3 use base qw(Class::Accessor::Fast Class::Data::Inheritable);
4 use UNIVERSAL::require;
9 use Maypole::Constants;
14 use File::MMagic::XS qw(:compat);
16 our $VERSION = '2.12';
17 our $mmagic = File::MMagic::XS->new();
19 # proposed privacy conventions:
20 # - no leading underscore - public to custom application code and plugins
21 # - single leading underscore - private to the main Maypole stack - *not*
23 # - double leading underscore - private to the current package
27 Maypole - MVC web application framework
31 The canonical example used in the Maypole documentation is the beer database:
37 # choose a frontend, initialise the config object, and load a plugin
38 use Maypole::Application qw/Relationship/;
41 __PACKAGE__->setup("dbi:SQLite:t/beerdb.db");
43 # get the empty config object created by Maypole::Application
44 my $config = __PACKAGE__->config;
47 $config->uri_base("http://localhost/beerdb");
48 $config->template_root("/path/to/templates");
49 $config->rows_per_page(10);
50 $config->display_tables([qw/beer brewery pub style/]);
53 $config->relationships([
54 "a brewery produces beers",
55 "a style defines beers",
56 "a pub has beers on handpumps",
60 BeerDB::Brewery->untaint_columns( printable => [qw/name notes url/] );
61 BeerDB::Pub->untaint_columns( printable => [qw/name notes url/] );
62 BeerDB::Style->untaint_columns( printable => [qw/name notes/] );
63 BeerDB::Beer->untaint_columns(
64 printable => [qw/abv name price notes/],
65 integer => [qw/style brewery score/],
69 # note : set up model before calling this method
70 BeerDB::Beer->required_columns([qw/name/]);
76 This documents the Maypole request object. See the L<Maypole::Manual>, for a
77 detailed guide to using Maypole.
79 Maypole is a Perl web application framework similar to Java's struts. It is
80 essentially completely abstracted, and so doesn't know anything about
81 how to talk to the outside world.
83 To use it, you need to create a driver package which represents your entire
84 application. This is the C<BeerDB> package used as an example in the manual.
86 This needs to first use L<Maypole::Application> which will make your package
87 inherit from the appropriate platform driver such as C<Apache::MVC> or
88 C<CGI::Maypole>. Then, the driver calls C<setup>. This sets up the model classes
89 and configures your application. The default model class for Maypole uses
90 L<Class::DBI> to map a database to classes, but this can be changed by altering
91 configuration (B<before> calling setup.)
94 =head1 DOCUMENTATION AND SUPPORT
96 Note that some details in some of these resources may be out of date.
100 =item The Maypole Manual
102 The primary documentation is the Maypole manual. This lives in the
103 C<Maypole::Manual> pod documents included with the distribution.
107 Individual packages within the distribution contain (more or less) detailed
108 reference documentation for their API.
112 There are two mailing lists - maypole-devel and maypole-users - see
113 http://maypole.perl.org/?MailingList
115 =item The Maypole Wiki
117 The Maypole wiki provides a useful store of extra documentation -
118 http://maypole.perl.org
120 In particular, there's a FAQ (http://maypole.perl.org/?FAQ) and a cookbook
121 (http://maypole.perl.org/?Cookbook). Again, certain information on these pages
124 =item Web applications with Maypole
126 A tutorial written by Simon Cozens for YAPC::EU 2005 -
127 http://www.aarontrevena.co.uk/opensource/maypole/maypole-tutorial.pdf [228KB].
129 =item A Database-Driven Web Application in 18 Lines of Code
131 By Paul Barry, published in Linux Journal, March 2005.
133 http://www.linuxjournal.com/article/7937
135 "From zero to Web-based database application in eight easy steps".
137 Maypole won a 2005 Linux Journal Editor's Choice Award
138 (http://www.linuxjournal.com/article/8293) after featuring in this article.
