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_pre2';
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();
456 die "status undefined after start_request_hook()" unless defined
460 my $status = $self->handler_guts;
461 return $status unless $status == OK;
462 # TODO: require send_output to return a status code
469 Run Maypole sub-requests as a component of the request
471 [% request.component("/beer/view_as_component/20") %]
473 Allows you to integrate the results of a Maypole request into an existing
474 request. You'll need to set up actions and templates
475 which return fragments of HTML rather than entire pages, but once you've
476 done that, you can use the C<component> method of the Maypole request object
477 to call those actions. You may pass a query string in the usual URL style.
479 You should not fully qualify the Maypole URLs.
481 Note: any HTTP POST or URL parameters passed to the parent are not passed to the
482 component sub-request, only what is included in the url passed as an argyument
488 my ( $r, $path ) = @_;
489 my $self = bless { parent => $r, config => $r->{config}, template_args => {}, }, ref $r;
491 my $url = URI->new($path);
492 warn "path : $path\n";
493 $self->{path} = $url->path;
495 $self->params( $url->query_form_hash );
497 return $self->output;
500 sub get_template_root {
503 return $r->parent->get_template_root if $r->{parent};
504 return $self->NEXT::DISTINCT::get_template_root( $r, @_ );
510 return $r->parent->view_object if $r->{parent};
511 return $self->NEXT::DISTINCT::view_object( $r, @_ );
514 # Instead of making plugin authors use the NEXT::DISTINCT hoopla to ensure other
515 # plugins also get to call the hook, we can cycle through the application's
516 # @ISA and call them all here. Doesn't work for setup() though, because it's
517 # too ingrained in the stack. We could add a run_setup() method, but we'd break
518 # lots of existing code.
521 my ($self, $hook) = @_;
525 my $class = ref($self);
527 @plugins = @{"$class\::ISA"};
530 # this is either a custom method in the driver, or the method in the 1st
531 # plugin, or the 'null' method in the frontend (i.e. inherited from
532 # Maypole.pm) - we need to be careful to only call it once
533 my $first_hook = $self->can($hook);
536 my %seen = ( $first_hook => 1 );
538 # @plugins includes the frontend
539 foreach my $plugin (@plugins)
541 next unless my $plugin_hook = $plugin->can($hook);
542 next if $seen{$plugin_hook}++;
549 This is the main request handling method and calls various methods to handle the
550 request/response and defines the workflow within Maypole.
552 B<Currently undocumented and liable to be refactored without warning>.
556 # The root of all evil
561 $self->__load_request_model;
563 my $applicable = $self->is_model_applicable == OK;
567 # handle authentication
568 eval { $status = $self->call_authenticate };
569 if ( my $error = $@ )
571 $status = $self->call_exception($error, "authentication");
574 warn "caught authenticate error: $error";
575 return $self->debug ?
576 $self->view_object->error($self, $error) : ERROR;
579 if ( $self->debug and $status != OK and $status != DECLINED )
581 $self->view_object->error( $self,
582 "Got unexpected status $status from calling authentication" );
585 return $status unless $status == OK;
587 # We run additional_data for every request
588 $self->additional_data;
591 eval { $self->model_class->process($self) };
592 if ( my $error = $@ )
594 $status = $self->call_exception($error, "model");
597 warn "caught model error: $error";
598 return $self->debug ?
599 $self->view_object->error($self, $error) : ERROR;
603 $self->__setup_plain_template;
606 # less frequent path - perhaps output has been set to an error message
607 return OK if $self->output;
609 # normal path - no output has been generated yet
610 my $processed_view_ok = $self->__call_process_view;
612 $self->{content_type} ||= $self->__get_mime_type();
613 $self->{document_encoding} ||= "utf-8";
616 return $processed_view_ok;
620 'js' => 'text/javascript',
622 'htm' => 'text/html',
623 'html' => 'text/html',
626 sub __get_mime_type {
628 my $type = 'text/html';
629 if ($self->path =~ m/.*\.(\w{3,4})$/) {
630 $type = $filetypes{$1};
632 my $output = $self->output;
633 if (defined $output) {
634 $type = $mmagic->checktype_contents($output);
640 sub __load_request_model
643 $self->model_class( $self->config->model->class_of($self, $self->table) );
646 # is_applicable() returned false, so set up a plain template. Model processing
647 # will be skipped, but need to remove the model anyway so the template can't
649 sub __setup_plain_template
653 # It's just a plain template
654 $self->model_class(undef);
656 my $path = $self->path;
657 $path =~ s{/$}{}; # De-absolutify
660 $self->template($self->path);
663 # The model has been processed or skipped (if is_applicable returned false),
664 # any exceptions have been handled, and there's no content in $self->output
665 sub __call_process_view {
668 my $status = eval { $self->view_object->process($self) };
670 my $error = $@ || $self->{error};
673 $status = $self->call_exception($error, "view");
675 if ( $status != OK ) {
676 warn "caught view error: $error" if $self->debug;
677 return $self->debug ?
