2 use base qw(Class::Accessor::Fast Class::Data::Inheritable);
3 use UNIVERSAL::require;
7 use Maypole::Constants;
12 use File::MMagic::XS qw(:compat);
14 our $VERSION = '2.11';
15 our $mmagic = File::MMagic::XS->new();
17 # proposed privacy conventions:
18 # - no leading underscore - public to custom application code and plugins
19 # - single leading underscore - private to the main Maypole stack - *not*
21 # - double leading underscore - private to the current package
25 Maypole - MVC web application framework
29 The canonical example used in the Maypole documentation is the beer database:
35 # choose a frontend, initialise the config object, and load a plugin
36 use Maypole::Application qw/Relationship/;
38 # get the empty config object created by Maypole::Application
39 my $config = __PACKAGE__->config;
42 $config->uri_base("http://localhost/beerdb");
43 $config->template_root("/path/to/templates");
44 $config->rows_per_page(10);
45 $config->display_tables([qw/beer brewery pub style/]);
48 $config->relationships([
49 "a brewery produces beers",
50 "a style defines beers",
51 "a pub has beers on handpumps",
55 BeerDB::Brewery->untaint_columns( printable => [qw/name notes url/] );
56 BeerDB::Pub->untaint_columns( printable => [qw/name notes url/] );
57 BeerDB::Style->untaint_columns( printable => [qw/name notes/] );
58 BeerDB::Beer->untaint_columns(
59 printable => [qw/abv name price notes/],
60 integer => [qw/style brewery score/],
65 __PACKAGE__->setup("dbi:SQLite:t/beerdb.db");
71 This documents the Maypole request object. See the L<Maypole::Manual>, for a
72 detailed guide to using Maypole.
74 Maypole is a Perl web application framework similar to Java's struts. It is
75 essentially completely abstracted, and so doesn't know anything about
76 how to talk to the outside world.
78 To use it, you need to create a driver package which represents your entire
79 application. This is the C<BeerDB> package used as an example in the manual.
81 This needs to first use L<Maypole::Application> which will make your package
82 inherit from the appropriate platform driver such as C<Apache::MVC> or
83 C<CGI::Maypole>. Then, the driver calls C<setup>. This sets up the model classes
84 and configures your application. The default model class for Maypole uses
85 L<Class::DBI> to map a database to classes, but this can be changed by altering
86 configuration (B<before> calling setup.)
89 =head1 DOCUMENTATION AND SUPPORT
91 Note that some details in some of these resources may be out of date.
95 =item The Maypole Manual
97 The primary documentation is the Maypole manual. This lives in the
98 C<Maypole::Manual> pod documents included with the distribution.
102 Individual packages within the distribution contain (more or less) detailed
103 reference documentation for their API.
107 There are two mailing lists - maypole-devel and maypole-users - see
108 http://maypole.perl.org/?MailingList
110 =item The Maypole Wiki
112 The Maypole wiki provides a useful store of extra documentation -
113 http://maypole.perl.org
115 In particular, there's a FAQ (http://maypole.perl.org/?FAQ) and a cookbook
116 (http://maypole.perl.org/?Cookbook). Again, certain information on these pages
119 =item Web applications with Maypole
121 A tutorial written by Simon Cozens for YAPC::EU 2005 -
122 http://www.droogs.org/perl/maypole/maypole-tutorial.pdf [228KB].
124 =item A Database-Driven Web Application in 18 Lines of Code
126 By Paul Barry, published in Linux Journal, March 2005.
128 http://www.linuxjournal.com/article/7937
130 "From zero to Web-based database application in eight easy steps".
132 Maypole won a 2005 Linux Journal Editor's Choice Award
133 (http://www.linuxjournal.com/article/8293) after featuring in this article.
