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_pre5';
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.aarontrevena.co.uk/opensource/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.aarontrevena.co.uk/opensource/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 __PACKAGE__->mk_classdata($_) for qw( config init_done view_object model_classes_loaded);
180 __PACKAGE__->mk_accessors(
181 qw( params query objects model_class template_args output path
182 args action template error document_encoding content_type table
183 headers_in headers_out stash status parent)
186 __PACKAGE__->config( Maypole::Config->new() );
188 __PACKAGE__->init_done(0);
190 __PACKAGE__->model_classes_loaded(0);
192 =head1 HOOKABLE METHODS
194 As a framework, Maypole provides a number of B<hooks> - methods that are
195 intended to be overridden. Some of these methods come with useful default
196 behaviour, others do nothing by default. Hooks include:
222 sub My::App::debug {1}
224 Returns the debugging flag. Override this in your application class to
225 enable/disable debugging.
227 You can also set the C<debug> flag via L<Maypole::Application>.
229 Some packages respond to higher debug levels, try increasing it to 2 or 3.
238 Returns the L<Maypole::Config> object
242 My::App->setup($data_source, $user, $password, \%attr);
244 Initialise the Maypole application and plugins and model classes.
245 Your application should call this B<after> setting up configuration data via
248 It calls the hook C<setup_model> to setup the model. The %attr hash contains
249 options and arguments used to set up the model. See the particular model's
250 documentation. However here is the most usage of setup where
251 Maypole::Model::CDBI is the base class.
253 My::App->setup($data_source, $user, $password,
254 { options => { # These are DB connection options
259 # These are Class::DBI::Loader arguments.
265 Also, see L<Maypole::Manual::Plugins>.
274 $class->setup_model(@_);
279 Called by C<setup>. This method builds the Maypole model hierarchy.
281 A likely target for over-riding, if you need to build a customised model.
283 This method also ensures any code in custom model classes is loaded, so you
284 don't need to load them in the driver.
290 $class = ref $class if ref $class;
291 my $config = $class->config;
292 $config->model || $config->model('Maypole::Model::CDBI');
293 $config->model->require or die sprintf
294 "Couldn't load the model class %s: %s", $config->model, $@;
296 # among other things, this populates $config->classes
297 $config->model->setup_database($config, $class, @_);
299 foreach my $subclass ( @{ $config->classes } ) {
300 next if $subclass->isa("Maypole::Model::Base");
302 unshift @{ $subclass . "::ISA" }, $config->model;
305 # Load custom model code, if it exists - nb this must happen after the
306 # unshift, 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 $self->template_args({});
396 Get/set the Maypole::View object
400 =head1 INSTANCE METHODS
408 This method sets up the class if it's not done yet, sets some defaults and
409 leaves the dirty work to C<handler_guts>.
413 # handler() has a method attribute so that mod_perl will invoke
414 # BeerDB->handler() as a method rather than a plain function
415 # BeerDB::handler() and so this inherited implementation will be
416 # found. See e.g. "Practical mod_perl" by Bekman & Cholet for
417 # more information <http://modperlbook.org/html/ch25_01.html>
418 sub handler : method {
419 # See Maypole::Workflow before trying to understand this.
420 my ($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
441 my $status = $self->handler_guts;
442 return $status unless $status == OK;
443 # TODO: require send_output to return a status code
450 Run Maypole sub-requests as a component of the request
452 [% request.component("/beer/view_as_component/20") %]
454 Allows you to integrate the results of a Maypole request into an existing
455 request. You'll need to set up actions and templates
456 which return fragments of HTML rather than entire pages, but once you've
457 done that, you can use the C<component> method of the Maypole request object
458 to call those actions. You may pass a query string in the usual URL style.
