2 use base qw(Class::Accessor::Fast Class::Data::Inheritable);
3 use UNIVERSAL::require;
7 use Maypole::Constants;
11 our $VERSION = '2.11';
13 # proposed privacy conventions:
14 # - no leading underscore - public to custom application code and plugins
15 # - single leading underscore - private to the main Maypole stack - *not*
17 # - double leading underscore - private to the current package
21 Maypole - MVC web application framework
25 See L<Maypole::Application>.
29 This documents the Maypole request object. See the L<Maypole::Manual>, for a
30 detailed guide to using Maypole.
32 Maypole is a Perl web application framework similar to Java's struts. It is
33 essentially completely abstracted, and so doesn't know anything about
34 how to talk to the outside world.
36 To use it, you need to create a driver package which represents your entire
37 application. This is the C<BeerDB> package used as an example in the manual.
39 This needs to first use L<Maypole::Application> which will make your package
40 inherit from the appropriate platform driver such as C<Apache::MVC> or
41 C<CGI::Maypole>. Then, the driver calls C<setup>. This sets up the model classes and
42 configures your application. The default model class for Maypole uses
43 L<Class::DBI> to map a database to classes, but this can be changed by altering
44 configuration (B<before> calling setup.)
47 =head1 DOCUMENTATION AND SUPPORT
49 Note that some details in some of these resources may be out of date.
53 =item The Maypole Manual
55 The primary documentation is the Maypole manual. This lives in the
56 C<Maypole::Manual> pod documents included with the distribution.
60 Individual packages within the distribution contain (more or less) detailed
61 reference documentation for their API.
65 There are two mailing lists - maypole-devel and maypole-users - see
66 http://maypole.perl.org/?MailingList
68 =item The Maypole Wiki
70 The Maypole wiki provides a useful store of extra documentation -
71 http://maypole.perl.org
73 In particular, there's a FAQ (http://maypole.perl.org/?FAQ) and a cookbook
74 (http://maypole.perl.org/?Cookbook). Again, certain information on these pages
77 =item Web applications with Maypole
79 A tutorial written by Simon Cozens for YAPC::EU 2005 -
80 http://www.droogs.org/perl/maypole/maypole-tutorial.pdf [228KB].
82 =item A Database-Driven Web Application in 18 Lines of Code
84 By Paul Barry, published in Linux Journal, March 2005.
86 http://www.linuxjournal.com/article/7937
88 "From zero to Web-based database application in eight easy steps".
90 Maypole won a 2005 Linux Journal Editor's Choice Award
91 (http://www.linuxjournal.com/article/8293) after featuring in this article.
93 =item Build Web apps with Maypole
95 By Simon Cozens, on IBM's DeveloperWorks website, May 2004.
97 http://www-128.ibm.com/developerworks/linux/library/l-maypole/
99 =item Rapid Web Application Deployment with Maypole
101 By Simon Cozens, on O'Reilly's Perl website, April 2004.
103 http://www.perl.com/pub/a/2004/04/15/maypole.html
107 Some notes written by Simon Cozens. A little bit out of date, but still
108 very useful: http://www.droogs.org/perl/maypole/authentication.html
112 There's a refcard for the Maypole (and Class::DBI) APIs on the wiki -
113 http://maypole.perl.org/?CheatSheet. Probably a little out of date now - it's a
114 wiki, so feel free to fix any errors!
116 =item Plugins and add-ons
118 There are a large and growing number of plugins and other add-on modules
119 available on CPAN - http://search.cpan.org/search?query=maypole&mode=module
123 You can find a range of useful Maypole links, particularly to several thoughtful
124 blog entries, starting here: http://del.icio.us/search/?all=maypole
128 There are a couple of short reviews here:
129 http://cpanratings.perl.org/dist/Maypole
135 A couple of demos are available, sometimes with source code and configs.
139 =item http://maypole.perl.org/beerdb/
141 The standard BeerDB example, using the TT factory templates supplied in the
144 =item beerdb.riverside-cms.co.uk
146 The standard BeerDB example, running on Mason, using the factory templates
147 supplied in the L<MasonX::Maypole> distribution.
