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 = '2.12';
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 $self->session($self->get_session);
440 $self->user($self->get_user);
442 my $status = $self->handler_guts;
443 return $status unless $status == OK;
444 # TODO: require send_output to return a status code
451 Run Maypole sub-requests as a component of the request
453 [% request.component("/beer/view_as_component/20") %]
455 Allows you to integrate the results of a Maypole request into an existing
456 request. You'll need to set up actions and templates
457 which return fragments of HTML rather than entire pages, but once you've
458 done that, you can use the C<component> method of the Maypole request object
459 to call those actions. You may pass a query string in the usual URL style.
461 You should not fully qualify the Maypole URLs.
463 Note: any HTTP POST or URL parameters passed to the parent are not passed to the
464 component sub-request, only what is included in the url passed as an argument
470 my ( $r, $path ) = @_;
471 my $self = bless { parent => $r, config => $r->{config}, } , ref $r;
475 $self->template_args({});
479 $self->session($self->get_session);
480 $self->user($self->get_user);
482 my $url = URI->new($path);
483 $self->{path} = $url->path;
485 $self->params( $url->query_form_hash );
487 return $self->output;
490 sub get_template_root {
493 return $r->parent->get_template_root if $r->{parent};
494 return $self->NEXT::DISTINCT::get_template_root( $r, @_ );
500 return $r->parent->view_object if $r->{parent};
501 return $self->NEXT::DISTINCT::view_object( $r, @_ );
504 # Instead of making plugin authors use the NEXT::DISTINCT hoopla to ensure other
505 # plugins also get to call the hook, we can cycle through the application's
506 # @ISA and call them all here. Doesn't work for setup() though, because it's
507 # too ingrained in the stack. We could add a run_setup() method, but we'd break
508 # lots of existing code.
511 my ($self, $hook) = @_;
515 my $class = ref($self);
517 @plugins = @{"$class\::ISA"};
520 # this is either a custom method in the driver, or the method in the 1st
521 # plugin, or the 'null' method in the frontend (i.e. inherited from
522 # Maypole.pm) - we need to be careful to only call it once
523 my $first_hook = $self->can($hook);
526 my %seen = ( $first_hook => 1 );
528 # @plugins includes the frontend
529 foreach my $plugin (@plugins)
531 next unless my $plugin_hook = $plugin->can($hook);
532 next if $seen{$plugin_hook}++;
539 This is the main request handling method and calls various methods to handle the
540 request/response and defines the workflow within Maypole.
544 # The root of all evil
547 $self->build_form_elements(1) unless (defined ($self->config->build_form_elements) && $self->config->build_form_elements == 0);
548 $self->__load_request_model;
550 my $applicable = $self->is_model_applicable == OK;
554 # handle authentication
555 eval { $status = $self->call_authenticate };
556 if ( my $error = $@ ) {
557 $status = $self->call_exception($error, "authentication");
558 if ( $status != OK ) {
559 $self->warn("caught authenticate error: $error");
560 return $self->debug ?
561 $self->view_object->error($self, $error) : ERROR;
564 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 = $@ ) {
577 $status = $self->call_exception($error, "model");
578 if ( $status != OK ) {
579 $self->warn("caught model error: $error");
580 return $self->debug ?
581 $self->view_object->error($self, $error) : ERROR;
585 $self->__setup_plain_template;
588 # less frequent path - perhaps output has been set to an error message
590 $self->{content_type} ||= $self->__get_mime_type();
591 $self->{document_encoding} ||= "utf-8";
595 # normal path - no output has been generated yet
596 my $processed_view_ok = $self->__call_process_view;
598 $self->{content_type} ||= $self->__get_mime_type();
599 $self->{document_encoding} ||= "utf-8";
601 return $processed_view_ok;
605 'js' => 'text/javascript',
607 'htm' => 'text/html',
608 'html' => 'text/html',
611 sub __get_mime_type {
613 my $type = 'text/html';
614 if ($self->path =~ m/.*\.(\w{3,4})$/) {
615 $type = $filetypes{$1};
617 my $output = $self->output;
618 if (defined $output) {
619 $type = $mmagic->checktype_contents($output);
625 sub __load_request_model
628 # We may get a made up class from class_of
629 my $mclass = $self->config->model->class_of($self, $self->table);
630 if ( eval {$mclass->isa('Maypole::Model::Base')} ) {
631 $self->model_class( $mclass );
633 elsif ($self->debug > 1) {
634 $self->warn("***Warning: No $mclass class appropriate for model. @_");
639 # is_applicable() returned false, so set up a plain template. Model processing
640 # will be skipped, but need to remove the model anyway so the template can't
642 sub __setup_plain_template
646 # It's just a plain template
647 $self->build_form_elements(0);
648 $self->model_class(undef);
650 unless ($self->template) {
651 # FIXME: this is likely to be redundant and is definately causing problems.
