Hello Monks,
I would like to set the accessors values of my class using an XML file.

I would like to build my class using a constructor that read an XML file and set the values.

Also, outside the constructor that values must be immutable.

So I have: 


package NavigationRules;
our $VERSION=0.01;

use Moose; 

use XML::Simple;

use FindBin qw($Bin);
use lib ("$Bin/classes");

has 'visitors' => (is=>'ro',isa=>'Int',required=>1,default=>1);
#has 'numVisits' => (is=>'ro',isa=>'Int',default=>1);

sub BUILD {
    my $self=shift;
    my $rules= XMLin("$Bin/conf/navigation_rules.xml",NormaliseSpace=>
+2);    
    
    $self->visitors=$rules->{navigation}->{visitors};
  #  $self->numVisits=$rules->{navigation}->{numVisits};

}


__PACKAGE__->meta->make_immutable;


1;

[download]


But in this way, I have this error: 

Can't modify non-lvalue subroutine call at /home/wolf/Scrivania/naviga
+tor/classes/NavigationRules.pm line 29.

[download]


That is beacause the BUILD method (constructor) tryed to modify an accesor method.

So I tried with: 

has 'visitors' => (is=>'ro',isa=>'Int',writer=>'BUILD',required=>1);

[download]
But without success: 

You are overwriting a locally defined method (BUILD) with an accessor 
+at /usr/local/lib/perl/5.10.0/Moose/Meta/Attribute.pm line 663

[download]


(I don't want to use a builder method for each accessor, beacause I would like read the XML file only one time).

So my question is:
how can I define an accessor value inside a constructor without that error?

Thank you in advance for your answers.

In reply to Moose object construction by saintex

Title:
Use:  <p> text here (a paragraph) </p>
and:  <code> code here </code>
to format your post, it's "PerlMonks-approved HTML":


  • Posts are HTML formatted. Put <p> </p> tags around your paragraphs. Put <code> </code> tags around your code and data!
  • Titles consisting of a single word are discouraged, and in most cases are disallowed outright.
  • Read Where should I post X? if you're not absolutely sure you're posting in the right place.
  • Please read these before you post! —
  • Posts may use any of the Perl Monks Approved HTML tags:
    a, abbr, b, big, blockquote, br, caption, center, col, colgroup, dd, del, details, div, dl, dt, em, font, h1, h2, h3, h4, h5, h6, hr, i, ins, li, ol, p, pre, readmore, small, span, spoiler, strike, strong, sub, summary, sup, table, tbody, td, tfoot, th, thead, tr, tt, u, ul, wbr
  • You may need to use entities for some characters, as follows. (Exception: Within code tags, you can put the characters literally.)
            For:     Use:
    & &amp;
    < &lt;
    > &gt;
    [ &#91;
    ] &#93;
  • Link using PerlMonks shortcuts! What shortcuts can I use for linking?
  • See Writeup Formatting Tips and other pages linked from there for more info.