2 use base qw(Class::Accessor::Fast Class::Data::Inheritable);
3 use UNIVERSAL::require;
8 use Maypole::Constants;
13 use File::MMagic::XS qw(:compat);
15 our $VERSION = '2.11';
16 our $mmagic = File::MMagic::XS->new();
18 # proposed privacy conventions:
19 # - no leading underscore - public to custom application code and plugins
20 # - single leading underscore - private to the main Maypole stack - *not*
22 # - double leading underscore - private to the current package
26 Maypole - MVC web application framework
30 The canonical example used in the Maypole documentation is the beer database:
36 # choose a frontend, initialise the config object, and load a plugin
37 use Maypole::Application qw/Relationship/;
39 # get the empty config object created by Maypole::Application
40 my $config = __PACKAGE__->config;
43 $config->uri_base("http://localhost/beerdb");
44 $config->template_root("/path/to/templates");
45 $config->rows_per_page(10);
46 $config->display_tables([qw/beer brewery pub style/]);
49 $config->relationships([
50 "a brewery produces beers",
51 "a style defines beers",
52 "a pub has beers on handpumps",
56 BeerDB::Brewery->untaint_columns( printable => [qw/name notes url/] );
57 BeerDB::Pub->untaint_columns( printable => [qw/name notes url/] );
58 BeerDB::Style->untaint_columns( printable => [qw/name notes/] );
59 BeerDB::Beer->untaint_columns(
60 printable => [qw/abv name price notes/],
61 integer => [qw/style brewery score/],
66 __PACKAGE__->setup("dbi:SQLite:t/beerdb.db");
72 This documents the Maypole request object. See the L<Maypole::Manual>, for a
73 detailed guide to using Maypole.
75 Maypole is a Perl web application framework similar to Java's struts. It is
76 essentially completely abstracted, and so doesn't know anything about
77 how to talk to the outside world.
79 To use it, you need to create a driver package which represents your entire
80 application. This is the C<BeerDB> package used as an example in the manual.
82 This needs to first use L<Maypole::Application> which will make your package
83 inherit from the appropriate platform driver such as C<Apache::MVC> or
84 C<CGI::Maypole>. Then, the driver calls C<setup>. This sets up the model classes
85 and configures your application. The default model class for Maypole uses
86 L<Class::DBI> to map a database to classes, but this can be changed by altering
87 configuration (B<before> calling setup.)
90 =head1 DOCUMENTATION AND SUPPORT
92 Note that some details in some of these resources may be out of date.
96 =item The Maypole Manual
98 The primary documentation is the Maypole manual. This lives in the
99 C<Maypole::Manual> pod documents included with the distribution.
103 Individual packages within the distribution contain (more or less) detailed
104 reference documentation for their API.
108 There are two mailing lists - maypole-devel and maypole-users - see
109 http://maypole.perl.org/?MailingList
111 =item The Maypole Wiki
113 The Maypole wiki provides a useful store of extra documentation -
114 http://maypole.perl.org
116 In particular, there's a FAQ (http://maypole.perl.org/?FAQ) and a cookbook
117 (http://maypole.perl.org/?Cookbook). Again, certain information on these pages
120 =item Web applications with Maypole
122 A tutorial written by Simon Cozens for YAPC::EU 2005 -
123 http://www.droogs.org/perl/maypole/maypole-tutorial.pdf [228KB].
125 =item A Database-Driven Web Application in 18 Lines of Code
127 By Paul Barry, published in Linux Journal, March 2005.
129 http://www.linuxjournal.com/article/7937
131 "From zero to Web-based database application in eight easy steps".
133 Maypole won a 2005 Linux Journal Editor's Choice Award
134 (http://www.linuxjournal.com/article/8293) after featuring in this article.
