Template::Toolkit - catching errors when plugin is missing?

Skeeve has asked for the wisdom of the Perl Monks concerning the following question:

I just had report of a user of my Dancer app because it crashed due to a missing module.

While it was my mistake that the debug code was still in my Template::Toolkit template, I have to admit that I did not put the module on the customer's machine on purpose.

This is the code which failed:

<!--[%
    USE Stash;
    USE Dumper Indent = 1;
    Dumper.dump( Stash.stash() )
%]-->
[download]

which I included in some templates to be able to see whether or not all my variables "arrived" at the template.

Since the "Stash" module is not on the customer's machine, the template failed.

Now I'm wondering if it's possible to instruct the template to silently do nothing when the module is missing.

s$$([},&%#}/&/]+}%&{})*;#$&&s&&$^X.($'^"%]=\&(|?*{%
+.+=%;.#_}\&"^"-+%*).}%:##%}={~=~:.")&e&&s""`$''`"e

Comment on Template::Toolkit - catching errors when plugin is missing? Select or Download Code

Replies are listed 'Best First'.
Re: Template::Toolkit - catching errors when plugin is missing? by DrHyde (Prior) on Jul 04, 2014 at 12:17 UTC
TT has `TRY` and `CATCH` keywords. Perhaps they'll help.	[reply] [d/l] [select]
Re^2: Template::Toolkit - catching errors when plugin is missing? by Skeeve (Parson) on Jul 04, 2014 at 12:25 UTC
Indeed they did! `<!--[% TRY; USE Stash; USE Dumper Indent = 1; Dumper.dump( Stash.stash() ) \| replace('-(?=-)', '- '); CATCH %] No dump without stash ERROR! Type: [% error.type %] Info: [% error.info %] [% END %]-->` [download] That's my new DUMP.tt `s$$([},&%#}/&/]+}%&{});#$&&s&&$^X.($'^"%]=\&(\|?{%` `+`.+=%;.#_}\&"^"-+%*).}%:##%}={~=~:.")&e&&s""`$''`"e	[reply] [d/l] [select]
Re: Template::Toolkit - catching errors when plugin is missing? by SimonPratt (Friar) on Jul 04, 2014 at 10:26 UTC
You should be able to pop the offending code into a BEGIN block, replacing use with require and wrap with eval to catch any failures: `BEGIN { eval { require Stash; require Dumper; $Dumper::Indent = 1; Dumper.dump( Stash.stash() ) }; }` [download] Another thing I tend to do with debug code is set a constant (such as `DEBUG`) and make sure all of my debug code is wrapped up with `if DEBUG` statements, which completely strips the code out when not running in debug mode	[reply] [d/l] [select]


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