sub load_class {
my $class = shift;
- return if ref($class);
- return unless defined($class) && length($class);
+
+ return 0 if ref($class) || !defined($class) || !length($class);
return 1 if is_class_loaded($class);
sub is_class_loaded {
my $class = shift;
- no strict 'refs';
- return 1 if defined ${"${class}::VERSION"} || defined @{"${class}::ISA"};
- foreach my $symbol (keys %{"${class}::"}) {
- next if substr($symbol, -2, 2) eq '::';
- return 1 if defined &{"${class}::${symbol}"};
+ return 0 if ref($class) || !defined($class) || !length($class);
+
+ # walk the symbol table tree to avoid autovififying
+ # \*{${main::}{"Foo::"}} == \*main::Foo::
+
+ my $pack = \*::;
+ foreach my $part (split('::', $class)) {
+ return 0 unless exists ${$$pack}{"${part}::"};
+ $pack = \*{${$$pack}{"${part}::"}};
}
+
+ # check for $VERSION or @ISA
+ return 1 if exists ${$$pack}{VERSION}
+ && defined *{${$$pack}{VERSION}}{SCALAR};
+ return 1 if exists ${$$pack}{ISA}
+ && defined *{${$$pack}{ISA}}{ARRAY};
+
+ # check for any method
+ foreach ( keys %{$$pack} ) {
+ next if substr($_, -2, 2) eq '::';
+ return 1 if defined *{${$$pack}{$_}}{CODE};
+ }
+
+ # fail
return 0;
}
This function can be used in place of tricks like
C<eval "use $module"> or using C<require>.
+=head2 is_class_loaded Class::Name -> Bool
+
+Returns whether this class is actually loaded or not. It uses a heuristic which
+involves checking for the existence of C<$VERSION>, C<@ISA>, and any
+locally-defined method.
+
=head1 AUTHOR
Shawn M Moore, C<< <sartak at gmail.com> >>