Howard
You wrote in message news:
[hidden email]...
>
> I've been fooling around with the CommandLineHelloWorld in an attempt to
> learn how to make a command line program. I've had a couple things that
> I don't understand happen.
>
> 1. After deploying the CommandLineHelloWorld via Lagoon and then
> running it, on my (W2K) box at home everything seems to work okay; the
> program launches in a console and after pressing Enter it goes away. On
> my (NT4) box at work, everything prints to the console, but pressing
> Enter seems to have no effect; the console never disappears.
Apart from Ian's suggestion about installing Patch Level 1, I wonder if it
might be the case that the machine in question is configured not to close
consoles automatically when the application finishes. Rather than
double-clicking the app., try running it from the command line itself.
You'll know if it is finishing correctly because it will return.
Alternatively try inserting a 'self stdout nextPutAll: 'Bye'; cr; flush'
after the 'self stdin nextLine' to see if it gets past that.
>
> 2. Let's say that I want to modify the program to pause before
> displaying the prompt to exit. I'd expect that adding a line like:
>
> Processor sleep: 1000.
>
> would make it pause for a second and then resume. However, when I do
> this it just hangs. Clearly I don't understand something that is
> happening.
Hmmm, not sure what the story is there. I'll try it.
> The ActiveX question is this: how does one deal with optional
> parameters? While I was experimenting, I found that I was able to omit
> them from the end and things seemed to work, e.g. if we had a selector
> arg1:arg2:arg3:arg4: where the last two are optional I could just send
> something like:
>
> Interface arg1: aNumber arg2: aNumber
>
> and things seemed to work as one would expect. Is this how things
> should work? Moreover, what if one wants to omit an optional parameter
> but use a later optional parameter (e.g. in my example I want to pass
> something for arg1, arg2, and arg4, but not arg3?).
It only works because you are going through #doesNotUnderstand: processing,
i.e. the Smalltalk object doesn't actually implement a method with the
"shorter" selector, but it asks the underlying COM object if it understands
the primary keyword, and if so tries calling it with the parameters you have
passed. If some are optional, then this will often work, but it will be
slow.
What I recommend you do instead is to add some further wrapper methods of
your own by copying the one with all the parameters generated by the AX
wizard. You can then follow the common Smalltalk idiom of having shortcuts
that omit/default some of the parameters. What to pass for the optional
parameters? Well that depends on their type: Commonly they are VARIANTs, in
which case you should pass "VARIANT unspecified", for other types nil is
often appropriate (pointers, BSTRs). Oh, and if you add wrapper methods just
make sure they aren't in the auto-generated category, and then the wizard
won't overwrite them should you regenerate the interface.
Regards
Blair
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