149 =item beerfb.riverside-cms.co.uk
151 A demo of L<Maypole::FormBuilder>. This site is running on the set of Mason
152 templates included in the L<Maypole::FormBuilder> distribution. See the
153 synopsis of L<Maypole::Plugin::FormBuilder> for an example driver
159 __PACKAGE__->mk_classdata($_) for qw( config init_done view_object );
161 __PACKAGE__->mk_accessors(
162 qw( params query objects model_class template_args output path
163 args action template error document_encoding content_type table
164 headers_in headers_out stash session)
167 __PACKAGE__->config( Maypole::Config->new() );
169 __PACKAGE__->init_done(0);
171 =head1 HOOKABLE METHODS
173 As a framework, Maypole provides a number of B<hooks> - methods that are
174 intended to be overridden. Some of these methods come with useful default
175 behaviour, others do nothing by default. Likely hooks include:
201 sub My::App::debug {1}
203 Returns the debugging flag. Override this in your application class to
204 enable/disable debugging.
206 You can also set the C<debug> flag via L<Maypole::Application>.
214 Returns the L<Maypole::Config> object
218 My::App->setup($data_source, $user, $password, \%attr);
220 Initialise the Maypole application and plugins and model classes - see
221 L<Maypole::Manual::Plugins>.
223 If your model is based on L<Maypole::Model::CDBI>, the C<\%attr> hashref can
224 contain options that are passed directly to L<Class::DBI::Loader>, to control
225 how the model hierarchy is constructed.
227 Your application should call this B<after> setting up configuration data via
236 $class->setup_model(@_);
241 Called by C<setup>. This method builds the Maypole model hierarchy.
243 A likely target for over-riding, if you need to build a customised model.
245 This method also ensures any code in custom model classes is loaded, so you
246 don't need to load them in the driver.
254 $class = ref $class if ref $class;
256 my $config = $class->config;
258 $config->model || $config->model('Maypole::Model::CDBI');
260 $config->model->require or die sprintf
261 "Couldn't load the model class %s: %s", $config->model, $@;
263 # among other things, this populates $config->classes
264 $config->model->setup_database($config, $class, @_);
266 foreach my $subclass ( @{ $config->classes } )
269 unshift @{ $subclass . "::ISA" }, $config->model;
271 # Load custom model code, if it exists - nb this must happen after the
272 # unshift, to allow code attributes to work, but before adopt(),
273 # in case adopt() calls overridden methods on $subclass
274 $class->load_model_subclass($subclass);
276 $config->model->adopt($subclass) if $config->model->can("adopt");
278 # eval "use $subclass";
279 # die "Error loading $subclass: $@"
280 # if $@ and $@ !~ /Can\'t locate \S+ in \@INC/;
284 =item load_model_subclass($subclass)
286 This method is called from C<setup_model()>. It attempts to load the
287 C<$subclass> package, if one exists. So if you make a customized C<BeerDB::Beer>
288 package, you don't need to explicitly load it.
290 If, perhaps during development, you don't want to load up custom classes, you
291 can override this method and load them manually.
295 sub load_model_subclass
297 my ($class, $subclass) = @_;
299 my $config = $class->config;
301 # Load any external files for the model base class or subclasses
302 # (e.g. BeerDB/DBI.pm or BeerDB/Beer.pm) based on code borrowed from
303 # Maypole::Plugin::Loader and Class::DBI.
304 if ( $subclass->require )
306 warn "Loaded external module for '$subclass'\n" if $class->debug > 1;
310 (my $filename = $subclass) =~ s!::!/!g;
311 die "Loading '$subclass' failed: $@\n"
312 unless $@ =~ /Can\'t locate \Q$filename\E\.pm/;
313 warn "Did not find external module for '$subclass'\n"
314 if $class->debug > 1;
320 Loads the view class and instantiates the view object.
322 You should not call this directly, but you may wish to override this to add
323 application-specific initialisation - see L<Maypole::Manual::Plugins>.
330 my $config = $class->config;
331 $config->view || $config->view("Maypole::View::TT");
332 $config->view->require;
333 die "Couldn't load the view class " . $config->view . ": $@" if $@;
334 $config->display_tables
335 || $config->display_tables( $class->config->tables );
336 $class->view_object( $class->config->view->new );
337 $class->init_done(1);
342 Constructs a very minimal new Maypole request object.
352 config => $class->config,
360 Get/set the Maypole::View object
364 =head1 INSTANCE METHODS
372 This method sets up the class if it's not done yet, sets some defaults and
373 leaves the dirty work to C<handler_guts>.
