2 use base qw(Class::Accessor::Fast Class::Data::Inheritable);
3 use UNIVERSAL::require;
8 use Maypole::Constants;
13 use File::MMagic::XS qw(:compat);
15 our $VERSION = '2.11';
16 our $mmagic = File::MMagic::XS->new();
18 # proposed privacy conventions:
19 # - no leading underscore - public to custom application code and plugins
20 # - single leading underscore - private to the main Maypole stack - *not*
22 # - double leading underscore - private to the current package
26 Maypole - MVC web application framework
30 The canonical example used in the Maypole documentation is the beer database:
36 # choose a frontend, initialise the config object, and load a plugin
37 use Maypole::Application qw/Relationship/;
39 # get the empty config object created by Maypole::Application
40 my $config = __PACKAGE__->config;
43 $config->uri_base("http://localhost/beerdb");
44 $config->template_root("/path/to/templates");
45 $config->rows_per_page(10);
46 $config->display_tables([qw/beer brewery pub style/]);
49 $config->relationships([
50 "a brewery produces beers",
51 "a style defines beers",
52 "a pub has beers on handpumps",
56 BeerDB::Brewery->untaint_columns( printable => [qw/name notes url/] );
57 BeerDB::Pub->untaint_columns( printable => [qw/name notes url/] );
58 BeerDB::Style->untaint_columns( printable => [qw/name notes/] );
59 BeerDB::Beer->untaint_columns(
60 printable => [qw/abv name price notes/],
61 integer => [qw/style brewery score/],
66 __PACKAGE__->setup("dbi:SQLite:t/beerdb.db");
72 This documents the Maypole request object. See the L<Maypole::Manual>, for a
73 detailed guide to using Maypole.
75 Maypole is a Perl web application framework similar to Java's struts. It is
76 essentially completely abstracted, and so doesn't know anything about
77 how to talk to the outside world.
79 To use it, you need to create a driver package which represents your entire
80 application. This is the C<BeerDB> package used as an example in the manual.
82 This needs to first use L<Maypole::Application> which will make your package
83 inherit from the appropriate platform driver such as C<Apache::MVC> or
84 C<CGI::Maypole>. Then, the driver calls C<setup>. This sets up the model classes
85 and configures your application. The default model class for Maypole uses
86 L<Class::DBI> to map a database to classes, but this can be changed by altering
87 configuration (B<before> calling setup.)
90 =head1 DOCUMENTATION AND SUPPORT
92 Note that some details in some of these resources may be out of date.
96 =item The Maypole Manual
98 The primary documentation is the Maypole manual. This lives in the
99 C<Maypole::Manual> pod documents included with the distribution.
103 Individual packages within the distribution contain (more or less) detailed
104 reference documentation for their API.
108 There are two mailing lists - maypole-devel and maypole-users - see
109 http://maypole.perl.org/?MailingList
111 =item The Maypole Wiki
113 The Maypole wiki provides a useful store of extra documentation -
114 http://maypole.perl.org
116 In particular, there's a FAQ (http://maypole.perl.org/?FAQ) and a cookbook
117 (http://maypole.perl.org/?Cookbook). Again, certain information on these pages
120 =item Web applications with Maypole
122 A tutorial written by Simon Cozens for YAPC::EU 2005 -
123 http://www.droogs.org/perl/maypole/maypole-tutorial.pdf [228KB].
125 =item A Database-Driven Web Application in 18 Lines of Code
127 By Paul Barry, published in Linux Journal, March 2005.
129 http://www.linuxjournal.com/article/7937
131 "From zero to Web-based database application in eight easy steps".
133 Maypole won a 2005 Linux Journal Editor's Choice Award
134 (http://www.linuxjournal.com/article/8293) after featuring in this article.
