error handling

[dik_coleman]

Anyone like to tell me why this 'snippet' will not resume counting??????

ui_msg_box("","Start",ui_ok)
on error goto error_handler

for x = 1 TO 10
if (x = 3) then
ui_msg_box("","Error",ui_ok)
goto error_handler
end if
ui_msg_box("Counting",(str(x)),ui_ok)
next x

ui_msg_box("END","Made it to end",ui_ok)

end

error_handler:
ui_msg_box("","Error processed.",ui_ok)
resume next
' end

[dik_coleman]

RE: error handling

why do I always see the answer AFTER I post it?????
D

[dik_coleman]

RE: error handling

Well, it still won't work...????
D

[dik_coleman]

RE: error handling

When I run this script, I get 4 error msgs on the first tbl, 3 on the second, and 2 on the third.... WHY?????
the first two msgs do not refer to any tbl name. the first just says 'not found' the second says 'tbl not found'.
Then 'd_customers tbl not found' and 'd_customers not found'.
On the second tbl, 'c_schedule tbl not found' and that repeats exactly; then 'c_schedule not found'.
On the third, 'b_main_menu tbl not found' and that repeats exactly....
Confusing
D


'Date Created: 02-Oct-2004 04:36:40 AM
'Last Updated: 02-Oct-2004 05:11:48 AM
'Created By : Administrator
'Updated By : Administrator


on error goto error_handler

dim mypointer as p
dim tblname as c

mypointer=d_customers
tbl.mypointer.open()
tblname="d_customers"
tbl.tblname.open()

mypointer=c_schedule
tblname="c_schedule"
tbl.mypointer.open()
tbl.tblname.open()

mypointer=b_main_menu
tblname="b_main_menu"
tbl.mypointer.open()
tbl.tblname.open()

end

error_handler:
err = error_code_get()
msg = error_text_get(err)
ui_msg_box("Error",tblname+" "+msg,ui_ok)
resume next
end
'on error goto next 'goes to next line - expects an error handler
'on error resume 'disables error handling
'on error resume label name 'ignore error and branch to label name
'on error resume next 'ignore error and resume next line

[T Sayers]

RE: error handling

Checkout "implicit declaration" in the manual. You have not declared your variable 'x' and A5 thinks it is a character variable. The code below works.

Regards,
Trevor

"Anyone like to tell me why this 'snippet' will not resume counting??????

ui_msg_box("","Start",ui_ok)
on error goto error_handler

dim x as n
for x = 1 TO 10
if x=3
ui_msg_box("","Error",ui_ok)
goto error_handler
end if
ui_msg_box("Counting",str(x),ui_ok)
next x
ui_msg_box("END","Made it to end",ui_ok)
end

error_handler:
ui_msg_box("","Error processed.",ui_ok)
resume next
' end

[T Sayers]

RE: error handling

Here you go. At the end of the second block, 'Mypointer' points to the 'd_customers' table. At the end of the third block it has been changed to point at the 'c_schedule' table.

If you want to interact with the tables simultaneously, you need to assign them different pointers (eg mypointer2, mypointer3) so that the later blocks does not change what the mypointer variable is originally set to point to.




dim ShortTblName as c
dim FullTblName as c
dim Mypointer as p

ShortTblName = "d_customers"
FullTblName = Table.actual_filename_get(ShortTblName)
Mypointer = table.open(FullTblName)

ShortTblName = "c_schedule"
FullTblName = Table.actual_filename_get(ShortTblName)
Mypointer = table.open(FullTblName)

etc.

[Tom Cone Jr]

RE: error handling

And.... this sequence leaves a trail of opened tables behind as new ones are opened using the same pointer. Probably cannot ever close them without a system reboot.

-- tom

[dik_coleman]

RE: error handling

not a system reboot, but had to get out of A5 and restart it...
thanx guys
I was just playing around trying to learn how to use some of these functions...
I will print out the thread and do some more learning

thanx again
D

[CALocklin]

RE: error handling

Just curious if you guys have a previous background in another programming language? VB?

You seem to be using a lot of pointers and references that don't seem necessary to me. On a very regular basis I do something like this to open a table....

tpc = table.open("Client")

Simple and straight-forward. Note that nothing is DIMed and the full table name with path is not used. (And, as Tom mentioned, I always make sure the table is explicitly closed before the script ends - or before the same pointer name is used to open another table. I seldom use the same pointer name for two tables but there's always an exception.)

The message with pointers like this:
mypointer=d_customers
tbl.mypointer.open()
tblname="d_customers"
tbl.tblname.open()
did not make any sense to me at all.

