[Gambas-user] Using command line arguments in GUI applications

[Tobias Boege]

On Wed, 20 Aug 2014, Geoffrey De Belie wrote:
> 
> Op 19-08-14 om 21:28 schreef Tobias Boege:
> >On Tue, 19 Aug 2014, Geoffrey De Belie wrote:
> >>Hi,
> >>
> >>After reading the documentation at http://gambasdoc.org/help/comp/gb.args/args/has?v3 I'm not sure how to use command line arguments in Gambas. Can you explain it to me?
> >>
> >>1) Is it possible to pass command line arguments to my GUI application? If so, how?
> >>2) How can I define command line arguments (options) like --execute, -e or --replace, -r?
> >>
> >Does the attached project help you?
> >
> >Note that you call the Gambas interpreter to start your Gambas program. The
> >interpreter takes arguments of its own so you have to take the canonical
> >measures (i.e. the sole double dash) to make gbx3 leave your argument to
> >gb.args:
> >
> >   $ gbc3 && gbx3 -- --replace ABC
> >
> >in your project directory will compile and call the program.
> >
> >Also, you wrote this message to the gambas-devel mailing list which is for
> >people who contribute to Gambas. To ask Gambas user/usage questions like
> >yours, there is the gambas-user mailing list (which I'm CC'ing now). You
> >will likely get an even quicker response there :-)
> >
> >Regards,
> >Tobi
> >
> Hi,
> 
> Thanks for the project. Just what I needed. One last question: how can I add
> the parameter to the --help text?
> 
> I read at http://gambasdoc.org/help/comp/gb.args/args/getinteger?v3
> "_ArgName_ is the name of the option argument used by the --help option."
> 
> Almost what I need, I just don't know how to define an option that takes an
> argument, like --replace sometext does.
> 

Args.Get() is for options which accept some data (in string form). There are
GetInteger() and GetFloat() which convert the argument to Integer or Float
for you. For argument-less options, you have the Has() method.

You specify the help text and stuff in the call to Args.Get()/GetInteger()/
GetFloat()/Has(), like so (adapting the project I sent):

  $sReplace = Args.Get("r", "replace", "Specify the replacement text", "rep")

Then

  $ gbc3 && gbx3 -- --help
  Usage: gui-args <options> <arguments>

  Options:
   -r --replace <rep>                     Specify the replacement text
   -V --version                           Display version
   -h --help                              Display this help

I first thought it was some non-deterministic black magic which makes the
arguments to some method call appear in that help text but if you experiment
a bit with gb.args (place Args.Begin(), ..., Args.End() blocks into different
sections of your program or look into its source code), you'll see that it is
still limited to the traditional idea of action before reaction.

Regards,
Tobi

-- 
"There's an old saying: Don't change anything... ever!" -- Mr. Monk