140 =item Build Web apps with Maypole
142 By Simon Cozens, on IBM's DeveloperWorks website, May 2004.
144 http://www-128.ibm.com/developerworks/linux/library/l-maypole/
146 =item Rapid Web Application Deployment with Maypole
148 By Simon Cozens, on O'Reilly's Perl website, April 2004.
150 http://www.perl.com/pub/a/2004/04/15/maypole.html
154 Some notes written by Simon Cozens. A little bit out of date, but still
155 very useful: http://www.aarontrevena.co.uk/opensource/maypole/authentication.html
159 There's a refcard for the Maypole (and Class::DBI) APIs on the wiki -
160 http://maypole.perl.org/?CheatSheet. Probably a little out of date now - it's a
161 wiki, so feel free to fix any errors!
163 =item Plugins and add-ons
165 There are a large and growing number of plugins and other add-on modules
166 available on CPAN - http://search.cpan.org/search?query=maypole&mode=module
170 You can find a range of useful Maypole links, particularly to several thoughtful
171 blog entries, starting here: http://del.icio.us/search/?all=maypole
175 There are a couple of short reviews here:
176 http://cpanratings.perl.org/dist/Maypole
182 __PACKAGE__->mk_classdata($_) for qw( config init_done view_object model_classes_loaded);
184 __PACKAGE__->mk_accessors(
185 qw( params query objects model_class template_args output path
186 args action template error document_encoding content_type table
187 headers_in headers_out stash status parent build_form_elements)
190 __PACKAGE__->config( Maypole::Config->new() );
192 __PACKAGE__->init_done(0);
194 __PACKAGE__->model_classes_loaded(0);
196 =head1 HOOKABLE METHODS
198 As a framework, Maypole provides a number of B<hooks> - methods that are
199 intended to be overridden. Some of these methods come with useful default
200 behaviour, others do nothing by default. Hooks include:
226 sub My::App::debug {1}
228 Returns the debugging flag. Override this in your application class to
229 enable/disable debugging.
231 You can also set the C<debug> flag via L<Maypole::Application>.
233 Some packages respond to higher debug levels, try increasing it to 2 or 3.
242 Returns the L<Maypole::Config> object
246 My::App->setup($data_source, $user, $password, \%attr);
248 Initialise the Maypole application and plugins and model classes.
249 Your application should call this B<after> setting up configuration data via
252 It calls the hook C<setup_model> to setup the model. The %attr hash contains
253 options and arguments used to set up the model. See the particular model's
254 documentation. However here is the most usage of setup where
255 Maypole::Model::CDBI is the base class.
257 My::App->setup($data_source, $user, $password,
258 { options => { # These are DB connection options
263 # These are Class::DBI::Loader arguments.
269 Also, see L<Maypole::Manual::Plugins>.
278 $class->setup_model(@_);
283 Called by C<setup>. This method builds the Maypole model hierarchy.
285 A likely target for over-riding, if you need to build a customised model.
287 This method also ensures any code in custom model classes is loaded, so you
288 don't need to load them in the driver.
294 $class = ref $class if ref $class;
295 my $config = $class->config;
296 $config->model || $config->model('Maypole::Model::CDBI');
297 $config->model->require or die sprintf
298 "Couldn't load the model class %s: %s", $config->model, $@;
300 # among other things, this populates $config->classes
301 $config->model->setup_database($config, $class, @_);
303 $config->model->add_model_superclass($config);
305 # Load custom model code, if it exists - nb this must happen after the
306 # adding the model superclass, to allow code attributes to work, but before adopt(),
307 # in case adopt() calls overridden methods on $subclass
308 foreach my $subclass ( @{ $config->classes } ) {
309 $class->load_model_subclass($subclass) unless ($class->model_classes_loaded());
310 $config->model->adopt($subclass) if $config->model->can("adopt");
315 =item load_model_subclass($subclass)
317 This method is called from C<setup_model()>. It attempts to load the
318 C<$subclass> package, if one exists. So if you make a customized C<BeerDB::Beer>
319 package, you don't need to explicitly load it.
321 If automatic loading causes problems, Override load_model_subclass in your driver.
323 sub load_model_subclass {};
325 Or perhaps during development, if you don't want to load up custom classes, you
326 can override this method and load them manually.
