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
191 __PACKAGE__->config( Maypole::Config->new() );
193 __PACKAGE__->init_done(0);
195 __PACKAGE__->model_classes_loaded(0);
197 =head1 HOOKABLE METHODS
199 As a framework, Maypole provides a number of B<hooks> - methods that are
200 intended to be overridden. Some of these methods come with useful default
201 behaviour, others do nothing by default. Hooks include:
227 sub My::App::debug {1}
229 Returns the debugging flag. Override this in your application class to
230 enable/disable debugging.
232 You can also set the C<debug> flag via L<Maypole::Application>.
234 Some packages respond to higher debug levels, try increasing it to 2 or 3.
243 Returns the L<Maypole::Config> object
247 My::App->setup($data_source, $user, $password, \%attr);
249 Initialise the Maypole application and plugins and model classes.
250 Your application should call this B<after> setting up configuration data via
253 It calls the hook C<setup_model> to setup the model. The %attr hash contains
254 options and arguments used to set up the model. See the particular model's
255 documentation. However here is the most usage of setup where
256 Maypole::Model::CDBI is the base class.
258 My::App->setup($data_source, $user, $password,
259 { options => { # These are DB connection options
264 # These are Class::DBI::Loader arguments.
270 Also, see L<Maypole::Manual::Plugins>.
279 $class->setup_model(@_);
284 Called by C<setup>. This method builds the Maypole model hierarchy.
286 A likely target for over-riding, if you need to build a customised model.
288 This method also ensures any code in custom model classes is loaded, so you
289 don't need to load them in the driver.
295 $class = ref $class if ref $class;
296 my $config = $class->config;
297 $config->model || $config->model('Maypole::Model::CDBI');
298 $config->model->require or die sprintf
299 "Couldn't load the model class %s: %s", $config->model, $@;
301 # among other things, this populates $config->classes
302 $config->model->setup_database($config, $class, @_);
304 $config->model->add_model_superclass($config);
306 # Load custom model code, if it exists - nb this must happen after the
307 # adding the model superclass, to allow code attributes to work, but before adopt(),
308 # in case adopt() calls overridden methods on $subclass
309 foreach my $subclass ( @{ $config->classes } ) {
310 $class->load_model_subclass($subclass) unless ($class->model_classes_loaded());
311 $config->model->adopt($subclass) if $config->model->can("adopt");
316 =item load_model_subclass($subclass)
318 This method is called from C<setup_model()>. It attempts to load the
319 C<$subclass> package, if one exists. So if you make a customized C<BeerDB::Beer>
320 package, you don't need to explicitly load it.
322 If automatic loading causes problems, Override load_model_subclass in your driver.
324 sub load_model_subclass {};
326 Or perhaps during development, if you don't want to load up custom classes, you
327 can override this method and load them manually.
331 sub load_model_subclass {
332 my ($class, $subclass) = @_;
334 my $config = $class->config;
336 # Load any external files for the model base class or subclasses
337 # (e.g. BeerDB/DBI.pm or BeerDB/Beer.pm) based on code borrowed from
338 # Maypole::Plugin::Loader and Class::DBI.
339 if ( $subclass->require ) {
340 warn "Loaded external module for '$subclass'\n" if $class->debug > 1;
342 (my $filename = $subclass) =~ s!::!/!g;
343 die "Loading '$subclass' failed: $@\n"
344 unless $@ =~ /Can\'t locate \Q$filename\E\.pm/;
345 warn "No external module for '$subclass'"
346 if $class->debug > 1;
352 Loads the view class and instantiates the view object.
354 You should not call this directly, but you may wish to override this to add
355 application-specific initialisation - see L<Maypole::Manual::Plugins>.