136 =item Build Web apps with Maypole
138 By Simon Cozens, on IBM's DeveloperWorks website, May 2004.
140 http://www-128.ibm.com/developerworks/linux/library/l-maypole/
142 =item Rapid Web Application Deployment with Maypole
144 By Simon Cozens, on O'Reilly's Perl website, April 2004.
146 http://www.perl.com/pub/a/2004/04/15/maypole.html
150 Some notes written by Simon Cozens. A little bit out of date, but still
151 very useful: http://www.droogs.org/perl/maypole/authentication.html
155 There's a refcard for the Maypole (and Class::DBI) APIs on the wiki -
156 http://maypole.perl.org/?CheatSheet. Probably a little out of date now - it's a
157 wiki, so feel free to fix any errors!
159 =item Plugins and add-ons
161 There are a large and growing number of plugins and other add-on modules
162 available on CPAN - http://search.cpan.org/search?query=maypole&mode=module
166 You can find a range of useful Maypole links, particularly to several thoughtful
167 blog entries, starting here: http://del.icio.us/search/?all=maypole
171 There are a couple of short reviews here:
172 http://cpanratings.perl.org/dist/Maypole
178 A couple of demos are available, sometimes with source code and configs.
182 =item http://maypole.perl.org/beerdb/
184 The standard BeerDB example, using the TT factory templates supplied in the
187 =item beerdb.riverside-cms.co.uk
189 The standard BeerDB example, running on Mason, using the factory templates
190 supplied in the L<MasonX::Maypole> distribution.
192 =item beerfb.riverside-cms.co.uk
194 A demo of L<Maypole::FormBuilder>. This site is running on the set of Mason
195 templates included in the L<Maypole::FormBuilder> distribution. See the
196 synopsis of L<Maypole::Plugin::FormBuilder> for an example driver
202 __PACKAGE__->mk_classdata($_) for qw( config init_done view_object model_classes_loaded);
204 __PACKAGE__->mk_accessors(
205 qw( params query objects model_class template_args output path
206 args action template error document_encoding content_type table
207 headers_in headers_out stash status parent)
210 __PACKAGE__->config( Maypole::Config->new() );
212 __PACKAGE__->init_done(0);
214 __PACKAGE__->model_classes_loaded(0);
216 =head1 HOOKABLE METHODS
218 As a framework, Maypole provides a number of B<hooks> - methods that are
219 intended to be overridden. Some of these methods come with useful default
220 behaviour, others do nothing by default. Hooks include:
246 sub My::App::debug {1}
248 Returns the debugging flag. Override this in your application class to
249 enable/disable debugging.
251 You can also set the C<debug> flag via L<Maypole::Application>.
253 Some packages respond to higher debug levels, try increasing it to 2 or 3.
262 Returns the L<Maypole::Config> object
266 My::App->setup($data_source, $user, $password, \%attr);
268 Initialise the Maypole application and plugins and model classes.
269 Your application should call this B<after> setting up configuration data via
272 It calls the hook C<setup_model> to setup the model. The %attr hash contains
273 options and arguments used to set up the model. See the particular model's
274 documentation. However here is the most usage of setup where
275 Maypole::Model::CDBI is the base class.
277 My::App->setup($data_source, $user, $password,
278 { options => { # These are DB connection options
283 # These are Class::DBI::Loader arguments.
289 Also, see L<Maypole::Manual::Plugins>.
298 $class->setup_model(@_);
303 Called by C<setup>. This method builds the Maypole model hierarchy.
305 A likely target for over-riding, if you need to build a customised model.
307 This method also ensures any code in custom model classes is loaded, so you
308 don't need to load them in the driver.
314 $class = ref $class if ref $class;
315 my $config = $class->config;
316 $config->model || $config->model('Maypole::Model::CDBI');
317 $config->model->require or die sprintf
318 "Couldn't load the model class %s: %s", $config->model, $@;
320 # among other things, this populates $config->classes
321 $config->model->setup_database($config, $class, @_);
323 foreach my $subclass ( @{ $config->classes } ) {
324 next if $subclass->isa("Maypole::Model::Base");
326 unshift @{ $subclass . "::ISA" }, $config->model;
329 # Load custom model code, if it exists - nb this must happen after the
330 # unshift, to allow code attributes to work, but before adopt(),
331 # in case adopt() calls overridden methods on $subclass
332 foreach my $subclass ( @{ $config->classes } ) {
333 $class->load_model_subclass($subclass) unless ($class->model_classes_loaded());
334 $config->model->adopt($subclass) if $config->model->can("adopt");
339 =item load_model_subclass($subclass)
341 This method is called from C<setup_model()>. It attempts to load the
342 C<$subclass> package, if one exists. So if you make a customized C<BeerDB::Beer>
343 package, you don't need to explicitly load it.
