CODEWITHSUNDEEP
perl
clt60
clt60

Reputation: 63892

How to discover the object type in perl?

Scenario:

so something like (very shortened):

package Some;
sub filename { file('/tmp/xxx') }   #Path::Class the filename->stringify' returns the string value
sub myobj { My::Module->new(....) } #the myobj->stringvalue returns the string value
sub text { 'some text' }

sub data {
    my $strhr;
    $strhr->{$_} = $self->make_string $self->$_ for(qw(filename myobj text));
    return $strhr;
}

sub make_string {
    my($self, $val) = @_;
    return $val->stringify if( VAL_IS_PATH::CLASS_OBJ ); #need help here
    return $val->stringvalue if( VAL_IS_My::Obj_OBJ ); #and here
    return $val if( VAL_IS_SIMPLE_STRING ); #and here
    croak "unknown value";
}

In the real code the filename and myobj are defined with Moose, like:

has 'myobj' => (isa => 'My::Module', builder => ... ...);

But IMHO doing some Moose-ish deep-coercion is in this case much more complicated than make a simple make_string filter sub. But, i'm opened to any recommented solution...

So, the question is - how discover what object is the $val, or if it is an simple Str.

EDIT:

Based on @David W.'s comment i got the next:

sub make_string {
    my($self, $val) = @_;
    my $vref = ref $val;   #for the "text"  returns the string itself
    return $val->stringify if( $vref =~ /^Path::Class/ ); #works
    return $val->stringvalue if( $vref =~ /^My::Module/ ); #works
    return $val if( VAL_IS_SIMPLE_STRING ); #returns the string itself, so how to check this???
    croak "unknown value";
}

Upvotes: 2

Views: 338

Answers (1)

tobyink
tobyink

Reputation: 13664

Use the isa method. It's defined in the UNIVERSAL package (see perldoc UNIVERSAL). All Perl classes implicitly inherit from UNIVERSAL.

use Scalar::Util qw( blessed );

if (blessed($val) and $val->isa('Path::Class')) {
    print "It's a Path::Class object!\n";
}

Upvotes: 6

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