652 my $path = $self->path;
653 $path =~ s{/$}{}; # De-absolutify
655 $self->template($self->path);
659 # The model has been processed or skipped (if is_applicable returned false),
660 # any exceptions have been handled, and there's no content in $self->output
661 sub __call_process_view {
664 my $status = eval { $self->view_object->process($self) };
666 my $error = $@ || $self->{error};
669 $status = $self->call_exception($error, "view");
671 if ( $status != OK ) {
672 warn "caught view error: $error" if $self->debug;
673 return $self->debug ?
674 $self->view_object->error($self, $error) : ERROR;
683 $r->warn('its all gone pete tong');
685 Warn must be implemented by the backend, i.e. Apache::MVC
686 and warn to stderr or appropriate logfile.
688 You can also over-ride this in your Maypole driver, should you
689 want to use something like Log::Log4perl instead.
695 =item build_form_elements
697 $r->build_form_elements(0);
699 Specify (in an action) whether to build HTML form elements and populate
700 the cgi element of classmetadata in the view.
702 You can set this globally using the accessor of the same name in Maypole::Config,
703 this method allows you to over-ride that setting per action.
709 You should only need to define this method if you are writing a new
710 Maypole backend. It should return something that looks like an Apache
711 or CGI request object, it defaults to blank.
719 Turns the backend request (e.g. Apache::MVC, Maypole, CGI) into a Maypole
720 request. It does this by setting the C<path>, and invoking C<parse_path> and
723 You should only need to define this method if you are writing a new Maypole
730 die "parse_location is a virtual method. Do not use Maypole directly; " .
731 "use Apache::MVC or similar";
734 =item start_request_hook
736 This is called immediately after setting up the basic request. The default
739 The value of C<< $r->status >> is set to C<OK> before this hook is run. Your
740 implementation can change the status code, or leave it alone.
742 After this hook has run, Maypole will check the value of C<status>. For any
743 value other than C<OK>, Maypole returns the C<status> immediately.
745 This is useful for filtering out requests for static files, e.g. images, which
746 should not be processed by Maypole or by the templating engine:
748 sub start_request_hook
752 $r->status(DECLINED) if $r->path =~ /\.jpg$/;
755 Multiple plugins, and the driver, can define this hook - Maypole will call all
756 of them. You should check for and probably not change any non-OK C<status>
759 package Maypole::Plugin::MyApp::SkipFavicon;
761 sub start_request_hook
765 # check if a previous plugin has already DECLINED this request
766 # - probably unnecessary in this example, but you get the idea
767 return unless $r->status == OK;
770 $r->status(DECLINED) if $r->path =~ /favicon\.ico/;
775 sub start_request_hook { }
779 B<This method is deprecated> as of version 2.11. If you have overridden it,
780 please override C<is_model_applicable> instead, and change the return type
781 from a Maypole:Constant to a true/false value.
783 Returns a Maypole::Constant to indicate whether the request is valid.
787 sub is_applicable { return shift->is_model_applicable(@_); }
789 =item is_model_applicable
791 Returns true or false to indicate whether the request is valid.
793 The default implementation checks that C<< $r->table >> is publicly
794 accessible and that the model class is configured to handle the
799 sub is_model_applicable {
802 # Establish which tables should be processed by the model
803 my $config = $self->config;
805 $config->ok_tables || $config->ok_tables( $config->display_tables );
807 $config->ok_tables( { map { $_ => 1 } @{ $config->ok_tables } } )
808 if ref $config->ok_tables eq "ARRAY";
810 my $ok_tables = $config->ok_tables;
812 # Does this request concern a table to be processed by the model?
813 my $table = $self->table;
817 if (exists $ok_tables->{$table})
824 $self->warn ("We don't have that table ($table).\n"
825 . "Available tables are: "
826 . join( ",", keys %$ok_tables ))
827 if $self->debug and not $ok_tables->{$table};
832 # Is the action public?
833 my $action = $self->action;
834 return OK if $self->model_class->is_public($action);
836 $self->warn("The action '$action' is not applicable to the table '$table'")
844 Called immediately after C<start_request_hook()>.
846 This method should return a session, which will be stored in the request's
847 C<session> attribute.
849 The default method is empty.
857 Called immediately after C<get_session>.
859 This method should return a user, which will be stored in the request's C<user>
862 The default method is empty.
868 =item call_authenticate
870 This method first checks if the relevant model class
871 can authenticate the user, or falls back to the default
872 authenticate method of your Maypole application.