135 =item Build Web apps with Maypole
137 By Simon Cozens, on IBM's DeveloperWorks website, May 2004.
139 http://www-128.ibm.com/developerworks/linux/library/l-maypole/
141 =item Rapid Web Application Deployment with Maypole
143 By Simon Cozens, on O'Reilly's Perl website, April 2004.
145 http://www.perl.com/pub/a/2004/04/15/maypole.html
149 Some notes written by Simon Cozens. A little bit out of date, but still
150 very useful: http://www.droogs.org/perl/maypole/authentication.html
154 There's a refcard for the Maypole (and Class::DBI) APIs on the wiki -
155 http://maypole.perl.org/?CheatSheet. Probably a little out of date now - it's a
156 wiki, so feel free to fix any errors!
158 =item Plugins and add-ons
160 There are a large and growing number of plugins and other add-on modules
161 available on CPAN - http://search.cpan.org/search?query=maypole&mode=module
165 You can find a range of useful Maypole links, particularly to several thoughtful
166 blog entries, starting here: http://del.icio.us/search/?all=maypole
170 There are a couple of short reviews here:
171 http://cpanratings.perl.org/dist/Maypole
177 A couple of demos are available, sometimes with source code and configs.
181 =item http://maypole.perl.org/beerdb/
183 The standard BeerDB example, using the TT factory templates supplied in the
186 =item beerdb.riverside-cms.co.uk
188 The standard BeerDB example, running on Mason, using the factory templates
189 supplied in the L<MasonX::Maypole> distribution.
191 =item beerfb.riverside-cms.co.uk
193 A demo of L<Maypole::FormBuilder>. This site is running on the set of Mason
194 templates included in the L<Maypole::FormBuilder> distribution. See the
195 synopsis of L<Maypole::Plugin::FormBuilder> for an example driver
201 __PACKAGE__->mk_classdata($_) for qw( config init_done view_object model_classes_loaded);
203 __PACKAGE__->mk_accessors(
204 qw( params query objects model_class template_args output path
205 args action template error document_encoding content_type table
206 headers_in headers_out stash status parent)
209 __PACKAGE__->config( Maypole::Config->new() );
211 __PACKAGE__->init_done(0);
213 __PACKAGE__->model_classes_loaded(0);
215 =head1 HOOKABLE METHODS
217 As a framework, Maypole provides a number of B<hooks> - methods that are
218 intended to be overridden. Some of these methods come with useful default
219 behaviour, others do nothing by default. Hooks include:
245 sub My::App::debug {1}
247 Returns the debugging flag. Override this in your application class to
248 enable/disable debugging.
250 You can also set the C<debug> flag via L<Maypole::Application>.
252 Some packages respond to higher debug levels, try increasing it to 2 or 3.
261 Returns the L<Maypole::Config> object
265 My::App->setup($data_source, $user, $password, \%attr);
267 Initialise the Maypole application and plugins and model classes.
268 Your application should call this B<after> setting up configuration data via
271 It calls the hook C<setup_model> to setup the model. The %attr hash contains
272 options and arguments used to set up the model. See the particular model's
273 documentation. However here is the most usage of setup where
274 Maypole::Model::CDBI is the base class.
276 My::App->setup($data_source, $user, $password,
277 { opitons => { # These are DB connection options
282 # These are Class::DBI::Loader arguments.
288 Also, see L<Maypole::Manual::Plugins>.
297 $class->setup_model(@_);
302 Called by C<setup>. This method builds the Maypole model hierarchy.
304 A likely target for over-riding, if you need to build a customised model.
306 This method also ensures any code in custom model classes is loaded, so you
307 don't need to load them in the driver.
313 $class = ref $class if ref $class;
314 my $config = $class->config;
315 $config->model || $config->model('Maypole::Model::CDBI');
316 $config->model->require or die sprintf
317 "Couldn't load the model class %s: %s", $config->model, $@;
319 # among other things, this populates $config->classes
320 $config->model->setup_database($config, $class, @_);
322 foreach my $subclass ( @{ $config->classes } ) {
323 next if $subclass->isa("Maypole::Model::Base");
325 unshift @{ $subclass . "::ISA" }, $config->model;
328 # Load custom model code, if it exists - nb this must happen after the
329 # unshift, to allow code attributes to work, but before adopt(),
330 # in case adopt() calls overridden methods on $subclass
331 foreach my $subclass ( @{ $config->classes } ) {
332 $class->load_model_subclass($subclass) unless ($class->model_classes_loaded());
333 $config->model->adopt($subclass) if $config->model->can("adopt");
338 =item load_model_subclass($subclass)
340 This method is called from C<setup_model()>. It attempts to load the
341 C<$subclass> package, if one exists. So if you make a customized C<BeerDB::Beer>
342 package, you don't need to explicitly load it.
