3 use base qw(Class::Accessor::Fast Class::Data::Inheritable);
4 use UNIVERSAL::require;
9 use Maypole::Constants;
14 use File::MMagic::XS qw(:compat);
16 our $VERSION = '2.12';
17 our $mmagic = File::MMagic::XS->new();
19 # proposed privacy conventions:
20 # - no leading underscore - public to custom application code and plugins
21 # - single leading underscore - private to the main Maypole stack - *not*
23 # - double leading underscore - private to the current package
27 Maypole - MVC web application framework
31 The canonical example used in the Maypole documentation is the beer database:
37 # choose a frontend, initialise the config object, and load a plugin
38 use Maypole::Application qw/Relationship/;
41 __PACKAGE__->setup("dbi:SQLite:t/beerdb.db");
43 # get the empty config object created by Maypole::Application
44 my $config = __PACKAGE__->config;
47 $config->uri_base("http://localhost/beerdb");
48 $config->template_root("/path/to/templates");
49 $config->rows_per_page(10);
50 $config->display_tables([qw/beer brewery pub style/]);
53 $config->relationships([
54 "a brewery produces beers",
55 "a style defines beers",
56 "a pub has beers on handpumps",
60 BeerDB::Brewery->untaint_columns( printable => [qw/name notes url/] );
61 BeerDB::Pub->untaint_columns( printable => [qw/name notes url/] );
62 BeerDB::Style->untaint_columns( printable => [qw/name notes/] );
63 BeerDB::Beer->untaint_columns(
64 printable => [qw/abv name price notes/],
65 integer => [qw/style brewery score/],
69 # note : set up model before calling this method
70 BeerDB::Beer->required_columns([qw/name/]);
76 This documents the Maypole request object. See the L<Maypole::Manual>, for a
77 detailed guide to using Maypole.
79 Maypole is a Perl web application framework similar to Java's struts. It is
80 essentially completely abstracted, and so doesn't know anything about
81 how to talk to the outside world.
83 To use it, you need to create a driver package which represents your entire
84 application. This is the C<BeerDB> package used as an example in the manual.
86 This needs to first use L<Maypole::Application> which will make your package
87 inherit from the appropriate platform driver such as C<Apache::MVC> or
88 C<CGI::Maypole>. Then, the driver calls C<setup>. This sets up the model classes
89 and configures your application. The default model class for Maypole uses
90 L<Class::DBI> to map a database to classes, but this can be changed by altering
91 configuration (B<before> calling setup.)
94 =head1 DOCUMENTATION AND SUPPORT
96 Note that some details in some of these resources may be out of date.
100 =item The Maypole Manual
102 The primary documentation is the Maypole manual. This lives in the
103 C<Maypole::Manual> pod documents included with the distribution.
107 Individual packages within the distribution contain (more or less) detailed
108 reference documentation for their API.
112 There are two mailing lists - maypole-devel and maypole-users - see
113 http://maypole.perl.org/?MailingList
115 =item The Maypole Wiki
117 The Maypole wiki provides a useful store of extra documentation -
118 http://maypole.perl.org
120 In particular, there's a FAQ (http://maypole.perl.org/?FAQ) and a cookbook
121 (http://maypole.perl.org/?Cookbook). Again, certain information on these pages
124 =item Web applications with Maypole
126 A tutorial written by Simon Cozens for YAPC::EU 2005 -
127 http://www.aarontrevena.co.uk/opensource/maypole/maypole-tutorial.pdf [228KB].
129 =item A Database-Driven Web Application in 18 Lines of Code
131 By Paul Barry, published in Linux Journal, March 2005.
133 http://www.linuxjournal.com/article/7937
135 "From zero to Web-based database application in eight easy steps".
137 Maypole won a 2005 Linux Journal Editor's Choice Award
138 (http://www.linuxjournal.com/article/8293) after featuring in this article.