876 sub call_authenticate
880 # Check if we have a model class with an authenticate() to delegate to
881 return $self->model_class->authenticate($self)
882 if $self->model_class and $self->model_class->can('authenticate');
884 # Interface consistency is a Good Thing -
885 # the invocant and the argument may one day be different things
886 # (i.e. controller and request), like they are when authenticate()
887 # is called on a model class (i.e. model and request)
888 return $self->authenticate($self);
893 Returns a Maypole::Constant to indicate whether the user is authenticated for
896 The default implementation returns C<OK>
900 sub authenticate { return OK }
905 This model is called to catch exceptions, first after authenticate, then after
906 processing the model class, and finally to check for exceptions from the view
909 This method first checks if the relevant model class
910 can handle exceptions the user, or falls back to the default
911 exception method of your Maypole application.
917 my ($self, $error, $when) = @_;
919 # Check if we have a model class with an exception() to delegate to
920 if ( $self->model_class && $self->model_class->can('exception') )
922 my $status = $self->model_class->exception( $self, $error, $when );
923 return $status if $status == OK;
926 return $self->exception($error, $when);
932 This method is called if any exceptions are raised during the authentication or
933 model/view processing. It should accept the exception as a parameter and return
934 a Maypole::Constant to indicate whether the request should continue to be
940 my ($self, $error, $when) = @_;
941 if (ref $self->view_object && $self->view_object->can("report_error") and $self->debug) {
942 $self->view_object->report_error($self, $error, $when);
948 =item additional_data
950 Called before the model processes the request, this method gives you a chance to
951 do some processing for each request, for example, manipulating C<template_args>.
955 sub additional_data { }
959 Sends the output and additional headers to the user.
964 die "send_output is a virtual method. Do not use Maypole directly; use Apache::MVC or similar";
970 =head2 Path processing and manipulation
976 Returns the request path
980 Parses the request path and sets the C<args>, C<action> and C<table>
981 properties. Calls C<preprocess_path> before parsing path and setting properties.
989 # Previous versions unconditionally set table, action and args to whatever
990 # was in @pi (or else to defaults, if @pi is empty).
991 # Adding preprocess_path(), and then setting table, action and args
992 # conditionally, broke lots of tests, hence this:
993 $self->$_(undef) for qw/action table args/;
994 $self->preprocess_path;
996 # use frontpage template for frontpage
997 unless ($self->path && $self->path ne '/') {
998 $self->path('frontpage');
1001 my @pi = grep {length} split '/', $self->path;
1003 $self->table || $self->table(shift @pi);
1004 $self->action || $self->action( shift @pi or 'index' );
1005 $self->args || $self->args(\@pi);
1008 =item preprocess_path
1010 Sometimes when you don't want to rewrite or over-ride parse_path but
1011 want to rewrite urls or extract data from them before it is parsed.
1013 This method is called after parse_location has populated the request
1014 information and before parse_path has populated the model and action
1015 information, and is passed the request object.
1017 You can set action, args or table in this method and parse_path will
1018 then leave those values in place or populate them if not present
1022 sub preprocess_path { };
1024 =item make_path( %args or \%args or @args )
1026 This is the counterpart to C<parse_path>. It generates a path to use
1027 in links, form actions etc. To implement your own path scheme, just override
1028 this method and C<parse_path>.
1030 %args = ( table => $table,
1032 additional => $additional, # optional - generally an object ID
1035 \%args = as above, but a ref
1037 @args = ( $table, $action, $additional ); # $additional is optional
1039 C<id> can be used as an alternative key to C<additional>.
1041 C<$additional> can be a string, an arrayref, or a hashref. An arrayref is
1042 expanded into extra path elements, whereas a hashref is translated into a query
1053 if (@_ == 1 and ref $_[0] and ref $_[0] eq 'HASH')
1057 elsif ( @_ > 1 and @_ < 4 )
1059 $args{table} = shift;
1060 $args{action} = shift;
1061 $args{additional} = shift;
1068 do { die "no $_" unless $args{$_} } for qw( table action );
1070 my $additional = $args{additional} || $args{id};
1076 # if $additional is a href, make_uri() will transform it into a query
1077 @add = (ref $additional eq 'ARRAY') ? @$additional : ($additional);
1080 my $uri = $r->make_uri($args{table}, $args{action}, @add);
1082 return $uri->as_string;
1087 =item make_uri( @segments )
1089 Make a L<URI> object given table, action etc. Automatically adds
1092 If the final element in C<@segments> is a hash ref, C<make_uri> will render it
1099 my ($r, @segments) = @_;
1101 my $query = (ref $segments[-1] eq 'HASH') ? pop(@segments) : undef;
1103 my $base = $r->config->uri_base;
1106 my $uri = URI->new($base);
1107 $uri->path_segments($uri->path_segments, grep {length} @segments);
1109 my $abs_uri = $uri->abs('/');
1110 $abs_uri->query_form($query) if $query;