344 If automatic loading causes problems, Override load_model_subclass in your driver.
346 sub load_model_subclass {};
348 Or perhaps during development, if you don't want to load up custom classes, you
349 can override this method and load them manually.
353 sub load_model_subclass {
354 my ($class, $subclass) = @_;
356 my $config = $class->config;
358 # Load any external files for the model base class or subclasses
359 # (e.g. BeerDB/DBI.pm or BeerDB/Beer.pm) based on code borrowed from
360 # Maypole::Plugin::Loader and Class::DBI.
361 if ( $subclass->require ) {
362 warn "Loaded external module for '$subclass'\n" if $class->debug > 1;
364 (my $filename = $subclass) =~ s!::!/!g;
365 die "Loading '$subclass' failed: $@\n"
366 unless $@ =~ /Can\'t locate \Q$filename\E\.pm/;
367 warn "No external module for '$subclass'"
368 if $class->debug > 1;
374 Loads the view class and instantiates the view object.
376 You should not call this directly, but you may wish to override this to add
377 application-specific initialisation - see L<Maypole::Manual::Plugins>.
384 my $config = $class->config;
385 $config->view || $config->view("Maypole::View::TT");
386 $config->view->require;
387 die "Couldn't load the view class " . $config->view . ": $@" if $@;
388 $config->display_tables
389 || $config->display_tables( $class->config->tables );
390 $class->view_object( $class->config->view->new );
391 $class->init_done(1);
396 Constructs a very minimal new Maypole request object.
406 config => $class->config,
414 Get/set the Maypole::View object
418 =head1 INSTANCE METHODS
426 This method sets up the class if it's not done yet, sets some defaults and
427 leaves the dirty work to C<handler_guts>.
431 # handler() has a method attribute so that mod_perl will invoke
432 # BeerDB->handler() as a method rather than a plain function
433 # BeerDB::handler() and so this inherited implementation will be
434 # found. See e.g. "Practical mod_perl" by Bekman & Cholet for
435 # more information <http://modperlbook.org/html/ch25_01.html>
436 sub handler : method {
437 # See Maypole::Workflow before trying to understand this.
438 my ($class, $req) = @_;
440 $class->init unless $class->init_done;
442 my $self = $class->new;
444 # initialise the request
445 $self->headers_out(Maypole::Headers->new);
446 $self->get_request($req);
447 $self->parse_location;
449 # hook useful for declining static requests e.g. images, or perhaps for
450 # sanitizing request parameters
451 $self->status(Maypole::Constants::OK()); # set the default
452 $self->__call_hook('start_request_hook');
453 return $self->status unless $self->status == Maypole::Constants::OK();
455 die "status undefined after start_request_hook()" unless defined
461 my $status = $self->handler_guts;
462 return $status unless $status == OK;
464 # TODO: require send_output to return a status code
472 Run Maypole sub-requests as a component of the request
474 [% request.component("/beer/view_as_component/20") %]
476 Allows you to integrate the results of a Maypole request into an existing
477 request. You'll need to set up actions and templates
478 which return fragments of HTML rather than entire pages, but once you've
479 done that, you can use the C<component> method of the Maypole request object
480 to call those actions. You may pass a query string in the usual URL style.
