Mark,
Yes! I agree with you about throw.
Do you, or dose anyone, have an example that shows the use of the throw
command in conjunction with the try-catch structure?
Jim
Message: 4
Date: Thu, 22 Mar 2012 22:33:42 -0700
From: Mark Wieder mwie...@ahsoftware.net
To:
Bob,
Maybe I'm missing something but you seem to be saying there are some
database errors that can only be detected by using try/catch, not by
checking the result or the revdberr string.
Taking your example of a database going away, I just created a small db,
opened it in LC, then deleted the db
The syntax is there at the top but it's not formatted -- tabs or space-runs
between the lines instead of cr's. Looks like a problem in the dictionary stack
with displaying the text from the customprop. If it were displayed properly you
could see the structure, and then the commentary would
try
put foo into myVar
put the value of myVarr
catch theError, theNum
-- breakpoint
answer theNum cr line1 of theError as sheet
exit to top
end try
Is that what you mean?
Bob
On Mar 22, 2012, at 8:33 AM, Jim Hurley wrote:
The dictionary needs an example of how the try command is
On Mar 22, 2012, at 11:33 AM, Jim Hurley wrote:
The dictionary needs an example of how the try command is used to catch an
error.
Anyone have an illustration?
For example, suppose one wanted to catch an error in the statement:
put the {some built-in property of an object] of button
Bob,
Yes that would be fine, except that I get a compilation error at the line:
catch theError, theNum
RR says: (try: not a command), char 7
Jim
Bob Sneidar wrote:
try
put foo into myVar
put the value of myVarr
catch theError, theNum
-- breakpoint
answer theNum cr line1
On Mar 22, 2012, at 11:33 AM, Jim Hurley wrote:
For example, suppose one wanted to catch an error in the statement:
put the {some built-in property of an object] of button soAndso into tProp
Where the built in property may not exist.How would one catch the error and
perhaps proceed on
On Mar 22, 2012, at 12:22 PM, Jim Hurley wrote:
Bob,
Yes that would be fine, except that I get a compilation error at the line:
catch theError, theNum
RR says: (try: not a command), char 7
The syntax for the try construction is
try
command here
catch tError
other commands
You're getting an error because the catch part of try takes only 1
parameter - the variable that holds the error - not two as in the script.
Also, as noted by Peter, the try statement doesn't help you with the
specific example you used since getting a non-existant custom property
doesn't cause an
Whoops maybe the second argument is not valid.
On Mar 22, 2012, at 9:22 AM, Jim Hurley wrote:
Bob,
Yes that would be fine, except that I get a compilation error at the line:
catch theError, theNum
RR says: (try: not a command), char 7
Jim
Bob Sneidar wrote:
try
put foo
Also I forgot the finally part
try
-- some statements
catch theError
-- do some stuff if there is an error
finally
-- do some other stuff no matter what
end try
On Mar 22, 2012, at 9:22 AM, Jim Hurley wrote:
Bob,
Yes that would be fine, except that I get a compilation error at
It does give an error here. I get the error message:
button Button: execution error at line n/a (Object: object does not have
this property)
Jim
Message: 2
Date: Thu, 22 Mar 2012 09:55:20 -0700
From: Pete p...@mollysrevenge.com
To: How to use LiveCode use-livecode@lists.runrev.com
Thanks Peter.
The problem now is what do these bloody error numbers translate into.
Is the a list somewhere?
When I try:
on mouseUP
try
put the cantdelete of me into temp
catch tErr
--- if tErr is ??
end try
end mouseUP
I get an error of 348,0,0
Jim
Peter Brigham wrote:
The
On 3/22/12 12:21 PM, Jim Hurley wrote:
Thanks Peter.
The problem now is what do these bloody error numbers translate into.
Is the a list somewhere?
The list is explained in the errordialog entry in the dictionary. You
can retrieve the list with the line of script the dictionary provides.
On Mar 22, 2012, at 1:11 PM, Jim Hurley wrote:
It does give an error here. I get the error message:
button Button: execution error at line n/a (Object: object does not have
this property)
Sounds as if you're trying to get a built-in property that doesn't apply to
that type of object. If
Does anyone have any guidelines as to when you should use the try and catch
structure? I don't really know when or when not to use it.