1116 Turns post data and query string paramaters into a hash of C<params>.
1118 You should only need to define this method if you are writing a new Maypole
1125 die "parse_args() is a virtual method. Do not use Maypole directly; ".
1126 "use Apache::MVC or similar";
1129 =item get_template_root
1131 Implementation-specific path to template root.
1133 You should only need to define this method if you are writing a new Maypole
1134 backend. Otherwise, see L<Maypole::Config/"template_root">
1140 =head2 Request properties
1146 Returns the perl package name that will serve as the model for the
1147 request. It corresponds to the request C<table> attribute.
1152 Get/set a list of model objects. The objects will be accessible in the view
1155 If the first item in C<$self-E<gt>args> can be C<retrieve()>d by the model
1156 class, it will be removed from C<args> and the retrieved object will be added to
1157 the C<objects> list. See L<Maypole::Model> for more information.
1162 Alias to get/set the first/only model object. The object will be accessible
1163 in the view templates.
1165 When used to set the object, will overwrite the request objects
1166 with a single object.
1171 my ($r,$object) = @_;
1172 $r->objects([$object]) if ($object);
1173 return undef unless $r->objects();
1174 return $r->objects->[0];
1179 $self->template_args->{foo} = 'bar';
1181 Get/set a hash of template variables.
1183 Maypole reserved words for template variables will over-ride values in template_variables.
1185 Reserved words are : r, request, object, objects, base, config and errors, as well as the
1186 current class or object name.
1190 A place to put custom application data. Not used by Maypole itself.
1194 Get/set the template to be used by the view. By default, it returns
1195 C<$self-E<gt>action>
1200 Get/set a request error
1204 Get/set the response output. This is usually populated by the view class. You
1205 can skip view processing by setting the C<output>.
1209 The table part of the Maypole request path
1213 The action part of the Maypole request path
1217 A list of remaining parts of the request path after table and action
1223 A L<Maypole::Headers> object containing HTTP headers for the request
1227 A L<HTTP::Headers> object that contains HTTP headers for the output
1229 =item document_encoding
1231 Get/set the output encoding. Default: utf-8.
1235 Get/set the output content type. Default: text/html
1239 Returns the protocol the request was made with, i.e. https
1244 die "get_protocol is a virtual method. Do not use Maypole directly; use Apache::MVC or similar";
1249 =head2 Request parameters
1251 The source of the parameters may vary depending on the Maypole backend, but they
1252 are usually populated from request query string and POST data.
1254 Maypole supplies several approaches for accessing the request parameters. Note
1255 that the current implementation (via a hashref) of C<query> and C<params> is
1256 likely to change in a future version of Maypole. So avoid direct access to these
1259 $r->{params}->{foo} # bad
1260 $r->params->{foo} # better
1262 $r->{query}->{foo} # bad
1263 $r->query->{foo} # better
1265 $r->param('foo') # best
1271 An accessor (get or set) for request parameters. It behaves similarly to
1272 CGI::param() for accessing CGI parameters, i.e.
1274 $r->param # returns list of keys
1275 $r->param($key) # returns value for $key
1276 $r->param($key => $value) # returns old value, sets to new value
1282 my ($self, $key) = (shift, shift);
1284 return keys %{$self->params} unless defined $key;
1286 return unless exists $self->params->{$key};
1288 my $val = $self->params->{$key};
1292 my $new_val = shift;
1293 $self->params->{$key} = $new_val;
1296 return (ref $val eq 'ARRAY') ? @$val : ($val) if wantarray;
1298 return (ref $val eq 'ARRAY') ? $val->[0] : $val;
1304 Returns a hashref of request parameters.
1306 B<Note:> Where muliple values of a parameter were supplied, the C<params> value
1307 will be an array reference.
