Object Oriented Perl: Calling another function within the same class - perl

Question

I have a to process some files in a directory.
So, I am using non-OO Perl code as below (just the important snippets are printed below):
#!/usr/bin/perl
use strict;
use warnings;
my $dnaFilesDirectory = "./projectGeneSequencingPfzr";
my %properties = &returnGeneticSequences($dnaFilesDirectory);
sub returnGeneticSequences {
my $dnaDirectory = shift;
my #dnaFiles = ();
opendir(DNADIR, $dnaFilesDirectory) or die "Cannot open directory:$!";
#dnaFiles = readdir(DIR);
foreach my $file (#dnaFiles) {
my $dnaFilePath = $dnaFilesDirectory."\/".$file;
if($file =~ /dna_file.*\.dnaPrj/) {
my %diseaseStages = &returnDiseasesStages($dnaFilePath);
## Do some data analysis on the %diseaseStages Hash;
}
}
}
sub returnDiseasesStages {
my $dnaFile = shift;
## Do something with DNA file and build a hash called %diseasesStagesHash;
return %diseasesStagesHash;
}
The above code works fine.
But we have to create the equivalent OO Perl code for the above functions.
I am trying to do the following, but it does not seem to work. Obviously, I am doing something wrong in calling the class method returnDiseasesStages from returnGeneticSequences.
#!/usr/bin/perl
use strict;
use warnings;
package main;
my $obj = GeneticSequences->new(dnaFilesDir => "./projectGeneSequencingPfzr");
$obj->returnGeneticSequences();
package GeneticSequences;
sub new {
my $class = shift;
my $self = {
dnaFilesDir => "dnaFilesDir",
#_,
};
return (bless($self,$class));
}
sub returnGeneticSequences {
my $self = shift;
my $dnaFilesDirectoryGS = $self->{dnaFilesDir};
my #dnaFiles = ();
opendir(DNADIR,$dnaFilesDirectoryGS) or die "Cannot open directory:$!";
#dnaFiles = readdir(DIR);
foreach my $file (#dnaFiles) {
my $dnaFilePath = $dnaFilesDirectory."\/".$file;
if($file =~ /dna_file.*\.dnaPrj/) {
my $gsObj = GeneticSequences->new();
my %diseaseStages = $gsObj->returnDiseasesStages($dnaFilePath);
## Do some data analysis on the %diseaseStages Hash;
}
}
}
sub returnDiseasesStages {
my $dnaFile = shift;
##Do something with DNA file and build a hash called %diseasesStagesHash;
return %diseasesStagesHash;
}
Please help me understand what I am doing wrong.

Answer 1

The syntax
$gsObj->returnDiseasesStages($dnaFilePath)
is equivalent to the syntax
returnDiseasesStages($gsObj, $dnaFilePath)
(with Perl checking the reference type of $gsObj to see what package to search for the returnDiseasesStages function in).
So your returnDiseasesStages function should expect two arguments:
sub returnDiseasesStages {
my ($self, $dnaFile) = #_;
...
}