460 You should not fully qualify the Maypole URLs.
462 Note: any HTTP POST or URL parameters passed to the parent are not passed to the
463 component sub-request, only what is included in the url passed as an argyument
469 my ( $r, $path ) = @_;
470 my $self = bless { parent => $r, config => $r->{config}, } , ref $r;
474 $self->template_args({});
479 my $url = URI->new($path);
480 warn "path : $path\n";
481 $self->{path} = $url->path;
483 $self->params( $url->query_form_hash );
485 return $self->output;
488 sub get_template_root {
491 return $r->parent->get_template_root if $r->{parent};
492 return $self->NEXT::DISTINCT::get_template_root( $r, @_ );
498 return $r->parent->view_object if $r->{parent};
499 return $self->NEXT::DISTINCT::view_object( $r, @_ );
502 # Instead of making plugin authors use the NEXT::DISTINCT hoopla to ensure other
503 # plugins also get to call the hook, we can cycle through the application's
504 # @ISA and call them all here. Doesn't work for setup() though, because it's
505 # too ingrained in the stack. We could add a run_setup() method, but we'd break
506 # lots of existing code.
509 my ($self, $hook) = @_;
513 my $class = ref($self);
515 @plugins = @{"$class\::ISA"};
518 # this is either a custom method in the driver, or the method in the 1st
519 # plugin, or the 'null' method in the frontend (i.e. inherited from
520 # Maypole.pm) - we need to be careful to only call it once
521 my $first_hook = $self->can($hook);
524 my %seen = ( $first_hook => 1 );
526 # @plugins includes the frontend
527 foreach my $plugin (@plugins)
529 next unless my $plugin_hook = $plugin->can($hook);
530 next if $seen{$plugin_hook}++;
537 This is the main request handling method and calls various methods to handle the
538 request/response and defines the workflow within Maypole.
540 B<Currently undocumented and liable to be refactored without warning>.
544 # The root of all evil
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 = $@ )
559 $status = $self->call_exception($error, "authentication");
562 warn "caught authenticate error: $error";
563 return $self->debug ?
564 $self->view_object->error($self, $error) : ERROR;
567 if ( $self->debug and $status != OK and $status != DECLINED )
569 $self->view_object->error( $self,
570 "Got unexpected status $status from calling authentication" );
573 return $status unless $status == OK;
575 # We run additional_data for every request
576 $self->additional_data;
579 eval { $self->model_class->process($self) };
580 if ( my $error = $@ )
582 $status = $self->call_exception($error, "model");
585 warn "caught model error: $error";
586 return $self->debug ?
587 $self->view_object->error($self, $error) : ERROR;
591 $self->__setup_plain_template;
594 # less frequent path - perhaps output has been set to an error message
595 return OK if $self->output;
597 # normal path - no output has been generated yet
598 my $processed_view_ok = $self->__call_process_view;
600 $self->{content_type} ||= $self->__get_mime_type();
601 $self->{document_encoding} ||= "utf-8";
604 return $processed_view_ok;
608 'js' => 'text/javascript',
610 'htm' => 'text/html',
611 'html' => 'text/html',
614 sub __get_mime_type {
616 my $type = 'text/html';
617 if ($self->path =~ m/.*\.(\w{3,4})$/) {
618 $type = $filetypes{$1};
620 my $output = $self->output;
621 if (defined $output) {
622 $type = $mmagic->checktype_contents($output);
628 sub __load_request_model
631 # We may get a made up class from class_of
632 my $mclass = $self->config->model->class_of($self, $self->table);
633 if ( eval {$mclass->isa('Maypole::Model::Base')} ) {
634 $self->model_class( $mclass );
636 elsif ($self->debug) {
637 warn "***Warning: No $mclass class appropriate for model. @_";
642 # is_applicable() returned false, so set up a plain template. Model processing
643 # will be skipped, but need to remove the model anyway so the template can't
645 sub __setup_plain_template
649 # It's just a plain template
650 $self->model_class(undef);
652 my $path = $self->path;
653 $path =~ s{/$}{}; # De-absolutify
656 $self->template($self->path);
659 # The model has been processed or skipped (if is_applicable returned false),
660 # any exceptions have been handled, and there's no content in $self->output
661 sub __call_process_view {
664 my $status = eval { $self->view_object->process($self) };
666 my $error = $@ || $self->{error};
669 $status = $self->call_exception($error, "view");
671 if ( $status != OK ) {
672 warn "caught view error: $error" if $self->debug;
673 return $self->debug ?