330 sub load_model_subclass {
331 my ($class, $subclass) = @_;
333 my $config = $class->config;
335 # Load any external files for the model base class or subclasses
336 # (e.g. BeerDB/DBI.pm or BeerDB/Beer.pm) based on code borrowed from
337 # Maypole::Plugin::Loader and Class::DBI.
338 if ( $subclass->require ) {
339 warn "Loaded external module for '$subclass'\n" if $class->debug > 1;
341 (my $filename = $subclass) =~ s!::!/!g;
342 die "Loading '$subclass' failed: $@\n"
343 unless $@ =~ /Can\'t locate \Q$filename\E\.pm/;
344 warn "No external module for '$subclass'"
345 if $class->debug > 1;
351 Loads the view class and instantiates the view object.
353 You should not call this directly, but you may wish to override this to add
354 application-specific initialisation - see L<Maypole::Manual::Plugins>.
361 my $config = $class->config;
362 $config->view || $config->view("Maypole::View::TT");
363 $config->view->require;
364 die "Couldn't load the view class " . $config->view . ": $@" if $@;
365 $config->display_tables
366 || $config->display_tables( $class->config->tables );
367 $class->view_object( $class->config->view->new );
368 $class->init_done(1);
373 Constructs a very minimal new Maypole request object.
381 config => $class->config,
387 $self->template_args({});
395 Get/set the Maypole::View object
399 =head1 INSTANCE METHODS
407 This method sets up the class if it's not done yet, sets some defaults and
408 leaves the dirty work to C<handler_guts>.
412 # handler() has a method attribute so that mod_perl will invoke
413 # BeerDB->handler() as a method rather than a plain function
414 # BeerDB::handler() and so this inherited implementation will be
415 # found. See e.g. "Practical mod_perl" by Bekman & Cholet for
416 # more information <http://modperlbook.org/html/ch25_01.html>
417 sub handler : method {
418 # See Maypole::Workflow before trying to understand this.
419 my ($class, $req) = @_;
421 $class->init unless $class->init_done;
423 my $self = $class->new;
425 # initialise the request
426 $self->headers_out(Maypole::Headers->new);
427 $self->get_request($req);
429 $self->parse_location;
431 # hook useful for declining static requests e.g. images, or perhaps for
432 # sanitizing request parameters
433 $self->status(Maypole::Constants::OK()); # set the default
434 $self->__call_hook('start_request_hook');
435 return $self->status unless $self->status == Maypole::Constants::OK();
436 die "status undefined after start_request_hook()" unless defined
440 my $status = $self->handler_guts;
441 return $status unless $status == OK;
442 # TODO: require send_output to return a status code
449 Run Maypole sub-requests as a component of the request
451 [% request.component("/beer/view_as_component/20") %]
453 Allows you to integrate the results of a Maypole request into an existing
454 request. You'll need to set up actions and templates
455 which return fragments of HTML rather than entire pages, but once you've
456 done that, you can use the C<component> method of the Maypole request object
457 to call those actions. You may pass a query string in the usual URL style.
459 You should not fully qualify the Maypole URLs.
461 Note: any HTTP POST or URL parameters passed to the parent are not passed to the
462 component sub-request, only what is included in the url passed as an argyument
468 my ( $r, $path ) = @_;
469 my $self = bless { parent => $r, config => $r->{config}, } , ref $r;
473 $self->template_args({});
478 my $url = URI->new($path);
479 $self->{path} = $url->path;
481 $self->params( $url->query_form_hash );
483 return $self->output;
486 sub get_template_root {
489 return $r->parent->get_template_root if $r->{parent};
490 return $self->NEXT::DISTINCT::get_template_root( $r, @_ );
496 return $r->parent->view_object if $r->{parent};
497 return $self->NEXT::DISTINCT::view_object( $r, @_ );
500 # Instead of making plugin authors use the NEXT::DISTINCT hoopla to ensure other
501 # plugins also get to call the hook, we can cycle through the application's
502 # @ISA and call them all here. Doesn't work for setup() though, because it's
503 # too ingrained in the stack. We could add a run_setup() method, but we'd break
504 # lots of existing code.