362 my $config = $class->config;
363 $config->view || $config->view("Maypole::View::TT");
364 $config->view->require;
365 die "Couldn't load the view class " . $config->view . ": $@" if $@;
366 $config->display_tables
367 || $config->display_tables( $class->config->tables );
368 $class->view_object( $class->config->view->new );
369 $class->init_done(1);
374 Constructs a very minimal new Maypole request object.
382 config => $class->config,
388 $self->template_args({});
396 Get/set the Maypole::View object
400 =head1 INSTANCE METHODS
408 This method sets up the class if it's not done yet, sets some defaults and
409 leaves the dirty work to C<handler_guts>.
413 # handler() has a method attribute so that mod_perl will invoke
414 # BeerDB->handler() as a method rather than a plain function
415 # BeerDB::handler() and so this inherited implementation will be
416 # found. See e.g. "Practical mod_perl" by Bekman & Cholet for
417 # more information <http://modperlbook.org/html/ch25_01.html>
418 sub handler : method {
419 # See Maypole::Workflow before trying to understand this.
420 my ($class, $req) = @_;
422 $class->init unless $class->init_done;
424 my $self = $class->new;
426 # initialise the request
427 $self->headers_out(Maypole::Headers->new);
428 $self->get_request($req);
430 $self->parse_location;
432 # hook useful for declining static requests e.g. images, or perhaps for
433 # sanitizing request parameters
434 $self->status(Maypole::Constants::OK()); # set the default
435 $self->__call_hook('start_request_hook');
436 return $self->status unless $self->status == Maypole::Constants::OK();
437 die "status undefined after start_request_hook()" unless defined
440 $self->session($self->get_session);
441 $self->user($self->get_user);
443 my $status = $self->handler_guts;
444 return $status unless $status == OK;
445 # TODO: require send_output to return a status code
452 Run Maypole sub-requests as a component of the request
454 [% request.component("/beer/view_as_component/20") %]
456 Allows you to integrate the results of a Maypole request into an existing
457 request. You'll need to set up actions and templates
458 which return fragments of HTML rather than entire pages, but once you've
459 done that, you can use the C<component> method of the Maypole request object
460 to call those actions. You may pass a query string in the usual URL style.
462 You should not fully qualify the Maypole URLs.
464 Note: any HTTP POST or URL parameters passed to the parent are not passed to the
465 component sub-request, only what is included in the url passed as an argument
471 my ( $r, $path ) = @_;
472 my $self = bless { parent => $r, config => $r->{config}, } , ref $r;
476 $self->template_args({});
480 $self->session($self->get_session);
481 $self->user($self->get_user);
483 my $url = URI->new($path);
484 $self->{path} = $url->path;
486 $self->params( $url->query_form_hash );
488 return $self->output;
491 sub get_template_root {
494 return $r->parent->get_template_root if $r->{parent};
495 return $self->NEXT::DISTINCT::get_template_root( $r, @_ );
501 return $r->parent->view_object if $r->{parent};
502 return $self->NEXT::DISTINCT::view_object( $r, @_ );
505 # Instead of making plugin authors use the NEXT::DISTINCT hoopla to ensure other
506 # plugins also get to call the hook, we can cycle through the application's
507 # @ISA and call them all here. Doesn't work for setup() though, because it's
508 # too ingrained in the stack. We could add a run_setup() method, but we'd break
509 # lots of existing code.
512 my ($self, $hook) = @_;
516 my $class = ref($self);
518 @plugins = @{"$class\::ISA"};
521 # this is either a custom method in the driver, or the method in the 1st
522 # plugin, or the 'null' method in the frontend (i.e. inherited from
523 # Maypole.pm) - we need to be careful to only call it once
524 my $first_hook = $self->can($hook);
527 my %seen = ( $first_hook => 1 );
529 # @plugins includes the frontend
530 foreach my $plugin (@plugins)
532 next unless my $plugin_hook = $plugin->can($hook);
533 next if $seen{$plugin_hook}++;
540 This is the main request handling method and calls various methods to handle the
541 request/response and defines the workflow within Maypole.