678 $self->view_object->error($self, $error) : ERROR;
687 You should only need to define this method if you are writing a new
688 Maypole backend. It should return something that looks like an Apache
689 or CGI request object, it defaults to blank.
697 Turns the backend request (e.g. Apache::MVC, Maypole, CGI) into a Maypole
698 request. It does this by setting the C<path>, and invoking C<parse_path> and
701 You should only need to define this method if you are writing a new Maypole
708 die "parse_location is a virtual method. Do not use Maypole directly; " .
709 "use Apache::MVC or similar";
712 =item start_request_hook
714 This is called immediately after setting up the basic request. The default
717 The value of C<< $r->status >> is set to C<OK> before this hook is run. Your
718 implementation can change the status code, or leave it alone.
720 After this hook has run, Maypole will check the value of C<status>. For any
721 value other than C<OK>, Maypole returns the C<status> immediately.
723 This is useful for filtering out requests for static files, e.g. images, which
724 should not be processed by Maypole or by the templating engine:
726 sub start_request_hook
730 $r->status(DECLINED) if $r->path =~ /\.jpg$/;
733 Multiple plugins, and the driver, can define this hook - Maypole will call all
734 of them. You should check for and probably not change any non-OK C<status>
737 package Maypole::Plugin::MyApp::SkipFavicon;
739 sub start_request_hook
743 # check if a previous plugin has already DECLINED this request
744 # - probably unnecessary in this example, but you get the idea
745 return unless $r->status == OK;
748 $r->status(DECLINED) if $r->path =~ /favicon\.ico/;
753 sub start_request_hook { }
757 B<This method is deprecated> as of version 2.11. If you have overridden it,
758 please override C<is_model_applicable> instead, and change the return type
759 from a Maypole:Constant to a true/false value.
761 Returns a Maypole::Constant to indicate whether the request is valid.
765 sub is_applicable { return shift->is_model_applicable(@_); }
767 =item is_model_applicable
769 Returns true or false to indicate whether the request is valid.
771 The default implementation checks that C<< $r->table >> is publicly
772 accessible and that the model class is configured to handle the
777 sub is_model_applicable {
780 # Establish which tables should be processed by the model
781 my $config = $self->config;
783 $config->ok_tables || $config->ok_tables( $config->display_tables );
785 $config->ok_tables( { map { $_ => 1 } @{ $config->ok_tables } } )
786 if ref $config->ok_tables eq "ARRAY";
788 my $ok_tables = $config->ok_tables;
790 # Does this request concern a table to be processed by the model?
791 my $table = $self->table;
795 if (exists $ok_tables->{$table})
802 warn "We don't have that table ($table).\n"
803 . "Available tables are: "
804 . join( ",", keys %$ok_tables )
805 if $self->debug and not $ok_tables->{$table};
810 # Is the action public?
811 my $action = $self->action;
812 return OK if $self->model_class->is_public($action);
814 warn "The action '$action' is not applicable to the table '$table'"
822 Called immediately after C<start_request_hook()>.
824 This method should return a session, which will be stored in the request's
825 C<session> attribute.
827 The default method is empty.
835 Called immediately after C<get_session>.
837 This method should return a user, which will be stored in the request's C<user>
840 The default method is empty.
846 =item call_authenticate
848 This method first checks if the relevant model class
849 can authenticate the user, or falls back to the default
850 authenticate method of your Maypole application.