507 my ($self, $hook) = @_;
511 my $class = ref($self);
513 @plugins = @{"$class\::ISA"};
516 # this is either a custom method in the driver, or the method in the 1st
517 # plugin, or the 'null' method in the frontend (i.e. inherited from
518 # Maypole.pm) - we need to be careful to only call it once
519 my $first_hook = $self->can($hook);
522 my %seen = ( $first_hook => 1 );
524 # @plugins includes the frontend
525 foreach my $plugin (@plugins)
527 next unless my $plugin_hook = $plugin->can($hook);
528 next if $seen{$plugin_hook}++;
535 This is the main request handling method and calls various methods to handle the
536 request/response and defines the workflow within Maypole.
540 # The root of all evil
544 $self->build_form_elements(1);
545 $self->__load_request_model;
547 my $applicable = $self->is_model_applicable == OK;
551 # handle authentication
552 eval { $status = $self->call_authenticate };
553 if ( my $error = $@ )
555 $status = $self->call_exception($error, "authentication");
558 warn "caught authenticate error: $error";
559 return $self->debug ?
560 $self->view_object->error($self, $error) : ERROR;
563 if ( $self->debug and $status != OK and $status != DECLINED )
565 $self->view_object->error( $self,
566 "Got unexpected status $status from calling authentication" );
569 return $status unless $status == OK;
571 # We run additional_data for every request
572 $self->additional_data;
575 eval { $self->model_class->process($self) };
576 if ( my $error = $@ )
578 $status = $self->call_exception($error, "model");
581 warn "caught model error: $error";
582 return $self->debug ?
583 $self->view_object->error($self, $error) : ERROR;
587 $self->__setup_plain_template;
590 # less frequent path - perhaps output has been set to an error message
591 return OK if $self->output;
593 # normal path - no output has been generated yet
594 my $processed_view_ok = $self->__call_process_view;
596 $self->{content_type} ||= $self->__get_mime_type();
597 $self->{document_encoding} ||= "utf-8";
600 return $processed_view_ok;
604 'js' => 'text/javascript',
606 'htm' => 'text/html',
607 'html' => 'text/html',
610 sub __get_mime_type {
612 my $type = 'text/html';
613 if ($self->path =~ m/.*\.(\w{3,4})$/) {
614 $type = $filetypes{$1};
616 my $output = $self->output;
617 if (defined $output) {
618 $type = $mmagic->checktype_contents($output);
624 sub __load_request_model
627 # We may get a made up class from class_of
628 my $mclass = $self->config->model->class_of($self, $self->table);
629 if ( eval {$mclass->isa('Maypole::Model::Base')} ) {
630 $self->model_class( $mclass );
632 elsif ($self->debug) {
633 warn "***Warning: No $mclass class appropriate for model. @_";
638 # is_applicable() returned false, so set up a plain template. Model processing
639 # will be skipped, but need to remove the model anyway so the template can't
641 sub __setup_plain_template
645 # It's just a plain template
646 $self->model_class(undef);
648 my $path = $self->path;
649 $path =~ s{/$}{}; # De-absolutify
652 $self->template($self->path);
655 # The model has been processed or skipped (if is_applicable returned false),
656 # any exceptions have been handled, and there's no content in $self->output
657 sub __call_process_view {
660 my $status = eval { $self->view_object->process($self) };
662 my $error = $@ || $self->{error};
665 $status = $self->call_exception($error, "view");
667 if ( $status != OK ) {
668 warn "caught view error: $error" if $self->debug;
669 return $self->debug ?
670 $self->view_object->error($self, $error) : ERROR;
679 $r->warn('its all gone pete tong');
681 Warn must be implemented by the backend, i.e. Apache::MVC
682 and warn to stderr or appropriate logfile.
684 You can also over-ride this in your Maypole driver, should you
685 want to use something like Log::Log4perl instead.
691 =item build_form_elements
693 $r->build_form_elements(0);
695 Specify whether to build HTML form elements and populate
696 the cgi element of classmetadata.
702 You should only need to define this method if you are writing a new
703 Maypole backend. It should return something that looks like an Apache
704 or CGI request object, it defaults to blank.