545 # The root of all evil
548 $self->build_form_elements(1) unless (defined ($self->config->build_form_elements) && $self->config->build_form_elements == 0);
549 $self->__load_request_model;
551 my $applicable = $self->is_model_applicable == OK;
555 # handle authentication
556 eval { $status = $self->call_authenticate };
557 if ( my $error = $@ ) {
558 $status = $self->call_exception($error, "authentication");
559 if ( $status != OK ) {
560 $self->warn("caught authenticate error: $error");
561 return $self->debug ?
562 $self->view_object->error($self, $error) : ERROR;
565 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 = $@ ) {
578 $status = $self->call_exception($error, "model");
579 if ( $status != OK ) {
580 $self->warn("caught model error: $error");
581 return $self->debug ?
582 $self->view_object->error($self, $error) : ERROR;
586 $self->__setup_plain_template;
589 # less frequent path - perhaps output has been set to an error message
591 $self->{content_type} ||= $self->__get_mime_type();
592 $self->{document_encoding} ||= "utf-8";
596 # normal path - no output has been generated yet
597 my $processed_view_ok = $self->__call_process_view;
599 $self->{content_type} ||= $self->__get_mime_type();
600 $self->{document_encoding} ||= "utf-8";
602 return $processed_view_ok;
606 'js' => 'text/javascript',
608 'htm' => 'text/html',
609 'html' => 'text/html',
612 sub __get_mime_type {
614 my $type = 'text/html';
615 if ($self->path =~ m/.*\.(\w{3,4})$/) {
616 $type = $filetypes{$1};
618 my $output = $self->output;
619 if (defined $output) {
620 $type = $mmagic->checktype_contents($output);
626 sub __load_request_model
629 # We may get a made up class from class_of
630 my $mclass = $self->config->model->class_of($self, $self->table);
631 if ( eval {$mclass->isa('Maypole::Model::Base')} ) {
632 $self->model_class( $mclass );
634 elsif ($self->debug > 1) {
635 $self->warn("***Warning: No $mclass class appropriate for model. @_");
640 # is_applicable() returned false, so set up a plain template. Model processing
641 # will be skipped, but need to remove the model anyway so the template can't
643 sub __setup_plain_template
647 # It's just a plain template
648 $self->build_form_elements(0);
649 $self->model_class(undef);
651 unless ($self->template) {
652 # FIXME: this is likely to be redundant and is definately causing problems.
653 my $path = $self->path;
654 $path =~ s{/$}{}; # De-absolutify
656 $self->template($self->path);
660 # The model has been processed or skipped (if is_applicable returned false),
661 # any exceptions have been handled, and there's no content in $self->output
662 sub __call_process_view {
665 my $status = eval { $self->view_object->process($self) };
667 my $error = $@ || $self->{error};
670 $status = $self->call_exception($error, "view");
672 if ( $status != OK ) {
673 warn "caught view error: $error" if $self->debug;
674 return $self->debug ?
675 $self->view_object->error($self, $error) : ERROR;
684 $r->warn('its all gone pete tong');
686 Warn must be implemented by the backend, i.e. Apache::MVC
687 and warn to stderr or appropriate logfile.
689 You can also over-ride this in your Maypole driver, should you
690 want to use something like Log::Log4perl instead.
696 =item build_form_elements
698 $r->build_form_elements(0);
700 Specify (in an action) whether to build HTML form elements and populate
701 the cgi element of classmetadata in the view.
703 You can set this globally using the accessor of the same name in Maypole::Config,
704 this method allows you to over-ride that setting per action.
710 You should only need to define this method if you are writing a new
711 Maypole backend. It should return something that looks like an Apache
712 or CGI request object, it defaults to blank.
720 Turns the backend request (e.g. Apache::MVC, Maypole, CGI) into a Maypole
721 request. It does this by setting the C<path>, and invoking C<parse_path> and
724 You should only need to define this method if you are writing a new Maypole
731 die "parse_location is a virtual method. Do not use Maypole directly; " .
732 "use Apache::MVC or similar";
735 =item start_request_hook
737 This is called immediately after setting up the basic request. The default
740 The value of C<< $r->status >> is set to C<OK> before this hook is run. Your
741 implementation can change the status code, or leave it alone.
