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 = '2.121';
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/;
40 __PACKAGE__->setup("dbi:SQLite:t/beerdb.db");
42 # get the empty config object created by Maypole::Application
43 my $config = __PACKAGE__->config;
46 $config->uri_base("http://localhost/beerdb");
47 $config->template_root("/path/to/templates");
48 $config->rows_per_page(10);
49 $config->display_tables([qw/beer brewery pub style/]);
52 $config->relationships([
53 "a brewery produces beers",
54 "a style defines beers",
55 "a pub has beers on handpumps",
59 BeerDB::Brewery->untaint_columns( printable => [qw/name notes url/] );
60 BeerDB::Pub->untaint_columns( printable => [qw/name notes url/] );
61 BeerDB::Style->untaint_columns( printable => [qw/name notes/] );
62 BeerDB::Beer->untaint_columns(
63 printable => [qw/abv name price notes/],
64 integer => [qw/style brewery score/],
68 # note : set up model before calling this method
69 BeerDB::Beer->required_columns([qw/name/]);
75 This documents the Maypole request object. See the L<Maypole::Manual>, for a
76 detailed guide to using Maypole.
78 Maypole is a Perl web application framework similar to Java's struts. It is
79 essentially completely abstracted, and so doesn't know anything about
80 how to talk to the outside world.
82 To use it, you need to create a driver package which represents your entire
83 application. This is the C<BeerDB> package used as an example in the manual.
85 This needs to first use L<Maypole::Application> which will make your package
86 inherit from the appropriate platform driver such as C<Apache::MVC> or
87 C<CGI::Maypole>. Then, the driver calls C<setup>. This sets up the model classes
88 and configures your application. The default model class for Maypole uses
89 L<Class::DBI> to map a database to classes, but this can be changed by altering
90 configuration (B<before> calling setup.)
93 =head1 DOCUMENTATION AND SUPPORT
95 Note that some details in some of these resources may be out of date.
99 =item The Maypole Manual
101 The primary documentation is the Maypole manual. This lives in the
102 C<Maypole::Manual> pod documents included with the distribution.
106 Individual packages within the distribution contain (more or less) detailed
107 reference documentation for their API.
111 There are two mailing lists - maypole-devel and maypole-users - see
112 http://maypole.perl.org/?MailingList
114 =item The Maypole Wiki
116 The Maypole wiki provides a useful store of extra documentation -
117 http://maypole.perl.org
119 In particular, there's a FAQ (http://maypole.perl.org/?FAQ) and a cookbook
120 (http://maypole.perl.org/?Cookbook). Again, certain information on these pages
123 =item Web applications with Maypole
125 A tutorial written by Simon Cozens for YAPC::EU 2005 -
126 http://www.aarontrevena.co.uk/opensource/maypole/maypole-tutorial.pdf [228KB].
128 =item A Database-Driven Web Application in 18 Lines of Code
130 By Paul Barry, published in Linux Journal, March 2005.
132 http://www.linuxjournal.com/article/7937
134 "From zero to Web-based database application in eight easy steps".
136 Maypole won a 2005 Linux Journal Editor's Choice Award
137 (http://www.linuxjournal.com/article/8293) after featuring in this article.
139 =item Build Web apps with Maypole
141 By Simon Cozens, on IBM's DeveloperWorks website, May 2004.
143 http://www-128.ibm.com/developerworks/linux/library/l-maypole/
145 =item Rapid Web Application Deployment with Maypole
147 By Simon Cozens, on O'Reilly's Perl website, April 2004.
149 http://www.perl.com/pub/a/2004/04/15/maypole.html
153 Some notes written by Simon Cozens. A little bit out of date, but still
154 very useful: http://www.aarontrevena.co.uk/opensource/maypole/authentication.html
158 There's a refcard for the Maypole (and Class::DBI) APIs on the wiki -
159 http://maypole.perl.org/?CheatSheet. Probably a little out of date now - it's a
160 wiki, so feel free to fix any errors!
