Review Request 113830: Allow unique apps to access command-line arguments of later invocations

[Alex Merry]

On 22/11/13 10:32, David Faure wrote:
> On Wednesday 13 November 2013 17:34:45 Alex Merry wrote:
>> Of course, if we wanted to support Ryan's use cases (like text editor use by
>> git), thing's get a little more complicated.
>>
>> He basically suggests the route of standardising application arguments,
>> AFAICS, but even without that, I think he's right about wanting to pass the
>> current working directory, and possibly also the environment.
> 
> Yes please add the working directory, that one is very much needed.

I can't do anything until next week, so I'm inclined to leave this until
Kevin has done the splitting.  But it's easy enough to add an extra
argument.

> Which reminds me that we don't have a replacement for KCmdLineArgs::url(i) 
> instead, i.e. a method that resolves "an absolute filename, a relative 
> filename (given a CWD), or a URL" into a QUrl, for convenience. Many (kio-
> based) apps need that. It doesn't have to be part of QCommandLineParser 
> though... maybe a QUrl::fromUserInput(string, cwd), but the need to call 
> QFile::exists() in there sounds like a bad location for it... I'm open to 
> suggestions :)
> 
> For apps that don't support URLs, something like QDir(cwd).filePath(str) is 
> enough.

If it's going to go in Qt, a static method on QProcess or
QProcessEnvironment might be logical?  Since it's dealing with relative
paths.

> To come back to the "text editor should exit once done editing", that sounds 
> like a use case for DBus transactions, on the "receiving" side. i.e. calling 
> setExitValue() would be mandatory, and would terminate the dbus call, and it 
> wouldn't have to be called synchronously.
> OTOH I don't see this as a huge priority; one can just use kwrite instead of 
> kate as the text editor, in practice :)

There's some complexity in this one.  While it's easy enough to add a
flag to enable this behaviour, there needs to be some "transaction id"
passed to the slot, to cope with multiple overlapping instances - just
which duplicate instance are you intending to terminate?  And adding
arguments to signals breaks BC.

OTOH, maybe those few apps that would find this useful should be cooking
their own solution.

Alex