674 $self->view_object->error($self, $error) : ERROR;
683 You should only need to define this method if you are writing a new
684 Maypole backend. It should return something that looks like an Apache
685 or CGI request object, it defaults to blank.
693 Turns the backend request (e.g. Apache::MVC, Maypole, CGI) into a Maypole
694 request. It does this by setting the C<path>, and invoking C<parse_path> and
697 You should only need to define this method if you are writing a new Maypole
704 die "parse_location is a virtual method. Do not use Maypole directly; " .
705 "use Apache::MVC or similar";
708 =item start_request_hook
710 This is called immediately after setting up the basic request. The default
713 The value of C<< $r->status >> is set to C<OK> before this hook is run. Your
714 implementation can change the status code, or leave it alone.
716 After this hook has run, Maypole will check the value of C<status>. For any
717 value other than C<OK>, Maypole returns the C<status> immediately.
719 This is useful for filtering out requests for static files, e.g. images, which
720 should not be processed by Maypole or by the templating engine:
722 sub start_request_hook
726 $r->status(DECLINED) if $r->path =~ /\.jpg$/;
729 Multiple plugins, and the driver, can define this hook - Maypole will call all
730 of them. You should check for and probably not change any non-OK C<status>
733 package Maypole::Plugin::MyApp::SkipFavicon;
735 sub start_request_hook
739 # check if a previous plugin has already DECLINED this request
740 # - probably unnecessary in this example, but you get the idea
741 return unless $r->status == OK;
744 $r->status(DECLINED) if $r->path =~ /favicon\.ico/;
749 sub start_request_hook { }
753 B<This method is deprecated> as of version 2.11. If you have overridden it,
754 please override C<is_model_applicable> instead, and change the return type
755 from a Maypole:Constant to a true/false value.
757 Returns a Maypole::Constant to indicate whether the request is valid.
761 sub is_applicable { return shift->is_model_applicable(@_); }
763 =item is_model_applicable
765 Returns true or false to indicate whether the request is valid.
767 The default implementation checks that C<< $r->table >> is publicly
768 accessible and that the model class is configured to handle the
773 sub is_model_applicable {
776 # Establish which tables should be processed by the model
777 my $config = $self->config;
779 $config->ok_tables || $config->ok_tables( $config->display_tables );
781 $config->ok_tables( { map { $_ => 1 } @{ $config->ok_tables } } )
782 if ref $config->ok_tables eq "ARRAY";
784 my $ok_tables = $config->ok_tables;
786 # Does this request concern a table to be processed by the model?
787 my $table = $self->table;
791 if (exists $ok_tables->{$table})
798 warn "We don't have that table ($table).\n"
799 . "Available tables are: "
800 . join( ",", keys %$ok_tables )
801 if $self->debug and not $ok_tables->{$table};
806 # Is the action public?
807 my $action = $self->action;
808 return OK if $self->model_class->is_public($action);
810 warn "The action '$action' is not applicable to the table '$table'"
818 Called immediately after C<start_request_hook()>.
820 This method should return a session, which will be stored in the request's
821 C<session> attribute.
823 The default method is empty.
831 Called immediately after C<get_session>.
833 This method should return a user, which will be stored in the request's C<user>
836 The default method is empty.
842 =item call_authenticate
844 This method first checks if the relevant model class
845 can authenticate the user, or falls back to the default
846 authenticate method of your Maypole application.
850 sub call_authenticate
854 # Check if we have a model class with an authenticate() to delegate to
855 return $self->model_class->authenticate($self)
856 if $self->model_class and $self->model_class->can('authenticate');
858 # Interface consistency is a Good Thing -
859 # the invocant and the argument may one day be different things
860 # (i.e. controller and request), like they are when authenticate()
861 # is called on a model class (i.e. model and request)
862 return $self->authenticate($self);
867 Returns a Maypole::Constant to indicate whether the user is authenticated for
870 The default implementation returns C<OK>
874 sub authenticate { return OK }
879 This model is called to catch exceptions, first after authenticate, then after
880 processing the model class, and finally to check for exceptions from the view
883 This method first checks if the relevant model class
884 can handle exceptions the user, or falls back to the default
885 exception method of your Maypole application.