136 =item Build Web apps with Maypole
138 By Simon Cozens, on IBM's DeveloperWorks website, May 2004.
140 http://www-128.ibm.com/developerworks/linux/library/l-maypole/
142 =item Rapid Web Application Deployment with Maypole
144 By Simon Cozens, on O'Reilly's Perl website, April 2004.
146 http://www.perl.com/pub/a/2004/04/15/maypole.html
150 Some notes written by Simon Cozens. A little bit out of date, but still
151 very useful: http://www.droogs.org/perl/maypole/authentication.html
155 There's a refcard for the Maypole (and Class::DBI) APIs on the wiki -
156 http://maypole.perl.org/?CheatSheet. Probably a little out of date now - it's a
157 wiki, so feel free to fix any errors!
159 =item Plugins and add-ons
161 There are a large and growing number of plugins and other add-on modules
162 available on CPAN - http://search.cpan.org/search?query=maypole&mode=module
166 You can find a range of useful Maypole links, particularly to several thoughtful
167 blog entries, starting here: http://del.icio.us/search/?all=maypole
171 There are a couple of short reviews here:
172 http://cpanratings.perl.org/dist/Maypole
178 A couple of demos are available, sometimes with source code and configs.
182 =item http://maypole.perl.org/beerdb/
184 The standard BeerDB example, using the TT factory templates supplied in the
187 =item beerdb.riverside-cms.co.uk
189 The standard BeerDB example, running on Mason, using the factory templates
190 supplied in the L<MasonX::Maypole> distribution.
192 =item beerfb.riverside-cms.co.uk
194 A demo of L<Maypole::FormBuilder>. This site is running on the set of Mason
195 templates included in the L<Maypole::FormBuilder> distribution. See the
196 synopsis of L<Maypole::Plugin::FormBuilder> for an example driver
202 __PACKAGE__->mk_classdata($_) for qw( config init_done view_object model_classes_loaded);
204 __PACKAGE__->mk_accessors(
205 qw( params query objects model_class template_args output path
206 args action template error document_encoding content_type table
207 headers_in headers_out stash status parent)
210 __PACKAGE__->config( Maypole::Config->new() );
212 __PACKAGE__->init_done(0);
214 __PACKAGE__->model_classes_loaded(0);
216 =head1 HOOKABLE METHODS
218 As a framework, Maypole provides a number of B<hooks> - methods that are
219 intended to be overridden. Some of these methods come with useful default
220 behaviour, others do nothing by default. Hooks include:
246 sub My::App::debug {1}
248 Returns the debugging flag. Override this in your application class to
249 enable/disable debugging.
251 You can also set the C<debug> flag via L<Maypole::Application>.
253 Some packages respond to higher debug levels, try increasing it to 2 or 3.
262 Returns the L<Maypole::Config> object
266 My::App->setup($data_source, $user, $password, \%attr);
268 Initialise the Maypole application and plugins and model classes.
269 Your application should call this B<after> setting up configuration data via
272 It calls the hook C<setup_model> to setup the model. The %attr hash contains
273 options and arguments used to set up the model. See the particular model's
274 documentation. However here is the most usage of setup where
275 Maypole::Model::CDBI is the base class.
277 My::App->setup($data_source, $user, $password,
278 { options => { # These are DB connection options
283 # These are Class::DBI::Loader arguments.
289 Also, see L<Maypole::Manual::Plugins>.
298 $class->setup_model(@_);
303 Called by C<setup>. This method builds the Maypole model hierarchy.
305 A likely target for over-riding, if you need to build a customised model.
307 This method also ensures any code in custom model classes is loaded, so you
308 don't need to load them in the driver.
314 $class = ref $class if ref $class;
315 my $config = $class->config;
316 $config->model || $config->model('Maypole::Model::CDBI');
317 $config->model->require or die sprintf
318 "Couldn't load the model class %s: %s", $config->model, $@;
320 # among other things, this populates $config->classes
321 $config->model->setup_database($config, $class, @_);
323 foreach my $subclass ( @{ $config->classes } ) {
324 next if $subclass->isa("Maypole::Model::Base");
326 unshift @{ $subclass . "::ISA" }, $config->model;
329 # Load custom model code, if it exists - nb this must happen after the
330 # unshift, to allow code attributes to work, but before adopt(),
331 # in case adopt() calls overridden methods on $subclass
332 foreach my $subclass ( @{ $config->classes } ) {
333 $class->load_model_subclass($subclass) unless ($class->model_classes_loaded());
334 $config->model->adopt($subclass) if $config->model->can("adopt");
339 =item load_model_subclass($subclass)
341 This method is called from C<setup_model()>. It attempts to load the
342 C<$subclass> package, if one exists. So if you make a customized C<BeerDB::Beer>
343 package, you don't need to explicitly load it.