377 # handler() has a method attribute so that mod_perl will invoke
378 # BeerDB->handler() as a method rather than a plain function
379 # BeerDB::handler() and so this inherited implementation will be
380 # found. See e.g. "Practical mod_perl" by Bekman & Cholet for
381 # more information <http://modperlbook.org/html/ch25_01.html>
384 # See Maypole::Workflow before trying to understand this.
385 my ($class, $req) = @_;
387 $class->init unless $class->init_done;
389 my $self = $class->new;
391 # initialise the request
392 $self->headers_out(Maypole::Headers->new);
393 $self->get_request($req);
394 $self->parse_location;
396 # hook useful for declining static requests e.g. images
397 my $status = $self->start_request_hook;
398 return $status unless $status == Maypole::Constants::OK();
400 $self->session($self->get_session);
402 $status = $self->handler_guts;
404 # moving this here causes unit test failures - need to check why
405 # before committing the move
406 #$status = $self->__call_process_view unless $self->output;
408 return $status unless $status == OK;
410 # TODO: require send_output to return a status code
418 This is the main request handling method and calls various methods to handle the
419 request/response and defines the workflow within Maypole.
421 B<Currently undocumented and liable to be refactored without warning>.
425 # The root of all evil
430 $self->__load_request_model;
432 my $applicable = $self->is_model_applicable;
434 $self->__setup_plain_template unless $applicable;
438 eval { $status = $self->call_authenticate };
440 if ( my $error = $@ )
442 $status = $self->call_exception($error);
446 warn "caught authenticate error: $error";
447 return $self->debug ?
448 $self->view_object->error($self, $error) : ERROR;
452 if ( $self->debug and $status != OK and $status != DECLINED )
454 $self->view_object->error( $self,
455 "Got unexpected status $status from calling authentication" );
458 return $status unless $status == OK;
460 # We run additional_data for every request
461 $self->additional_data;
465 eval { $self->model_class->process($self) };
467 if ( my $error = $@ )
469 $status = $self->call_exception($error);
473 warn "caught model error: $error";
474 return $self->debug ?
475 $self->view_object->error($self, $error) : ERROR;
480 # less frequent path - perhaps output has been set to an error message
481 return OK if $self->output;
483 # normal path - no output has been generated yet
484 return $self->__call_process_view;
487 sub __load_request_model
490 $self->model_class( $self->config->model->class_of($self, $self->table) );
493 # is_applicable() returned false, so set up a plain template. Model processing
494 # will be skipped, but need to remove the model anyway so the template can't
496 sub __setup_plain_template
500 # It's just a plain template
501 $self->model_class(undef);
503 my $path = $self->path;
504 $path =~ s{/$}{}; # De-absolutify
507 $self->template($self->path);
510 # The model has been processed or skipped (if is_applicable returned false),
511 # any exceptions have been handled, and there's no content in $self->output
512 sub __call_process_view
518 eval { $status = $self->view_object->process($self) };
520 if ( my $error = $@ )
522 $status = $self->call_exception($error);
526 warn "caught view error: $error" if $self->debug;
527 return $self->debug ?
528 $self->view_object->error($self, $error) : ERROR;
537 You should only need to define this method if you are writing a new
538 Maypole backend. It should return something that looks like an Apache
539 or CGI request object, it defaults to blank.
547 Turns the backend request (e.g. Apache::MVC, Maypole, CGI) into a Maypole
548 request. It does this by setting the C<path>, and invoking C<parse_path> and
551 You should only need to define this method if you are writing a new Maypole
558 die "parse_location is a virtual method. Do not use Maypole directly; " .
559 "use Apache::MVC or similar";
562 =item start_request_hook
564 This is called immediately after setting up the basic request. The default
565 method simply returns C<Maypole::Constants::OK>.
567 Any other return value causes Maypole to abort further processing of the
568 request. This is useful for filtering out requests for static files, e.g.
569 images, which should not be processed by Maypole or by the templating engine:
571 sub start_request_hook
575 return Maypole::Constants::DECLINED if $r->path =~ /\.jpg$/;
576 return Maypole::Constants::OK;
581 sub start_request_hook { Maypole::Constants::OK }
585 B<This method is deprecated> as of version 2.11. If you have overridden it,
586 please override C<is_model_applicable> instead, and change the return type
587 from a Maypole:Constant to a true/false value.