712 Turns the backend request (e.g. Apache::MVC, Maypole, CGI) into a Maypole
713 request. It does this by setting the C<path>, and invoking C<parse_path> and
716 You should only need to define this method if you are writing a new Maypole
723 die "parse_location is a virtual method. Do not use Maypole directly; " .
724 "use Apache::MVC or similar";
727 =item start_request_hook
729 This is called immediately after setting up the basic request. The default
732 The value of C<< $r->status >> is set to C<OK> before this hook is run. Your
733 implementation can change the status code, or leave it alone.
735 After this hook has run, Maypole will check the value of C<status>. For any
736 value other than C<OK>, Maypole returns the C<status> immediately.
738 This is useful for filtering out requests for static files, e.g. images, which
739 should not be processed by Maypole or by the templating engine:
741 sub start_request_hook
745 $r->status(DECLINED) if $r->path =~ /\.jpg$/;
748 Multiple plugins, and the driver, can define this hook - Maypole will call all
749 of them. You should check for and probably not change any non-OK C<status>
752 package Maypole::Plugin::MyApp::SkipFavicon;
754 sub start_request_hook
758 # check if a previous plugin has already DECLINED this request
759 # - probably unnecessary in this example, but you get the idea
760 return unless $r->status == OK;
763 $r->status(DECLINED) if $r->path =~ /favicon\.ico/;
768 sub start_request_hook { }
772 B<This method is deprecated> as of version 2.11. If you have overridden it,
773 please override C<is_model_applicable> instead, and change the return type
774 from a Maypole:Constant to a true/false value.
776 Returns a Maypole::Constant to indicate whether the request is valid.
780 sub is_applicable { return shift->is_model_applicable(@_); }
782 =item is_model_applicable
784 Returns true or false to indicate whether the request is valid.
786 The default implementation checks that C<< $r->table >> is publicly
787 accessible and that the model class is configured to handle the
792 sub is_model_applicable {
795 # Establish which tables should be processed by the model
796 my $config = $self->config;
798 $config->ok_tables || $config->ok_tables( $config->display_tables );
800 $config->ok_tables( { map { $_ => 1 } @{ $config->ok_tables } } )
801 if ref $config->ok_tables eq "ARRAY";
803 my $ok_tables = $config->ok_tables;
805 # Does this request concern a table to be processed by the model?
806 my $table = $self->table;
810 if (exists $ok_tables->{$table})
817 $self->warn ("We don't have that table ($table).\n"
818 . "Available tables are: "
819 . join( ",", keys %$ok_tables ))
820 if $self->debug and not $ok_tables->{$table};
825 # Is the action public?
826 my $action = $self->action;
827 return OK if $self->model_class->is_public($action);
829 $self->warn("The action '$action' is not applicable to the table '$table'")
837 Called immediately after C<start_request_hook()>.
839 This method should return a session, which will be stored in the request's
840 C<session> attribute.
842 The default method is empty.
850 Called immediately after C<get_session>.
852 This method should return a user, which will be stored in the request's C<user>
855 The default method is empty.
861 =item call_authenticate
863 This method first checks if the relevant model class
864 can authenticate the user, or falls back to the default
865 authenticate method of your Maypole application.
869 sub call_authenticate
873 # Check if we have a model class with an authenticate() to delegate to
874 return $self->model_class->authenticate($self)
875 if $self->model_class and $self->model_class->can('authenticate');
877 # Interface consistency is a Good Thing -
878 # the invocant and the argument may one day be different things
879 # (i.e. controller and request), like they are when authenticate()
880 # is called on a model class (i.e. model and request)
881 return $self->authenticate($self);
886 Returns a Maypole::Constant to indicate whether the user is authenticated for
889 The default implementation returns C<OK>
893 sub authenticate { return OK }
898 This model is called to catch exceptions, first after authenticate, then after
899 processing the model class, and finally to check for exceptions from the view
902 This method first checks if the relevant model class
903 can handle exceptions the user, or falls back to the default
904 exception method of your Maypole application.
