=head1 NAME

YATT::Lite::Object - fields based, Tcl/Tk like object

=head1 SYNOPSIS

  package MyProduct {
     sub MY () {__PACKAGE__}          # Shorthand alias.
     use base qw/YATT::Lite::Object/; # For fields, you must use 'base'.
     use fields qw/cf_name cf_price/; # Or YATT::Lite::MFields, if you like.

     sub as_string {
       (my MY $self, my ($fmt)) = @_;
       $fmt //= '%s (%d)';
       sprintf $fmt, $self->{cf_name}, $self->{cf_price}; # statically checked!
     }
  }

  1;

Then you can use this class like this:

  my $prod = MyProduct->new(name => 'foo', price => 100);
  print $prod->cget('name');

=head1 DESCRIPTION



XXX: See L<YATT::Lite::docs::whyfields>.
(But it is not yet translated to English:-<)

=head1 METHODS

=head2 new

  my $obj = YATT::Lite::Object->new(cf1 => val1, cf2 => val2, ...);

  my $obj = YATT::Lite::Object->new({cf1 => val1, cf2 => val2, ...});

=head2 configure

Bulk setter(sets multiple configs at once).

  $obj->configure(cf1 => val1, cf2 => val2, ...);

  $obj->configure({cf1 => val1, cf2 => val2, ...});


=head2 cget

  $obj->cget('cf1')

  $obj->cget('cf1', 'default')

=head1 HOOKS



=head2 configure_CFx

If your class has method named C<configure_CFx>,
it is called whenever C<< $obj->configure(CFx => val) >> is called.

=head2 after_new

Mainly used for initializing default config values. Typical code will be:

   sub after_new {
     (my MY $self) = @_;
     $self->SUPER::after_new;
     $self->{cf_xxx} //= "foo";
     $self->{cf_yyy} //= "bar";
     # ...
   }

=head2 _before_after_new

Ideally, having two hooks is useless. But user-level programmers
could forget to call C<SUPER::new> in their <after_new> hook,
which can lead hard to debug situation. So, I divided hooks,
one for user-level programmers and the other for framework designers.
This C<_before_after_new> is the later one.