in reply to Yet another Can't locate object method question

I had some fun with this: 
package MyFilehandler;

my $fh;

sub openForRead {    
    my $class = shift();
    my $filename = shift();
    bless \$filename, $class;
    
    open FH, '<', $filename  
      or die "could not open file: $!";
    $fh = \*FH;
    
    sub writeOut {
        my (@lines) = <$fh>;
        print @lines;
    };
}
close $fh;

writeOut( 
    my $testfh = MyFilehandler->openForRead('somefile') 
);

[download]

Replies are listed 'Best First'.
Re^2: Yet another Can't locate object method question
by GrandFather (Saint) on Mar 16, 2012 at 08:47 UTC

    You may have had fun, but maintenance programmers or those seeking inspiration or enlightenment would not. Your code contains the same errors that choroba describes, it adds a needlessly nested named sub, a bogus close statement and a nonsensical call to writeOut. The following more conventional code would have served as a simpler and better example:

    #!/usr/bin/perl
use strict;
use warnings;

package MyFilehandler;

sub openForRead {
    my ($class, $file) = @_;
    my $self = bless {file => $file}, $class;

    open $self->{fh}, '<', $file or die "could not open '$self->{file}
+': $!";
    return $self;
}

sub DESTROY {
    my ($self) = @_;

    close $self->{fh};
}

sub writeOut {
    my ($self) = @_;
    my $fh = $self->{fh};

    print <$fh>;
}

package main;

my $testfh = MyFilehandler->openForRead('somefile');

$testfh->writeOut();

    [download]
    True laziness is hard work
[reply]
[d/l]
      Thank you for your answer and solution. It works of course, but one thing is not clear to me: $self->{fh} seems to pop out of nowhere. Is it a filehandle which is immediately bound to $self?
[reply]
        From where do you think OUT pops out in 
        open OUT, '<', $file;

        [download]
        $self is a hash ref, $self->{fh} does not exist, so it is created by Perl when calling open, and the filehandle is assigned to it.
[reply]
[d/l]
[select]

In Section Seekers of Perl Wisdom