1311 Alias for C<params>.
1315 =head3 Utility methods
1319 =item redirect_request
1321 Sets output headers to redirect based on the arguments provided
1323 Accepts either a single argument of the full url to redirect to, or a hash of
1326 $r->redirect_request('http://www.example.com/path');
1330 $r->redirect_request(protocol=>'https', domain=>'www.example.com', path=>'/path/file?arguments', status=>'302', url=>'..');
1332 The named parameters are protocol, domain, path, status and url
1334 Only 1 named parameter is required but other than url, they can be combined as
1335 required and current values (from the request) will be used in place of any
1336 missing arguments. The url argument must be a full url including protocol and
1337 can only be combined with status.
1341 sub redirect_request {
1342 die "redirect_request is a virtual method. Do not use Maypole directly; use Apache::MVC or similar";
1345 # =item redirect_internal_request
1349 # sub redirect_internal_request {
1354 =item make_random_id
1356 returns a unique id for this request can be used to prevent or detect repeat
1361 # Session and Repeat Submission Handling
1362 sub make_random_id {
1363 use Maypole::Session;
1364 return Maypole::Session::generate_unique_id();
1369 =head1 SEQUENCE DIAGRAMS
1371 See L<Maypole::Manual::Workflow> for a detailed discussion of the sequence of
1372 calls during processing of a request. This is a brief summary:
1376 BeerDB Maypole::Model::CDBI
1380 || setup_model | setup_database() creates
1381 ||------+ | a subclass of the Model
1382 |||<----+ | for each table
1384 ||| setup_database | |
1385 |||--------------------->|| 'create' *
1386 ||| ||----------> $subclass
1388 ||| load_model_subclass | |
1389 foreach |||------+ ($subclass) | |
1390 $subclass ||||<----+ | require |
1391 ||||--------------------------------------->|
1393 ||| adopt($subclass) | |
1394 |||--------------------->|| |
1399 || | new | view_object: e.g.
1400 ||---------------------------------------------> Maypole::View::TT
1412 BeerDB Model $subclass view_object
1415 o-------->| new | | |
1416 |-----> r:BeerDB | | |
1420 | ||-----+ parse_location | | |
1423 | ||-----+ start_request_hook | | |
1426 | ||-----+ get_session | | |
1429 | ||-----+ get_user | | |
1432 | ||-----+ handler_guts | | |
1434 | ||| class_of($table) | | |
1435 | |||------------------------->|| | |
1436 | ||| $subclass || | |
1437 | |||<-------------------------|| | |
1439 | |||-----+ is_model_applicable| | |
1442 | |||-----+ call_authenticate | | |
1445 | |||-----+ additional_data | | |
1448 | |||--------------------------------->|| fetch_objects
1456 | |||------------------------------------------->|| template
1460 | || send_output | | |
1464 <------------------|| | | |
1475 There's more documentation, examples, and information on our mailing lists
1476 at the Maypole web site:
1478 L<http://maypole.perl.org/>
1480 L<Maypole::Application>, L<Apache::MVC>, L<CGI::Maypole>.
1484 Maypole is currently maintained by Aaron Trevena.
1486 =head1 AUTHOR EMERITUS
1488 Simon Cozens, C<simon#cpan.org>
1490 Simon Flack maintained Maypole from 2.05 to 2.09
1492 Sebastian Riedel, C<sri#oook.de> maintained Maypole from 1.99_01 to 2.04
1496 Sebastian Riedel, Danijel Milicevic, Dave Slack, Jesse Sheidlower, Jody Belka,
1497 Marcus Ramberg, Mickael Joanne, Randal Schwartz, Simon Flack, Steve Simms,
1498 Veljko Vidovic and all the others who've helped.
1502 You may distribute this code under the same terms as Perl itself.
1510 =item register_cleanup($coderef)
1512 Analogous to L<Apache>'s C<register_cleanup>. If an Apache request object is
1513 available, this call simply redispatches there. If not, the cleanup is
1514 registered in the Maypole request, and executed when the request is
1517 This method is only useful in persistent environments, where you need to ensure
1518 that some code runs when the request finishes, no matter how it finishes (e.g.
1519 after an unexpected error).
1526 sub register_cleanup
1528 my ($self, $cleanup) = @_;
1530 die "register_cleanup() is an instance method, not a class method"
1532 die "Cleanup must be a coderef" unless ref($cleanup) eq 'CODE';
1534 if ($self->can('ar') && $self->ar)
1536 $self->ar->register_cleanup($cleanup);
1540 push @_cleanups, $cleanup;
1548 while (my $cleanup = shift @_cleanups)
1550 eval { $cleanup->() };
1553 warn "Error during request cleanup: $@";