345 If automatic loading causes problems, Override load_model_subclass in your driver.
347 sub load_model_subclass {};
349 Or perhaps during development, if you don't want to load up custom classes, you
350 can override this method and load them manually.
354 sub load_model_subclass {
355 my ($class, $subclass) = @_;
357 my $config = $class->config;
359 # Load any external files for the model base class or subclasses
360 # (e.g. BeerDB/DBI.pm or BeerDB/Beer.pm) based on code borrowed from
361 # Maypole::Plugin::Loader and Class::DBI.
362 if ( $subclass->require ) {
363 warn "Loaded external module for '$subclass'\n" if $class->debug > 1;
365 (my $filename = $subclass) =~ s!::!/!g;
366 die "Loading '$subclass' failed: $@\n"
367 unless $@ =~ /Can\'t locate \Q$filename\E\.pm/;
368 warn "No external module for '$subclass'"
369 if $class->debug > 1;
375 Loads the view class and instantiates the view object.
377 You should not call this directly, but you may wish to override this to add
378 application-specific initialisation - see L<Maypole::Manual::Plugins>.
385 my $config = $class->config;
386 $config->view || $config->view("Maypole::View::TT");
387 $config->view->require;
388 die "Couldn't load the view class " . $config->view . ": $@" if $@;
389 $config->display_tables
390 || $config->display_tables( $class->config->tables );
391 $class->view_object( $class->config->view->new );
392 $class->init_done(1);
397 Constructs a very minimal new Maypole request object.
405 config => $class->config,
411 $self->template_args({});
420 Get/set the Maypole::View object
424 =head1 INSTANCE METHODS
432 This method sets up the class if it's not done yet, sets some defaults and
433 leaves the dirty work to C<handler_guts>.
437 # handler() has a method attribute so that mod_perl will invoke
438 # BeerDB->handler() as a method rather than a plain function
439 # BeerDB::handler() and so this inherited implementation will be
440 # found. See e.g. "Practical mod_perl" by Bekman & Cholet for
441 # more information <http://modperlbook.org/html/ch25_01.html>
442 sub handler : method {
443 # See Maypole::Workflow before trying to understand this.
444 my ($class, $req) = @_;
446 $class->init unless $class->init_done;
448 my $self = $class->new;
450 # initialise the request
451 $self->headers_out(Maypole::Headers->new);
452 $self->get_request($req);
454 $self->parse_location;
456 # hook useful for declining static requests e.g. images, or perhaps for
457 # sanitizing request parameters
458 $self->status(Maypole::Constants::OK()); # set the default
459 $self->__call_hook('start_request_hook');
460 return $self->status unless $self->status == Maypole::Constants::OK();
461 die "status undefined after start_request_hook()" unless defined
465 my $status = $self->handler_guts;
466 return $status unless $status == OK;
467 # TODO: require send_output to return a status code
474 Run Maypole sub-requests as a component of the request
476 [% request.component("/beer/view_as_component/20") %]
478 Allows you to integrate the results of a Maypole request into an existing
479 request. You'll need to set up actions and templates
480 which return fragments of HTML rather than entire pages, but once you've
481 done that, you can use the C<component> method of the Maypole request object
482 to call those actions. You may pass a query string in the usual URL style.
484 You should not fully qualify the Maypole URLs.
486 Note: any HTTP POST or URL parameters passed to the parent are not passed to the
487 component sub-request, only what is included in the url passed as an argyument
493 my ( $r, $path ) = @_;
494 my $self = bless { parent => $r, config => $r->{config}, } , ref $r;
498 $self->template_args({});
503 my $url = URI->new($path);
504 warn "path : $path\n";
505 $self->{path} = $url->path;
507 $self->params( $url->query_form_hash );
509 return $self->output;
512 sub get_template_root {
515 return $r->parent->get_template_root if $r->{parent};
516 return $self->NEXT::DISTINCT::get_template_root( $r, @_ );
522 return $r->parent->view_object if $r->{parent};
523 return $self->NEXT::DISTINCT::view_object( $r, @_ );
526 # Instead of making plugin authors use the NEXT::DISTINCT hoopla to ensure other
527 # plugins also get to call the hook, we can cycle through the application's
528 # @ISA and call them all here. Doesn't work for setup() though, because it's
529 # too ingrained in the stack. We could add a run_setup() method, but we'd break
530 # lots of existing code.