345 If automatic loading causes problems, Override load_model_subclass in your driver.
347 sub load_model_subclass {};
349 Or perhaps during development, if you don't want to load up custom classes, you
350 can override this method and load them manually.
354 sub load_model_subclass {
355 my ($class, $subclass) = @_;
357 my $config = $class->config;
359 # Load any external files for the model base class or subclasses
360 # (e.g. BeerDB/DBI.pm or BeerDB/Beer.pm) based on code borrowed from
361 # Maypole::Plugin::Loader and Class::DBI.
362 if ( $subclass->require ) {
363 warn "Loaded external module for '$subclass'\n" if $class->debug > 1;
365 (my $filename = $subclass) =~ s!::!/!g;
366 die "Loading '$subclass' failed: $@\n"
367 unless $@ =~ /Can\'t locate \Q$filename\E\.pm/;
368 warn "No external module for '$subclass'"
369 if $class->debug > 1;
375 Loads the view class and instantiates the view object.
377 You should not call this directly, but you may wish to override this to add
378 application-specific initialisation - see L<Maypole::Manual::Plugins>.
385 my $config = $class->config;
386 $config->view || $config->view("Maypole::View::TT");
387 $config->view->require;
388 die "Couldn't load the view class " . $config->view . ": $@" if $@;
389 $config->display_tables
390 || $config->display_tables( $class->config->tables );
391 $class->view_object( $class->config->view->new );
392 $class->init_done(1);
397 Constructs a very minimal new Maypole request object.
407 config => $class->config,
415 Get/set the Maypole::View object
419 =head1 INSTANCE METHODS
427 This method sets up the class if it's not done yet, sets some defaults and
428 leaves the dirty work to C<handler_guts>.
432 # handler() has a method attribute so that mod_perl will invoke
433 # BeerDB->handler() as a method rather than a plain function
434 # BeerDB::handler() and so this inherited implementation will be
435 # found. See e.g. "Practical mod_perl" by Bekman & Cholet for
436 # more information <http://modperlbook.org/html/ch25_01.html>
437 sub handler : method {
438 # See Maypole::Workflow before trying to understand this.
439 my ($class, $req) = @_;
441 $class->init unless $class->init_done;
443 my $self = $class->new;
445 # initialise the request
446 $self->headers_out(Maypole::Headers->new);
447 $self->get_request($req);
449 $self->parse_location;
451 # hook useful for declining static requests e.g. images, or perhaps for
452 # sanitizing request parameters
453 $self->status(Maypole::Constants::OK()); # set the default
454 $self->__call_hook('start_request_hook');
455 return $self->status unless $self->status == Maypole::Constants::OK();
457 die "status undefined after start_request_hook()" unless defined
463 my $status = $self->handler_guts;
465 return $status unless $status == OK;
467 # TODO: require send_output to return a status code
475 Run Maypole sub-requests as a component of the request
477 [% request.component("/beer/view_as_component/20") %]
479 Allows you to integrate the results of a Maypole request into an existing
480 request. You'll need to set up actions and templates
481 which return fragments of HTML rather than entire pages, but once you've
482 done that, you can use the C<component> method of the Maypole request object
483 to call those actions. You may pass a query string in the usual URL style.
