throw custom error in perl

Hi,

how can I throw an error message in Perl and abort PT compilation?

I have a Perl module that is supposed to create an ODBC connection and I'd like to stop the compilation of the presentation template in case there's a connection error. In addition, I'd like to print a custom error message. Currently I do:


if (!($db = new Win32:DBC ($ODBCConnectString))) {
 iwpt_outout ("
Error connecting to database: " . Win32:DBC::Error () . "

");
 print ("
Error connecting to database: " . Win32:DBC::Error () . "

");
 TeamSite:Tparser::error ("custom error message"); 
}

The problem is the code that requires a connection to exist. If the connection does not exist, the PT compilation fails with a "Could not process template" error but it does neither show my custom error message nor my message sent through iwpt_output().

Thanks in advance!

Best regards,

Ronny Rentner

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ISCBorisB

Hi,

how can I throw an error message in Perl and abort PT compilation?

I have a Perl module that is supposed to create an ODBC connection and I'd like to stop the compilation of the presentation template in case there's a connection error. In addition, I'd like to print a custom error message. Currently I do:
if (!($db = new Win32:DBC ($ODBCConnectString))) {
 iwpt_outout ("
Error connecting to database: " . Win32:DBC::Error () . "

");
 print ("
Error connecting to database: " . Win32:DBC::Error () . "

");
 TeamSite:Tparser::error ("custom error message"); 
}
The problem is the code that requires a connection to exist. If the connection does not exist, the PT compilation fails with a "Could not process template" error but it does neither show my custom error message nor my message sent through iwpt_output().

Thanks in advance!

Best regards,

Ronny Rentner

In general, it's a bad idea to put raw 'print' into presentation templates. The reason is that your PT processing is two-phase process,
Perl script is generated and then executed. Chances are, your 'print' renders syntactically invalid code. Use iwpt_output only and comment
out print command, see if that helps.

For better help you would have to provide way more information than tiny code fragment, starting perhaps with product and platform versions,
SP Level and complete PT

Ronny

In general, it's a bad idea to put raw 'print' into presentation templates. The reason is that your PT processing is two-phase process,

Yes, I'm aware of that. Those 3 lines were just meant to show what I've already tried without success. I've, of course, tried to comment them all before posting here.

Perl script is generated and then executed. Chances are, your 'print' renders syntactically invalid code. Use iwpt_output only and comment out print command, see if that helps.

I'm sure the print/iwpt_output is syntactically correct, because it works correctly if I comment all lines in the PT that depend on the odbc connection. Then, if the connection fails, the error is shown correctly.

The problem is Perl code that requires the connection, as I've said in my original posting. I need a way to abort template compilation (so it does not reach the code which doesn't work without an odbc connection) and to print an error message. I can abort the compilation with an "exit 0", but that doesn't let me print an error message.

ISCBorisB

I'm sure the print/iwpt_output is syntactically correct...
The problem is Perl code that requires the connection...

Do I miss something here? Why can't you just fork?

if ($db = new Win32: Smiley Surprised

DBC ($ODBCConnectString)) {
 # Connection succesfull, Process...
}
else {
 # Connection Failed
 iwpt_output (" Error connecting to database: " . Win32: Smiley Surprised

DBC::Error() . " ");
}

nipper

Also be kind to the people who have to debug this after the fact and instead of just dumping it to the screen, dump the error information to a debug file as well. I spent a significant amount of time once trying to chase down why an inline callout did not work only to find it was a well hidden ODBC error.

Ronny

Do I miss something here? Why can't you just fork?

if ($db = new Win32:DBC ($ODBCConnectString)) {
 # Connection succesfull, Process...
}
else {
 # Connection Failed
 iwpt_output (" Error connecting to database: " . Win32:DBC::Error() . " ");
}

Well, yes, but then I'd have to wrap the if condition around the whole code. That's ugly (especially if you want to put the connection handling into a module), but as far as I can see the only solution.

Also be kind to the people who have to debug this after the fact and instead of just dumping it to the screen, dump the error information to a debug file as well. I spent a significant amount of time once trying to chase down why an inline callout did not work only to find it was a well hidden ODBC error.

That's exactly why I'm asking. I want to show a usefull error message instead of the usual "Could not process template". A log file would probably be one of the possibilities but you'd have to know there is one and where to look for it. A real error message in the browser would be better.

nipper

Well, yes, but then I'd have to wrap the if condition around the whole code. That's ugly (especially if you want to put the connection handling into a module), but as far as I can see the only solution.

You can make a Perl TPL, basically build up a perl variable called $html. If you have a failure, put the appropriate data in that variable. Otherwise put ALL HTML in the variable and you TPL will look something like this:

[html]

lots of perl here

[/html]

nipper

Now there is one serious issue with your approach. While you have informed your users of the details of an error, you have also created a new output file (if the person hit generate) and you *may* not fail a iwpt_compile.

So, if you have a WF that builds outputs from DCRs, and it runs, and builds up a file that says, cannot connect to DB, and this goes off to production, I suspect that would be a bad thing.