533 my ($self, $hook) = @_;
537 my $class = ref($self);
539 @plugins = @{"$class\::ISA"};
542 # this is either a custom method in the driver, or the method in the 1st
543 # plugin, or the 'null' method in the frontend (i.e. inherited from
544 # Maypole.pm) - we need to be careful to only call it once
545 my $first_hook = $self->can($hook);
548 my %seen = ( $first_hook => 1 );
550 # @plugins includes the frontend
551 foreach my $plugin (@plugins)
553 next unless my $plugin_hook = $plugin->can($hook);
554 next if $seen{$plugin_hook}++;
561 This is the main request handling method and calls various methods to handle the
562 request/response and defines the workflow within Maypole.
564 B<Currently undocumented and liable to be refactored without warning>.
568 # The root of all evil
573 $self->__load_request_model;
575 my $applicable = $self->is_model_applicable == OK;
579 # handle authentication
580 eval { $status = $self->call_authenticate };
581 if ( my $error = $@ )
583 $status = $self->call_exception($error, "authentication");
586 warn "caught authenticate error: $error";
587 return $self->debug ?
588 $self->view_object->error($self, $error) : ERROR;
591 if ( $self->debug and $status != OK and $status != DECLINED )
593 $self->view_object->error( $self,
594 "Got unexpected status $status from calling authentication" );
597 return $status unless $status == OK;
599 # We run additional_data for every request
600 $self->additional_data;
603 eval { $self->model_class->process($self) };
604 if ( my $error = $@ )
606 $status = $self->call_exception($error, "model");
609 warn "caught model error: $error";
610 return $self->debug ?
611 $self->view_object->error($self, $error) : ERROR;
615 $self->__setup_plain_template;
618 # less frequent path - perhaps output has been set to an error message
619 return OK if $self->output;
621 # normal path - no output has been generated yet
622 my $processed_view_ok = $self->__call_process_view;
624 $self->{content_type} ||= $self->__get_mime_type();
625 $self->{document_encoding} ||= "utf-8";
628 return $processed_view_ok;
632 'js' => 'text/javascript',
634 'htm' => 'text/html',
635 'html' => 'text/html',
638 sub __get_mime_type {
640 my $type = 'text/html';
641 if ($self->path =~ m/.*\.(\w{3,4})$/) {
642 $type = $filetypes{$1};
644 my $output = $self->output;
645 if (defined $output) {
646 $type = $mmagic->checktype_contents($output);
652 sub __load_request_model
655 # We may get a made up class from class_of
656 my $mclass = $self->config->model->class_of($self, $self->table);
657 if ( eval {$mclass->isa('Maypole::Model::Base')} ) {
658 $self->model_class( $mclass );
660 elsif ($self->debug) {
661 warn "\n***Warning: No $mclass class appropriate to set as request model : $@***\n"
666 # is_applicable() returned false, so set up a plain template. Model processing
667 # will be skipped, but need to remove the model anyway so the template can't
669 sub __setup_plain_template
673 # It's just a plain template
674 $self->model_class(undef);
676 my $path = $self->path;
677 $path =~ s{/$}{}; # De-absolutify
680 $self->template($self->path);
683 # The model has been processed or skipped (if is_applicable returned false),
684 # any exceptions have been handled, and there's no content in $self->output
685 sub __call_process_view {
688 my $status = eval { $self->view_object->process($self) };
690 my $error = $@ || $self->{error};
693 $status = $self->call_exception($error, "view");
695 if ( $status != OK ) {
696 warn "caught view error: $error" if $self->debug;
697 return $self->debug ?