743 After this hook has run, Maypole will check the value of C<status>. For any
744 value other than C<OK>, Maypole returns the C<status> immediately.
746 This is useful for filtering out requests for static files, e.g. images, which
747 should not be processed by Maypole or by the templating engine:
749 sub start_request_hook
753 $r->status(DECLINED) if $r->path =~ /\.jpg$/;
756 Multiple plugins, and the driver, can define this hook - Maypole will call all
757 of them. You should check for and probably not change any non-OK C<status>
760 package Maypole::Plugin::MyApp::SkipFavicon;
762 sub start_request_hook
766 # check if a previous plugin has already DECLINED this request
767 # - probably unnecessary in this example, but you get the idea
768 return unless $r->status == OK;
771 $r->status(DECLINED) if $r->path =~ /favicon\.ico/;
776 sub start_request_hook { }
780 B<This method is deprecated> as of version 2.11. If you have overridden it,
781 please override C<is_model_applicable> instead, and change the return type
782 from a Maypole:Constant to a true/false value.
784 Returns a Maypole::Constant to indicate whether the request is valid.
788 sub is_applicable { return shift->is_model_applicable(@_); }
790 =item is_model_applicable
792 Returns true or false to indicate whether the request is valid.
794 The default implementation checks that C<< $r->table >> is publicly
795 accessible and that the model class is configured to handle the
800 sub is_model_applicable {
803 # Establish which tables should be processed by the model
804 my $config = $self->config;
806 $config->ok_tables || $config->ok_tables( $config->display_tables );
808 $config->ok_tables( { map { $_ => 1 } @{ $config->ok_tables } } )
809 if ref $config->ok_tables eq "ARRAY";
811 my $ok_tables = $config->ok_tables;
813 # Does this request concern a table to be processed by the model?
814 my $table = $self->table;
818 if (exists $ok_tables->{$table})
825 $self->warn ("We don't have that table ($table).\n"
826 . "Available tables are: "
827 . join( ",", keys %$ok_tables ))
828 if $self->debug and not $ok_tables->{$table};
833 # Is the action public?
834 my $action = $self->action;
835 return OK if $self->model_class->is_public($action);
837 $self->warn("The action '$action' is not applicable to the table '$table'")
845 Called immediately after C<start_request_hook()>.
847 This method should return a session, which will be stored in the request's
848 C<session> attribute.
850 The default method is empty.
858 Called immediately after C<get_session>.
860 This method should return a user, which will be stored in the request's C<user>
863 The default method is empty.
869 =item call_authenticate
871 This method first checks if the relevant model class
872 can authenticate the user, or falls back to the default
873 authenticate method of your Maypole application.
877 sub call_authenticate
881 # Check if we have a model class with an authenticate() to delegate to
882 return $self->model_class->authenticate($self)
883 if $self->model_class and $self->model_class->can('authenticate');
885 # Interface consistency is a Good Thing -
886 # the invocant and the argument may one day be different things
887 # (i.e. controller and request), like they are when authenticate()
888 # is called on a model class (i.e. model and request)
889 return $self->authenticate($self);
894 Returns a Maypole::Constant to indicate whether the user is authenticated for
897 The default implementation returns C<OK>
901 sub authenticate { return OK }
906 This model is called to catch exceptions, first after authenticate, then after
907 processing the model class, and finally to check for exceptions from the view
910 This method first checks if the relevant model class
911 can handle exceptions the user, or falls back to the default
912 exception method of your Maypole application.
918 my ($self, $error, $when) = @_;
920 # Check if we have a model class with an exception() to delegate to
921 if ( $self->model_class && $self->model_class->can('exception') )
923 my $status = $self->model_class->exception( $self, $error, $when );
924 return $status if $status == OK;
927 return $self->exception($error, $when);
933 This method is called if any exceptions are raised during the authentication or
934 model/view processing. It should accept the exception as a parameter and return
935 a Maypole::Constant to indicate whether the request should continue to be
941 my ($self, $error, $when) = @_;
942 if (ref $self->view_object && $self->view_object->can("report_error") and $self->debug) {
943 $self->view_object->report_error($self, $error, $when);
949 =item additional_data
951 Called before the model processes the request, this method gives you a chance to
952 do some processing for each request, for example, manipulating C<template_args>.