910 my ($self, $error, $when) = @_;
912 # Check if we have a model class with an exception() to delegate to
913 if ( $self->model_class && $self->model_class->can('exception') )
915 my $status = $self->model_class->exception( $self, $error, $when );
916 return $status if $status == OK;
919 return $self->exception($error, $when);
925 This method is called if any exceptions are raised during the authentication or
926 model/view processing. It should accept the exception as a parameter and return
927 a Maypole::Constant to indicate whether the request should continue to be
933 my ($self, $error, $when) = @_;
934 if (ref $self->view_object && $self->view_object->can("report_error") and $self->debug) {
935 $self->view_object->report_error($self, $error, $when);
941 =item additional_data
943 Called before the model processes the request, this method gives you a chance to
944 do some processing for each request, for example, manipulating C<template_args>.
948 sub additional_data { }
952 Sends the output and additional headers to the user.
957 die "send_output is a virtual method. Do not use Maypole directly; use Apache::MVC or similar";
963 =head2 Path processing and manipulation
969 Returns the request path
973 Parses the request path and sets the C<args>, C<action> and C<table>
974 properties. Calls C<preprocess_path> before parsing path and setting properties.
982 # Previous versions unconditionally set table, action and args to whatever
983 # was in @pi (or else to defaults, if @pi is empty).
984 # Adding preprocess_path(), and then setting table, action and args
985 # conditionally, broke lots of tests, hence this:
986 $self->$_(undef) for qw/action table args/;
987 $self->preprocess_path;
988 $self->path || $self->path('frontpage');
990 my @pi = grep {length} split '/', $self->path;
992 $self->table || $self->table(shift @pi);
993 $self->action || $self->action( shift @pi or 'index' );
994 $self->args || $self->args(\@pi);
997 =item preprocess_path
999 Sometimes when you don't want to rewrite or over-ride parse_path but
1000 want to rewrite urls or extract data from them before it is parsed.
1002 This method is called after parse_location has populated the request
1003 information and before parse_path has populated the model and action
1004 information, and is passed the request object.
1006 You can set action, args or table in this method and parse_path will
1007 then leave those values in place or populate them if not present
1011 sub preprocess_path { };
1013 =item make_path( %args or \%args or @args )
1015 This is the counterpart to C<parse_path>. It generates a path to use
1016 in links, form actions etc. To implement your own path scheme, just override
1017 this method and C<parse_path>.
1019 %args = ( table => $table,
1021 additional => $additional, # optional - generally an object ID
1024 \%args = as above, but a ref
1026 @args = ( $table, $action, $additional ); # $additional is optional
1028 C<id> can be used as an alternative key to C<additional>.
1030 C<$additional> can be a string, an arrayref, or a hashref. An arrayref is
1031 expanded into extra path elements, whereas a hashref is translated into a query
1042 if (@_ == 1 and ref $_[0] and ref $_[0] eq 'HASH')
1046 elsif ( @_ > 1 and @_ < 4 )
1048 $args{table} = shift;
1049 $args{action} = shift;
1050 $args{additional} = shift;
1057 do { die "no $_" unless $args{$_} } for qw( table action );
1059 my $additional = $args{additional} || $args{id};
1065 # if $additional is a href, make_uri() will transform it into a query
1066 @add = (ref $additional eq 'ARRAY') ? @$additional : ($additional);
1069 my $uri = $r->make_uri($args{table}, $args{action}, @add);
1071 return $uri->as_string;
1076 =item make_uri( @segments )
1078 Make a L<URI> object given table, action etc. Automatically adds
1081 If the final element in C<@segments> is a hash ref, C<make_uri> will render it
1088 my ($r, @segments) = @_;
1090 my $query = (ref $segments[-1] eq 'HASH') ? pop(@segments) : undef;
1092 my $base = $r->config->uri_base;
1095 my $uri = URI->new($base);
1096 $uri->path_segments($uri->path_segments, grep {length} @segments);
1098 my $abs_uri = $uri->abs('/');
1099 $abs_uri->query_form($query) if $query;
1105 Turns post data and query string paramaters into a hash of C<params>.
1107 You should only need to define this method if you are writing a new Maypole
1114 die "parse_args() is a virtual method. Do not use Maypole directly; ".