162 =item Plugins and add-ons
164 There are a large and growing number of plugins and other add-on modules
165 available on CPAN - http://search.cpan.org/search?query=maypole&mode=module
169 You can find a range of useful Maypole links, particularly to several thoughtful
170 blog entries, starting here: http://del.icio.us/search/?all=maypole
174 There are a couple of short reviews here:
175 http://cpanratings.perl.org/dist/Maypole
181 __PACKAGE__->mk_classdata($_) for qw( config init_done view_object model_classes_loaded);
183 __PACKAGE__->mk_accessors(
184 qw( params query objects model_class template_args output path
185 args action template error document_encoding content_type table
186 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
439 my $session = $self->get_session;
440 $self->session($self->{session} || $session);
441 my $user = $self->get_user;
442 $self->user($self->{user} || $user);
444 my $status = $self->handler_guts;
445 return $status unless $status == OK;
446 # TODO: require send_output to return a status code
453 Run Maypole sub-requests as a component of the request
455 [% request.component("/beer/view_as_component/20") %]
457 Allows you to integrate the results of a Maypole request into an existing
458 request. You'll need to set up actions and templates
459 which return fragments of HTML rather than entire pages, but once you've
460 done that, you can use the C<component> method of the Maypole request object
461 to call those actions. You may pass a query string in the usual URL style.
463 You should not fully qualify the Maypole URLs.
465 Note: any HTTP POST or URL parameters passed to the parent are not passed to the
466 component sub-request, only what is included in the url passed as an argument
472 my ( $r, $path ) = @_;
473 my $self = bless { parent => $r, config => $r->{config}, } , ref $r;
477 $self->template_args({});
481 $self->session($self->get_session);
482 $self->user($self->get_user);
484 my $url = URI->new($path);
485 $self->{path} = $url->path;
487 $self->params( $url->query_form_hash );
489 return $self->output;
492 sub get_template_root {
495 return $r->parent->get_template_root if $r->{parent};
496 return $self->NEXT::DISTINCT::get_template_root( $r, @_ );
502 return $r->parent->view_object if $r->{parent};
503 return $self->NEXT::DISTINCT::view_object( $r, @_ );
506 # Instead of making plugin authors use the NEXT::DISTINCT hoopla to ensure other
507 # plugins also get to call the hook, we can cycle through the application's
508 # @ISA and call them all here. Doesn't work for setup() though, because it's
509 # too ingrained in the stack. We could add a run_setup() method, but we'd break
510 # lots of existing code.
513 my ($self, $hook) = @_;
517 my $class = ref($self);
519 @plugins = @{"$class\::ISA"};
522 # this is either a custom method in the driver, or the method in the 1st
523 # plugin, or the 'null' method in the frontend (i.e. inherited from
524 # Maypole.pm) - we need to be careful to only call it once
525 my $first_hook = $self->can($hook);
528 my %seen = ( $first_hook => 1 );
530 # @plugins includes the frontend
531 foreach my $plugin (@plugins)
533 next unless my $plugin_hook = $plugin->can($hook);
534 next if $seen{$plugin_hook}++;
541 This is the main request handling method and calls various methods to handle the
542 request/response and defines the workflow within Maypole.
546 # The root of all evil
549 $self->build_form_elements(1) unless (defined ($self->config->build_form_elements) && $self->config->build_form_elements == 0);
550 $self->__load_request_model;
552 my $applicable = $self->is_model_applicable == OK;
556 # handle authentication
557 eval { $status = $self->call_authenticate };
558 if ( my $error = $@ ) {
559 $status = $self->call_exception($error, "authentication");
560 if ( $status != OK ) {
561 $self->warn("caught authenticate error: $error");
562 return $self->debug ?