854 sub call_authenticate
858 # Check if we have a model class with an authenticate() to delegate to
859 return $self->model_class->authenticate($self)
860 if $self->model_class and $self->model_class->can('authenticate');
862 # Interface consistency is a Good Thing -
863 # the invocant and the argument may one day be different things
864 # (i.e. controller and request), like they are when authenticate()
865 # is called on a model class (i.e. model and request)
866 return $self->authenticate($self);
871 Returns a Maypole::Constant to indicate whether the user is authenticated for
874 The default implementation returns C<OK>
878 sub authenticate { return OK }
883 This model is called to catch exceptions, first after authenticate, then after
884 processing the model class, and finally to check for exceptions from the view
887 This method first checks if the relevant model class
888 can handle exceptions the user, or falls back to the default
889 exception method of your Maypole application.
895 my ($self, $error, $when) = @_;
897 # Check if we have a model class with an exception() to delegate to
898 if ( $self->model_class && $self->model_class->can('exception') )
900 my $status = $self->model_class->exception( $self, $error, $when );
901 return $status if $status == OK;
904 return $self->exception($error, $when);
910 This method is called if any exceptions are raised during the authentication or
911 model/view processing. It should accept the exception as a parameter and return
912 a Maypole::Constant to indicate whether the request should continue to be
918 my ($self, $error, $when) = @_;
919 if (ref $self->view_object && $self->view_object->can("report_error") and $self->debug) {
920 $self->view_object->report_error($self, $error, $when);
926 =item additional_data
928 Called before the model processes the request, this method gives you a chance to
929 do some processing for each request, for example, manipulating C<template_args>.
933 sub additional_data { }
937 Sends the output and additional headers to the user.
942 die "send_output is a virtual method. Do not use Maypole directly; use Apache::MVC or similar";
950 =head2 Path processing and manipulation
956 Returns the request path
960 Parses the request path and sets the C<args>, C<action> and C<table>
961 properties. Calls C<preprocess_path> before parsing path and setting properties.
969 # Previous versions unconditionally set table, action and args to whatever
970 # was in @pi (or else to defaults, if @pi is empty).
971 # Adding preprocess_path(), and then setting table, action and args
972 # conditionally, broke lots of tests, hence this:
973 $self->$_(undef) for qw/action table args/;
975 $self->preprocess_path;
976 $self->path || $self->path('frontpage');
978 my @pi = grep {length} split '/', $self->path;
981 $self->table || $self->table(shift @pi);
982 $self->action || $self->action( shift @pi or 'index' );
983 $self->args || $self->args(\@pi);
986 =item preprocess_path
988 Sometimes when you don't want to rewrite or over-ride parse_path but
989 want to rewrite urls or extract data from them before it is parsed.
991 This method is called after parse_location has populated the request
992 information and before parse_path has populated the model and action
993 information, and is passed the request object.
995 You can set action, args or table in this method and parse_path will
996 then leave those values in place or populate them if not present
1000 sub preprocess_path { };
1002 =item make_path( %args or \%args or @args )
1004 This is the counterpart to C<parse_path>. It generates a path to use
1005 in links, form actions etc. To implement your own path scheme, just override
1006 this method and C<parse_path>.
1008 %args = ( table => $table,
1010 additional => $additional, # optional - generally an object ID
1013 \%args = as above, but a ref
1015 @args = ( $table, $action, $additional ); # $additional is optional
1017 C<id> can be used as an alternative key to C<additional>.
1019 C<$additional> can be a string, an arrayref, or a hashref. An arrayref is
1020 expanded into extra path elements, whereas a hashref is translated into a query
1031 if (@_ == 1 and ref $_[0] and ref $_[0] eq 'HASH')
1035 elsif ( @_ > 1 and @_ < 4 )
1037 $args{table} = shift;
1038 $args{action} = shift;
1039 $args{additional} = shift;
1046 do { die "no $_" unless $args{$_} } for qw( table action );
1048 my $additional = $args{additional} || $args{id};
1054 # if $additional is a href, make_uri() will transform it into a query
1055 @add = (ref $additional eq 'ARRAY') ? @$additional : ($additional);
1058 my $uri = $r->make_uri($args{table}, $args{action}, @add);
1060 return $uri->as_string;
1065 =item make_uri( @segments )
1067 Make a L<URI> object given table, action etc. Automatically adds
1070 If the final element in C<@segments> is a hash ref, C<make_uri> will render it
1077 my ($r, @segments) = @_;
1079 my $query = (ref $segments[-1] eq 'HASH') ? pop(@segments) : undef;
1081 my $base = $r->config->uri_base;
1084 my $uri = URI->new($base);
1085 $uri->path_segments($uri->path_segments, grep {length} @segments);
1087 my $abs_uri = $uri->abs('/');
1088 $abs_uri->query_form($query) if $query;