140 =item Build Web apps with Maypole
142 By Simon Cozens, on IBM's DeveloperWorks website, May 2004.
144 http://www-128.ibm.com/developerworks/linux/library/l-maypole/
146 =item Rapid Web Application Deployment with Maypole
148 By Simon Cozens, on O'Reilly's Perl website, April 2004.
150 http://www.perl.com/pub/a/2004/04/15/maypole.html
154 Some notes written by Simon Cozens. A little bit out of date, but still
155 very useful: http://www.aarontrevena.co.uk/opensource/maypole/authentication.html
159 There's a refcard for the Maypole (and Class::DBI) APIs on the wiki -
160 http://maypole.perl.org/?CheatSheet. Probably a little out of date now - it's a
161 wiki, so feel free to fix any errors!
163 =item Plugins and add-ons
165 There are a large and growing number of plugins and other add-on modules
166 available on CPAN - http://search.cpan.org/search?query=maypole&mode=module
170 You can find a range of useful Maypole links, particularly to several thoughtful
171 blog entries, starting here: http://del.icio.us/search/?all=maypole
175 There are a couple of short reviews here:
176 http://cpanratings.perl.org/dist/Maypole
182 __PACKAGE__->mk_classdata($_) for qw( config init_done view_object model_classes_loaded);
184 __PACKAGE__->mk_accessors(
185 qw( params query objects model_class template_args output path
186 args action template error document_encoding content_type table
187 headers_in headers_out stash status parent build_form_elements)
190 __PACKAGE__->config( Maypole::Config->new() );
192 __PACKAGE__->init_done(0);
194 __PACKAGE__->model_classes_loaded(0);
196 =head1 HOOKABLE METHODS
198 As a framework, Maypole provides a number of B<hooks> - methods that are
199 intended to be overridden. Some of these methods come with useful default
200 behaviour, others do nothing by default. Hooks include:
226 sub My::App::debug {1}
228 Returns the debugging flag. Override this in your application class to
229 enable/disable debugging.
231 You can also set the C<debug> flag via L<Maypole::Application>.
233 Some packages respond to higher debug levels, try increasing it to 2 or 3.
242 Returns the L<Maypole::Config> object
246 My::App->setup($data_source, $user, $password, \%attr);
248 Initialise the Maypole application and plugins and model classes.
249 Your application should call this B<after> setting up configuration data via
252 It calls the hook C<setup_model> to setup the model. The %attr hash contains
253 options and arguments used to set up the model. See the particular model's
254 documentation. However here is the most usage of setup where
255 Maypole::Model::CDBI is the base class.
257 My::App->setup($data_source, $user, $password,
258 { options => { # These are DB connection options
263 # These are Class::DBI::Loader arguments.
269 Also, see L<Maypole::Manual::Plugins>.
278 $class->setup_model(@_);
283 Called by C<setup>. This method builds the Maypole model hierarchy.
285 A likely target for over-riding, if you need to build a customised model.
287 This method also ensures any code in custom model classes is loaded, so you
288 don't need to load them in the driver.
294 $class = ref $class if ref $class;
295 my $config = $class->config;
296 $config->model || $config->model('Maypole::Model::CDBI');
297 $config->model->require or die sprintf
298 "Couldn't load the model class %s: %s", $config->model, $@;
300 # among other things, this populates $config->classes
301 $config->model->setup_database($config, $class, @_);
303 $config->model->add_model_superclass($config);
305 # Load custom model code, if it exists - nb this must happen after the
306 # adding the model superclass, to allow code attributes to work, but before adopt(),
307 # in case adopt() calls overridden methods on $subclass
308 foreach my $subclass ( @{ $config->classes } ) {
309 $class->load_model_subclass($subclass) unless ($class->model_classes_loaded());
310 $config->model->adopt($subclass) if $config->model->can("adopt");
315 =item load_model_subclass($subclass)
317 This method is called from C<setup_model()>. It attempts to load the
318 C<$subclass> package, if one exists. So if you make a customized C<BeerDB::Beer>
319 package, you don't need to explicitly load it.