563 $self->view_object->error($self, $error) : ERROR;
566 if ( $self->debug and $status != OK and $status != DECLINED ) {
567 $self->view_object->error( $self,
568 "Got unexpected status $status from calling authentication" );
571 return $status unless $status == OK;
573 # We run additional_data for every request
574 $self->additional_data;
577 eval { $self->model_class->process($self) };
578 if ( my $error = $@ ) {
579 $status = $self->call_exception($error, "model");
580 if ( $status != OK ) {
581 $self->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
592 $self->{content_type} ||= $self->__get_mime_type();
593 $self->{document_encoding} ||= "utf-8";
597 # normal path - no output has been generated yet
598 my $processed_view_ok = $self->__call_process_view;
600 $self->{content_type} ||= $self->__get_mime_type();
601 $self->{document_encoding} ||= "utf-8";
603 return $processed_view_ok;
607 'js' => 'text/javascript',
609 'htm' => 'text/html',
610 'html' => 'text/html',
613 sub __get_mime_type {
615 my $type = 'text/html';
616 if ($self->path =~ m/.*\.(\w{3,4})$/) {
617 $type = $filetypes{$1};
619 my $output = $self->output;
620 if (defined $output) {
621 $type = $mmagic->checktype_contents($output);
627 sub __load_request_model
630 # We may get a made up class from class_of
631 my $mclass = $self->config->model->class_of($self, $self->table);
632 if ( eval {$mclass->isa('Maypole::Model::Base')} ) {
633 $self->model_class( $mclass );
635 elsif ($self->debug > 1) {
636 $self->warn("***Warning: No $mclass class appropriate for model. @_");
641 # is_applicable() returned false, so set up a plain template. Model processing
642 # will be skipped, but need to remove the model anyway so the template can't
644 sub __setup_plain_template
648 # It's just a plain template
649 $self->build_form_elements(0);
650 $self->model_class(undef);
652 unless ($self->template) {
653 # FIXME: this is likely to be redundant and is definately causing problems.
654 my $path = $self->path;
655 $path =~ s{/$}{}; # De-absolutify
657 $self->template($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 {
666 my $status = eval { $self->view_object->process($self) };
668 my $error = $@ || $self->{error};
671 $status = $self->call_exception($error, "view");
673 if ( $status != OK ) {
674 warn "caught view error: $error" if $self->debug;
675 return $self->debug ?
676 $self->view_object->error($self, $error) : ERROR;
685 $r->warn('its all gone pete tong');
687 Warn must be implemented by the backend, i.e. Apache::MVC
688 and warn to stderr or appropriate logfile.
690 You can also over-ride this in your Maypole driver, should you
691 want to use something like Log::Log4perl instead.
697 =item build_form_elements
699 $r->build_form_elements(0);
701 Specify (in an action) whether to build HTML form elements and populate
702 the cgi element of classmetadata in the view.
704 You can set this globally using the accessor of the same name in Maypole::Config,
705 this method allows you to over-ride that setting per action.
711 You should only need to define this method if you are writing a new
712 Maypole backend. It should return something that looks like an Apache
713 or CGI request object, it defaults to blank.
721 Turns the backend request (e.g. Apache::MVC, Maypole, CGI) into a Maypole
722 request. It does this by setting the C<path>, and invoking C<parse_path> and
725 You should only need to define this method if you are writing a new Maypole
732 die "parse_location is a virtual method. Do not use Maypole directly; " .
733 "use Apache::MVC or similar";
736 =item start_request_hook
738 This is called immediately after setting up the basic request. The default
741 The value of C<< $r->status >> is set to C<OK> before this hook is run. Your
742 implementation can change the status code, or leave it alone.
744 After this hook has run, Maypole will check the value of C<status>. For any
745 value other than C<OK>, Maypole returns the C<status> immediately.