956 sub additional_data { }
960 Sends the output and additional headers to the user.
965 die "send_output is a virtual method. Do not use Maypole directly; use Apache::MVC or similar";
971 =head2 Path processing and manipulation
977 Returns the request path
981 Parses the request path and sets the C<args>, C<action> and C<table>
982 properties. Calls C<preprocess_path> before parsing path and setting properties.
990 # Previous versions unconditionally set table, action and args to whatever
991 # was in @pi (or else to defaults, if @pi is empty).
992 # Adding preprocess_path(), and then setting table, action and args
993 # conditionally, broke lots of tests, hence this:
994 $self->$_(undef) for qw/action table args/;
995 $self->preprocess_path;
997 # use frontpage template for frontpage
998 unless ($self->path && $self->path ne '/') {
999 $self->path('frontpage');
1002 my @pi = grep {length} split '/', $self->path;
1004 $self->table || $self->table(shift @pi);
1005 $self->action || $self->action( shift @pi or 'index' );
1006 $self->args || $self->args(\@pi);
1009 =item preprocess_path
1011 Sometimes when you don't want to rewrite or over-ride parse_path but
1012 want to rewrite urls or extract data from them before it is parsed.
1014 This method is called after parse_location has populated the request
1015 information and before parse_path has populated the model and action
1016 information, and is passed the request object.
1018 You can set action, args or table in this method and parse_path will
1019 then leave those values in place or populate them if not present
1023 sub preprocess_path { };
1025 =item make_path( %args or \%args or @args )
1027 This is the counterpart to C<parse_path>. It generates a path to use
1028 in links, form actions etc. To implement your own path scheme, just override
1029 this method and C<parse_path>.
1031 %args = ( table => $table,
1033 additional => $additional, # optional - generally an object ID
1036 \%args = as above, but a ref
1038 @args = ( $table, $action, $additional ); # $additional is optional
1040 C<id> can be used as an alternative key to C<additional>.
1042 C<$additional> can be a string, an arrayref, or a hashref. An arrayref is
1043 expanded into extra path elements, whereas a hashref is translated into a query
1054 if (@_ == 1 and ref $_[0] and ref $_[0] eq 'HASH')
1058 elsif ( @_ > 1 and @_ < 4 )
1060 $args{table} = shift;
1061 $args{action} = shift;
1062 $args{additional} = shift;
1069 do { die "no $_" unless $args{$_} } for qw( table action );
1071 my $additional = $args{additional} || $args{id};
1077 # if $additional is a href, make_uri() will transform it into a query
1078 @add = (ref $additional eq 'ARRAY') ? @$additional : ($additional);
1081 my $uri = $r->make_uri($args{table}, $args{action}, @add);
1083 return $uri->as_string;
1088 =item make_uri( @segments )
1090 Make a L<URI> object given table, action etc. Automatically adds
1093 If the final element in C<@segments> is a hash ref, C<make_uri> will render it
1100 my ($r, @segments) = @_;
1102 my $query = (ref $segments[-1] eq 'HASH') ? pop(@segments) : undef;
1104 my $base = $r->config->uri_base;
1107 my $uri = URI->new($base);
1108 $uri->path_segments($uri->path_segments, grep {length} @segments);
1110 my $abs_uri = $uri->abs('/');
1111 $abs_uri->query_form($query) if $query;
1117 Turns post data and query string paramaters into a hash of C<params>.
1119 You should only need to define this method if you are writing a new Maypole
1126 die "parse_args() is a virtual method. Do not use Maypole directly; ".