1115 "use Apache::MVC or similar";
1118 =item get_template_root
1120 Implementation-specific path to template root.
1122 You should only need to define this method if you are writing a new Maypole
1123 backend. Otherwise, see L<Maypole::Config/"template_root">
1129 =head2 Request properties
1135 Returns the perl package name that will serve as the model for the
1136 request. It corresponds to the request C<table> attribute.
1141 Get/set a list of model objects. The objects will be accessible in the view
1144 If the first item in C<$self-E<gt>args> can be C<retrieve()>d by the model
1145 class, it will be removed from C<args> and the retrieved object will be added to
1146 the C<objects> list. See L<Maypole::Model> for more information.
1151 Alias to get/set the first/only model object. The object will be accessible
1152 in the view templates.
1154 When used to set the object, will overwrite the request objects
1155 with a single object.
1160 my ($r,$object) = @_;
1161 $r->objects([$object]) if ($object);
1162 return undef unless $r->objects();
1163 return $r->objects->[0];
1168 $self->template_args->{foo} = 'bar';
1170 Get/set a hash of template variables.
1172 Maypole reserved words for template variables will over-ride values in template_variables.
1174 Reserved words are : r, request, object, objects, base, config and errors, as well as the
1175 current class or object name.
1179 A place to put custom application data. Not used by Maypole itself.
1183 Get/set the template to be used by the view. By default, it returns
1184 C<$self-E<gt>action>
1189 Get/set a request error
1193 Get/set the response output. This is usually populated by the view class. You
1194 can skip view processing by setting the C<output>.
1198 The table part of the Maypole request path
1202 The action part of the Maypole request path
1206 A list of remaining parts of the request path after table and action
1212 A L<Maypole::Headers> object containing HTTP headers for the request
1216 A L<HTTP::Headers> object that contains HTTP headers for the output
1218 =item document_encoding
1220 Get/set the output encoding. Default: utf-8.
1224 Get/set the output content type. Default: text/html
1228 Returns the protocol the request was made with, i.e. https
1233 die "get_protocol is a virtual method. Do not use Maypole directly; use Apache::MVC or similar";
1238 =head2 Request parameters
1240 The source of the parameters may vary depending on the Maypole backend, but they
1241 are usually populated from request query string and POST data.
1243 Maypole supplies several approaches for accessing the request parameters. Note
1244 that the current implementation (via a hashref) of C<query> and C<params> is
1245 likely to change in a future version of Maypole. So avoid direct access to these
1248 $r->{params}->{foo} # bad
1249 $r->params->{foo} # better
1251 $r->{query}->{foo} # bad
1252 $r->query->{foo} # better
1254 $r->param('foo') # best
1260 An accessor (get or set) for request parameters. It behaves similarly to
1261 CGI::param() for accessing CGI parameters, i.e.
1263 $r->param # returns list of keys
1264 $r->param($key) # returns value for $key
1265 $r->param($key => $value) # returns old value, sets to new value
1271 my ($self, $key) = (shift, shift);
1273 return keys %{$self->params} unless defined $key;
1275 return unless exists $self->params->{$key};
1277 my $val = $self->params->{$key};
1281 my $new_val = shift;
1282 $self->params->{$key} = $new_val;
1285 return ref $val ? @$val : ($val) if wantarray;
1287 return ref $val ? $val->[0] : $val;
1293 Returns a hashref of request parameters.
1295 B<Note:> Where muliple values of a parameter were supplied, the C<params> value
1296 will be an array reference.
1300 Alias for C<params>.
1304 =head3 Utility methods
1308 =item redirect_request
1310 Sets output headers to redirect based on the arguments provided
1312 Accepts either a single argument of the full url to redirect to, or a hash of
1315 $r->redirect_request('http://www.example.com/path');
1319 $r->redirect_request(protocol=>'https', domain=>'www.example.com', path=>'/path/file?arguments', status=>'302', url=>'..');
1321 The named parameters are protocol, domain, path, status and url
1323 Only 1 named parameter is required but other than url, they can be combined as
1324 required and current values (from the request) will be used in place of any
1325 missing arguments. The url argument must be a full url including protocol and
1326 can only be combined with status.