747 This is useful for filtering out requests for static files, e.g. images, which
748 should not be processed by Maypole or by the templating engine:
750 sub start_request_hook
754 $r->status(DECLINED) if $r->path =~ /\.jpg$/;
757 Multiple plugins, and the driver, can define this hook - Maypole will call all
758 of them. You should check for and probably not change any non-OK C<status>
761 package Maypole::Plugin::MyApp::SkipFavicon;
763 sub start_request_hook
767 # check if a previous plugin has already DECLINED this request
768 # - probably unnecessary in this example, but you get the idea
769 return unless $r->status == OK;
772 $r->status(DECLINED) if $r->path =~ /favicon\.ico/;
777 sub start_request_hook { }
781 B<This method is deprecated> as of version 2.11. If you have overridden it,
782 please override C<is_model_applicable> instead, and change the return type
783 from a Maypole:Constant to a true/false value.
785 Returns a Maypole::Constant to indicate whether the request is valid.
789 sub is_applicable { return shift->is_model_applicable(@_); }
791 =item is_model_applicable
793 Returns true or false to indicate whether the request is valid.
795 The default implementation checks that C<< $r->table >> is publicly
796 accessible and that the model class is configured to handle the
801 sub is_model_applicable {
804 # Establish which tables should be processed by the model
805 my $config = $self->config;
807 $config->ok_tables || $config->ok_tables( $config->display_tables );
809 $config->ok_tables( { map { $_ => 1 } @{ $config->ok_tables } } )
810 if ref $config->ok_tables eq "ARRAY";
812 my $ok_tables = $config->ok_tables;
814 # Does this request concern a table to be processed by the model?
815 my $table = $self->table;
819 if (exists $ok_tables->{$table})
826 $self->warn ("We don't have that table ($table).\n"
827 . "Available tables are: "
828 . join( ",", keys %$ok_tables ))
829 if $self->debug and not $ok_tables->{$table};
834 # Is the action public?
835 my $action = $self->action;
836 return OK if $self->model_class->is_public($action);
838 $self->warn("The action '$action' is not applicable to the table '$table'")
846 Called immediately after C<start_request_hook()>.
848 This method should return a session, which will be stored in the request's
849 C<session> attribute.
851 The default method is empty.
859 Called immediately after C<get_session>.
861 This method should return a user, which will be stored in the request's C<user>
864 The default method is empty.
870 =item call_authenticate
872 This method first checks if the relevant model class
873 can authenticate the user, or falls back to the default
874 authenticate method of your Maypole application.
878 sub call_authenticate
882 # Check if we have a model class with an authenticate() to delegate to
883 return $self->model_class->authenticate($self)
884 if $self->model_class and $self->model_class->can('authenticate');
886 # Interface consistency is a Good Thing -
887 # the invocant and the argument may one day be different things
888 # (i.e. controller and request), like they are when authenticate()
889 # is called on a model class (i.e. model and request)
890 return $self->authenticate($self);
895 Returns a Maypole::Constant to indicate whether the user is authenticated for
898 The default implementation returns C<OK>
902 sub authenticate { return OK }
907 This model is called to catch exceptions, first after authenticate, then after
908 processing the model class, and finally to check for exceptions from the view
911 This method first checks if the relevant model class
912 can handle exceptions the user, or falls back to the default
913 exception method of your Maypole application.
919 my ($self, $error, $when) = @_;
921 # Check if we have a model class with an exception() to delegate to
922 if ( $self->model_class && $self->model_class->can('exception') )
924 my $status = $self->model_class->exception( $self, $error, $when );
925 return $status if $status == OK;
928 return $self->exception($error, $when);
934 This method is called if any exceptions are raised during the authentication or
935 model/view processing. It should accept the exception as a parameter and return
936 a Maypole::Constant to indicate whether the request should continue to be
942 my ($self, $error, $when) = @_;
943 if (ref $self->view_object && $self->view_object->can("report_error") and $self->debug) {
944 $self->view_object->report_error($self, $error, $when);
950 =item additional_data
952 Called before the model processes the request, this method gives you a chance to
953 do some processing for each request, for example, manipulating C<template_args>.
957 sub additional_data { }
961 Sends the output and additional headers to the user.
966 die "send_output is a virtual method. Do not use Maypole directly; use Apache::MVC or similar";
972 =head2 Path processing and manipulation
978 Returns the request path
982 Parses the request path and sets the C<args>, C<action> and C<table>
983 properties. Calls C<preprocess_path> before parsing path and setting properties.
