saintex has asked for the wisdom of the Perl Monks concerning the following question:

Hello,
I would like to extends a package in order to have some default values.

The module I would like to extend is WWW::Selenium .

I would like to extend the package in my code, just to have some defualt values.
Ususally you call WWW::Selenium like this: 

my $b=Selenium->new( host => "localhost", 
                                  port => 4444, 
                                  browser => "*firefox", 
                                  browser_url => 'http://www.google.co
+m',
                                );

[download]
I would like to call it just with new, without args:
So I tried to write an extension: 
package Selenium;
our $VERSION=0.01;

use 5.010;
use Moose;
use MooseX::NonMoose; 

use Test::WWW::Selenium;

extends  'Test::WWW::Selenium';


around BUILDARGS => sub {


    my $orig  = shift;
    my $class = shift;
    

     my %args  = ( @_ == 1 ? %{ $_[0] } : @_ );
    
     $args{host}//="localhost";
     $args{port}//=4444;
     $args{browser}//="*firefox";
     $args{browser_url}//='http://wwww.google.com';
     
    return $class->$orig(%args);
};


sub BUILD     {
    my $self = shift;
    

    #$self->start;
}

[download]


But it doesn't work. Without arguments I have an error.
Where I'm wrong?

Replies are listed 'Best First'.
Re: Problem with around BUILDARGS
by stvn (Monsignor) on Mar 24, 2011 at 13:32 UTC

    With MooseX::NonMoose, you want to use FOREIGNBUILDARGS and it should return the arguments for the extended NonMoose class, this version works. 

    sub FOREIGNBUILDARGS {
    my $class = shift;

     my %args  = ( @_ == 1 ? %{ $_[0] } : @_ );

     $args{host}//="localhost";
     $args{port}//=4444;
     $args{browser}//="*firefox";
     $args{browser_url}//='http://wwww.google.com';

    return %args;
}

    [download]

    -stvn
[reply]
[d/l]
      Thank you very much!
[reply]
      It works,
      but how can I use some class proprieties inside FOREIGNBUILDARGS ?
      for example, If I try: 
      has 'serverLocation' => (is=>'ro',isa=>'Str',default=>"$Bin/lib/seleni
+um-server-standalone-2.0b2.jar");

sub FOREIGNBUILDARGS {
    my $self = shift;

print $self->serverLocation;

     my %args  = ( @_ == 1 ? %{ $_[0] } : @_ );

     $args{host}//="localhost";
     $args{port}//=4444;
     $args{browser}//="*firefox";
     $args{browser_url}//='http://wwww.google.com';

    return %args;
}

      [download]
      I have this error:

      Can't use string ("Selenium2") as a HASH ref while "strict refs" in us
+e at accessor serverLocation defined at /home/saintex/workspace/perl_
+scripts/navigator/classes/Browser/Selenium2.pm line 18.

      [download]

      because the propriety "serverLocation" has not been read yet.
      How can I fix it?
[reply]
[d/l]
[select]

        So the problem is that $self is not an object instance, but rather the class. One way to solve this is to use builder instead of default like so. 

        
has 'serverLocation' => (is=>'ro',isa=>'Str',builder =>'buildServerLoc
+ation');

sub buildServerLocation {
    return "$Bin/lib/selenium-server-standalone-2.0b2.jar"
}


sub FOREIGNBUILDARGS {
    my $class = shift;

     my %args  = ( @_ == 1 ? %{ $_[0] } : @_ );

     $args{serverLocation} ||= $class->buildServerLocation;

     $args{host}//="localhost";
     $args{port}//=4444;
     $args{browser}//="*firefox";
     $args{browser_url}//='http://wwww.google.com';

    return %args;
}

        [download]

        -stvn
[reply]
[d/l]
[select]

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