321 If automatic loading causes problems, Override load_model_subclass in your driver.
323 sub load_model_subclass {};
325 Or perhaps during development, if you don't want to load up custom classes, you
326 can override this method and load them manually.
330 sub load_model_subclass {
331 my ($class, $subclass) = @_;
333 my $config = $class->config;
335 # Load any external files for the model base class or subclasses
336 # (e.g. BeerDB/DBI.pm or BeerDB/Beer.pm) based on code borrowed from
337 # Maypole::Plugin::Loader and Class::DBI.
338 if ( $subclass->require ) {
339 warn "Loaded external module for '$subclass'\n" if $class->debug > 1;
341 (my $filename = $subclass) =~ s!::!/!g;
342 die "Loading '$subclass' failed: $@\n"
343 unless $@ =~ /Can\'t locate \Q$filename\E\.pm/;
344 warn "No external module for '$subclass'"
345 if $class->debug > 1;
351 Loads the view class and instantiates the view object.
353 You should not call this directly, but you may wish to override this to add
354 application-specific initialisation - see L<Maypole::Manual::Plugins>.
361 my $config = $class->config;
362 $config->view || $config->view("Maypole::View::TT");
363 $config->view->require;
364 die "Couldn't load the view class " . $config->view . ": $@" if $@;
365 $config->display_tables
366 || $config->display_tables( $class->config->tables );
367 $class->view_object( $class->config->view->new );
368 $class->init_done(1);
373 Constructs a very minimal new Maypole request object.
381 config => $class->config,
387 $self->template_args({});
395 Get/set the Maypole::View object
399 =head1 INSTANCE METHODS
407 This method sets up the class if it's not done yet, sets some defaults and
408 leaves the dirty work to C<handler_guts>.
412 # handler() has a method attribute so that mod_perl will invoke
413 # BeerDB->handler() as a method rather than a plain function
414 # BeerDB::handler() and so this inherited implementation will be
415 # found. See e.g. "Practical mod_perl" by Bekman & Cholet for
416 # more information <http://modperlbook.org/html/ch25_01.html>
417 sub handler : method {
418 # See Maypole::Workflow before trying to understand this.
419 my ($class, $req) = @_;
421 $class->init unless $class->init_done;
423 my $self = $class->new;
425 # initialise the request
426 $self->headers_out(Maypole::Headers->new);
427 $self->get_request($req);
429 $self->parse_location;
431 # hook useful for declining static requests e.g. images, or perhaps for
432 # sanitizing request parameters
433 $self->status(Maypole::Constants::OK()); # set the default
434 $self->__call_hook('start_request_hook');
435 return $self->status unless $self->status == Maypole::Constants::OK();
436 die "status undefined after start_request_hook()" unless defined
440 my $status = $self->handler_guts;
441 return $status unless $status == OK;
442 # TODO: require send_output to return a status code
449 Run Maypole sub-requests as a component of the request
451 [% request.component("/beer/view_as_component/20") %]
453 Allows you to integrate the results of a Maypole request into an existing
454 request. You'll need to set up actions and templates
455 which return fragments of HTML rather than entire pages, but once you've
456 done that, you can use the C<component> method of the Maypole request object
457 to call those actions. You may pass a query string in the usual URL style.
459 You should not fully qualify the Maypole URLs.
461 Note: any HTTP POST or URL parameters passed to the parent are not passed to the
462 component sub-request, only what is included in the url passed as an argyument
468 my ( $r, $path ) = @_;
469 my $self = bless { parent => $r, config => $r->{config}, } , ref $r;
473 $self->template_args({});
478 my $url = URI->new($path);
479 warn "path : $path\n";
480 $self->{path} = $url->path;
482 $self->params( $url->query_form_hash );
484 return $self->output;
487 sub get_template_root {
490 return $r->parent->get_template_root if $r->{parent};
491 return $self->NEXT::DISTINCT::get_template_root( $r, @_ );
497 return $r->parent->view_object if $r->{parent};
498 return $self->NEXT::DISTINCT::view_object( $r, @_ );
501 # Instead of making plugin authors use the NEXT::DISTINCT hoopla to ensure other
502 # plugins also get to call the hook, we can cycle through the application's
503 # @ISA and call them all here. Doesn't work for setup() though, because it's
504 # too ingrained in the stack. We could add a run_setup() method, but we'd break
505 # lots of existing code.