698 $self->view_object->error($self, $error) : ERROR;
707 You should only need to define this method if you are writing a new
708 Maypole backend. It should return something that looks like an Apache
709 or CGI request object, it defaults to blank.
717 Turns the backend request (e.g. Apache::MVC, Maypole, CGI) into a Maypole
718 request. It does this by setting the C<path>, and invoking C<parse_path> and
721 You should only need to define this method if you are writing a new Maypole
728 die "parse_location is a virtual method. Do not use Maypole directly; " .
729 "use Apache::MVC or similar";
732 =item start_request_hook
734 This is called immediately after setting up the basic request. The default
737 The value of C<< $r->status >> is set to C<OK> before this hook is run. Your
738 implementation can change the status code, or leave it alone.
740 After this hook has run, Maypole will check the value of C<status>. For any
741 value other than C<OK>, Maypole returns the C<status> immediately.
743 This is useful for filtering out requests for static files, e.g. images, which
744 should not be processed by Maypole or by the templating engine:
746 sub start_request_hook
750 $r->status(DECLINED) if $r->path =~ /\.jpg$/;
753 Multiple plugins, and the driver, can define this hook - Maypole will call all
754 of them. You should check for and probably not change any non-OK C<status>
757 package Maypole::Plugin::MyApp::SkipFavicon;
759 sub start_request_hook
763 # check if a previous plugin has already DECLINED this request
764 # - probably unnecessary in this example, but you get the idea
765 return unless $r->status == OK;
768 $r->status(DECLINED) if $r->path =~ /favicon\.ico/;
773 sub start_request_hook { }
777 B<This method is deprecated> as of version 2.11. If you have overridden it,
778 please override C<is_model_applicable> instead, and change the return type
779 from a Maypole:Constant to a true/false value.
781 Returns a Maypole::Constant to indicate whether the request is valid.
785 sub is_applicable { return shift->is_model_applicable(@_); }
787 =item is_model_applicable
789 Returns true or false to indicate whether the request is valid.
791 The default implementation checks that C<< $r->table >> is publicly
792 accessible and that the model class is configured to handle the
797 sub is_model_applicable {
800 # Establish which tables should be processed by the model
801 my $config = $self->config;
803 $config->ok_tables || $config->ok_tables( $config->display_tables );
805 $config->ok_tables( { map { $_ => 1 } @{ $config->ok_tables } } )
806 if ref $config->ok_tables eq "ARRAY";
808 my $ok_tables = $config->ok_tables;
810 # Does this request concern a table to be processed by the model?
811 my $table = $self->table;
815 if (exists $ok_tables->{$table})
822 warn "We don't have that table ($table).\n"
823 . "Available tables are: "
824 . join( ",", keys %$ok_tables )
825 if $self->debug and not $ok_tables->{$table};
830 # Is the action public?
831 my $action = $self->action;
832 return OK if $self->model_class->is_public($action);
834 warn "The action '$action' is not applicable to the table '$table'"
842 Called immediately after C<start_request_hook()>.
844 This method should return a session, which will be stored in the request's
845 C<session> attribute.
847 The default method is empty.
855 Called immediately after C<get_session>.
857 This method should return a user, which will be stored in the request's C<user>
860 The default method is empty.
866 =item call_authenticate
868 This method first checks if the relevant model class
869 can authenticate the user, or falls back to the default
870 authenticate method of your Maypole application.
874 sub call_authenticate
878 # Check if we have a model class with an authenticate() to delegate to
879 return $self->model_class->authenticate($self)
880 if $self->model_class and $self->model_class->can('authenticate');
882 # Interface consistency is a Good Thing -
883 # the invocant and the argument may one day be different things
884 # (i.e. controller and request), like they are when authenticate()
885 # is called on a model class (i.e. model and request)
886 return $self->authenticate($self);
891 Returns a Maypole::Constant to indicate whether the user is authenticated for
894 The default implementation returns C<OK>
898 sub authenticate { return OK }
903 This model is called to catch exceptions, first after authenticate, then after
904 processing the model class, and finally to check for exceptions from the view
907 This method first checks if the relevant model class
908 can handle exceptions the user, or falls back to the default
909 exception method of your Maypole application.