990 # Previous versions unconditionally set table, action and args to whatever
991 # was in @pi (or else to defaults, if @pi is empty).
992 # Adding preprocess_path(), and then setting table, action and args
993 # conditionally, broke lots of tests, hence this:
994 $self->$_(undef) for qw/action table args/;
995 $self->preprocess_path;
997 # use frontpage template for frontpage
998 unless ($self->path && $self->path ne '/') {
999 $self->path('frontpage');
1002 my @pi = grep {length} split '/', $self->path;
1004 $self->table || $self->table(shift @pi);
1005 $self->action || $self->action( shift @pi or 'index' );
1006 $self->args || $self->args(\@pi);
1009 =item preprocess_path
1011 Sometimes when you don't want to rewrite or over-ride parse_path but
1012 want to rewrite urls or extract data from them before it is parsed,
1013 the preprocess_path/location methods allow you to munge paths and urls
1014 before maypole maps them to actions, classes, etc.
1016 This method is called after parse_location has populated the request
1017 information and before parse_path has populated the model and action
1018 information, and is passed the request object.
1020 You can set action, args or table in this method and parse_path will
1021 then leave those values in place or populate them based on the current
1022 value of the path attribute if they are not present.
1026 sub preprocess_path { };
1028 =item preprocess_location
1030 This method is called at the start of parse_location, after the headers in, and allows you
1031 to rewrite the url used by maypole, or dynamically set configuration
1032 like the base_uri based on the hostname or path.
1036 sub preprocess_location { };
1038 =item make_path( %args or \%args or @args )
1040 This is the counterpart to C<parse_path>. It generates a path to use
1041 in links, form actions etc. To implement your own path scheme, just override
1042 this method and C<parse_path>.
1044 %args = ( table => $table,
1046 additional => $additional, # optional - generally an object ID
1049 \%args = as above, but a ref
1051 @args = ( $table, $action, $additional ); # $additional is optional
1053 C<id> can be used as an alternative key to C<additional>.
1055 C<$additional> can be a string, an arrayref, or a hashref. An arrayref is
1056 expanded into extra path elements, whereas a hashref is translated into a query
1068 if (@_ == 1 and ref $_[0] and ref $_[0] eq 'HASH')
1072 elsif ( @_ > 1 and @_ < 4 )
1074 $args{table} = shift;
1075 $args{action} = shift;
1076 $args{additional} = shift;
1083 do { die "no $_" unless $args{$_} } for qw( table action );
1085 my $additional = $args{additional} || $args{id};
1091 # if $additional is a href, make_uri() will transform it into a query
1092 @add = (ref $additional eq 'ARRAY') ? @$additional : ($additional);
1095 my $uri = $r->make_uri($args{table}, $args{action}, @add);
1097 return $uri->as_string;
1102 =item make_uri( @segments )
1104 Make a L<URI> object given table, action etc. Automatically adds
1107 If the final element in C<@segments> is a hash ref, C<make_uri> will render it
1114 my ($r, @segments) = @_;
1116 my $query = (ref $segments[-1] eq 'HASH') ? pop(@segments) : undef;
1118 my $base = $r->config->uri_base;
1121 my $uri = URI->new($base);
1122 $uri->path_segments($uri->path_segments, grep {length} @segments);
1124 my $abs_uri = $uri->abs('/');
1125 $abs_uri->query_form($query) if $query;
1131 Turns post data and query string paramaters into a hash of C<params>.
1133 You should only need to define this method if you are writing a new Maypole
1140 die "parse_args() is a virtual method. Do not use Maypole directly; ".
1141 "use Apache::MVC or similar";
1144 =item get_template_root
1146 Implementation-specific path to template root.
1148 You should only need to define this method if you are writing a new Maypole
1149 backend. Otherwise, see L<Maypole::Config/"template_root">
1155 =head2 Request properties
1161 Returns the perl package name that will serve as the model for the
1162 request. It corresponds to the request C<table> attribute.