-= Mike
On Mar 22, 2012, at 1:21 PM, Jim Hurley wrote:
Thanks Peter.
The problem now is what do these bloody error numbers translate into.
Is the a
On Mar 22, 2012, at 1:21 PM, Jim Hurley wrote:
Thanks Peter.
The problem now is what do these bloody error numbers translate into.
Is the a list somewhere?
Jacque posted this two days ago:
On 3/20/12 12:37 PM, Ralph DiMola wrote:
OK, I give up. How do you translate error number
I second this!
Ralph DiMola
IT Director
Evergreen Information Services
rdim...@evergreeninfo.net
Also, as noted by Peter, the try statement doesn't help you with the
specific example you used since getting a non-existant custom property
doesn't cause an error. I've sometimes wished there was a
On Mar 22, 2012, at 1:32 PM, J. Landman Gay wrote:
On 3/22/12 12:21 PM, Jim Hurley wrote:
Thanks Peter.
The problem now is what do these bloody error numbers translate into.
Is the a list somewhere?
The list is explained in the errordialog entry in the dictionary. You can
retrieve the
I use it to determine if there has been an error executing a sequel query for
example. All my database calls go inside a try catch statement. If you put it
into a repeat loop, you can test to see if perhaps you have been disconnected,
or if a runtime error occurred due to a bad query, and then
Interesting, never thought of that. Is there an advantage to doing that
over just issuing the database call and checking for an error right after?
I've mostly thought of try/catch for as a debugging tool. I also use it
any place where I put together a command in a variable and execute the
On Mar 22, 2012, at 10:33 AM, Michael Doub wrote:
Does anyone have any guidelines as to when you should use the try and catch
structure? I don't really know
when or when not to use it.
Here's another use (and apropos a different thread here)
In order to recreate a control you'd want to
No advantage per se, but I use sqlYoga and the only way to determine what went
wrong is in a try catch statement as the libSQLYoga stack is locked.
Bob
On Mar 22, 2012, at 11:49 AM, Pete wrote:
Interesting, never thought of that. Is there an advantage to doing that
over just issuing the
RunRev was thinking of calling the try construct,
TryAndDontStopDeadInYourTracksUponAnError but they opted for the shorter
version. ;-)
Bob
On Mar 22, 2012, at 1:08 PM, Mark Wieder wrote:
On Mar 22, 2012, at 10:33 AM, Michael Doub wrote:
Does anyone have any guidelines as to when you
I have been using the try/catch idiom for years. I like the structure
it gives my code - visually it makes it very clear where I am
expecting problematic sections to be. I rarely use 'finally'.
However the problem has always been with interpreting the error codes
that arise. For years I got
The following script will provide a start in finding all the property values of
a given object, in this case the button button
It starts with the propertynames which is a list of ALL built-in property
names in LC.
It then attempts to put the value of each of these properties for the given
When you are in a standalone, a runtime error that would halt execution might
be fatal. Try/Catch allows you to handle the error gracefully without
presenting the user with an ugly dialog and a QTD afterwards. You can politely
inform the user that something has gone wrong and you have to exit
Or - this can be applied to a night out clubbing -
try
put myBestPickupLine into myMouth
catch theResponse
If theResponse is not negative
-- Oh yeah!
set luckynight to true
else
put wittingComback into myMouth
move body to new location
finally
if not
Jacque,
Thanks.
LC is an English muffin. So many nooks and crannies.
Jim
P.S. There really ought to be an illustration of the try-catch syntax in the
dictionary.
Message: 5
Date: Thu, 22 Mar 2012 12:32:01 -0500
From: J. Landman Gay jac...@hyperactivesw.com
To: How to use LiveCode
On 3/22/12 11:59 PM, Jim Hurley wrote:
LC is an English muffin. So many nooks and crannies.
I like that. :)
P.S. There really ought to be an illustration of the try-catch syntax
in the dictionary.
I just looked, and I'm amazed there isn't. Myabe you could add a user note.
--
Jacqueline
Jacque-
Thursday, March 22, 2012, 10:19:59 PM, you wrote:
P.S. There really ought to be an illustration of the try-catch syntax
in the dictionary.
I just looked, and I'm amazed there isn't. Myabe you could add a user note.
Yeah - the throw command should be mentioned there as well.
--
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