[Webfetch-commits] SF.net SVN: webfetch:[55] branches/v0.13/lib/WebFetch.pm

[<ik...@us...>]

Revision: 55
          http://webfetch.svn.sourceforge.net/webfetch/?rev=55&view=rev
Author:   ikluft
Date:     2009-09-07 21:51:29 +0000 (Mon, 07 Sep 2009)

Log Message:
-----------
streamline autoload, exceptions

Modified Paths:
--------------
    branches/v0.13/lib/WebFetch.pm

Modified: branches/v0.13/lib/WebFetch.pm
===================================================================
--- branches/v0.13/lib/WebFetch.pm	2009-09-07 01:56:55 UTC (rev 54)
+++ branches/v0.13/lib/WebFetch.pm	2009-09-07 21:51:29 UTC (rev 55)
@@ -146,6 +146,7 @@
 
 	'WebFetch::Exception::MustOverride' => {
                 isa => 'WebFetch::TracedException',
+		alias => 'throw_abstract',
 		description => "A WebFetch function was called which is "
 			."supposed to be overridden by a subclass",
 	},
@@ -1120,8 +1121,7 @@
 # placeholder for fetch routines by derived classes
 sub fetch
 {
-	WebFetch::Exception::MustOverride->throw(
-		"fetch() function must be overridden by a derived module\n" );
+	throw_abstract "fetch is an abstract function and must be overridden";
 }
 
 
@@ -1671,32 +1671,45 @@
 		? $self->{wk2fnum}{$wk} : undef;
 }
 
-=item AUTOLOAD
+=item AUTOLOAD functionality
 
+When a WebFetch input object is passed to an output class, operations
+on $self would not usually work.  WebFetch subclasses are considered to be
+cooperating with each other.  So WebFetch provides AUTOLOAD functionality
+to catch undefined function calls for its subclasses.  If the calling 
+class provides a function by the name that was attempted, then it will
+be redirected there.
+
 =cut
 
 # autoloader catches calls to unknown functions
-# first try: redirect to the class which made the call, if the function exists
-# second try: act as a read-only accessor for object data
-# (want a read/write accessor? define the function explicitly)
+# redirect to the class which made the call, if the function exists
 sub AUTOLOAD
 {
 	my $self = shift;
 	my $type = ref($self) or throw_autoload_fail "self is not an object";
 
 	my $name = $AUTOLOAD;
-	$name =~ s/.*://;   # strip fully-qualified portion
+	$name =~ s/.*://;   # strip fully-qualified portion, just want function
 
-	# skip all-caps special Perl functions
+	# decline all-caps names - reserved for special Perl functions
+	# if Perl core didn't handle this name, we won't mess with it either
+	my ( $package, $filename, $line ) = caller;
 	if ( $name =~ /^[A-Z]+$/ ) {
-		return;
+		throw_autoload_fail "reserved function $name declined "
+			." - called by $package ($filename line $line)";
 	}
 
 	# check for function in caller package
 	# (WebFetch may hand an input module's object to an output module)
-	my ( $package, $filename, $line ) = caller;
 	if ( $package->can( $name )) {
-		my $retval = eval $package."::".$name."( \$self, \@_ )";
+		# make an alias of the sub
+		{
+			no strict 'refs';
+			*{__PACKAGE__."::".$name} = \&{$package."::".$name};
+		}
+		#my $retval = eval $package."::".$name."( \$self, \@_ )";
+		my $retval = eval { $self->$name( @_ ); };
 		if ( $@ ) {
 			my $e = Exception::Class->caught();
 			ref $e ? $e->rethrow
@@ -1706,14 +1719,6 @@
 		return $retval;
 	}
 
-	# act as a read-only accessor
-	# add write accessors when API can specify what's OK to write
-	if ( exists $self->{$name}) {
-		# define the sub for better efficiency next time
-		eval "sub WebFetch::$name { return \$_[0]->{$name}; }";
-		return $self->{$name};
-	}
-
 	# if we got here, we failed
 	throw_autoload_fail "function $name not found - "
 		."called by $package ($filename line $line)";


This was sent by the SourceForge.net collaborative development platform, the world's largest Open Source development site.