1127 "use Apache::MVC or similar";
1130 =item get_template_root
1132 Implementation-specific path to template root.
1134 You should only need to define this method if you are writing a new Maypole
1135 backend. Otherwise, see L<Maypole::Config/"template_root">
1141 =head2 Request properties
1147 Returns the perl package name that will serve as the model for the
1148 request. It corresponds to the request C<table> attribute.
1153 Get/set a list of model objects. The objects will be accessible in the view
1156 If the first item in C<$self-E<gt>args> can be C<retrieve()>d by the model
1157 class, it will be removed from C<args> and the retrieved object will be added to
1158 the C<objects> list. See L<Maypole::Model> for more information.
1163 Alias to get/set the first/only model object. The object will be accessible
1164 in the view templates.
1166 When used to set the object, will overwrite the request objects
1167 with a single object.
1172 my ($r,$object) = @_;
1173 $r->objects([$object]) if ($object);
1174 return undef unless $r->objects();
1175 return $r->objects->[0];
1180 $self->template_args->{foo} = 'bar';
1182 Get/set a hash of template variables.
1184 Maypole reserved words for template variables will over-ride values in template_variables.
1186 Reserved words are : r, request, object, objects, base, config and errors, as well as the
1187 current class or object name.
1191 A place to put custom application data. Not used by Maypole itself.
1195 Get/set the template to be used by the view. By default, it returns
1196 C<$self-E<gt>action>
1201 Get/set a request error
1205 Get/set the response output. This is usually populated by the view class. You
1206 can skip view processing by setting the C<output>.
1210 The table part of the Maypole request path
1214 The action part of the Maypole request path
1218 A list of remaining parts of the request path after table and action
1224 A L<Maypole::Headers> object containing HTTP headers for the request
1228 A L<HTTP::Headers> object that contains HTTP headers for the output
1230 =item document_encoding
1232 Get/set the output encoding. Default: utf-8.
1236 Get/set the output content type. Default: text/html
1240 Returns the protocol the request was made with, i.e. https
1245 die "get_protocol is a virtual method. Do not use Maypole directly; use Apache::MVC or similar";
1250 =head2 Request parameters
1252 The source of the parameters may vary depending on the Maypole backend, but they
1253 are usually populated from request query string and POST data.
1255 Maypole supplies several approaches for accessing the request parameters. Note
1256 that the current implementation (via a hashref) of C<query> and C<params> is
1257 likely to change in a future version of Maypole. So avoid direct access to these
1260 $r->{params}->{foo} # bad
1261 $r->params->{foo} # better
1263 $r->{query}->{foo} # bad
1264 $r->query->{foo} # better
1266 $r->param('foo') # best
1272 An accessor (get or set) for request parameters. It behaves similarly to
1273 CGI::param() for accessing CGI parameters, i.e.
1275 $r->param # returns list of keys
1276 $r->param($key) # returns value for $key
1277 $r->param($key => $value) # returns old value, sets to new value
1283 my ($self, $key) = (shift, shift);
1285 return keys %{$self->params} unless defined $key;
1287 return unless exists $self->params->{$key};
1289 my $val = $self->params->{$key};
1293 my $new_val = shift;
1294 $self->params->{$key} = $new_val;
1297 return ref $val ? @$val : ($val) if wantarray;
1299 return ref $val ? $val->[0] : $val;
1305 Returns a hashref of request parameters.
1307 B<Note:> Where muliple values of a parameter were supplied, the C<params> value
1308 will be an array reference.
1312 Alias for C<params>.
1316 =head3 Utility methods
1320 =item redirect_request
1322 Sets output headers to redirect based on the arguments provided
1324 Accepts either a single argument of the full url to redirect to, or a hash of
1327 $r->redirect_request('http://www.example.com/path');
1331 $r->redirect_request(protocol=>'https', domain=>'www.example.com', path=>'/path/file?arguments', status=>'302', url=>'..');
1333 The named parameters are protocol, domain, path, status and url
1335 Only 1 named parameter is required but other than url, they can be combined as
1336 required and current values (from the request) will be used in place of any
1337 missing arguments. The url argument must be a full url including protocol and
1338 can only be combined with status.