485 You should not fully qualify the Maypole URLs.
487 Note: any HTTP POST or URL parameters passed to the parent are not passed to the
488 component sub-request, only what is included in the url passed as an argyument
494 my ( $r, $path ) = @_;
495 my $self = bless { parent => $r, config => $r->{config}, template_args => {}, }, ref $r;
497 my $url = URI->new($path);
498 warn "path : $path\n";
499 $self->{path} = $url->path;
501 $self->params( $url->query_form_hash );
503 return $self->output;
506 sub get_template_root {
509 return $r->parent->get_template_root if $r->{parent};
510 return $self->NEXT::DISTINCT::get_template_root( $r, @_ );
516 return $r->parent->view_object if $r->{parent};
517 return $self->NEXT::DISTINCT::view_object( $r, @_ );
520 # Instead of making plugin authors use the NEXT::DISTINCT hoopla to ensure other
521 # plugins also get to call the hook, we can cycle through the application's
522 # @ISA and call them all here. Doesn't work for setup() though, because it's
523 # too ingrained in the stack. We could add a run_setup() method, but we'd break
524 # lots of existing code.
527 my ($self, $hook) = @_;
531 my $class = ref($self);
533 @plugins = @{"$class\::ISA"};
536 # this is either a custom method in the driver, or the method in the 1st
537 # plugin, or the 'null' method in the frontend (i.e. inherited from
538 # Maypole.pm) - we need to be careful to only call it once
539 my $first_hook = $self->can($hook);
542 my %seen = ( $first_hook => 1 );
544 # @plugins includes the frontend
545 foreach my $plugin (@plugins)
547 next unless my $plugin_hook = $plugin->can($hook);
548 next if $seen{$plugin_hook}++;
555 This is the main request handling method and calls various methods to handle the
556 request/response and defines the workflow within Maypole.
558 B<Currently undocumented and liable to be refactored without warning>.
562 # The root of all evil
567 $self->__load_request_model;
569 my $applicable = $self->is_model_applicable == OK;
573 # handle authentication
574 eval { $status = $self->call_authenticate };
575 if ( my $error = $@ )
577 $status = $self->call_exception($error, "authentication");
580 warn "caught authenticate error: $error";
581 return $self->debug ?
582 $self->view_object->error($self, $error) : ERROR;
585 if ( $self->debug and $status != OK and $status != DECLINED )
587 $self->view_object->error( $self,
588 "Got unexpected status $status from calling authentication" );
591 return $status unless $status == OK;
593 # We run additional_data for every request
594 $self->additional_data;
597 eval { $self->model_class->process($self) };
598 if ( my $error = $@ )
600 $status = $self->call_exception($error, "model");
603 warn "caught model error: $error";
604 return $self->debug ?
605 $self->view_object->error($self, $error) : ERROR;
609 $self->__setup_plain_template;
612 # less frequent path - perhaps output has been set to an error message
613 return OK if $self->output;
615 # normal path - no output has been generated yet
616 my $processed_view_ok = $self->__call_process_view;
618 $self->{content_type} ||= $self->__get_mime_type();
619 $self->{document_encoding} ||= "utf-8";
622 return $processed_view_ok;
626 'js' => 'text/javascript',
628 'htm' => 'text/html',
629 'html' => 'text/html',
632 sub __get_mime_type {
634 my $type = 'text/html';
635 if ($self->path =~ m/.*\.(\w{3,4})$/) {
636 $type = $filetypes{$1};
638 my $output = $self->output;
639 if (defined $output) {
640 $type = $mmagic->checktype_contents($output);
646 sub __load_request_model
649 $self->model_class( $self->config->model->class_of($self, $self->table) );
652 # is_applicable() returned false, so set up a plain template. Model processing
653 # will be skipped, but need to remove the model anyway so the template can't
655 sub __setup_plain_template
659 # It's just a plain template
660 $self->model_class(undef);
662 my $path = $self->path;
663 $path =~ s{/$}{}; # De-absolutify
666 $self->template($self->path);
669 # The model has been processed or skipped (if is_applicable returned false),
670 # any exceptions have been handled, and there's no content in $self->output
671 sub __call_process_view {
674 my $status = eval { $self->view_object->process($self) };
676 my $error = $@ || $self->{error};
679 $status = $self->call_exception($error, "view");
681 if ( $status != OK ) {
682 warn "caught view error: $error" if $self->debug;
683 return $self->debug ?