915 my ($self, $error, $when) = @_;
917 # Check if we have a model class with an exception() to delegate to
918 if ( $self->model_class && $self->model_class->can('exception') )
920 my $status = $self->model_class->exception( $self, $error, $when );
921 return $status if $status == OK;
924 return $self->exception($error, $when);
930 This method is called if any exceptions are raised during the authentication or
931 model/view processing. It should accept the exception as a parameter and return
932 a Maypole::Constant to indicate whether the request should continue to be
938 my ($self, $error, $when) = @_;
939 if (ref $self->view_object && $self->view_object->can("report_error") and $self->debug) {
940 $self->view_object->report_error($self, $error, $when);
946 =item additional_data
948 Called before the model processes the request, this method gives you a chance to
949 do some processing for each request, for example, manipulating C<template_args>.
953 sub additional_data { }
957 Sends the output and additional headers to the user.
962 die "send_output is a virtual method. Do not use Maypole directly; use Apache::MVC or similar";
968 =head2 Path processing and manipulation
974 Returns the request path
978 Parses the request path and sets the C<args>, C<action> and C<table>
979 properties. Calls C<preprocess_path> before parsing path and setting properties.
987 # Previous versions unconditionally set table, action and args to whatever
988 # was in @pi (or else to defaults, if @pi is empty).
989 # Adding preprocess_path(), and then setting table, action and args
990 # conditionally, broke lots of tests, hence this:
991 $self->$_(undef) for qw/action table args/;
993 $self->preprocess_path;
994 $self->path || $self->path('frontpage');
996 my @pi = grep {length} split '/', $self->path;
999 $self->table || $self->table(shift @pi);
1000 $self->action || $self->action( shift @pi or 'index' );
1001 $self->args || $self->args(\@pi);
1004 =item preprocess_path
1006 Sometimes when you don't want to rewrite or over-ride parse_path but
1007 want to rewrite urls or extract data from them before it is parsed.
1009 This method is called after parse_location has populated the request
1010 information and before parse_path has populated the model and action
1011 information, and is passed the request object.
1013 You can set action, args or table in this method and parse_path will
1014 then leave those values in place or populate them if not present
1018 sub preprocess_path { };
1020 =item make_path( %args or \%args or @args )
1022 This is the counterpart to C<parse_path>. It generates a path to use
1023 in links, form actions etc. To implement your own path scheme, just override
1024 this method and C<parse_path>.
1026 %args = ( table => $table,
1028 additional => $additional, # optional - generally an object ID
1031 \%args = as above, but a ref
1033 @args = ( $table, $action, $additional ); # $additional is optional
1035 C<id> can be used as an alternative key to C<additional>.
1037 C<$additional> can be a string, an arrayref, or a hashref. An arrayref is
1038 expanded into extra path elements, whereas a hashref is translated into a query
1049 if (@_ == 1 and ref $_[0] and ref $_[0] eq 'HASH')
1053 elsif ( @_ > 1 and @_ < 4 )
1055 $args{table} = shift;
1056 $args{action} = shift;
1057 $args{additional} = shift;
1064 do { die "no $_" unless $args{$_} } for qw( table action );
1066 my $additional = $args{additional} || $args{id};
1072 # if $additional is a href, make_uri() will transform it into a query
1073 @add = (ref $additional eq 'ARRAY') ? @$additional : ($additional);
1076 my $uri = $r->make_uri($args{table}, $args{action}, @add);
1078 return $uri->as_string;
1083 =item make_uri( @segments )
1085 Make a L<URI> object given table, action etc. Automatically adds
1088 If the final element in C<@segments> is a hash ref, C<make_uri> will render it
1095 my ($r, @segments) = @_;
1097 my $query = (ref $segments[-1] eq 'HASH') ? pop(@segments) : undef;
1099 my $base = $r->config->uri_base;
1102 my $uri = URI->new($base);
1103 $uri->path_segments($uri->path_segments, grep {length} @segments);
1105 my $abs_uri = $uri->abs('/');
1106 $abs_uri->query_form($query) if $query;
1112 Turns post data and query string paramaters into a hash of C<params>.
1114 You should only need to define this method if you are writing a new Maypole
1121 die "parse_args() is a virtual method. Do not use Maypole directly; ".
