in reply to Question on XML output using Perl

sub error_excerpt{
return defined($error_excerpt)?$self->{_error_excerpt}:"No Error Excer
+pt.";
}

[download]

...what the A.M. said.  In particular, where do $self and $error_excerpt come from?  For example, did you just leave out the my $self = shift; at the beginning of the routine in this sample code only, or is it also missing from the real code?

In case $error_excerpt is not available in the scope of the routine, you'd always get "No Error Excerpt.".  This would be the case if $error_excerpt is defined as a lexical variable in another routine.  In this case, an empty package variable of the same name would (silently) be used instead — unless you enable strictures...

Always use strict; use warnings; — it would likely have warned you of these types of errors.

Replies are listed 'Best First'.
Re^2: Question on XML output using Perl
by siddheshsawant (Sexton) on Mar 16, 2010 at 16:08 UTC

    I have typed this at initial part of the code... 

    sub new
{
    my ($class) = @_;
    
    #my ($proto) = @_;
    #to make the constructor both class and object method
    #my $class = ref($proto) || $proto;
    
    my $self = {
        #attributes of object
        _id                 => undef,
        _user_scenario      => undef,
        _result_type        => undef,
        _result_log_link    => undef,
        _not_exposed_reason => undef,
        _error_excerpt      => undef,
        _triage             => undef,
    };
    
    bless $self, $class;
    return  $self;
}

    [download]

    then I wrote sub error_excerpt.For general output also I am not getting error_excerpt if there is any when I used 

    sub error_excerpt{
return defined($error_excerpt)?$self->{_error_excerpt}:"No Error Excer
+pt.";
}

    [download]

    Is there anything missing? I have used use strict and use warnings as well.Where I am doing mistake?

[reply]
[d/l]
[select]
      Perhaps, as other monks have mentioned, something along these lines might point you in the right direction. 
      #!/usr/bin/perl

use strict;
use warnings;

my $e = Error::Excerpt->new;

print $e->get_error_excerpt, qq{\n};

$e->set_error_excerpt(q{We have an error});

print $e->get_error_excerpt, qq{\n};


package Error::Excerpt;

sub new {
  my $class = shift;
  my $self = {
    _error_excerpt => undef,
  };
  bless ($self, $class);
  return $self;
} 

sub set_error_excerpt{
  my $self  = shift;
  my $ee    = shift;
  $self->{_error_excerpt} = $ee;
} 

sub get_error_excerpt{
  my $self  = shift;
  my $ee    = $self->{_error_excerpt};
  return $ee?$ee:q{No Error Excerpt};
}

      [download]
      No Error Excerpt
We have an error

      [download]
      imo, dividing up the task using getters and setters is often worth considering. Add error checking as appropriate.
[reply]
[d/l]
[select]

        If I keep a code like this then I gets error_escrpt where ever it is defined ....I am getting the value from the database...the code is as follows:

        $self->{_error_excerpt} = $error_excerpt if defined($error_excerpt); r
+eturn $self->{_error_excerpt};

        [download]

        But the problem with this code is it do not print anything when there is no error excerpt.

[reply]
[d/l]

      You still haven't answered where $error_excerpt comes from... but on second thought, maybe you meant (?)

      sub error_excerpt{
    my $self = shift;
    return defined($self->{_error_excerpt}) ? $self->{_error_excerpt} 
+: "No Error Excerpt.";
}

      [download]
[reply]
[d/l]
[select]

        If I keep a code like this then I gets error_escrpt where ever it is defined ....I am getting the value from the database...the code is as follows:

         $self->{_error_excerpt} = $error_excerpt if defined($error_excerpt);
    return $self->{_error_excerpt};

        [download]

        But the problem with this code is it do not print anything when there is no error excerpt.

[reply]
[d/l]

In Section Seekers of Perl Wisdom