684 $self->view_object->error($self, $error) : ERROR;
693 You should only need to define this method if you are writing a new
694 Maypole backend. It should return something that looks like an Apache
695 or CGI request object, it defaults to blank.
703 Turns the backend request (e.g. Apache::MVC, Maypole, CGI) into a Maypole
704 request. It does this by setting the C<path>, and invoking C<parse_path> and
707 You should only need to define this method if you are writing a new Maypole
714 die "parse_location is a virtual method. Do not use Maypole directly; " .
715 "use Apache::MVC or similar";
718 =item start_request_hook
720 This is called immediately after setting up the basic request. The default
723 The value of C<< $r->status >> is set to C<OK> before this hook is run. Your
724 implementation can change the status code, or leave it alone.
726 After this hook has run, Maypole will check the value of C<status>. For any
727 value other than C<OK>, Maypole returns the C<status> immediately.
729 This is useful for filtering out requests for static files, e.g. images, which
730 should not be processed by Maypole or by the templating engine:
732 sub start_request_hook
736 $r->status(DECLINED) if $r->path =~ /\.jpg$/;
739 Multiple plugins, and the driver, can define this hook - Maypole will call all
740 of them. You should check for and probably not change any non-OK C<status>
743 package Maypole::Plugin::MyApp::SkipFavicon;
745 sub start_request_hook
749 # check if a previous plugin has already DECLINED this request
750 # - probably unnecessary in this example, but you get the idea
751 return unless $r->status == OK;
754 $r->status(DECLINED) if $r->path =~ /favicon\.ico/;
759 sub start_request_hook { }
763 B<This method is deprecated> as of version 2.11. If you have overridden it,
764 please override C<is_model_applicable> instead, and change the return type
765 from a Maypole:Constant to a true/false value.
767 Returns a Maypole::Constant to indicate whether the request is valid.
771 sub is_applicable { return shift->is_model_applicable(@_); }
773 =item is_model_applicable
775 Returns true or false to indicate whether the request is valid.
777 The default implementation checks that C<< $r->table >> is publicly
778 accessible and that the model class is configured to handle the
783 sub is_model_applicable {
786 # Establish which tables should be processed by the model
787 my $config = $self->config;
789 $config->ok_tables || $config->ok_tables( $config->display_tables );
791 $config->ok_tables( { map { $_ => 1 } @{ $config->ok_tables } } )
792 if ref $config->ok_tables eq "ARRAY";
794 my $ok_tables = $config->ok_tables;
796 # Does this request concern a table to be processed by the model?
797 my $table = $self->table;
801 if (exists $ok_tables->{$table})
808 warn "We don't have that table ($table).\n"
809 . "Available tables are: "
810 . join( ",", keys %$ok_tables )
811 if $self->debug and not $ok_tables->{$table};
816 # Is the action public?
817 my $action = $self->action;
818 return OK if $self->model_class->is_public($action);
820 warn "The action '$action' is not applicable to the table '$table'"
828 Called immediately after C<start_request_hook()>.
830 This method should return a session, which will be stored in the request's
831 C<session> attribute.
833 The default method is empty.
841 Called immediately after C<get_session>.
843 This method should return a user, which will be stored in the request's C<user>
846 The default method is empty.
852 =item call_authenticate
854 This method first checks if the relevant model class
855 can authenticate the user, or falls back to the default
856 authenticate method of your Maypole application.
860 sub call_authenticate
864 # Check if we have a model class with an authenticate() to delegate to
865 return $self->model_class->authenticate($self)
866 if $self->model_class and $self->model_class->can('authenticate');
868 # Interface consistency is a Good Thing -
869 # the invocant and the argument may one day be different things
870 # (i.e. controller and request), like they are when authenticate()
871 # is called on a model class (i.e. model and request)
872 return $self->authenticate($self);
877 Returns a Maypole::Constant to indicate whether the user is authenticated for
880 The default implementation returns C<OK>
884 sub authenticate { return OK }
889 This model is called to catch exceptions, first after authenticate, then after
890 processing the model class, and finally to check for exceptions from the view
893 This method first checks if the relevant model class
894 can handle exceptions the user, or falls back to the default
895 exception method of your Maypole application.
