File Coverage

blib/lib/Class/Inspector.pm

Criterion	Covered	Total	%
statement	170	193	88.0
branch	86	108	79.6
condition	8	16	50.0
subroutine	23	25	92.0
pod	10	12	83.3
total	297	354	83.9

package Class::Inspector;

use 5.006;
# We don't want to use strict refs anywhere in this module, since we do a
# lot of things in here that aren't strict refs friendly.
use strict qw{vars subs};
use warnings;
use File::Spec ();

# ABSTRACT: Get information about a class and its structure
our $VERSION = '1.34'; # VERSION


# If Unicode is available, enable it so that the
# pattern matches below match unicode method names.
# We can safely ignore any failure here.
BEGIN {
  local $@;
  eval "require utf8; utf8->import";
}

# Predefine some regexs
our $RE_IDENTIFIER = qr/\A[^\W\d]\w*\z/s;
our $RE_CLASS      = qr/\A[^\W\d]\w*(?:(?:\'|::)\w+)*\z/s;

# Are we on something Unix-like?
our $UNIX  = !! ( $File::Spec::ISA[0] eq 'File::Spec::Unix'  );


#####################################################################
# Basic Methods


sub _resolved_inc_handler {
  my $class    = shift;
  my $filename = $class->_inc_filename(shift) or return undef;

  foreach my $inc ( @INC ) {
    my $ref = ref $inc;
    if($ref eq 'CODE') {
      my @ret = $inc->($inc, $filename);
      if(@ret == 1 && ! defined $ret[0]) {
        # do nothing.
      } elsif(@ret) {
        return 1;
      }
    }
    elsif($ref eq 'ARRAY' && ref($inc->[0]) eq 'CODE') {
      my @ret = $inc->[0]->($inc, $filename);
      if(@ret) {
        return 1;
      }
    }
    elsif($ref && eval { $inc->can('INC') }) {
      my @ret = $inc->INC($filename);
      if(@ret) {
        return 1;
      }
    }
  }

  '';
}

sub installed {
  my $class = shift;
  !! ($class->loaded_filename($_[0]) or $class->resolved_filename($_[0]) or $class->_resolved_inc_handler($_[0]));
}


sub loaded {
  my $class = shift;
  my $name  = $class->_class(shift) or return undef;
  $class->_loaded($name);
}

sub _loaded {
  my $class = shift;
  my $name  = shift;

  # Handle by far the two most common cases
  # This is very fast and handles 99% of cases.
  return 1 if defined ${"${name}::VERSION"};
  return 1 if @{"${name}::ISA"};

  # Are there any symbol table entries other than other namespaces
  foreach ( keys %{"${name}::"} ) {
    next if substr($_, -2, 2) eq '::';
    return 1 if defined &{"${name}::$_"};
  }

  # No functions, and it doesn't have a version, and isn't anything.
  # As an absolute last resort, check for an entry in %INC
  my $filename = $class->_inc_filename($name);
  return 1 if defined $INC{$filename};

  '';
}


sub filename {
  my $class = shift;
  my $name  = $class->_class(shift) or return undef;
  File::Spec->catfile( split /(?:\'|::)/, $name ) . '.pm';
}


sub resolved_filename {
  my $class     = shift;
  my $filename  = $class->_inc_filename(shift) or return undef;
  my @try_first = @_;

  # Look through the @INC path to find the file
  foreach ( @try_first, @INC ) {
    my $full = "$_/$filename";
    next unless -e $full;
    return $UNIX ? $full : $class->_inc_to_local($full);
  }

  # File not found
  '';
}


sub loaded_filename {
  my $class    = shift;
  my $filename = $class->_inc_filename(shift);
  $UNIX ? $INC{$filename} : $class->_inc_to_local($INC{$filename});
}





#####################################################################
# Sub Related Methods


sub functions {
  my $class = shift;
  my $name  = $class->_class(shift) or return undef;
  return undef unless $class->loaded( $name );

  # Get all the CODE symbol table entries
  my @functions = sort grep { /$RE_IDENTIFIER/o }
    grep { defined &{"${name}::$_"} }
    keys %{"${name}::"};
  \@functions;
}


sub function_refs {
  my $class = shift;
  my $name  = $class->_class(shift) or return undef;
  return undef unless $class->loaded( $name );

  # Get all the CODE symbol table entries, but return
  # the actual CODE refs this time.
  my @functions = map { \&{"${name}::$_"} }
    sort grep { /$RE_IDENTIFIER/o }
    grep { defined &{"${name}::$_"} }
    keys %{"${name}::"};
  \@functions;
}


sub function_exists {
  my $class    = shift;
  my $name     = $class->_class( shift ) or return undef;
  my $function = shift or return undef;

  # Only works if the class is loaded
  return undef unless $class->loaded( $name );

  # Does the GLOB exist and its CODE part exist
  defined &{"${name}::$function"};
}


sub methods {
  my $class     = shift;
  my $name      = $class->_class( shift ) or return undef;
  my @arguments = map { lc $_ } @_;

  # Process the arguments to determine the options
  my %options = ();
  foreach ( @arguments ) {
    if ( $_ eq 'public' ) {
      # Only get public methods
      return undef if $options{private};
      $options{public} = 1;

    } elsif ( $_ eq 'private' ) {
      # Only get private methods
      return undef if $options{public};
      $options{private} = 1;