508 my ($self, $hook) = @_;
512 my $class = ref($self);
514 @plugins = @{"$class\::ISA"};
517 # this is either a custom method in the driver, or the method in the 1st
518 # plugin, or the 'null' method in the frontend (i.e. inherited from
519 # Maypole.pm) - we need to be careful to only call it once
520 my $first_hook = $self->can($hook);
523 my %seen = ( $first_hook => 1 );
525 # @plugins includes the frontend
526 foreach my $plugin (@plugins)
528 next unless my $plugin_hook = $plugin->can($hook);
529 next if $seen{$plugin_hook}++;
536 This is the main request handling method and calls various methods to handle the
537 request/response and defines the workflow within Maypole.
541 # The root of all evil
545 $self->build_form_elements(1);
546 $self->__load_request_model;
548 my $applicable = $self->is_model_applicable == OK;
552 # handle authentication
553 eval { $status = $self->call_authenticate };
554 if ( my $error = $@ )
556 $status = $self->call_exception($error, "authentication");
559 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 )
566 $self->view_object->error( $self,
567 "Got unexpected status $status from calling authentication" );
570 return $status unless $status == OK;
572 # We run additional_data for every request
573 $self->additional_data;
576 eval { $self->model_class->process($self) };
577 if ( my $error = $@ )
579 $status = $self->call_exception($error, "model");
582 warn "caught model error: $error";
583 return $self->debug ?
584 $self->view_object->error($self, $error) : ERROR;
588 $self->__setup_plain_template;
591 # less frequent path - perhaps output has been set to an error message
592 return OK if $self->output;
594 # normal path - no output has been generated yet
595 my $processed_view_ok = $self->__call_process_view;
597 $self->{content_type} ||= $self->__get_mime_type();
598 $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) {
634 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->model_class(undef);
649 my $path = $self->path;
650 $path =~ s{/$}{}; # De-absolutify
653 $self->template($self->path);
656 # The model has been processed or skipped (if is_applicable returned false),
657 # any exceptions have been handled, and there's no content in $self->output
658 sub __call_process_view {
661 my $status = eval { $self->view_object->process($self) };
663 my $error = $@ || $self->{error};
666 $status = $self->call_exception($error, "view");
668 if ( $status != OK ) {
669 warn "caught view error: $error" if $self->debug;
670 return $self->debug ?
671 $self->view_object->error($self, $error) : ERROR;
680 $r->warn('its all gone pete tong');
682 Warn must be implemented by the backend, i.e. Apache::MVC
683 and warn to stderr or appropriate logfile.
685 You can also over-ride this in your Maypole driver, should you
686 want to use something like Log::Log4perl instead.
692 =item build_form_elements
694 $r->build_form_elements(0);
696 Specify whether to build HTML form elements and populate
697 the cgi element of classmetadata.
703 You should only need to define this method if you are writing a new
704 Maypole backend. It should return something that looks like an Apache
705 or CGI request object, it defaults to blank.
713 Turns the backend request (e.g. Apache::MVC, Maypole, CGI) into a Maypole
714 request. It does this by setting the C<path>, and invoking C<parse_path> and
717 You should only need to define this method if you are writing a new Maypole
724 die "parse_location is a virtual method. Do not use Maypole directly; " .
725 "use Apache::MVC or similar";
728 =item start_request_hook
730 This is called immediately after setting up the basic request. The default
733 The value of C<< $r->status >> is set to C<OK> before this hook is run. Your
734 implementation can change the status code, or leave it alone.