1094 Turns post data and query string paramaters into a hash of C<params>.
1096 You should only need to define this method if you are writing a new Maypole
1103 die "parse_args() is a virtual method. Do not use Maypole directly; ".
1104 "use Apache::MVC or similar";
1107 =item get_template_root
1109 Implementation-specific path to template root.
1111 You should only need to define this method if you are writing a new Maypole
1112 backend. Otherwise, see L<Maypole::Config/"template_root">
1118 =head2 Request properties
1124 Returns the perl package name that will serve as the model for the
1125 request. It corresponds to the request C<table> attribute.
1130 Get/set a list of model objects. The objects will be accessible in the view
1133 If the first item in C<$self-E<gt>args> can be C<retrieve()>d by the model
1134 class, it will be removed from C<args> and the retrieved object will be added to
1135 the C<objects> list. See L<Maypole::Model> for more information.
1139 $self->template_args->{foo} = 'bar';
1141 Get/set a hash of template variables.
1145 A place to put custom application data. Not used by Maypole itself.
1149 Get/set the template to be used by the view. By default, it returns
1150 C<$self-E<gt>action>
1155 Get/set a request error
1159 Get/set the response output. This is usually populated by the view class. You
1160 can skip view processing by setting the C<output>.
1164 The table part of the Maypole request path
1168 The action part of the Maypole request path
1172 A list of remaining parts of the request path after table and action
1178 A L<Maypole::Headers> object containing HTTP headers for the request
1182 A L<HTTP::Headers> object that contains HTTP headers for the output
1184 =item document_encoding
1186 Get/set the output encoding. Default: utf-8.
1190 Get/set the output content type. Default: text/html
1194 Returns the protocol the request was made with, i.e. https
1199 die "get_protocol is a virtual method. Do not use Maypole directly; use Apache::MVC or similar";
1204 =head2 Request parameters
1206 The source of the parameters may vary depending on the Maypole backend, but they
1207 are usually populated from request query string and POST data.
1209 Maypole supplies several approaches for accessing the request parameters. Note
1210 that the current implementation (via a hashref) of C<query> and C<params> is
1211 likely to change in a future version of Maypole. So avoid direct access to these
1214 $r->{params}->{foo} # bad
1215 $r->params->{foo} # better
1217 $r->{query}->{foo} # bad
1218 $r->query->{foo} # better
1220 $r->param('foo') # best
1226 An accessor (get or set) for request parameters. It behaves similarly to
1227 CGI::param() for accessing CGI parameters, i.e.
1229 $r->param # returns list of keys
1230 $r->param($key) # returns value for $key
1231 $r->param($key => $value) # returns old value, sets to new value
1237 my ($self, $key) = (shift, shift);
1239 return keys %{$self->params} unless defined $key;
1241 return unless exists $self->params->{$key};
1243 my $val = $self->params->{$key};
1247 my $new_val = shift;
1248 $self->params->{$key} = $new_val;
1251 return ref $val ? @$val : ($val) if wantarray;
1253 return ref $val ? $val->[0] : $val;
1259 Returns a hashref of request parameters.
1261 B<Note:> Where muliple values of a parameter were supplied, the C<params> value
1262 will be an array reference.
1266 Alias for C<params>.
1270 =head3 Utility methods
1274 =item redirect_request
1276 Sets output headers to redirect based on the arguments provided
1278 Accepts either a single argument of the full url to redirect to, or a hash of
1281 $r->redirect_request('http://www.example.com/path');
1285 $r->redirect_request(protocol=>'https', domain=>'www.example.com', path=>'/path/file?arguments', status=>'302', url=>'..');
1287 The named parameters are protocol, domain, path, status and url
1289 Only 1 named parameter is required but other than url, they can be combined as
1290 required and current values (from the request) will be used in place of any
1291 missing arguments. The url argument must be a full url including protocol and
1292 can only be combined with status.