891 my ($self, $error, $when) = @_;
893 # Check if we have a model class with an exception() to delegate to
894 if ( $self->model_class && $self->model_class->can('exception') )
896 my $status = $self->model_class->exception( $self, $error, $when );
897 return $status if $status == OK;
900 return $self->exception($error, $when);
906 This method is called if any exceptions are raised during the authentication or
907 model/view processing. It should accept the exception as a parameter and return
908 a Maypole::Constant to indicate whether the request should continue to be
914 my ($self, $error, $when) = @_;
915 if (ref $self->view_object && $self->view_object->can("report_error") and $self->debug) {
916 $self->view_object->report_error($self, $error, $when);
922 =item additional_data
924 Called before the model processes the request, this method gives you a chance to
925 do some processing for each request, for example, manipulating C<template_args>.
929 sub additional_data { }
933 Sends the output and additional headers to the user.
938 die "send_output is a virtual method. Do not use Maypole directly; use Apache::MVC or similar";
944 =head2 Path processing and manipulation
950 Returns the request path
954 Parses the request path and sets the C<args>, C<action> and C<table>
955 properties. Calls C<preprocess_path> before parsing path and setting properties.
963 # Previous versions unconditionally set table, action and args to whatever
964 # was in @pi (or else to defaults, if @pi is empty).
965 # Adding preprocess_path(), and then setting table, action and args
966 # conditionally, broke lots of tests, hence this:
967 $self->$_(undef) for qw/action table args/;
968 $self->preprocess_path;
969 $self->path || $self->path('frontpage');
971 my @pi = grep {length} split '/', $self->path;
974 $self->table || $self->table(shift @pi);
975 $self->action || $self->action( shift @pi or 'index' );
976 $self->args || $self->args(\@pi);
979 =item preprocess_path
981 Sometimes when you don't want to rewrite or over-ride parse_path but
982 want to rewrite urls or extract data from them before it is parsed.
984 This method is called after parse_location has populated the request
985 information and before parse_path has populated the model and action
986 information, and is passed the request object.
988 You can set action, args or table in this method and parse_path will
989 then leave those values in place or populate them if not present
993 sub preprocess_path { };
995 =item make_path( %args or \%args or @args )
997 This is the counterpart to C<parse_path>. It generates a path to use
998 in links, form actions etc. To implement your own path scheme, just override
999 this method and C<parse_path>.
1001 %args = ( table => $table,
1003 additional => $additional, # optional - generally an object ID
1006 \%args = as above, but a ref
1008 @args = ( $table, $action, $additional ); # $additional is optional
1010 C<id> can be used as an alternative key to C<additional>.
1012 C<$additional> can be a string, an arrayref, or a hashref. An arrayref is
1013 expanded into extra path elements, whereas a hashref is translated into a query
1024 if (@_ == 1 and ref $_[0] and ref $_[0] eq 'HASH')
1028 elsif ( @_ > 1 and @_ < 4 )
1030 $args{table} = shift;
1031 $args{action} = shift;
1032 $args{additional} = shift;
1039 do { die "no $_" unless $args{$_} } for qw( table action );
1041 my $additional = $args{additional} || $args{id};
1047 # if $additional is a href, make_uri() will transform it into a query
1048 @add = (ref $additional eq 'ARRAY') ? @$additional : ($additional);
1051 my $uri = $r->make_uri($args{table}, $args{action}, @add);
1053 return $uri->as_string;
1058 =item make_uri( @segments )
1060 Make a L<URI> object given table, action etc. Automatically adds
1063 If the final element in C<@segments> is a hash ref, C<make_uri> will render it
1070 my ($r, @segments) = @_;
1072 my $query = (ref $segments[-1] eq 'HASH') ? pop(@segments) : undef;
1074 my $base = $r->config->uri_base;
1077 my $uri = URI->new($base);
1078 $uri->path_segments($uri->path_segments, grep {length} @segments);
1080 my $abs_uri = $uri->abs('/');
1081 $abs_uri->query_form($query) if $query;
1087 Turns post data and query string paramaters into a hash of C<params>.
1089 You should only need to define this method if you are writing a new Maypole
1096 die "parse_args() is a virtual method. Do not use Maypole directly; ".