589 Returns a Maypole::Constant to indicate whether the request is valid.
591 =item is_model_applicable
593 Returns true or false to indicate whether the request is valid.
595 The default implementation checks that C<< $r->table >> is publicly
596 accessible and that the model class is configured to handle the
601 sub is_model_applicable
605 # cater for applications that are using obsolete version
606 if ($self->can('is_applicable'))
608 warn "DEPRECATION WARNING: rewrite is_applicable to the interface ".
609 "of Maypole::is_model_applicable\n";
610 return $self->is_applicable == OK;
613 # Establish which tables should be processed by the model
614 my $config = $self->config;
616 $config->ok_tables || $config->ok_tables( $config->display_tables );
618 $config->ok_tables( { map { $_ => 1 } @{ $config->ok_tables } } )
619 if ref $config->ok_tables eq "ARRAY";
621 my $ok_tables = $config->ok_tables;
623 # Does this request concern a table to be processed by the model?
624 my $table = $self->table;
628 if (exists $ok_tables->{$table})
635 warn "We don't have that table ($table).\n"
636 . "Available tables are: "
637 . join( ",", keys %$ok_tables )
638 if $self->debug and not $ok_tables->{$table};
643 # Is the action public?
644 my $action = $self->action;
645 return 1 if $self->model_class->is_public($action);
647 warn "The action '$action' is not applicable to the table $table"
655 The default method is empty.
661 =item call_authenticate
663 This method first checks if the relevant model class
664 can authenticate the user, or falls back to the default
665 authenticate method of your Maypole application.
669 sub call_authenticate
673 # Check if we have a model class with an authenticate() to delegate to
674 return $self->model_class->authenticate($self)
675 if $self->model_class and $self->model_class->can('authenticate');
677 # Interface consistency is a Good Thing -
678 # the invocant and the argument may one day be different things
679 # (i.e. controller and request), like they are when authenticate()
680 # is called on a model class (i.e. model and request)
681 return $self->authenticate($self);
686 Returns a Maypole::Constant to indicate whether the user is authenticated for
689 The default implementation returns C<OK>
693 sub authenticate { return OK }
698 This model is called to catch exceptions, first after authenticate, then after
699 processing the model class, and finally to check for exceptions from the view
702 This method first checks if the relevant model class
703 can handle exceptions the user, or falls back to the default
704 exception method of your Maypole application.
710 my ($self, $error) = @_;
712 # Check if we have a model class with an exception() to delegate to
713 if ( $self->model_class && $self->model_class->can('exception') )
715 my $status = $self->model_class->exception( $self, $error );
716 return $status if $status == OK;
719 return $self->exception($error);
724 This method is called if any exceptions are raised during the authentication or
725 model/view processing. It should accept the exception as a parameter and return
726 a Maypole::Constant to indicate whether the request should continue to be
731 sub exception { return ERROR }
733 =item additional_data
735 Called before the model processes the request, this method gives you a chance to
736 do some processing for each request, for example, manipulating C<template_args>.
740 sub additional_data { }
744 Sends the output and additional headers to the user.
749 die "send_output is a virtual method. Do not use Maypole directly; use Apache::MVC or similar";
757 =head2 Path processing and manipulation
763 Returns the request path
767 Parses the request path and sets the C<args>, C<action> and C<table>
768 properties. Calls C<preprocess_path> before parsing path and setting properties.
776 # Previous versions unconditionally set table, action and args to whatever
777 # was in @pi (or else to defaults, if @pi is empty).
778 # Adding preprocess_path(), and then setting table, action and args
779 # conditionally, broke lots of tests, hence this:
780 $self->$_(undef) for qw/action table args/;
782 $self->preprocess_path;
784 $self->path || $self->path('frontpage');
786 my @pi = grep {length} split '/', $self->path;
788 $self->table || $self->table(shift @pi);
789 $self->action || $self->action( shift @pi or 'index' );
790 $self->args || $self->args(\@pi);
793 =item preprocess_path
795 Sometimes when you don't want to rewrite or over-ride parse_path but
796 want to rewrite urls or extract data from them before it is parsed.
798 This method is called after parse_location has populated the request
799 information and before parse_path has populated the model and action
800 information, and is passed the request object.