901 my ($self, $error, $when) = @_;
903 # Check if we have a model class with an exception() to delegate to
904 if ( $self->model_class && $self->model_class->can('exception') )
906 my $status = $self->model_class->exception( $self, $error, $when );
907 return $status if $status == OK;
910 return $self->exception($error, $when);
916 This method is called if any exceptions are raised during the authentication or
917 model/view processing. It should accept the exception as a parameter and return
918 a Maypole::Constant to indicate whether the request should continue to be
924 my ($self, $error, $when) = @_;
925 if (ref $self->view_object && $self->view_object->can("report_error") and $self->debug) {
926 $self->view_object->report_error($self, $error, $when);
932 =item additional_data
934 Called before the model processes the request, this method gives you a chance to
935 do some processing for each request, for example, manipulating C<template_args>.
939 sub additional_data { }
943 Sends the output and additional headers to the user.
948 die "send_output is a virtual method. Do not use Maypole directly; use Apache::MVC or similar";
956 =head2 Path processing and manipulation
962 Returns the request path
966 Parses the request path and sets the C<args>, C<action> and C<table>
967 properties. Calls C<preprocess_path> before parsing path and setting properties.
975 # Previous versions unconditionally set table, action and args to whatever
976 # was in @pi (or else to defaults, if @pi is empty).
977 # Adding preprocess_path(), and then setting table, action and args
978 # conditionally, broke lots of tests, hence this:
979 $self->$_(undef) for qw/action table args/;
981 $self->preprocess_path;
982 $self->path || $self->path('frontpage');
984 my @pi = grep {length} split '/', $self->path;
987 $self->table || $self->table(shift @pi);
988 $self->action || $self->action( shift @pi or 'index' );
989 $self->args || $self->args(\@pi);
992 =item preprocess_path
994 Sometimes when you don't want to rewrite or over-ride parse_path but
995 want to rewrite urls or extract data from them before it is parsed.
997 This method is called after parse_location has populated the request
998 information and before parse_path has populated the model and action
999 information, and is passed the request object.
1001 You can set action, args or table in this method and parse_path will
1002 then leave those values in place or populate them if not present
1006 sub preprocess_path { };
1008 =item make_path( %args or \%args or @args )
1010 This is the counterpart to C<parse_path>. It generates a path to use
1011 in links, form actions etc. To implement your own path scheme, just override
1012 this method and C<parse_path>.
1014 %args = ( table => $table,
1016 additional => $additional, # optional - generally an object ID
1019 \%args = as above, but a ref
1021 @args = ( $table, $action, $additional ); # $additional is optional
1023 C<id> can be used as an alternative key to C<additional>.
1025 C<$additional> can be a string, an arrayref, or a hashref. An arrayref is
1026 expanded into extra path elements, whereas a hashref is translated into a query
1037 if (@_ == 1 and ref $_[0] and ref $_[0] eq 'HASH')
1041 elsif ( @_ > 1 and @_ < 4 )
1043 $args{table} = shift;
1044 $args{action} = shift;
1045 $args{additional} = shift;
1052 do { die "no $_" unless $args{$_} } for qw( table action );
1054 my $additional = $args{additional} || $args{id};
1060 # if $additional is a href, make_uri() will transform it into a query
1061 @add = (ref $additional eq 'ARRAY') ? @$additional : ($additional);
1064 my $uri = $r->make_uri($args{table}, $args{action}, @add);
1066 return $uri->as_string;
1071 =item make_uri( @segments )
1073 Make a L<URI> object given table, action etc. Automatically adds
1076 If the final element in C<@segments> is a hash ref, C<make_uri> will render it
1083 my ($r, @segments) = @_;
1085 my $query = (ref $segments[-1] eq 'HASH') ? pop(@segments) : undef;
1087 my $base = $r->config->uri_base;
1090 my $uri = URI->new($base);
1091 $uri->path_segments($uri->path_segments, grep {length} @segments);
1093 my $abs_uri = $uri->abs('/');
1094 $abs_uri->query_form($query) if $query;
1100 Turns post data and query string paramaters into a hash of C<params>.
1102 You should only need to define this method if you are writing a new Maypole
1109 die "parse_args() is a virtual method. Do not use Maypole directly; ".
