Hue-Bond has asked for the wisdom of the Perl Monks concerning the following question:

Esteemed monks,

I'm reading a configuration file using Config::General and validating it via Config::Validate. The goal is to reject the configuration and die if there are any errors in it.

One of the requirements I want to impose is that some configuration keys shouldn't be repeated. When I repeat a key, Config::General creates an array to hold all the given values. I expect Config::Validate to reject that array (since it's not a plain string) but that's not happening. Funnily, if I tell Config::Validate that I want an integer instead of a string, it does die as desired.

Here is some code to show the problem:

#!/opt/QNDperl5.10/bin/perl

use warnings;
use strict;
use 5.010;
use Data::Dumper;
use Config::General;
use Config::Validate;

my $schema = {
    section => {
        type => 'nested',
        child => {
            key => {
                ## change this to see the code die if 'integer' is use
+d
                type => 'string',
                #type => 'integer',
            },
        },
    },
};

my $cfgfile = <<'EOF';
<section>
    key Foo
    key Bar
</section>
EOF

my $config = Config::General->new (-String => $cfgfile);
print Dumper { $config->getall };  ## you can see the array that Confi
+g::General creates
Config::Validate->new (schema => $schema)->validate (config => $config
+);
say "Still alive!";

[download]

How do I reject such a configuration?

Update: I just reported this bug.

--
 David Serrano
 (Please treat my english text just like Perl code, i.e. feel free to notify me of any syntax, grammar, style and/or spelling error. Thank you!).

Replies are listed 'Best First'.
Re: Config::Validate: problem with a key type
by zwon (Abbot) on Mar 22, 2010 at 18:44 UTC

    You can specify callback for the parameter and check it there: 

    my $schema = {
    section => {
        type => 'nested',
        child => {
            key => {
                type => 'string',
                callback => sub { die 'Should be a scalar' if ref $_[1
+] eq 'ARRAY' },
            },
        },
    },
};

    [download]
    Also you can add your own type if you want to check multiple parameters.

    Update: and here's the example: 

    use warnings;
use strict;
use 5.010;
use Data::Dumper;
use Config::General;
use Config::Validate qw(mkpath);

my $schema = {
    section => {
        type  => 'nested',
        child => { key => { type => 'MyString', }, },
    },
};

my $cfgfile = <<'EOF';
<section>
    key Foo
    key Bar
</section>
EOF

my $config = Config::General->new( -String => $cfgfile );
print Dumper { $config->getall };    ## you can see the array that Con
+fig::General creates
my $validate = Config::Validate->new( schema => $schema );
$validate->add_type( name => 'MyString', validate => \&is_string );
$validate->validate( config => $config );
say "Still alive!";

sub is_string {
    return unless ref $_[1];
    die "Parameter " . mkpath( $_[3] ) . " should be a scalar!";
}

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      I have several keys, each of them with its own callback. That's what I'll do. Thank you!

      --
       David Serrano
       (Please treat my english text just like Perl code, i.e. feel free to notify me of any syntax, grammar, style and/or spelling error. Thank you!).

[reply]
Re: Config::Validate: problem with a key type
by spazm (Monk) on Mar 22, 2010 at 17:02 UTC
    Quoting the perldoc:
    string

    The string type does no validation if no addition restrictions are specified. Valid options are:

    * min
    Minimum length
    * max
    Maximum length
    * regex
    String must match the regex provided.
[reply]

      Adding those additional restrictions has no effect. This is my current $schema:

      my $schema = {
    section => { 
        type => 'nested',
        child => { 
            key => { 
                type  => 'string',
                regex => qr/^ ARRAY \( 0x\p{HexDigit}{1,8} \) $/x,
            },   
        },   
    },   
};

      [download]

      The code still runs to completion. If I make the regex different (e.g. by changing "ARRAY" into "ARAY"), the code complains about the data not matching the schema. Looks like a bug to me...

      Thank you for giving me the clue!

      --
       David Serrano
       (Please treat my english text just like Perl code, i.e. feel free to notify me of any syntax, grammar, style and/or spelling error. Thank you!).

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