1097 "use Apache::MVC or similar";
1100 =item get_template_root
1102 Implementation-specific path to template root.
1104 You should only need to define this method if you are writing a new Maypole
1105 backend. Otherwise, see L<Maypole::Config/"template_root">
1111 =head2 Request properties
1117 Returns the perl package name that will serve as the model for the
1118 request. It corresponds to the request C<table> attribute.
1123 Get/set a list of model objects. The objects will be accessible in the view
1126 If the first item in C<$self-E<gt>args> can be C<retrieve()>d by the model
1127 class, it will be removed from C<args> and the retrieved object will be added to
1128 the C<objects> list. See L<Maypole::Model> for more information.
1133 Alias to get/set the first/only model object. The object will be accessible
1134 in the view templates.
1136 When used to set the object, will overwrite the request objects
1137 with a single object.
1142 my ($r,$object) = @_;
1143 $r->objects([$object]) if ($object);
1144 return undef unless $r->objects();
1145 return $r->objects->[0];
1150 $self->template_args->{foo} = 'bar';
1152 Get/set a hash of template variables.
1156 A place to put custom application data. Not used by Maypole itself.
1160 Get/set the template to be used by the view. By default, it returns
1161 C<$self-E<gt>action>
1166 Get/set a request error
1170 Get/set the response output. This is usually populated by the view class. You
1171 can skip view processing by setting the C<output>.
1175 The table part of the Maypole request path
1179 The action part of the Maypole request path
1183 A list of remaining parts of the request path after table and action
1189 A L<Maypole::Headers> object containing HTTP headers for the request
1193 A L<HTTP::Headers> object that contains HTTP headers for the output
1195 =item document_encoding
1197 Get/set the output encoding. Default: utf-8.
1201 Get/set the output content type. Default: text/html
1205 Returns the protocol the request was made with, i.e. https
1210 die "get_protocol is a virtual method. Do not use Maypole directly; use Apache::MVC or similar";
1215 =head2 Request parameters
1217 The source of the parameters may vary depending on the Maypole backend, but they
1218 are usually populated from request query string and POST data.
1220 Maypole supplies several approaches for accessing the request parameters. Note
1221 that the current implementation (via a hashref) of C<query> and C<params> is
1222 likely to change in a future version of Maypole. So avoid direct access to these
1225 $r->{params}->{foo} # bad
1226 $r->params->{foo} # better
1228 $r->{query}->{foo} # bad
1229 $r->query->{foo} # better
1231 $r->param('foo') # best
1237 An accessor (get or set) for request parameters. It behaves similarly to
1238 CGI::param() for accessing CGI parameters, i.e.
1240 $r->param # returns list of keys
1241 $r->param($key) # returns value for $key
1242 $r->param($key => $value) # returns old value, sets to new value
1248 my ($self, $key) = (shift, shift);
1250 return keys %{$self->params} unless defined $key;
1252 return unless exists $self->params->{$key};
1254 my $val = $self->params->{$key};
1258 my $new_val = shift;
1259 $self->params->{$key} = $new_val;
1262 return ref $val ? @$val : ($val) if wantarray;
1264 return ref $val ? $val->[0] : $val;
1270 Returns a hashref of request parameters.
1272 B<Note:> Where muliple values of a parameter were supplied, the C<params> value
1273 will be an array reference.
1277 Alias for C<params>.
1281 =head3 Utility methods
1285 =item redirect_request
1287 Sets output headers to redirect based on the arguments provided
1289 Accepts either a single argument of the full url to redirect to, or a hash of
1292 $r->redirect_request('http://www.example.com/path');
1296 $r->redirect_request(protocol=>'https', domain=>'www.example.com', path=>'/path/file?arguments', status=>'302', url=>'..');
1298 The named parameters are protocol, domain, path, status and url
1300 Only 1 named parameter is required but other than url, they can be combined as
1301 required and current values (from the request) will be used in place of any
1302 missing arguments. The url argument must be a full url including protocol and
1303 can only be combined with status.