736 After this hook has run, Maypole will check the value of C<status>. For any
737 value other than C<OK>, Maypole returns the C<status> immediately.
739 This is useful for filtering out requests for static files, e.g. images, which
740 should not be processed by Maypole or by the templating engine:
742 sub start_request_hook
746 $r->status(DECLINED) if $r->path =~ /\.jpg$/;
749 Multiple plugins, and the driver, can define this hook - Maypole will call all
750 of them. You should check for and probably not change any non-OK C<status>
753 package Maypole::Plugin::MyApp::SkipFavicon;
755 sub start_request_hook
759 # check if a previous plugin has already DECLINED this request
760 # - probably unnecessary in this example, but you get the idea
761 return unless $r->status == OK;
764 $r->status(DECLINED) if $r->path =~ /favicon\.ico/;
769 sub start_request_hook { }
773 B<This method is deprecated> as of version 2.11. If you have overridden it,
774 please override C<is_model_applicable> instead, and change the return type
775 from a Maypole:Constant to a true/false value.
777 Returns a Maypole::Constant to indicate whether the request is valid.
781 sub is_applicable { return shift->is_model_applicable(@_); }
783 =item is_model_applicable
785 Returns true or false to indicate whether the request is valid.
787 The default implementation checks that C<< $r->table >> is publicly
788 accessible and that the model class is configured to handle the
793 sub is_model_applicable {
796 # Establish which tables should be processed by the model
797 my $config = $self->config;
799 $config->ok_tables || $config->ok_tables( $config->display_tables );
801 $config->ok_tables( { map { $_ => 1 } @{ $config->ok_tables } } )
802 if ref $config->ok_tables eq "ARRAY";
804 my $ok_tables = $config->ok_tables;
806 # Does this request concern a table to be processed by the model?
807 my $table = $self->table;
811 if (exists $ok_tables->{$table})
818 $self->warn ("We don't have that table ($table).\n"
819 . "Available tables are: "
820 . join( ",", keys %$ok_tables ))
821 if $self->debug and not $ok_tables->{$table};
826 # Is the action public?
827 my $action = $self->action;
828 return OK if $self->model_class->is_public($action);
830 $self->warn("The action '$action' is not applicable to the table '$table'")
838 Called immediately after C<start_request_hook()>.
840 This method should return a session, which will be stored in the request's
841 C<session> attribute.
843 The default method is empty.
851 Called immediately after C<get_session>.
853 This method should return a user, which will be stored in the request's C<user>
856 The default method is empty.
862 =item call_authenticate
864 This method first checks if the relevant model class
865 can authenticate the user, or falls back to the default
866 authenticate method of your Maypole application.
870 sub call_authenticate
874 # Check if we have a model class with an authenticate() to delegate to
875 return $self->model_class->authenticate($self)
876 if $self->model_class and $self->model_class->can('authenticate');
878 # Interface consistency is a Good Thing -
879 # the invocant and the argument may one day be different things
880 # (i.e. controller and request), like they are when authenticate()
881 # is called on a model class (i.e. model and request)
882 return $self->authenticate($self);
887 Returns a Maypole::Constant to indicate whether the user is authenticated for
890 The default implementation returns C<OK>
894 sub authenticate { return OK }
899 This model is called to catch exceptions, first after authenticate, then after
900 processing the model class, and finally to check for exceptions from the view
903 This method first checks if the relevant model class
904 can handle exceptions the user, or falls back to the default
905 exception method of your Maypole application.
911 my ($self, $error, $when) = @_;
913 # Check if we have a model class with an exception() to delegate to
914 if ( $self->model_class && $self->model_class->can('exception') )
916 my $status = $self->model_class->exception( $self, $error, $when );
917 return $status if $status == OK;
920 return $self->exception($error, $when);
926 This method is called if any exceptions are raised during the authentication or
927 model/view processing. It should accept the exception as a parameter and return
928 a Maypole::Constant to indicate whether the request should continue to be
934 my ($self, $error, $when) = @_;
935 if (ref $self->view_object && $self->view_object->can("report_error") and $self->debug) {
936 $self->view_object->report_error($self, $error, $when);
942 =item additional_data
944 Called before the model processes the request, this method gives you a chance to
945 do some processing for each request, for example, manipulating C<template_args>.
