did for RAD.
If I remember the shit we had with VB and its OCXes, DLLs and whatnot. 
No thanks...

Michael.