1167 Get/set a list of model objects. The objects will be accessible in the view
1170 If the first item in C<$self-E<gt>args> can be C<retrieve()>d by the model
1171 class, it will be removed from C<args> and the retrieved object will be added to
1172 the C<objects> list. See L<Maypole::Model> for more information.
1177 Alias to get/set the first/only model object. The object will be accessible
1178 in the view templates.
1180 When used to set the object, will overwrite the request objects
1181 with a single object.
1186 my ($r,$object) = @_;
1187 $r->objects([$object]) if ($object);
1188 return undef unless $r->objects();
1189 return $r->objects->[0];
1194 $self->template_args->{foo} = 'bar';
1196 Get/set a hash of template variables.
1198 Maypole reserved words for template variables will over-ride values in template_variables.
1200 Reserved words are : r, request, object, objects, base, config and errors, as well as the
1201 current class or object name.
1205 A place to put custom application data. Not used by Maypole itself.
1209 Get/set the template to be used by the view. By default, it returns
1210 C<$self-E<gt>action>
1215 Get/set a request error
1219 Get/set the response output. This is usually populated by the view class. You
1220 can skip view processing by setting the C<output>.
1224 The table part of the Maypole request path
1228 The action part of the Maypole request path
1232 A list of remaining parts of the request path after table and action
1238 A L<Maypole::Headers> object containing HTTP headers for the request
1242 A L<HTTP::Headers> object that contains HTTP headers for the output
1244 =item document_encoding
1246 Get/set the output encoding. Default: utf-8.
1250 Get/set the output content type. Default: text/html
1254 Returns the protocol the request was made with, i.e. https
1259 die "get_protocol is a virtual method. Do not use Maypole directly; use Apache::MVC or similar";
1264 =head2 Request parameters
1266 The source of the parameters may vary depending on the Maypole backend, but they
1267 are usually populated from request query string and POST data.
1269 Maypole supplies several approaches for accessing the request parameters. Note
1270 that the current implementation (via a hashref) of C<query> and C<params> is
1271 likely to change in a future version of Maypole. So avoid direct access to these
1274 $r->{params}->{foo} # bad
1275 $r->params->{foo} # better
1277 $r->{query}->{foo} # bad
1278 $r->query->{foo} # better
1280 $r->param('foo') # best
1286 An accessor (get or set) for request parameters. It behaves similarly to
1287 CGI::param() for accessing CGI parameters, i.e.
1289 $r->param # returns list of keys
1290 $r->param($key) # returns value for $key
1291 $r->param($key => $value) # returns old value, sets to new value
1297 my ($self, $key) = (shift, shift);
1299 return keys %{$self->params} unless defined $key;
1301 return unless exists $self->params->{$key};
1303 my $val = $self->params->{$key};
1307 my $new_val = shift;
1308 $self->params->{$key} = $new_val;
1311 return (ref $val eq 'ARRAY') ? @$val : ($val) if wantarray;
1313 return (ref $val eq 'ARRAY') ? $val->[0] : $val;
1319 Returns a hashref of request parameters.
1321 B<Note:> Where muliple values of a parameter were supplied, the C<params> value
1322 will be an array reference.
1326 Alias for C<params>.
1330 =head3 Utility methods
1334 =item redirect_request
1336 Sets output headers to redirect based on the arguments provided
1338 Accepts either a single argument of the full url to redirect to, or a hash of
1341 $r->redirect_request('http://www.example.com/path');
1345 $r->redirect_request(protocol=>'https', domain=>'www.example.com', path=>'/path/file?arguments', status=>'302', url=>'..');
1347 The named parameters are protocol, domain, path, status and url
1349 Only 1 named parameter is required but other than url, they can be combined as
1350 required and current values (from the request) will be used in place of any
1351 missing arguments. The url argument must be a full url including protocol and
1352 can only be combined with status.