949 sub additional_data { }
953 Sends the output and additional headers to the user.
958 die "send_output is a virtual method. Do not use Maypole directly; use Apache::MVC or similar";
964 =head2 Path processing and manipulation
970 Returns the request path
974 Parses the request path and sets the C<args>, C<action> and C<table>
975 properties. Calls C<preprocess_path> before parsing path and setting properties.
983 # Previous versions unconditionally set table, action and args to whatever
984 # was in @pi (or else to defaults, if @pi is empty).
985 # Adding preprocess_path(), and then setting table, action and args
986 # conditionally, broke lots of tests, hence this:
987 $self->$_(undef) for qw/action table args/;
988 $self->preprocess_path;
989 $self->path || $self->path('frontpage');
991 my @pi = grep {length} split '/', $self->path;
994 $self->table || $self->table(shift @pi);
995 $self->action || $self->action( shift @pi or 'index' );
996 $self->args || $self->args(\@pi);
999 =item preprocess_path
1001 Sometimes when you don't want to rewrite or over-ride parse_path but
1002 want to rewrite urls or extract data from them before it is parsed.
1004 This method is called after parse_location has populated the request
1005 information and before parse_path has populated the model and action
1006 information, and is passed the request object.
1008 You can set action, args or table in this method and parse_path will
1009 then leave those values in place or populate them if not present
1013 sub preprocess_path { };
1015 =item make_path( %args or \%args or @args )
1017 This is the counterpart to C<parse_path>. It generates a path to use
1018 in links, form actions etc. To implement your own path scheme, just override
1019 this method and C<parse_path>.
1021 %args = ( table => $table,
1023 additional => $additional, # optional - generally an object ID
1026 \%args = as above, but a ref
1028 @args = ( $table, $action, $additional ); # $additional is optional
1030 C<id> can be used as an alternative key to C<additional>.
1032 C<$additional> can be a string, an arrayref, or a hashref. An arrayref is
1033 expanded into extra path elements, whereas a hashref is translated into a query
1044 if (@_ == 1 and ref $_[0] and ref $_[0] eq 'HASH')
1048 elsif ( @_ > 1 and @_ < 4 )
1050 $args{table} = shift;
1051 $args{action} = shift;
1052 $args{additional} = shift;
1059 do { die "no $_" unless $args{$_} } for qw( table action );
1061 my $additional = $args{additional} || $args{id};
1067 # if $additional is a href, make_uri() will transform it into a query
1068 @add = (ref $additional eq 'ARRAY') ? @$additional : ($additional);
1071 my $uri = $r->make_uri($args{table}, $args{action}, @add);
1073 return $uri->as_string;
1078 =item make_uri( @segments )
1080 Make a L<URI> object given table, action etc. Automatically adds
1083 If the final element in C<@segments> is a hash ref, C<make_uri> will render it
1090 my ($r, @segments) = @_;
1092 my $query = (ref $segments[-1] eq 'HASH') ? pop(@segments) : undef;
1094 my $base = $r->config->uri_base;
1097 my $uri = URI->new($base);
1098 $uri->path_segments($uri->path_segments, grep {length} @segments);
1100 my $abs_uri = $uri->abs('/');
1101 $abs_uri->query_form($query) if $query;
1107 Turns post data and query string paramaters into a hash of C<params>.
1109 You should only need to define this method if you are writing a new Maypole
1116 die "parse_args() is a virtual method. Do not use Maypole directly; ".
1117 "use Apache::MVC or similar";
1120 =item get_template_root
1122 Implementation-specific path to template root.
1124 You should only need to define this method if you are writing a new Maypole
1125 backend. Otherwise, see L<Maypole::Config/"template_root">
1131 =head2 Request properties
1137 Returns the perl package name that will serve as the model for the
1138 request. It corresponds to the request C<table> attribute.
