defining a file handle attribute in moose

Question

I am trying to define a file handle attribute in my Perl code using moose as follows:

has validation_log_file_handler => (
   is => 'ro', isa => 'File',  builder => '_build_validation_log_file_handler'
);

The builder:

sub _build_validation_log_file_handler {
   my ($self) = @_;
   open(my $fh, ">", $self->validation_log_file)
      or die ("ERROR:Can't open file "
         . $self->validation_log_file
         . " for writing");
   return $fh;
}

But when trying to write to a file:

sub run {
    my ($self) = @_;
    print $self->validation_log_file_handler "Hello\n";
    .
    .
    .
}

I new at Moose. Am I doing something wrong? I get the following compilation error:

syntax error. String found where operator expected

score 3 · Accepted Answer · edited Aug 12 '14 at 12:23

3

Printing to complex filehandles requires curlies:

print { $self->validation_log_file_handler } "Hello\n";

or you could use the OO notation

use IO::Handle;  # Required in older versions of Perl

$self->validation_log_file_handler->print("Hello\n");

Did you define a File class? If not, use IO::Handle as the isa.

edited Aug 12 '14 at 12:23

ikegami

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answered Aug 12 '14 at 09:44

choroba

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Handles aren't `FileHandle` objects; they are IO::Handle or IO::File objects. Not sure how well it works to actually use that as `isa`, though. – ikegami Aug 12 '14 at 12:23

defining a file handle attribute in moose

1 Answers1