1307 sub redirect_request {
1308 die "redirect_request is a virtual method. Do not use Maypole directly; use Apache::MVC or similar";
1311 =item redirect_internal_request
1315 sub redirect_internal_request {
1320 =item make_random_id
1322 returns a unique id for this request can be used to prevent or detect repeat
1327 # Session and Repeat Submission Handling
1328 sub make_random_id {
1329 use Maypole::Session;
1330 return Maypole::Session::generate_unique_id();
1335 =head1 SEQUENCE DIAGRAMS
1337 See L<Maypole::Manual::Workflow> for a detailed discussion of the sequence of
1338 calls during processing of a request. This is a brief summary:
1342 BeerDB Maypole::Model::CDBI
1346 || setup_model | setup_database() creates
1347 ||------+ | a subclass of the Model
1348 |||<----+ | for each table
1350 ||| setup_database | |
1351 |||--------------------->|| 'create' *
1352 ||| ||----------> $subclass
1354 ||| load_model_subclass | |
1355 foreach |||------+ ($subclass) | |
1356 $subclass ||||<----+ | require |
1357 ||||--------------------------------------->|
1359 ||| adopt($subclass) | |
1360 |||--------------------->|| |
1365 || | new | view_object: e.g.
1366 ||---------------------------------------------> Maypole::View::TT
1378 BeerDB Model $subclass view_object
1381 o-------->| new | | |
1382 |-----> r:BeerDB | | |
1386 | ||-----+ parse_location | | |
1389 | ||-----+ start_request_hook | | |
1392 | ||-----+ get_session | | |
1395 | ||-----+ get_user | | |
1398 | ||-----+ handler_guts | | |
1400 | ||| class_of($table) | | |
1401 | |||------------------------->|| | |
1402 | ||| $subclass || | |
1403 | |||<-------------------------|| | |
1405 | |||-----+ is_model_applicable| | |
1408 | |||-----+ call_authenticate | | |
1411 | |||-----+ additional_data | | |
1414 | |||--------------------------------->|| fetch_objects
1422 | |||------------------------------------------->|| template
1426 | || send_output | | |
1430 <------------------|| | | |
1441 There's more documentation, examples, and information on our mailing lists
1442 at the Maypole web site:
1444 L<http://maypole.perl.org/>
1446 L<Maypole::Application>, L<Apache::MVC>, L<CGI::Maypole>.
1450 Maypole is currently maintained by Aaron Trevena.
1452 =head1 AUTHOR EMERITUS
1454 Simon Cozens, C<simon#cpan.org>
1456 Simon Flack maintained Maypole from 2.05 to 2.09
1458 Sebastian Riedel, C<sri#oook.de> maintained Maypole from 1.99_01 to 2.04
1462 Sebastian Riedel, Danijel Milicevic, Dave Slack, Jesse Sheidlower, Jody Belka,
1463 Marcus Ramberg, Mickael Joanne, Randal Schwartz, Simon Flack, Steve Simms,
1464 Veljko Vidovic and all the others who've helped.
1468 You may distribute this code under the same terms as Perl itself.
1476 =item register_cleanup($coderef)
1478 Analogous to L<Apache>'s C<register_cleanup>. If an Apache request object is
1479 available, this call simply redispatches there. If not, the cleanup is
1480 registered in the Maypole request, and executed when the request is
1483 This method is only useful in persistent environments, where you need to ensure
1484 that some code runs when the request finishes, no matter how it finishes (e.g.
1485 after an unexpected error).
1492 sub register_cleanup
1494 my ($self, $cleanup) = @_;
1496 die "register_cleanup() is an instance method, not a class method"
1498 die "Cleanup must be a coderef" unless ref($cleanup) eq 'CODE';
1500 if ($self->can('ar') && $self->ar)
1502 $self->ar->register_cleanup($cleanup);
1506 push @_cleanups, $cleanup;
1514 while (my $cleanup = shift @_cleanups)
1516 eval { $cleanup->() };
1519 warn "Error during request cleanup: $@";