1143 Get/set a list of model objects. The objects will be accessible in the view
1146 If the first item in C<$self-E<gt>args> can be C<retrieve()>d by the model
1147 class, it will be removed from C<args> and the retrieved object will be added to
1148 the C<objects> list. See L<Maypole::Model> for more information.
1153 Alias to get/set the first/only model object. The object will be accessible
1154 in the view templates.
1156 When used to set the object, will overwrite the request objects
1157 with a single object.
1162 my ($r,$object) = @_;
1163 $r->objects([$object]) if ($object);
1164 return undef unless $r->objects();
1165 return $r->objects->[0];
1170 $self->template_args->{foo} = 'bar';
1172 Get/set a hash of template variables.
1174 Maypole reserved words for template variables will over-ride values in template_variables.
1176 Reserved words are : r, request, object, objects, base, config and errors, as well as the
1177 current class or object name.
1181 A place to put custom application data. Not used by Maypole itself.
1185 Get/set the template to be used by the view. By default, it returns
1186 C<$self-E<gt>action>
1191 Get/set a request error
1195 Get/set the response output. This is usually populated by the view class. You
1196 can skip view processing by setting the C<output>.
1200 The table part of the Maypole request path
1204 The action part of the Maypole request path
1208 A list of remaining parts of the request path after table and action
1214 A L<Maypole::Headers> object containing HTTP headers for the request
1218 A L<HTTP::Headers> object that contains HTTP headers for the output
1220 =item document_encoding
1222 Get/set the output encoding. Default: utf-8.
1226 Get/set the output content type. Default: text/html
1230 Returns the protocol the request was made with, i.e. https
1235 die "get_protocol is a virtual method. Do not use Maypole directly; use Apache::MVC or similar";
1240 =head2 Request parameters
1242 The source of the parameters may vary depending on the Maypole backend, but they
1243 are usually populated from request query string and POST data.
1245 Maypole supplies several approaches for accessing the request parameters. Note
1246 that the current implementation (via a hashref) of C<query> and C<params> is
1247 likely to change in a future version of Maypole. So avoid direct access to these
1250 $r->{params}->{foo} # bad
1251 $r->params->{foo} # better
1253 $r->{query}->{foo} # bad
1254 $r->query->{foo} # better
1256 $r->param('foo') # best
1262 An accessor (get or set) for request parameters. It behaves similarly to
1263 CGI::param() for accessing CGI parameters, i.e.
1265 $r->param # returns list of keys
1266 $r->param($key) # returns value for $key
1267 $r->param($key => $value) # returns old value, sets to new value
1273 my ($self, $key) = (shift, shift);
1275 return keys %{$self->params} unless defined $key;
1277 return unless exists $self->params->{$key};
1279 my $val = $self->params->{$key};
1283 my $new_val = shift;
1284 $self->params->{$key} = $new_val;
1287 return ref $val ? @$val : ($val) if wantarray;
1289 return ref $val ? $val->[0] : $val;
1295 Returns a hashref of request parameters.
1297 B<Note:> Where muliple values of a parameter were supplied, the C<params> value
1298 will be an array reference.
1302 Alias for C<params>.
1306 =head3 Utility methods
1310 =item redirect_request
1312 Sets output headers to redirect based on the arguments provided
1314 Accepts either a single argument of the full url to redirect to, or a hash of
1317 $r->redirect_request('http://www.example.com/path');
1321 $r->redirect_request(protocol=>'https', domain=>'www.example.com', path=>'/path/file?arguments', status=>'302', url=>'..');
1323 The named parameters are protocol, domain, path, status and url
1325 Only 1 named parameter is required but other than url, they can be combined as
1326 required and current values (from the request) will be used in place of any
1327 missing arguments. The url argument must be a full url including protocol and
1328 can only be combined with status.