1122 "use Apache::MVC or similar";
1125 =item get_template_root
1127 Implementation-specific path to template root.
1129 You should only need to define this method if you are writing a new Maypole
1130 backend. Otherwise, see L<Maypole::Config/"template_root">
1136 =head2 Request properties
1142 Returns the perl package name that will serve as the model for the
1143 request. It corresponds to the request C<table> attribute.
1148 Get/set a list of model objects. The objects will be accessible in the view
1151 If the first item in C<$self-E<gt>args> can be C<retrieve()>d by the model
1152 class, it will be removed from C<args> and the retrieved object will be added to
1153 the C<objects> list. See L<Maypole::Model> for more information.
1158 Alias to get/set the first/only model object. The object will be accessible
1159 in the view templates.
1161 When used to set the object, will overwrite the request objects
1162 with a single object.
1167 my ($r,$object) = @_;
1168 $r->objects([$object]) if ($object);
1169 return undef unless $r->objects();
1170 return $r->objects->[0];
1175 $self->template_args->{foo} = 'bar';
1177 Get/set a hash of template variables.
1181 A place to put custom application data. Not used by Maypole itself.
1185 Get/set the template to be used by the view. By default, it returns
1186 C<$self-E<gt>action>
1191 Get/set a request error
1195 Get/set the response output. This is usually populated by the view class. You
1196 can skip view processing by setting the C<output>.
1200 The table part of the Maypole request path
1204 The action part of the Maypole request path
1208 A list of remaining parts of the request path after table and action
1214 A L<Maypole::Headers> object containing HTTP headers for the request
1218 A L<HTTP::Headers> object that contains HTTP headers for the output
1220 =item document_encoding
1222 Get/set the output encoding. Default: utf-8.
1226 Get/set the output content type. Default: text/html
1230 Returns the protocol the request was made with, i.e. https
1235 die "get_protocol is a virtual method. Do not use Maypole directly; use Apache::MVC or similar";
1240 =head2 Request parameters
1242 The source of the parameters may vary depending on the Maypole backend, but they
1243 are usually populated from request query string and POST data.
1245 Maypole supplies several approaches for accessing the request parameters. Note
1246 that the current implementation (via a hashref) of C<query> and C<params> is
1247 likely to change in a future version of Maypole. So avoid direct access to these
1250 $r->{params}->{foo} # bad
1251 $r->params->{foo} # better
1253 $r->{query}->{foo} # bad
1254 $r->query->{foo} # better
1256 $r->param('foo') # best
1262 An accessor (get or set) for request parameters. It behaves similarly to
1263 CGI::param() for accessing CGI parameters, i.e.
1265 $r->param # returns list of keys
1266 $r->param($key) # returns value for $key
1267 $r->param($key => $value) # returns old value, sets to new value
1273 my ($self, $key) = (shift, shift);
1275 return keys %{$self->params} unless defined $key;
1277 return unless exists $self->params->{$key};
1279 my $val = $self->params->{$key};
1283 my $new_val = shift;
1284 $self->params->{$key} = $new_val;
1287 return ref $val ? @$val : ($val) if wantarray;
1289 return ref $val ? $val->[0] : $val;
1295 Returns a hashref of request parameters.
1297 B<Note:> Where muliple values of a parameter were supplied, the C<params> value
1298 will be an array reference.
1302 Alias for C<params>.
1306 =head3 Utility methods
1310 =item redirect_request
1312 Sets output headers to redirect based on the arguments provided
1314 Accepts either a single argument of the full url to redirect to, or a hash of
1317 $r->redirect_request('http://www.example.com/path');
1321 $r->redirect_request(protocol=>'https', domain=>'www.example.com', path=>'/path/file?arguments', status=>'302', url=>'..');
1323 The named parameters are protocol, domain, path, status and url
1325 Only 1 named parameter is required but other than url, they can be combined as
1326 required and current values (from the request) will be used in place of any
1327 missing arguments. The url argument must be a full url including protocol and
1328 can only be combined with status.