Please don't take offense at these comments, I'm just trying to figure out where you're coming from. I'm trying to figure out if answers should consider this a learning process or an unlearning process. I know I have a terrible time trying to read VB, C languages, etc.

[dik_coleman]

RE: error handling

not a system reboot, but had to get out of A5 and restart it...
thanx guys
I was just playing around trying to learn how to use some of these functions...
I will print out the thread and do some more learning

thanx again
D

[dik_coleman]

RE: error handling

you beat me back...
I have changed the 'corrected version' of my 'abberation' to illustrate what I had in mind...
I was trying to 'see' exactly what a5 would report as an error when the tables did not exist... None in the original script were actual tables. I wanted to see what the errors would be if the table were opened using a pointer and by direct name. The errors are quite different and that is what I was trying to find out...
Sorry to cause a mix-up

d

'Date Created: 02-Oct-2004 04:36:40 AM
'Last Updated: 02-Oct-2004 05:36:00 AM
'Created By : Administrator
'Updated By : Administrator


on error goto error_handler

dim ShortTblName as c
dim FullTblName as c
dim Mypointer as p

ShortTblName = "d_customers"
FullTblName = Table.actual_filename_get(ShortTblName)
Mypointer = table.open(FullTblName)
tbl.shorttblname.open()

ShortTblName = "c_schedule"
FullTblName = Table.actual_filename_get(ShortTblName)
Mypointer = table.open(FullTblName)
tbl.shorttblname.open()

end

error_handler:
err = error_code_get()
msg = error_text_get(err)
ui_msg_box("Error",shorttblname+" "+msg,ui_ok)
resume next
end

[dik_coleman]

RE: error handling

One solved, one to go..
I cannot get the 'snippet' to count past the error.
I expected that 'resume next' would allow the code to continue to count up to 10 and then display the 'end' msg box....????

Is it my computer????
Can you really get it to count to 10?????
D

[CALocklin]

RE: error handling

I think your tbl.shorttblname.open() syntax is wrong and this is what is causing the error on that line. It isn't that it can't find the file; it's that it can't find a child object (if that's the right term) called "shorttblname" that is a child of the pointer "tbl".

I tried it with a table that does exist and got the same error.

As far as I know, there is no sytax like that for opening a table.

[CALocklin]

RE: error handling

The first message was the one that got my initial interest. The answer is easy - GOTO is not the same as ON ERROR GOTO. A GOTO can't be resumed but an ON ERROR can be.

Change the inner IF...END IF to this and try it:
IF x = 3 THEN
ui_msg_box("", "Error", ui_ok)
ON ERROR GOTO error_handler
error_generate("This is a user generated error.")
END IF

Cal Locklin
www.aimsdc.net

[T Sayers]

RE: error handling

Cal, as to your question, I do not have a background in some other language. You are quite correct about being able to open a table with...
ANYTHING = table.open("Client")
Use of the long table name came from the first couple of examples in the manual's explanation of table.open()
i.e.
"tbl = table.open("d:\a5\a_sports\customer.dbf")
tbl.fetch_first()"

In Richard's code, the tbl.shorttblname.open() is neither correct nor necessary. The table is already open with the line...
Mypointer = table.open(FullTblName)
I must admit, when I write this stuff myself, it does not have all the long names. So, Richard, this is an example of what my code would look like for you...


tbl = table.open("d_customers")
'You now have two things. Firstly you have a pointer called 'tbl' which points to the table 'd_customers', and secondly that table is open. To do something in the table, you now reference the table using the pointer...

tbl.index_primary_put("Last_name") 'order by lastname
tbl.fetch_first() 'go to the 1st rec
tbl.change_begin() 'enter change mode. Don't forget to exit change mode later with tbl.change_end()
'To add a rec instead of changing one, use the pair tbl.enter_begin(.T.) and tbl.enter_end(.T.)
'now we can change fields in that 1st rec
tbl.last_name = "Washington"
tbl.first_name = "George"
tbl.fetch_next() 'Go the next rec (by last_name order as we set the active index to "last_name" earlier

tbl.change_end(.T.) 'exit rec change mode
tbl.close() 'close the table in memory


'Now, if you want to open your 2nd table...
tbl = table.open("c_schedule")


NOTE: the above code opens one instance of 'd_customers', changes values in the first rec and then closes the table before opening the next table. If you want to open the tables simultaneously you'll need a different pointer name, so instead of using "tbl", we'll use "tbl2" for the second table...

tbl2 = table.open("c_schedule")
then all your code lines for that 2nd table begin "tbl2." instead of "tbl.".