481 You should not fully qualify the Maypole URLs.
486 my ( $r, $path ) = @_;
487 my $self = bless { parent => $r }, ref $r;
488 my $url = URI->new($path);
489 $self->{path} = $url->path;
491 $self->params( $url->query_form_hash );
492 $self->query( $r->params );
494 return $self->output;
497 sub get_template_root {
500 return $r->parent->get_template_root if $r->{parent};
501 return $self->NEXT::DISTINCT::get_template_root( $r, @_ );
507 return $r->parent->view_object if $r->{parent};
508 return $self->NEXT::DISTINCT::view_object( $r, @_ );
511 # Instead of making plugin authors use the NEXT::DISTINCT hoopla to ensure other
512 # plugins also get to call the hook, we can cycle through the application's
513 # @ISA and call them all here. Doesn't work for setup() though, because it's
514 # too ingrained in the stack. We could add a run_setup() method, but we'd break
515 # lots of existing code.
518 my ($self, $hook) = @_;
522 my $class = ref($self);
524 @plugins = @{"$class\::ISA"};
527 # this is either a custom method in the driver, or the method in the 1st
528 # plugin, or the 'null' method in the frontend (i.e. inherited from
529 # Maypole.pm) - we need to be careful to only call it once
530 my $first_hook = $self->can($hook);
533 my %seen = ( $first_hook => 1 );
535 # @plugins includes the frontend
536 foreach my $plugin (@plugins)
538 next unless my $plugin_hook = $plugin->can($hook);
539 next if $seen{$plugin_hook}++;
546 This is the main request handling method and calls various methods to handle the
547 request/response and defines the workflow within Maypole.
549 B<Currently undocumented and liable to be refactored without warning>.
553 # The root of all evil
558 $self->__load_request_model;
560 my $applicable = $self->is_model_applicable == OK;
562 $self->__setup_plain_template unless $applicable;
566 eval { $status = $self->call_authenticate };
568 if ( my $error = $@ )
570 $status = $self->call_exception($error, "authentication");
574 warn "caught authenticate error: $error";
575 return $self->debug ?
576 $self->view_object->error($self, $error) : ERROR;
580 if ( $self->debug and $status != OK and $status != DECLINED )
582 $self->view_object->error( $self,
583 "Got unexpected status $status from calling authentication" );
586 return $status unless $status == OK;
588 # We run additional_data for every request
589 $self->additional_data;
593 eval { $self->model_class->process($self) };
595 if ( my $error = $@ )
597 $status = $self->call_exception($error, "model");
601 warn "caught model error: $error";
602 return $self->debug ?
603 $self->view_object->error($self, $error) : ERROR;
608 # less frequent path - perhaps output has been set to an error message
609 return OK if $self->output;
611 # normal path - no output has been generated yet
612 my $processed_view_ok = $self->__call_process_view;
614 $self->{content_type} ||= $self->__get_mime_type();
615 $self->{document_encoding} ||= "utf-8";
617 return $processed_view_ok;
621 'js' => 'text/javascript',
623 'htm' => 'text/html',
624 'html' => 'text/html',
627 sub __get_mime_type {
630 if ($self->path =~ m/.*\.(\w{3,4})$/) {
631 $type = $filetypes{$1};
633 $type = $mmagic->checktype_contents($self->output);
638 sub __load_request_model
641 $self->model_class( $self->config->model->class_of($self, $self->table) );
644 # is_applicable() returned false, so set up a plain template. Model processing
645 # will be skipped, but need to remove the model anyway so the template can't
647 sub __setup_plain_template
651 # It's just a plain template
652 $self->model_class(undef);
654 my $path = $self->path;
655 $path =~ s{/$}{}; # De-absolutify
658 $self->template($self->path);
661 # The model has been processed or skipped (if is_applicable returned false),
662 # any exceptions have been handled, and there's no content in $self->output
663 sub __call_process_view
669 eval { $status = $self->view_object->process($self) };
671 if ( my $error = $@ )
673 $status = $self->call_exception($error, "view");
677 warn "caught view error: $error" if $self->debug;
678 return $self->debug ?
679 $self->view_object->error($self, $error) : ERROR;
688 You should only need to define this method if you are writing a new
689 Maypole backend. It should return something that looks like an Apache
690 or CGI request object, it defaults to blank.