1332 sub redirect_request {
1333 die "redirect_request is a virtual method. Do not use Maypole directly; use Apache::MVC or similar";
1336 =item redirect_internal_request
1340 sub redirect_internal_request {
1345 =item make_random_id
1347 returns a unique id for this request can be used to prevent or detect repeat
1352 # Session and Repeat Submission Handling
1353 sub make_random_id {
1354 use Maypole::Session;
1355 return Maypole::Session::generate_unique_id();
1360 =head1 SEQUENCE DIAGRAMS
1362 See L<Maypole::Manual::Workflow> for a detailed discussion of the sequence of
1363 calls during processing of a request. This is a brief summary:
1367 BeerDB Maypole::Model::CDBI
1371 || setup_model | setup_database() creates
1372 ||------+ | a subclass of the Model
1373 |||<----+ | for each table
1375 ||| setup_database | |
1376 |||--------------------->|| 'create' *
1377 ||| ||----------> $subclass
1379 ||| load_model_subclass | |
1380 foreach |||------+ ($subclass) | |
1381 $subclass ||||<----+ | require |
1382 ||||--------------------------------------->|
1384 ||| adopt($subclass) | |
1385 |||--------------------->|| |
1390 || | new | view_object: e.g.
1391 ||---------------------------------------------> Maypole::View::TT
1403 BeerDB Model $subclass view_object
1406 o-------->| new | | |
1407 |-----> r:BeerDB | | |
1411 | ||-----+ parse_location | | |
1414 | ||-----+ start_request_hook | | |
1417 | ||-----+ get_session | | |
1420 | ||-----+ get_user | | |
1423 | ||-----+ handler_guts | | |
1425 | ||| class_of($table) | | |
1426 | |||------------------------->|| | |
1427 | ||| $subclass || | |
1428 | |||<-------------------------|| | |
1430 | |||-----+ is_model_applicable| | |
1433 | |||-----+ call_authenticate | | |
1436 | |||-----+ additional_data | | |
1439 | |||--------------------------------->|| fetch_objects
1447 | |||------------------------------------------->|| template
1451 | || send_output | | |
1455 <------------------|| | | |
1466 There's more documentation, examples, and information on our mailing lists
1467 at the Maypole web site:
1469 L<http://maypole.perl.org/>
1471 L<Maypole::Application>, L<Apache::MVC>, L<CGI::Maypole>.
1475 Maypole is currently maintained by Aaron Trevena.
1477 =head1 AUTHOR EMERITUS
1479 Simon Cozens, C<simon#cpan.org>
1481 Simon Flack maintained Maypole from 2.05 to 2.09
1483 Sebastian Riedel, C<sri#oook.de> maintained Maypole from 1.99_01 to 2.04
1487 Sebastian Riedel, Danijel Milicevic, Dave Slack, Jesse Sheidlower, Jody Belka,
1488 Marcus Ramberg, Mickael Joanne, Randal Schwartz, Simon Flack, Steve Simms,
1489 Veljko Vidovic and all the others who've helped.
1493 You may distribute this code under the same terms as Perl itself.
1501 =item register_cleanup($coderef)
1503 Analogous to L<Apache>'s C<register_cleanup>. If an Apache request object is
1504 available, this call simply redispatches there. If not, the cleanup is
1505 registered in the Maypole request, and executed when the request is
1508 This method is only useful in persistent environments, where you need to ensure
1509 that some code runs when the request finishes, no matter how it finishes (e.g.
1510 after an unexpected error).
1517 sub register_cleanup
1519 my ($self, $cleanup) = @_;
1521 die "register_cleanup() is an instance method, not a class method"
1523 die "Cleanup must be a coderef" unless ref($cleanup) eq 'CODE';
1525 if ($self->can('ar') && $self->ar)
1527 $self->ar->register_cleanup($cleanup);
1531 push @_cleanups, $cleanup;
1539 while (my $cleanup = shift @_cleanups)
1541 eval { $cleanup->() };
1544 warn "Error during request cleanup: $@";