Re: Proper way of connecting to apps

[Richard Frith-Macdonald]

On Sunday, June 22, 2003, at 12:07  pm, Stefan Urbanek wrote:

> This API will be useful for *lots* of people. It is new API for new 
> GNUstep functionality, not publicaly present on OSX. That 
> functionality is: easy cooperation of applications by using 
> communication with application listeners. This will make GNUstep 
> environment more integrated.
> As I have said, there is currently  only one such kind of service and 
> that is implemented in Terminal.app. With this method more services 
> can be created and accessed very easily.

I guess I must have missed it ... What new functionality are you 
proposing?
I thought you were talking about wrapping a small piece of code in a 
convenience method.

> > The problem is, people work on their own code, and see a feature they 
> > want for what they happen to be doing now.  Psychologically, it's 
> > hard to step back from the current work and look at whether the 
> > feature will be used.  Over the past few years I have removed a *lot* 
> > of non-standard stuff from the base library (some things that I added 
> > myself in earlier days) as it became clear that nobody was using it 
> > and it was just confusing newbies.
>
> I agree with you. However, think about this proposal. I think it is 
> not 'just another non standard stuff'.
>
>
> > The code to handle launching and connecting to an application is 
> > pretty simple really, and very few applications ever need to use it 
> > ... so adding a public convenience method to do it is IMO a bad >> thing.
>
> Well, few or many? At this time, just a few. Why? Because it is 
> complicated to make cooperative applications at this time. If we make 
> it easier for applications to cooperate, then people stop writing 'all 
> in one' applications and start delegating functionalities to other 
> applications. Applications then can start to serve as 'active objects' 
> and can eb complementary to frameworks. Applications are just 
> 'frameworks with user interface'.

It seems very simple (but very badly documented) to write cooperating 
applications ...
but I am probably not completely understanding how you are using the 
term.

Use of the services  mechanism (services menu in apps) is superbly 
simple
for non-programmers, and is pretty versatile.  Its great advantage is 
that apps
really need to know nothing about each other to use it.  I'm not sure 
if you call
this 'cooperating', as the applications are pretty much independent.

Use of NSConnection is extremely clean/simple (about as simple as it is 
possible to
make inter-process messaging) and wrapping another layer round it is 
only likely to
make it less simple.  However, the programmers of the applications need 
to know
what the other applications are expecting.

Are you suggesting something between these in some way?