698 Turns the backend request (e.g. Apache::MVC, Maypole, CGI) into a Maypole
699 request. It does this by setting the C<path>, and invoking C<parse_path> and
702 You should only need to define this method if you are writing a new Maypole
709 die "parse_location is a virtual method. Do not use Maypole directly; " .
710 "use Apache::MVC or similar";
713 =item start_request_hook
715 This is called immediately after setting up the basic request. The default
718 The value of C<< $r->status >> is set to C<OK> before this hook is run. Your
719 implementation can change the status code, or leave it alone.
721 After this hook has run, Maypole will check the value of C<status>. For any
722 value other than C<OK>, Maypole returns the C<status> immediately.
724 This is useful for filtering out requests for static files, e.g. images, which
725 should not be processed by Maypole or by the templating engine:
727 sub start_request_hook
731 $r->status(DECLINED) if $r->path =~ /\.jpg$/;
734 Multiple plugins, and the driver, can define this hook - Maypole will call all
735 of them. You should check for and probably not change any non-OK C<status>
738 package Maypole::Plugin::MyApp::SkipFavicon;
740 sub start_request_hook
744 # check if a previous plugin has already DECLINED this request
745 # - probably unnecessary in this example, but you get the idea
746 return unless $r->status == OK;
749 $r->status(DECLINED) if $r->path =~ /favicon\.ico/;
754 sub start_request_hook { }
758 B<This method is deprecated> as of version 2.11. If you have overridden it,
759 please override C<is_model_applicable> instead, and change the return type
760 from a Maypole:Constant to a true/false value.
762 Returns a Maypole::Constant to indicate whether the request is valid.
766 sub is_applicable { return shift->is_model_applicable(@_); }
768 =item is_model_applicable
770 Returns true or false to indicate whether the request is valid.
772 The default implementation checks that C<< $r->table >> is publicly
773 accessible and that the model class is configured to handle the
778 sub is_model_applicable {
781 # Establish which tables should be processed by the model
782 my $config = $self->config;
784 $config->ok_tables || $config->ok_tables( $config->display_tables );
786 $config->ok_tables( { map { $_ => 1 } @{ $config->ok_tables } } )
787 if ref $config->ok_tables eq "ARRAY";
789 my $ok_tables = $config->ok_tables;
791 # Does this request concern a table to be processed by the model?
792 my $table = $self->table;
796 if (exists $ok_tables->{$table})
803 warn "We don't have that table ($table).\n"
804 . "Available tables are: "
805 . join( ",", keys %$ok_tables )
806 if $self->debug and not $ok_tables->{$table};
811 # Is the action public?
812 my $action = $self->action;
813 return OK if $self->model_class->is_public($action);
815 warn "The action '$action' is not applicable to the table '$table'"
823 Called immediately after C<start_request_hook()>.
825 This method should return a session, which will be stored in the request's
826 C<session> attribute.
828 The default method is empty.
836 Called immediately after C<get_session>.
838 This method should return a user, which will be stored in the request's C<user>
841 The default method is empty.
847 =item call_authenticate
849 This method first checks if the relevant model class
850 can authenticate the user, or falls back to the default
851 authenticate method of your Maypole application.
855 sub call_authenticate
859 # Check if we have a model class with an authenticate() to delegate to
860 return $self->model_class->authenticate($self)
861 if $self->model_class and $self->model_class->can('authenticate');
863 # Interface consistency is a Good Thing -
864 # the invocant and the argument may one day be different things
865 # (i.e. controller and request), like they are when authenticate()
866 # is called on a model class (i.e. model and request)
867 return $self->authenticate($self);
872 Returns a Maypole::Constant to indicate whether the user is authenticated for
875 The default implementation returns C<OK>
879 sub authenticate { return OK }
884 This model is called to catch exceptions, first after authenticate, then after
885 processing the model class, and finally to check for exceptions from the view
888 This method first checks if the relevant model class
889 can handle exceptions the user, or falls back to the default
890 exception method of your Maypole application.