1342 sub redirect_request {
1343 die "redirect_request is a virtual method. Do not use Maypole directly; use Apache::MVC or similar";
1346 # =item redirect_internal_request
1350 # sub redirect_internal_request {
1355 =item make_random_id
1357 returns a unique id for this request can be used to prevent or detect repeat
1362 # Session and Repeat Submission Handling
1363 sub make_random_id {
1364 use Maypole::Session;
1365 return Maypole::Session::generate_unique_id();
1370 =head1 SEQUENCE DIAGRAMS
1372 See L<Maypole::Manual::Workflow> for a detailed discussion of the sequence of
1373 calls during processing of a request. This is a brief summary:
1377 BeerDB Maypole::Model::CDBI
1381 || setup_model | setup_database() creates
1382 ||------+ | a subclass of the Model
1383 |||<----+ | for each table
1385 ||| setup_database | |
1386 |||--------------------->|| 'create' *
1387 ||| ||----------> $subclass
1389 ||| load_model_subclass | |
1390 foreach |||------+ ($subclass) | |
1391 $subclass ||||<----+ | require |
1392 ||||--------------------------------------->|
1394 ||| adopt($subclass) | |
1395 |||--------------------->|| |
1400 || | new | view_object: e.g.
1401 ||---------------------------------------------> Maypole::View::TT
1413 BeerDB Model $subclass view_object
1416 o-------->| new | | |
1417 |-----> r:BeerDB | | |
1421 | ||-----+ parse_location | | |
1424 | ||-----+ start_request_hook | | |
1427 | ||-----+ get_session | | |
1430 | ||-----+ get_user | | |
1433 | ||-----+ handler_guts | | |
1435 | ||| class_of($table) | | |
1436 | |||------------------------->|| | |
1437 | ||| $subclass || | |
1438 | |||<-------------------------|| | |
1440 | |||-----+ is_model_applicable| | |
1443 | |||-----+ call_authenticate | | |
1446 | |||-----+ additional_data | | |
1449 | |||--------------------------------->|| fetch_objects
1457 | |||------------------------------------------->|| template
1461 | || send_output | | |
1465 <------------------|| | | |
1476 There's more documentation, examples, and information on our mailing lists
1477 at the Maypole web site:
1479 L<http://maypole.perl.org/>
1481 L<Maypole::Application>, L<Apache::MVC>, L<CGI::Maypole>.
1485 Maypole is currently maintained by Aaron Trevena.
1487 =head1 AUTHOR EMERITUS
1489 Simon Cozens, C<simon#cpan.org>
1491 Simon Flack maintained Maypole from 2.05 to 2.09
1493 Sebastian Riedel, C<sri#oook.de> maintained Maypole from 1.99_01 to 2.04
1497 Sebastian Riedel, Danijel Milicevic, Dave Slack, Jesse Sheidlower, Jody Belka,
1498 Marcus Ramberg, Mickael Joanne, Randal Schwartz, Simon Flack, Steve Simms,
1499 Veljko Vidovic and all the others who've helped.
1503 You may distribute this code under the same terms as Perl itself.
1511 =item register_cleanup($coderef)
1513 Analogous to L<Apache>'s C<register_cleanup>. If an Apache request object is
1514 available, this call simply redispatches there. If not, the cleanup is
1515 registered in the Maypole request, and executed when the request is
1518 This method is only useful in persistent environments, where you need to ensure
1519 that some code runs when the request finishes, no matter how it finishes (e.g.
1520 after an unexpected error).
1527 sub register_cleanup
1529 my ($self, $cleanup) = @_;
1531 die "register_cleanup() is an instance method, not a class method"
1533 die "Cleanup must be a coderef" unless ref($cleanup) eq 'CODE';
1535 if ($self->can('ar') && $self->ar)
1537 $self->ar->register_cleanup($cleanup);
1541 push @_cleanups, $cleanup;
1549 while (my $cleanup = shift @_cleanups)
1551 eval { $cleanup->() };
1554 warn "Error during request cleanup: $@";