802 You can set action, args or table in this method and parse_path will
803 then leave those values in place or populate them if not present
807 sub preprocess_path { };
809 =item make_path( %args or \%args or @args )
811 This is the counterpart to C<parse_path>. It generates a path to use
812 in links, form actions etc. To implement your own path scheme, just override
813 this method and C<parse_path>.
815 %args = ( table => $table,
817 additional => $additional, # optional - generally an object ID
820 \%args = as above, but a ref
822 @args = ( $table, $action, $additional ); # $additional is optional
824 C<id> can be used as an alternative key to C<additional>.
826 C<$additional> can be a string, an arrayref, or a hashref. An arrayref is
827 expanded into extra path elements, whereas a hashref is translated into a query
838 if (@_ == 1 and ref $_[0] and ref $_[0] eq 'HASH')
842 elsif ( @_ > 1 and @_ < 4 )
844 $args{table} = shift;
845 $args{action} = shift;
846 $args{additional} = shift;
853 do { die "no $_" unless $args{$_} } for qw( table action );
855 my $additional = $args{additional} || $args{id};
861 # if $additional is a href, make_uri() will transform it into a query
862 @add = (ref $additional eq 'ARRAY') ? @$additional : ($additional);
865 my $uri = $r->make_uri($args{table}, $args{action}, @add);
867 return $uri->as_string;
872 =item make_uri( @segments )
874 Make a L<URI> object given table, action etc. Automatically adds
877 If the final element in C<@segments> is a hash ref, C<make_uri> will render it
884 my ($r, @segments) = @_;
886 my $query = (ref $segments[-1] eq 'HASH') ? pop(@segments) : undef;
888 my $base = $r->config->uri_base;
891 my $uri = URI->new($base);
892 $uri->path_segments($uri->path_segments, grep {length} @segments);
894 my $abs_uri = $uri->abs('/');
895 $abs_uri->query_form($query) if $query;
901 Turns post data and query string paramaters into a hash of C<params>.
903 You should only need to define this method if you are writing a new Maypole
910 die "parse_args() is a virtual method. Do not use Maypole directly; ".
911 "use Apache::MVC or similar";
914 =item get_template_root
916 Implementation-specific path to template root.
918 You should only need to define this method if you are writing a new Maypole
919 backend. Otherwise, see L<Maypole::Config/"template_root">
923 sub get_template_root {'.'}
927 =head2 Request properties
933 Returns the perl package name that will serve as the model for the
934 request. It corresponds to the request C<table> attribute.
939 Get/set a list of model objects. The objects will be accessible in the view
942 If the first item in C<$self-E<gt>args> can be C<retrieve()>d by the model
943 class, it will be removed from C<args> and the retrieved object will be added to
944 the C<objects> list. See L<Maypole::Model> for more information.
948 $self->template_args->{foo} = 'bar';
950 Get/set a hash of template variables.
954 A place to put custom application data. Not used by Maypole itself.
958 Get/set the template to be used by the view. By default, it returns
964 Get/set a request error
968 Get/set the response output. This is usually populated by the view class. You
969 can skip view processing by setting the C<output>.
973 The table part of the Maypole request path
977 The action part of the Maypole request path
981 A list of remaining parts of the request path after table and action
987 A L<Maypole::Headers> object containing HTTP headers for the request
991 A L<HTTP::Headers> object that contains HTTP headers for the output
993 =item document_encoding
995 Get/set the output encoding. Default: utf-8.
999 Get/set the output content type. Default: text/html
1003 Returns the protocol the request was made with, i.e. https
1008 die "get_protocol is a virtual method. Do not use Maypole directly; use Apache::MVC or similar";
1013 =head2 Request parameters
1015 The source of the parameters may vary depending on the Maypole backend, but they
1016 are usually populated from request query string and POST data.