1296 sub redirect_request {
1297 die "redirect_request is a virtual method. Do not use Maypole directly; use Apache::MVC or similar";
1300 =item redirect_internal_request
1304 sub redirect_internal_request {
1309 =item make_random_id
1311 returns a unique id for this request can be used to prevent or detect repeat
1316 # Session and Repeat Submission Handling
1317 sub make_random_id {
1318 use Maypole::Session;
1319 return Maypole::Session::generate_unique_id();
1324 =head1 SEQUENCE DIAGRAMS
1326 See L<Maypole::Manual::Workflow> for a detailed discussion of the sequence of
1327 calls during processing of a request. This is a brief summary:
1331 BeerDB Maypole::Model::CDBI
1335 || setup_model | setup_database() creates
1336 ||------+ | a subclass of the Model
1337 |||<----+ | for each table
1339 ||| setup_database | |
1340 |||--------------------->|| 'create' *
1341 ||| ||----------> $subclass
1343 ||| load_model_subclass | |
1344 foreach |||------+ ($subclass) | |
1345 $subclass ||||<----+ | require |
1346 ||||--------------------------------------->|
1348 ||| adopt($subclass) | |
1349 |||--------------------->|| |
1354 || | new | view_object: e.g.
1355 ||---------------------------------------------> Maypole::View::TT
1367 BeerDB Model $subclass view_object
1370 o-------->| new | | |
1371 |-----> r:BeerDB | | |
1375 | ||-----+ parse_location | | |
1378 | ||-----+ start_request_hook | | |
1381 | ||-----+ get_session | | |
1384 | ||-----+ get_user | | |
1387 | ||-----+ handler_guts | | |
1389 | ||| class_of($table) | | |
1390 | |||------------------------->|| | |
1391 | ||| $subclass || | |
1392 | |||<-------------------------|| | |
1394 | |||-----+ is_model_applicable| | |
1397 | |||-----+ call_authenticate | | |
1400 | |||-----+ additional_data | | |
1403 | |||--------------------------------->|| fetch_objects
1411 | |||------------------------------------------->|| template
1415 | || send_output | | |
1419 <------------------|| | | |
1430 There's more documentation, examples, and information on our mailing lists
1431 at the Maypole web site:
1433 L<http://maypole.perl.org/>
1435 L<Maypole::Application>, L<Apache::MVC>, L<CGI::Maypole>.
1439 Maypole is currently maintained by Aaron Trevena.
1441 =head1 AUTHOR EMERITUS
1443 Simon Cozens, C<simon#cpan.org>
1445 Simon Flack maintained Maypole from 2.05 to 2.09
1447 Sebastian Riedel, C<sri#oook.de> maintained Maypole from 1.99_01 to 2.04
1451 Sebastian Riedel, Danijel Milicevic, Dave Slack, Jesse Sheidlower, Jody Belka,
1452 Marcus Ramberg, Mickael Joanne, Randal Schwartz, Simon Flack, Steve Simms,
1453 Veljko Vidovic and all the others who've helped.
1457 You may distribute this code under the same terms as Perl itself.
1465 =item register_cleanup($coderef)
1467 Analogous to L<Apache>'s C<register_cleanup>. If an Apache request object is
1468 available, this call simply redispatches there. If not, the cleanup is
1469 registered in the Maypole request, and executed when the request is
1472 This method is only useful in persistent environments, where you need to ensure
1473 that some code runs when the request finishes, no matter how it finishes (e.g.
1474 after an unexpected error).
1481 sub register_cleanup
1483 my ($self, $cleanup) = @_;
1485 die "register_cleanup() is an instance method, not a class method"
1487 die "Cleanup must be a coderef" unless ref($cleanup) eq 'CODE';
1489 if ($self->can('ar') && $self->ar)
1491 $self->ar->register_cleanup($cleanup);
1495 push @_cleanups, $cleanup;
1503 while (my $cleanup = shift @_cleanups)
1505 eval { $cleanup->() };
1508 warn "Error during request cleanup: $@";