Checking Submitted Form Data

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

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Re: Checking Submitted Form Data by gellyfish (Monsignor) on Feb 27, 2002 at 12:39 UTC
You might consider changing your : `my %form = (var1 => $q->param('var1'), var2 => $q->param('var2'), var3 => $q->param('var3'));` [download] to: `my %form = $q->Vars();` [download] for a spot of maintainer efficiency :) /J\	[reply] [d/l] [select]
Re: Checking Submitted Form Data by projekt21 (Friar) on Feb 27, 2002 at 11:45 UTC
I'm puzzled that you say, it works, as I get errors: Global symbol "@reqform" requires explicit package name at test017.pl +line 16. Global symbol "@reqform" requires explicit package name at test017.pl +line 21. Global symbol "@errormsg" requires explicit package name at test017.pl + line 22. Global symbol "@errormsg" requires explicit package name at test017.pl + line 22. Global symbol "@errormsg" requires explicit package name at test017.pl + line 24. Global symbol "@errormsg" requires explicit package name at test017.pl + line 34. Bareword "var1" not allowed while "strict subs" in use at test017.pl l +ine 16. Bareword "var2" not allowed while "strict subs" in use at test017.pl l +ine 16. Bareword "var3" not allowed while "strict subs" in use at test017.pl l +ine 16. test017.pl had compilation errors. [download] change `my @reqform = qw(var1 var2 var3); # quote them!` [download] and add `my @errormsg;` [download] alex pleiner <alex@zeitform.de> zeitform Internet Dienste	[reply] [d/l] [select]
Re: Checking Submitted Form Data by Ido (Hermit) on Feb 27, 2002 at 12:27 UTC
I think you should call your subs as: `PrintError()` and `CARRAY_ON_PROCESSING_FORM()` As the `&sub` way to call a sub passes @_ as arguments and disables prototype checking, as described in perlsub. Also, I would pass @errormsg to PrintError as arguments. `PrintError(@errormsg)` And then in PrintError: `foreach(@_){}`	[reply] [d/l] [select]
Re: Checking Submitted Form Data by particle (Vicar) on Feb 27, 2002 at 14:28 UTC
i think this should be a comprehensive solution to your problem. this folds in suggestions by the other monks, and adds accuracy (which is important). first off, i've turned on warnings and diagnostics, and disabled output buffering (this last one may be cargo-cult programming, but i always do it by default). i've used the object-oriented style of CGI programming, as it's my preference, and it's faster as per the documentation. the meat of the error checking algorithm is this: error if number of passed parameters does not match number of required parameters (this assumes the all required parameters, and only required parameters, should be passed -- your logic may vary) `scalar( @reqform ) != scalar( $q->param() )` [download] error if passed parameter names do not match required parameter names `join( $; , sort( @reqform ) ) ne join( $; , sort( $q->param() ) )` [download] error if required parameters are missing values `while( ( $key, $value) = each %form ) { push @missing_params, $key if $value eq ''; } if( scalar @missing_params ) # ...` [download] here's the full code. i must say, i've done all this work, but i haven't tested it. feel free to come down on me if it doesn't work, i deserve it. #!/usr/bin/perl -w use strict; use diagnostics; $\|++; use CGI; my $q = new CGI; my @reqform = qw( var1, var2, var3 ); print $q->header(); if( ( # different number of elements scalar( @reqform ) != scalar( $q->param() ) ) \|\| ( # element names do not match join( $; , sort( @reqform ) ) ne join( $; , sort( $q->param() ) ) ) ) { # print error message for mismatched parameters print $q->start_html(), $q->p( "ERROR: mismatched parameters:" ), $q->p( "required: ", join ' ', sort @reqform ), $q->p( "passed: ", join ' ', sort $q->param() ), $q->end_html(); } # get variables from submitted form my %form = $q->Vars(); # note: this does not work with isindex tags my ( $key, $value, @missing_params ); while( ( $key, $value) = each %form ) { push @missing_params, $key if $value eq ''; } if( scalar @missing_params ) { print error message print $q->start_html(), $q->p( "ERROR: undefined parameter(s): @missing_params" ), $q->end_html(); } # carry on... [download] ~Particle ;� riding the unicode bandwagon...	[reply] [d/l] [select]
Re: Re: Checking Submitted Form Data by Thathom (Acolyte) on Feb 27, 2002 at 16:30 UTC
Thanks everyone!! Im going to take all these tips and stick them together. Im still learning but getting there :) ThAtH0M	[reply]
Re: Checking Submitted Form Data by Dog and Pony (Priest) on Feb 27, 2002 at 12:32 UTC
One minor detail - since you are useing CGI.pm, you might as well replace `print "Content-type: text/html\n\n";` with the cross-platform, OO, more correct and stylish `print $q->header();` grin. Even though, as was pointed out to me in this node, it usually doesn't matter, it is the right thing to do. :) You have moved into a dark place. It is pitch black. You are likely to be eaten by a grue.	[reply] [d/l] [select]


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