1332 sub redirect_request {
1333 die "redirect_request is a virtual method. Do not use Maypole directly; use Apache::MVC or similar";
1336 =item redirect_internal_request
1340 sub redirect_internal_request {
1345 =item make_random_id
1347 returns a unique id for this request can be used to prevent or detect repeat
1352 # Session and Repeat Submission Handling
1353 sub make_random_id {
1354 use Maypole::Session;
1355 return Maypole::Session::generate_unique_id();
1360 =head1 SEQUENCE DIAGRAMS
1362 See L<Maypole::Manual::Workflow> for a detailed discussion of the sequence of
1363 calls during processing of a request. This is a brief summary:
1367 BeerDB Maypole::Model::CDBI
1371 || setup_model | setup_database() creates
1372 ||------+ | a subclass of the Model
1373 |||<----+ | for each table
1375 ||| setup_database | |
1376 |||--------------------->|| 'create' *
1377 ||| ||----------> $subclass
1379 ||| load_model_subclass | |
1380 foreach |||------+ ($subclass) | |
1381 $subclass ||||<----+ | require |
1382 ||||--------------------------------------->|
1384 ||| adopt($subclass) | |
1385 |||--------------------->|| |
1390 || | new | view_object: e.g.
1391 ||---------------------------------------------> Maypole::View::TT
1403 BeerDB Model $subclass view_object
1406 o-------->| new | | |
1407 |-----> r:BeerDB | | |
1411 | ||-----+ parse_location | | |
1414 | ||-----+ start_request_hook | | |
1417 | ||-----+ get_session | | |
1420 | ||-----+ get_user | | |
1423 | ||-----+ handler_guts | | |
1425 | ||| class_of($table) | | |
1426 | |||------------------------->|| | |
1427 | ||| $subclass || | |
1428 | |||<-------------------------|| | |
1430 | |||-----+ is_model_applicable| | |
1433 | |||-----+ call_authenticate | | |
1436 | |||-----+ additional_data | | |
1439 | |||--------------------------------->|| fetch_objects
1447 | |||------------------------------------------->|| template
1451 | || send_output | | |
1455 <------------------|| | | |
1466 There's more documentation, examples, and information on our mailing lists
1467 at the Maypole web site:
1469 L<http://maypole.perl.org/>
1471 L<Maypole::Application>, L<Apache::MVC>, L<CGI::Maypole>.
1475 Maypole is currently maintained by Aaron Trevena.
1477 =head1 AUTHOR EMERITUS
1479 Simon Cozens, C<simon#cpan.org>
1481 Simon Flack maintained Maypole from 2.05 to 2.09
1483 Sebastian Riedel, C<sri#oook.de> maintained Maypole from 1.99_01 to 2.04
1487 Sebastian Riedel, Danijel Milicevic, Dave Slack, Jesse Sheidlower, Jody Belka,
1488 Marcus Ramberg, Mickael Joanne, Randal Schwartz, Simon Flack, Steve Simms,
1489 Veljko Vidovic and all the others who've helped.
1493 You may distribute this code under the same terms as Perl itself.
1501 =item register_cleanup($coderef)
1503 Analogous to L<Apache>'s C<register_cleanup>. If an Apache request object is
1504 available, this call simply redispatches there. If not, the cleanup is
1505 registered in the Maypole request, and executed when the request is
1508 This method is only useful in persistent environments, where you need to ensure
1509 that some code runs when the request finishes, no matter how it finishes (e.g.
1510 after an unexpected error).
1517 sub register_cleanup
1519 my ($self, $cleanup) = @_;
1521 die "register_cleanup() is an instance method, not a class method"
1523 die "Cleanup must be a coderef" unless ref($cleanup) eq 'CODE';
1525 if ($self->can('ar') && $self->ar)
1527 $self->ar->register_cleanup($cleanup);
1531 push @_cleanups, $cleanup;
1539 while (my $cleanup = shift @_cleanups)
1541 eval { $cleanup->() };
1544 warn "Error during request cleanup: $@";