896 my ($self, $error, $when) = @_;
898 # Check if we have a model class with an exception() to delegate to
899 if ( $self->model_class && $self->model_class->can('exception') )
901 my $status = $self->model_class->exception( $self, $error, $when );
902 return $status if $status == OK;
905 return $self->exception($error, $when);
911 This method is called if any exceptions are raised during the authentication or
912 model/view processing. It should accept the exception as a parameter and return
913 a Maypole::Constant to indicate whether the request should continue to be
919 my ($self, $error, $when) = @_;
920 if ($self->view_object->can("report_error") and $self->debug) {
921 $self->view_object->report_error($self, $error, $when);
927 =item additional_data
929 Called before the model processes the request, this method gives you a chance to
930 do some processing for each request, for example, manipulating C<template_args>.
934 sub additional_data { }
938 Sends the output and additional headers to the user.
943 die "send_output is a virtual method. Do not use Maypole directly; use Apache::MVC or similar";
951 =head2 Path processing and manipulation
957 Returns the request path
961 Parses the request path and sets the C<args>, C<action> and C<table>
962 properties. Calls C<preprocess_path> before parsing path and setting properties.
970 # Previous versions unconditionally set table, action and args to whatever
971 # was in @pi (or else to defaults, if @pi is empty).
972 # Adding preprocess_path(), and then setting table, action and args
973 # conditionally, broke lots of tests, hence this:
974 $self->$_(undef) for qw/action table args/;
976 $self->preprocess_path;
977 $self->path || $self->path('frontpage');
979 my @pi = grep {length} split '/', $self->path;
982 $self->table || $self->table(shift @pi);
983 $self->action || $self->action( shift @pi or 'index' );
984 $self->args || $self->args(\@pi);
987 =item preprocess_path
989 Sometimes when you don't want to rewrite or over-ride parse_path but
990 want to rewrite urls or extract data from them before it is parsed.
992 This method is called after parse_location has populated the request
993 information and before parse_path has populated the model and action
994 information, and is passed the request object.
996 You can set action, args or table in this method and parse_path will
997 then leave those values in place or populate them if not present
1001 sub preprocess_path { };
1003 =item make_path( %args or \%args or @args )
1005 This is the counterpart to C<parse_path>. It generates a path to use
1006 in links, form actions etc. To implement your own path scheme, just override
1007 this method and C<parse_path>.
1009 %args = ( table => $table,
1011 additional => $additional, # optional - generally an object ID
1014 \%args = as above, but a ref
1016 @args = ( $table, $action, $additional ); # $additional is optional
1018 C<id> can be used as an alternative key to C<additional>.
1020 C<$additional> can be a string, an arrayref, or a hashref. An arrayref is
1021 expanded into extra path elements, whereas a hashref is translated into a query
1032 if (@_ == 1 and ref $_[0] and ref $_[0] eq 'HASH')
1036 elsif ( @_ > 1 and @_ < 4 )
1038 $args{table} = shift;
1039 $args{action} = shift;
1040 $args{additional} = shift;
1047 do { die "no $_" unless $args{$_} } for qw( table action );
1049 my $additional = $args{additional} || $args{id};
1055 # if $additional is a href, make_uri() will transform it into a query
1056 @add = (ref $additional eq 'ARRAY') ? @$additional : ($additional);
1059 my $uri = $r->make_uri($args{table}, $args{action}, @add);
1061 return $uri->as_string;
1066 =item make_uri( @segments )
1068 Make a L<URI> object given table, action etc. Automatically adds
1071 If the final element in C<@segments> is a hash ref, C<make_uri> will render it
1078 my ($r, @segments) = @_;
1080 my $query = (ref $segments[-1] eq 'HASH') ? pop(@segments) : undef;
1082 my $base = $r->config->uri_base;
1085 my $uri = URI->new($base);
1086 $uri->path_segments($uri->path_segments, grep {length} @segments);
1088 my $abs_uri = $uri->abs('/');
1089 $abs_uri->query_form($query) if $query;
1095 Turns post data and query string paramaters into a hash of C<params>.
1097 You should only need to define this method if you are writing a new Maypole
1104 die "parse_args() is a virtual method. Do not use Maypole directly; ".
