my $mockOb = SomeClass->new;

my $search = $contentFrame->new_ttk__entry(-takefocus => 1, -font => 'Arial 11', -width => 40, -validate => 'focusout',  -textvariable =>\$mockOb->search, -validatecommand  => [\&searchValidation, Tkx::Ev('%P')]
);

# Write information back to our $mockOb
$search->bind('<FocusOut>', sub { $mockOb->search( $search->value )});

sub searchValidation{
....do crazy stuff
}

SomeClass
sub new {
	my $class = shift;
	my $self = {	
	        search = ""
	};
		
	bless $self, $class;
	return $self;
}

sub search{
	my $self = shift();
	if(@_) {
		$self->{search} = shift();
	}
	return $self->{search};
}