Check if a path exists?
[1/3] from: stefan:falk:slg:se at: 21-Mar-2001 11:59
Hi list,
how can I check if a path has a value.
I've decode some cgi into objects, something like this:
data/name
data/comment
Now, if I want to check if there's actually something in data/comment (as it
sometimes isn't), how should do?
comment: data/comment
if (length? comment) > 0 [ some code...]
doesn't work...
and if exists? data/comment doesn't work either..
Any tips?
/Regards Stefan
[2/3] from: jelinem1::nationwide::com at: 21-Mar-2001 8:32
If the path (eg) data/comment exists and it IS set to SOME value, eg an
empty string or an empty block, then your first example should have worked:
comment: data/comment
if (length? comment) > 0 [ some code...]
Since it doesn't, then the path could exist yet not set to a value, in
which case the following should work:
if value? (in data 'comment) [ some code...]
Not having used CGI stuff I'm not exactly sure about the nature of your
problem, but I suspect that you want to determine whether a word is an
element of an object, that is, whether 'comment exists at all in 'data. I
use this:
if find next first data 'comment [ some code...]
Need me to explain it?
- Michael Jelinek
[stefan--falk--slg--se]@rebol.com on 03/21/2001 04:59:30 AM
From: [stefan--falk--slg--se]@rebol.com on 03/21/2001 04:59 AM
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Subject: [REBOL] Check if a path exists?
Hi list,
how can I check if a path has a value.
I've decode some cgi into objects, something like this:
data/name
data/comment
Now, if I want to check if there's actually something in data/comment (as
it
sometimes isn't), how should do?
comment: data/comment
if (length? comment) > 0 [ some code...]
doesn't work...
and if exists? data/comment doesn't work either..
Any tips?
/Regards Stefan
[3/3] from: stefan:falk:slg:se at: 21-Mar-2001 15:48
Hi,
I understand that last line, and I think it might work, because I want to
know if there actually is something in /comment, I'll try it immediately,
thanks!
/Regards Stefan