1356 sub redirect_request {
1357 die "redirect_request is a virtual method. Do not use Maypole directly; use Apache::MVC or similar";
1360 # =item redirect_internal_request
1364 # sub redirect_internal_request {
1369 =item make_random_id
1371 returns a unique id for this request can be used to prevent or detect repeat
1376 # Session and Repeat Submission Handling
1377 sub make_random_id {
1378 use Maypole::Session;
1379 return Maypole::Session::generate_unique_id();
1384 =head1 SEQUENCE DIAGRAMS
1386 See L<Maypole::Manual::Workflow> for a detailed discussion of the sequence of
1387 calls during processing of a request. This is a brief summary:
1391 BeerDB Maypole::Model::CDBI
1395 || setup_model | setup_database() creates
1396 ||------+ | a subclass of the Model
1397 |||<----+ | for each table
1399 ||| setup_database | |
1400 |||--------------------->|| 'create' *
1401 ||| ||----------> $subclass
1403 ||| load_model_subclass | |
1404 foreach |||------+ ($subclass) | |
1405 $subclass ||||<----+ | require |
1406 ||||--------------------------------------->|
1408 ||| adopt($subclass) | |
1409 |||--------------------->|| |
1414 || | new | view_object: e.g.
1415 ||---------------------------------------------> Maypole::View::TT
1427 BeerDB Model $subclass view_object
1430 o-------->| new | | |
1431 |-----> r:BeerDB | | |
1435 | ||-----+ parse_location | | |
1438 | ||-----+ start_request_hook | | |
1441 | ||-----+ get_session | | |
1444 | ||-----+ get_user | | |
1447 | ||-----+ handler_guts | | |
1449 | ||| class_of($table) | | |
1450 | |||------------------------->|| | |
1451 | ||| $subclass || | |
1452 | |||<-------------------------|| | |
1454 | |||-----+ is_model_applicable| | |
1457 | |||-----+ call_authenticate | | |
1460 | |||-----+ additional_data | | |
1463 | |||--------------------------------->|| fetch_objects
1471 | |||------------------------------------------->|| template
1475 | || send_output | | |
1479 <------------------|| | | |
1490 There's more documentation, examples, and information on our mailing lists
1491 at the Maypole web site:
1493 L<http://maypole.perl.org/>
1495 L<Maypole::Application>, L<Apache::MVC>, L<CGI::Maypole>.
1499 Maypole is currently maintained by Aaron Trevena.
1501 =head1 AUTHOR EMERITUS
1503 Simon Cozens, C<simon#cpan.org>
1505 Simon Flack maintained Maypole from 2.05 to 2.09
1507 Sebastian Riedel, C<sri#oook.de> maintained Maypole from 1.99_01 to 2.04
1511 Sebastian Riedel, Danijel Milicevic, Dave Slack, Jesse Sheidlower, Jody Belka,
1512 Marcus Ramberg, Mickael Joanne, Randal Schwartz, Simon Flack, Steve Simms,
1513 Veljko Vidovic and all the others who've helped.
1517 You may distribute this code under the same terms as Perl itself.
1525 =item register_cleanup($coderef)
1527 Analogous to L<Apache>'s C<register_cleanup>. If an Apache request object is
1528 available, this call simply redispatches there. If not, the cleanup is
1529 registered in the Maypole request, and executed when the request is
1532 This method is only useful in persistent environments, where you need to ensure
1533 that some code runs when the request finishes, no matter how it finishes (e.g.
1534 after an unexpected error).
1541 sub register_cleanup
1543 my ($self, $cleanup) = @_;
1545 die "register_cleanup() is an instance method, not a class method"
1547 die "Cleanup must be a coderef" unless ref($cleanup) eq 'CODE';
1549 if ($self->can('ar') && $self->ar)
1551 $self->ar->register_cleanup($cleanup);
1555 push @_cleanups, $cleanup;
1563 while (my $cleanup = shift @_cleanups)
1565 eval { $cleanup->() };
1568 warn "Error during request cleanup: $@";