1105 "use Apache::MVC or similar";
1108 =item get_template_root
1110 Implementation-specific path to template root.
1112 You should only need to define this method if you are writing a new Maypole
1113 backend. Otherwise, see L<Maypole::Config/"template_root">
1119 =head2 Request properties
1125 Returns the perl package name that will serve as the model for the
1126 request. It corresponds to the request C<table> attribute.
1131 Get/set a list of model objects. The objects will be accessible in the view
1134 If the first item in C<$self-E<gt>args> can be C<retrieve()>d by the model
1135 class, it will be removed from C<args> and the retrieved object will be added to
1136 the C<objects> list. See L<Maypole::Model> for more information.
1140 $self->template_args->{foo} = 'bar';
1142 Get/set a hash of template variables.
1146 A place to put custom application data. Not used by Maypole itself.
1150 Get/set the template to be used by the view. By default, it returns
1151 C<$self-E<gt>action>
1156 Get/set a request error
1160 Get/set the response output. This is usually populated by the view class. You
1161 can skip view processing by setting the C<output>.
1165 The table part of the Maypole request path
1169 The action part of the Maypole request path
1173 A list of remaining parts of the request path after table and action
1179 A L<Maypole::Headers> object containing HTTP headers for the request
1183 A L<HTTP::Headers> object that contains HTTP headers for the output
1185 =item document_encoding
1187 Get/set the output encoding. Default: utf-8.
1191 Get/set the output content type. Default: text/html
1195 Returns the protocol the request was made with, i.e. https
1200 die "get_protocol is a virtual method. Do not use Maypole directly; use Apache::MVC or similar";
1205 =head2 Request parameters
1207 The source of the parameters may vary depending on the Maypole backend, but they
1208 are usually populated from request query string and POST data.
1210 Maypole supplies several approaches for accessing the request parameters. Note
1211 that the current implementation (via a hashref) of C<query> and C<params> is
1212 likely to change in a future version of Maypole. So avoid direct access to these
1215 $r->{params}->{foo} # bad
1216 $r->params->{foo} # better
1218 $r->{query}->{foo} # bad
1219 $r->query->{foo} # better
1221 $r->param('foo') # best
1227 An accessor (get or set) for request parameters. It behaves similarly to
1228 CGI::param() for accessing CGI parameters, i.e.
1230 $r->param # returns list of keys
1231 $r->param($key) # returns value for $key
1232 $r->param($key => $value) # returns old value, sets to new value
1238 my ($self, $key) = (shift, shift);
1240 return keys %{$self->params} unless defined $key;
1242 return unless exists $self->params->{$key};
1244 my $val = $self->params->{$key};
1248 my $new_val = shift;
1249 $self->params->{$key} = $new_val;
1252 return ref $val ? @$val : ($val) if wantarray;
1254 return ref $val ? $val->[0] : $val;
1260 Returns a hashref of request parameters.
1262 B<Note:> Where muliple values of a parameter were supplied, the C<params> value
1263 will be an array reference.
1267 Alias for C<params>.
1271 =head3 Utility methods
1275 =item redirect_request
1277 Sets output headers to redirect based on the arguments provided
1279 Accepts either a single argument of the full url to redirect to, or a hash of
1282 $r->redirect_request('http://www.example.com/path');
1286 $r->redirect_request(protocol=>'https', domain=>'www.example.com', path=>'/path/file?arguments', status=>'302', url=>'..');
1288 The named parameters are protocol, domain, path, status and url
1290 Only 1 named parameter is required but other than url, they can be combined as
1291 required and current values (from the request) will be used in place of any
1292 missing arguments. The url argument must be a full url including protocol and
1293 can only be combined with status.