1110 "use Apache::MVC or similar";
1113 =item get_template_root
1115 Implementation-specific path to template root.
1117 You should only need to define this method if you are writing a new Maypole
1118 backend. Otherwise, see L<Maypole::Config/"template_root">
1124 =head2 Request properties
1130 Returns the perl package name that will serve as the model for the
1131 request. It corresponds to the request C<table> attribute.
1136 Get/set a list of model objects. The objects will be accessible in the view
1139 If the first item in C<$self-E<gt>args> can be C<retrieve()>d by the model
1140 class, it will be removed from C<args> and the retrieved object will be added to
1141 the C<objects> list. See L<Maypole::Model> for more information.
1145 $self->template_args->{foo} = 'bar';
1147 Get/set a hash of template variables.
1151 A place to put custom application data. Not used by Maypole itself.
1155 Get/set the template to be used by the view. By default, it returns
1156 C<$self-E<gt>action>
1161 Get/set a request error
1165 Get/set the response output. This is usually populated by the view class. You
1166 can skip view processing by setting the C<output>.
1170 The table part of the Maypole request path
1174 The action part of the Maypole request path
1178 A list of remaining parts of the request path after table and action
1184 A L<Maypole::Headers> object containing HTTP headers for the request
1188 A L<HTTP::Headers> object that contains HTTP headers for the output
1190 =item document_encoding
1192 Get/set the output encoding. Default: utf-8.
1196 Get/set the output content type. Default: text/html
1200 Returns the protocol the request was made with, i.e. https
1205 die "get_protocol is a virtual method. Do not use Maypole directly; use Apache::MVC or similar";
1210 =head2 Request parameters
1212 The source of the parameters may vary depending on the Maypole backend, but they
1213 are usually populated from request query string and POST data.
1215 Maypole supplies several approaches for accessing the request parameters. Note
1216 that the current implementation (via a hashref) of C<query> and C<params> is
1217 likely to change in a future version of Maypole. So avoid direct access to these
1220 $r->{params}->{foo} # bad
1221 $r->params->{foo} # better
1223 $r->{query}->{foo} # bad
1224 $r->query->{foo} # better
1226 $r->param('foo') # best
1232 An accessor (get or set) for request parameters. It behaves similarly to
1233 CGI::param() for accessing CGI parameters, i.e.
1235 $r->param # returns list of keys
1236 $r->param($key) # returns value for $key
1237 $r->param($key => $value) # returns old value, sets to new value
1243 my ($self, $key) = (shift, shift);
1245 return keys %{$self->params} unless defined $key;
1247 return unless exists $self->params->{$key};
1249 my $val = $self->params->{$key};
1253 my $new_val = shift;
1254 $self->params->{$key} = $new_val;
1257 return ref $val ? @$val : ($val) if wantarray;
1259 return ref $val ? $val->[0] : $val;
1265 Returns a hashref of request parameters.
1267 B<Note:> Where muliple values of a parameter were supplied, the C<params> value
1268 will be an array reference.
1272 Alias for C<params>.
1276 =head3 Utility methods
1280 =item redirect_request
1282 Sets output headers to redirect based on the arguments provided
1284 Accepts either a single argument of the full url to redirect to, or a hash of
1287 $r->redirect_request('http://www.example.com/path');
1291 $r->redirect_request(protocol=>'https', domain=>'www.example.com', path=>'/path/file?arguments', status=>'302', url=>'..');
1293 The named parameters are protocol, domain, path, status and url
1295 Only 1 named parameter is required but other than url, they can be combined as
1296 required and current values (from the request) will be used in place of any
1297 missing arguments. The url argument must be a full url including protocol and
1298 can only be combined with status.