1018 Maypole supplies several approaches for accessing the request parameters. Note
1019 that the current implementation (via a hashref) of C<query> and C<params> is
1020 likely to change in a future version of Maypole. So avoid direct access to these
1023 $r->{params}->{foo} # bad
1024 $r->params->{foo} # better
1026 $r->{query}->{foo} # bad
1027 $r->query->{foo} # better
1029 $r->param('foo') # best
1035 An accessor (get or set) for request parameters. It behaves similarly to
1036 CGI::param() for accessing CGI parameters, i.e.
1038 $r->param # returns list of keys
1039 $r->param($key) # returns value for $key
1040 $r->param($key => $value) # returns old value, sets to new value
1046 my ($self, $key) = (shift, shift);
1048 return keys %{$self->params} unless defined $key;
1050 return unless exists $self->params->{$key};
1052 my $val = $self->params->{$key};
1056 my $new_val = shift;
1057 $self->params->{$key} = $new_val;
1060 return ref $val ? @$val : ($val) if wantarray;
1062 return ref $val ? $val->[0] : $val;
1068 Returns a hashref of request parameters.
1070 B<Note:> Where muliple values of a parameter were supplied, the C<params> value
1071 will be an array reference.
1075 Alias for C<params>.
1079 =head3 Utility methods
1083 =item redirect_request
1085 Sets output headers to redirect based on the arguments provided
1087 Accepts either a single argument of the full url to redirect to, or a hash of
1090 $r->redirect_request('http://www.example.com/path');
1094 $r->redirect_request(protocol=>'https', domain=>'www.example.com', path=>'/path/file?arguments', status=>'302', url=>'..');
1096 The named parameters are protocol, domain, path, status and url
1098 Only 1 named parameter is required but other than url, they can be combined as
1099 required and current values (from the request) will be used in place of any
1100 missing arguments. The url argument must be a full url including protocol and
1101 can only be combined with status.
1105 sub redirect_request {
1106 die "redirect_request is a virtual method. Do not use Maypole directly; use Apache::MVC or similar";
1109 =item redirect_internal_request
1113 sub redirect_internal_request {
1118 =item make_random_id
1120 returns a unique id for this request can be used to prevent or detect repeat
1125 # Session and Repeat Submission Handling
1126 sub make_random_id {
1127 use Maypole::Session;
1128 return Maypole::Session::generate_unique_id();
1133 =head1 SEQUENCE DIAGRAMS
1135 See L<Maypole::Manual::Workflow> for a detailed discussion of the sequence of
1136 calls during processing of a request. This is a brief summary:
1140 BeerDB Maypole::Model::CDBI
1144 || setup_model | setup_database() creates
1145 ||------+ | a subclass of the Model
1146 |||<----+ | for each table
1148 ||| setup_database | |
1149 |||--------------------->|| 'create' *
1150 ||| ||----------> $subclass
1152 ||| load_model_subclass | |
1153 foreach |||------+ ($subclass) | |
1154 $subclass ||||<----+ | require |
1155 ||||--------------------------------------->|
1157 ||| adopt($subclass) | |
1158 |||--------------------->|| |
1163 || | new | view_object: e.g
1164 ||---------------------------------------------> Maypole::View::TT
1176 BeerDB Model $subclass view_object
1179 o-------->| new | | |
1180 |-----> r:BeerDB | | |
1184 | ||-----+ parse_location | | |
1187 | ||-----+ start_request_hook | | |
1190 | ||-----+ get_session | | |
1193 | ||-----+ handler_guts | | |
1195 | ||| class_of($table) | | |
1196 | |||------------------------->|| | |
1197 | ||| $subclass || | |
1198 | |||<-------------------------|| | |
1200 | |||-----+ is_model_applicable| | |
1203 | |||-----+ call_authenticate | | |
1206 | |||-----+ additional_data | | |
1208 | ||| process | | fetch_objects
1209 | |||--------------------------------->||-----+ |
1217 | |||------------------------------------------->|| template
1221 | || send_output | | |
1225 <------------------|| | | |
1236 There's more documentation, examples, and a information on our mailing lists
1237 at the Maypole web site:
1239 L<http://maypole.perl.org/>
1241 L<Maypole::Application>, L<Apache::MVC>, L<CGI::Maypole>.
1245 Maypole is currently maintained by Aaron Trevena
1247 =head1 AUTHOR EMERITUS
1249 Simon Cozens, C<simon#cpan.org>
1251 Sebastian Riedel, C<sri#oook.de> maintained Maypole from 1.99_01 to 2.04
1255 Sebastian Riedel, Danijel Milicevic, Dave Slack, Jesse Sheidlower, Jody Belka,
1256 Marcus Ramberg, Mickael Joanne, Randal Schwartz, Simon Flack, Steve Simms,
1257 Veljko Vidovic and all the others who've helped.
1261 You may distribute this code under the same terms as Perl itself.