1297 sub redirect_request {
1298 die "redirect_request is a virtual method. Do not use Maypole directly; use Apache::MVC or similar";
1301 =item redirect_internal_request
1305 sub redirect_internal_request {
1310 =item make_random_id
1312 returns a unique id for this request can be used to prevent or detect repeat
1317 # Session and Repeat Submission Handling
1318 sub make_random_id {
1319 use Maypole::Session;
1320 return Maypole::Session::generate_unique_id();
1325 =head1 SEQUENCE DIAGRAMS
1327 See L<Maypole::Manual::Workflow> for a detailed discussion of the sequence of
1328 calls during processing of a request. This is a brief summary:
1332 BeerDB Maypole::Model::CDBI
1336 || setup_model | setup_database() creates
1337 ||------+ | a subclass of the Model
1338 |||<----+ | for each table
1340 ||| setup_database | |
1341 |||--------------------->|| 'create' *
1342 ||| ||----------> $subclass
1344 ||| load_model_subclass | |
1345 foreach |||------+ ($subclass) | |
1346 $subclass ||||<----+ | require |
1347 ||||--------------------------------------->|
1349 ||| adopt($subclass) | |
1350 |||--------------------->|| |
1355 || | new | view_object: e.g.
1356 ||---------------------------------------------> Maypole::View::TT
1368 BeerDB Model $subclass view_object
1371 o-------->| new | | |
1372 |-----> r:BeerDB | | |
1376 | ||-----+ parse_location | | |
1379 | ||-----+ start_request_hook | | |
1382 | ||-----+ get_session | | |
1385 | ||-----+ get_user | | |
1388 | ||-----+ handler_guts | | |
1390 | ||| class_of($table) | | |
1391 | |||------------------------->|| | |
1392 | ||| $subclass || | |
1393 | |||<-------------------------|| | |
1395 | |||-----+ is_model_applicable| | |
1398 | |||-----+ call_authenticate | | |
1401 | |||-----+ additional_data | | |
1404 | |||--------------------------------->|| fetch_objects
1412 | |||------------------------------------------->|| template
1416 | || send_output | | |
1420 <------------------|| | | |
1431 There's more documentation, examples, and information on our mailing lists
1432 at the Maypole web site:
1434 L<http://maypole.perl.org/>
1436 L<Maypole::Application>, L<Apache::MVC>, L<CGI::Maypole>.
1440 Maypole is currently maintained by Aaron Trevena, David Baird, Dave Howorth and
1443 =head1 AUTHOR EMERITUS
1445 Simon Cozens, C<simon#cpan.org>
1447 Simon Flack maintained Maypole from 2.05 to 2.09
1449 Sebastian Riedel, C<sri#oook.de> maintained Maypole from 1.99_01 to 2.04
1453 Sebastian Riedel, Danijel Milicevic, Dave Slack, Jesse Sheidlower, Jody Belka,
1454 Marcus Ramberg, Mickael Joanne, Randal Schwartz, Simon Flack, Steve Simms,
1455 Veljko Vidovic and all the others who've helped.
1459 You may distribute this code under the same terms as Perl itself.
1467 =item register_cleanup($coderef)
1469 Analogous to L<Apache>'s C<register_cleanup>. If an Apache request object is
1470 available, this call simply redispatches there. If not, the cleanup is
1471 registered in the Maypole request, and executed when the request is
1474 This method is only useful in persistent environments, where you need to ensure
1475 that some code runs when the request finishes, no matter how it finishes (e.g.
1476 after an unexpected error).
1483 sub register_cleanup
1485 my ($self, $cleanup) = @_;
1487 die "register_cleanup() is an instance method, not a class method"
1489 die "Cleanup must be a coderef" unless ref($cleanup) eq 'CODE';
1491 if ($self->can('ar') && $self->ar)
1493 $self->ar->register_cleanup($cleanup);
1497 push @_cleanups, $cleanup;
1505 while (my $cleanup = shift @_cleanups)
1507 eval { $cleanup->() };
1510 warn "Error during request cleanup: $@";