    } elsif ( $_ eq 'full' ) {
      # Return the full method name
      return undef if $options{expanded};
      $options{full} = 1;

    } elsif ( $_ eq 'expanded' ) {
      # Returns class, method and function ref
      return undef if $options{full};
      $options{expanded} = 1;

    } else {
      # Unknown or unsupported options
      return undef;
    }
  }

  # Only works if the class is loaded
  return undef unless $class->loaded( $name );

  # Get the super path ( not including UNIVERSAL )
  # Rather than using Class::ISA, we'll use an inlined version
  # that implements the same basic algorithm.
  my @path  = ();
  my @queue = ( $name );
  my %seen  = ( $name => 1 );
  while ( my $cl = shift @queue ) {
    push @path, $cl;
    unshift @queue, grep { ! $seen{$_}++ }
      map { s/^::/main::/; s/\'/::/g; $_ }
      ( @{"${cl}::ISA"} );
  }

  # Find and merge the function names across the entire super path.
  # Sort alphabetically and return.
  my %methods = ();
  foreach my $namespace ( @path ) {
    my @functions = grep { ! $methods{$_} }
      grep { /$RE_IDENTIFIER/o }
      grep { defined &{"${namespace}::$_"} }
      keys %{"${namespace}::"};
    foreach ( @functions ) {
      $methods{$_} = $namespace;
    }
  }

  # Filter to public or private methods if needed
  my @methodlist = sort keys %methods;
  @methodlist = grep { ! /^\_/ } @methodlist if $options{public};
  @methodlist = grep {   /^\_/ } @methodlist if $options{private};

  # Return in the correct format
  @methodlist = map { "$methods{$_}::$_" } @methodlist if $options{full};
  @methodlist = map {
    [ "$methods{$_}::$_", $methods{$_}, $_, \&{"$methods{$_}::$_"} ]
    } @methodlist if $options{expanded};

  \@methodlist;
}





#####################################################################
# Search Methods


sub subclasses {
  my $class = shift;
  my $name  = $class->_class( shift ) or return undef;

  # Prepare the search queue
  my @found = ();
  my @queue = grep { $_ ne 'main' } $class->_subnames('');
  while ( @queue ) {
    my $c = shift(@queue); # c for class
    if ( $class->_loaded($c) ) {
      # At least one person has managed to misengineer
      # a situation in which ->isa could die, even if the
      # class is real. Trap these cases and just skip
      # over that (bizarre) class. That would at limit
      # problems with finding subclasses to only the
      # modules that have broken ->isa implementation.
      local $@;
      eval {
        if ( $c->isa($name) ) {
          # Add to the found list, but don't add the class itself
          push @found, $c unless $c eq $name;
        }
      };
    }

    # Add any child namespaces to the head of the queue.
    # This keeps the queue length shorted, and allows us
    # not to have to do another sort at the end.
    unshift @queue, map { "${c}::$_" } $class->_subnames($c);
  }

  @found ? \@found : '';
}

sub _subnames {
  my ($class, $name) = @_;
  return sort
    grep {
      substr($_, -2, 2, '') eq '::'
      and
      /$RE_IDENTIFIER/o
    }
    keys %{"${name}::"};
}





#####################################################################
# Children Related Methods

# These can go undocumented for now, until I decide if its best to
# just search the children in namespace only, or if I should do it via
# the file system.

# Find all the loaded classes below us
sub children {
  my $class = shift;
  my $name  = $class->_class(shift) or return ();

  # Find all the Foo:: elements in our symbol table
  no strict 'refs';
  map { "${name}::$_" } sort grep { s/::$// } keys %{"${name}::"};
}

# As above, but recursively
sub recursive_children {
  my $class    = shift;
  my $name     = $class->_class(shift) or return ();
  my @children = ( $name );

  # Do the search using a nicer, more memory efficient
  # variant of actual recursion.
  my $i = 0;
  no strict 'refs';
  while ( my $namespace = $children[$i++] ) {
    push @children, map { "${namespace}::$_" }
      grep { ! /^::/ } # Ignore things like ::ISA::CACHE::
      grep { s/::$// }
      keys %{"${namespace}::"};
  }

  sort @children;
}





#####################################################################
# Private Methods

# Checks and expands ( if needed ) a class name
sub _class {
  my $class = shift;
  my $name  = shift or return '';

  # Handle main shorthand
  return 'main' if $name eq '::';
  $name =~ s/\A::/main::/;

  # Check the class name is valid
  $name =~ /$RE_CLASS/o ? $name : '';
}

# Create a INC-specific filename, which always uses '/'
# regardless of platform.
sub _inc_filename {
  my $class = shift;
  my $name  = $class->_class(shift) or return undef;
  join( '/', split /(?:\'|::)/, $name ) . '.pm';
}

# Convert INC-specific file name to local file name
sub _inc_to_local {
  # Shortcut in the Unix case
  return $_[1] if $UNIX;

  # On other places, we have to deal with an unusual path that might look
  # like C:/foo/bar.pm which doesn't fit ANY normal pattern.
  # Putting it through splitpath/dir and back again seems to normalise
  # it to a reasonable amount.
  my $class              = shift;
  my $inc_name           = shift or return undef;
  my ($vol, $dir, $file) = File::Spec->splitpath( $inc_name );
  $dir = File::Spec->catdir( File::Spec->splitdir( $dir || "" ) );
  File::Spec->catpath( $vol, $dir, $file || "" );
}

1;

__END__