1302 sub redirect_request {
1303 die "redirect_request is a virtual method. Do not use Maypole directly; use Apache::MVC or similar";
1306 =item redirect_internal_request
1310 sub redirect_internal_request {
1315 =item make_random_id
1317 returns a unique id for this request can be used to prevent or detect repeat
1322 # Session and Repeat Submission Handling
1323 sub make_random_id {
1324 use Maypole::Session;
1325 return Maypole::Session::generate_unique_id();
1330 =head1 SEQUENCE DIAGRAMS
1332 See L<Maypole::Manual::Workflow> for a detailed discussion of the sequence of
1333 calls during processing of a request. This is a brief summary:
1337 BeerDB Maypole::Model::CDBI
1341 || setup_model | setup_database() creates
1342 ||------+ | a subclass of the Model
1343 |||<----+ | for each table
1345 ||| setup_database | |
1346 |||--------------------->|| 'create' *
1347 ||| ||----------> $subclass
1349 ||| load_model_subclass | |
1350 foreach |||------+ ($subclass) | |
1351 $subclass ||||<----+ | require |
1352 ||||--------------------------------------->|
1354 ||| adopt($subclass) | |
1355 |||--------------------->|| |
1360 || | new | view_object: e.g.
1361 ||---------------------------------------------> Maypole::View::TT
1373 BeerDB Model $subclass view_object
1376 o-------->| new | | |
1377 |-----> r:BeerDB | | |
1381 | ||-----+ parse_location | | |
1384 | ||-----+ start_request_hook | | |
1387 | ||-----+ get_session | | |
1390 | ||-----+ get_user | | |
1393 | ||-----+ handler_guts | | |
1395 | ||| class_of($table) | | |
1396 | |||------------------------->|| | |
1397 | ||| $subclass || | |
1398 | |||<-------------------------|| | |
1400 | |||-----+ is_model_applicable| | |
1403 | |||-----+ call_authenticate | | |
1406 | |||-----+ additional_data | | |
1409 | |||--------------------------------->|| fetch_objects
1417 | |||------------------------------------------->|| template
1421 | || send_output | | |
1425 <------------------|| | | |
1436 There's more documentation, examples, and information on our mailing lists
1437 at the Maypole web site:
1439 L<http://maypole.perl.org/>
1441 L<Maypole::Application>, L<Apache::MVC>, L<CGI::Maypole>.
1445 Maypole is currently maintained by Aaron Trevena.
1447 =head1 AUTHOR EMERITUS
1449 Simon Cozens, C<simon#cpan.org>
1451 Simon Flack maintained Maypole from 2.05 to 2.09
1453 Sebastian Riedel, C<sri#oook.de> maintained Maypole from 1.99_01 to 2.04
1457 Sebastian Riedel, Danijel Milicevic, Dave Slack, Jesse Sheidlower, Jody Belka,
1458 Marcus Ramberg, Mickael Joanne, Randal Schwartz, Simon Flack, Steve Simms,
1459 Veljko Vidovic and all the others who've helped.
1463 You may distribute this code under the same terms as Perl itself.
1471 =item register_cleanup($coderef)
1473 Analogous to L<Apache>'s C<register_cleanup>. If an Apache request object is
1474 available, this call simply redispatches there. If not, the cleanup is
1475 registered in the Maypole request, and executed when the request is
1478 This method is only useful in persistent environments, where you need to ensure
1479 that some code runs when the request finishes, no matter how it finishes (e.g.
1480 after an unexpected error).
1487 sub register_cleanup
1489 my ($self, $cleanup) = @_;
1491 die "register_cleanup() is an instance method, not a class method"
1493 die "Cleanup must be a coderef" unless ref($cleanup) eq 'CODE';
1495 if ($self->can('ar') && $self->ar)
1497 $self->ar->register_cleanup($cleanup);
1501 push @_cleanups, $cleanup;
1509 while (my $cleanup = shift @_cleanups)
1511 eval { $cleanup->() };
1514 warn "Error during request cleanup: $@";