1330 sub redirect_request {
1331 die "redirect_request is a virtual method. Do not use Maypole directly; use Apache::MVC or similar";
1334 =item redirect_internal_request
1338 sub redirect_internal_request {
1343 =item make_random_id
1345 returns a unique id for this request can be used to prevent or detect repeat
1350 # Session and Repeat Submission Handling
1351 sub make_random_id {
1352 use Maypole::Session;
1353 return Maypole::Session::generate_unique_id();
1358 =head1 SEQUENCE DIAGRAMS
1360 See L<Maypole::Manual::Workflow> for a detailed discussion of the sequence of
1361 calls during processing of a request. This is a brief summary:
1365 BeerDB Maypole::Model::CDBI
1369 || setup_model | setup_database() creates
1370 ||------+ | a subclass of the Model
1371 |||<----+ | for each table
1373 ||| setup_database | |
1374 |||--------------------->|| 'create' *
1375 ||| ||----------> $subclass
1377 ||| load_model_subclass | |
1378 foreach |||------+ ($subclass) | |
1379 $subclass ||||<----+ | require |
1380 ||||--------------------------------------->|
1382 ||| adopt($subclass) | |
1383 |||--------------------->|| |
1388 || | new | view_object: e.g.
1389 ||---------------------------------------------> Maypole::View::TT
1401 BeerDB Model $subclass view_object
1404 o-------->| new | | |
1405 |-----> r:BeerDB | | |
1409 | ||-----+ parse_location | | |
1412 | ||-----+ start_request_hook | | |
1415 | ||-----+ get_session | | |
1418 | ||-----+ get_user | | |
1421 | ||-----+ handler_guts | | |
1423 | ||| class_of($table) | | |
1424 | |||------------------------->|| | |
1425 | ||| $subclass || | |
1426 | |||<-------------------------|| | |
1428 | |||-----+ is_model_applicable| | |
1431 | |||-----+ call_authenticate | | |
1434 | |||-----+ additional_data | | |
1437 | |||--------------------------------->|| fetch_objects
1445 | |||------------------------------------------->|| template
1449 | || send_output | | |
1453 <------------------|| | | |
1464 There's more documentation, examples, and information on our mailing lists
1465 at the Maypole web site:
1467 L<http://maypole.perl.org/>
1469 L<Maypole::Application>, L<Apache::MVC>, L<CGI::Maypole>.
1473 Maypole is currently maintained by Aaron Trevena.
1475 =head1 AUTHOR EMERITUS
1477 Simon Cozens, C<simon#cpan.org>
1479 Simon Flack maintained Maypole from 2.05 to 2.09
1481 Sebastian Riedel, C<sri#oook.de> maintained Maypole from 1.99_01 to 2.04
1485 Sebastian Riedel, Danijel Milicevic, Dave Slack, Jesse Sheidlower, Jody Belka,
1486 Marcus Ramberg, Mickael Joanne, Randal Schwartz, Simon Flack, Steve Simms,
1487 Veljko Vidovic and all the others who've helped.
1491 You may distribute this code under the same terms as Perl itself.
1499 =item register_cleanup($coderef)
1501 Analogous to L<Apache>'s C<register_cleanup>. If an Apache request object is
1502 available, this call simply redispatches there. If not, the cleanup is
1503 registered in the Maypole request, and executed when the request is
1506 This method is only useful in persistent environments, where you need to ensure
1507 that some code runs when the request finishes, no matter how it finishes (e.g.
1508 after an unexpected error).
1515 sub register_cleanup
1517 my ($self, $cleanup) = @_;
1519 die "register_cleanup() is an instance method, not a class method"
1521 die "Cleanup must be a coderef" unless ref($cleanup) eq 'CODE';
1523 if ($self->can('ar') && $self->ar)
1525 $self->ar->register_cleanup($cleanup);
1529 push @_cleanups, $cleanup;
1537 while (my $cleanup = shift @_cleanups)
1539 eval { $cleanup->() };
1542 warn "Error during request cleanup: $@";