From dc05783cf83b60a298f12e52ac6d67c489f35868 Mon Sep 17 00:00:00 2001 From: Simon Cozens Date: Wed, 11 Feb 2004 14:43:02 +0000 Subject: [PATCH] This is the original Apache::MVC with renaming. git-svn-id: http://svn.maypole.perl.org/Maypole/trunk@56 48953598-375a-da11-a14b-00016c27c3ee --- lib/Maypole.pm | 255 +++++++++++++++++++++++++++++++++++++++++++++++++ 1 file changed, 255 insertions(+) create mode 100644 lib/Maypole.pm diff --git a/lib/Maypole.pm b/lib/Maypole.pm new file mode 100644 index 0000000..55aa509 --- /dev/null +++ b/lib/Maypole.pm @@ -0,0 +1,255 @@ +package Maypole; +use base qw(Class::Accessor Class::Data::Inheritable); +use attributes (); +use Class::DBI::Loader; +use UNIVERSAL::require; +use Apache::Constants ":common"; +use strict; +use warnings; +our $VERSION = "0.2"; +__PACKAGE__->mk_classdata($_) for qw( config init_done view_object ); +__PACKAGE__->mk_accessors ( qw( ar params query objects model_class +args action template )); +__PACKAGE__->config({}); +__PACKAGE__->init_done(0); + + +sub import { + my $real = shift; + if ($real ne "Apache::MVC") { + no strict 'refs'; + *{$real."::handler"} = sub { Apache::MVC::handler($real, @_) }; + } +} + +sub set_database { + my ($calling_class, $dsn) = @_; + $calling_class = ref $calling_class if ref $calling_class; + my $config = $calling_class->config; + $config->{model} ||= "Apache::MVC::Model::CDBI"; + $config->{model}->require; + $config->{dsn} = $dsn; + $config->{loader} = Class::DBI::Loader->new( + namespace => $calling_class, + dsn => $dsn + ); + $config->{classes} = [ $config->{loader}->classes ]; + for my $subclass (@{$config->{classes}}) { + no strict 'refs'; + unshift @{$subclass."::ISA"}, $config->{model}; + $config->{model}->adopt($subclass) + if $config->{model}->can("adopt"); + } +} + +sub init { + my $class = shift; + my $config = $class->config; + $config->{view} ||= "Apache::MVC::View::TT"; + $config->{view}->require; + $config->{display_tables} ||= [ $class->config->{loader}->tables ]; + $class->view_object($class->config->{view}->new); + $class->init_done(1); + +} + +sub class_of { + my ($self, $table) = @_; + return $self->config->{loader}->_table2class($table); +} + +sub handler { + # See Apache::MVC::Workflow before trying to understand this. + my $class = shift; + $class->init unless $class->init_done; + my $r = bless { config => $class->config }, $class; + $r->get_request(); + $r->parse_location(); + + $r->model_class($r->class_of($r->{table})); + my $status = $r->is_applicable; + if ($status == OK) { + $status = $r->call_authenticate; + return $status unless $status == OK; + $r->additional_data(); + + $r->model_class->process($r); + } else { + # Otherwise, it's just a plain template. + delete $r->{model_class}; + $r->{path} =~ s{/}{}; # De-absolutify + $r->template($r->{path}); + } + return $r->view_object->process($r); +} + +sub get_request { + my $self = shift; + require Apache; require Apache::Request; + $self->{ar} = Apache::Request->new(Apache->request); +} + +sub parse_location { + my $self = shift; + $self->{path} = $self->{ar}->uri; + my $loc = $self->{ar}->location; + $self->{path} =~ s/^$loc//; # I shouldn't need to do this? + $self->{path} ||= "frontpage"; + my @pi = split /\//, $self->{path}; + shift @pi while @pi and !$pi[0]; + $self->{table} = shift @pi; + $self->{action} = shift @pi; + $self->{args} = \@pi; + + $self->{params} = { $self->{ar}->content }; + $self->{query} = { $self->{ar}->args }; +} + +sub is_applicable { + my $self = shift; + my $config = $self->config; + $config->{ok_tables} = {map {$_ => 1} @{$config->{display_tables}}}; + warn "We don't have that table ($self->{table})" + unless $config->{ok_tables}{$self->{table}}; + return DECLINED() unless exists $config->{ok_tables}{$self->{table}}; + + # Does the action method exist? + my $cv = $self->model_class->can($self->{action}); + warn "We don't have that action ($self->{action})" unless $cv; + return DECLINED() unless $cv; + + # Is it exported? + $self->{method_attribs} = join " ", attributes::get($cv); + do { warn "$self->{action} not exported"; + return DECLINED() + } unless $self->{method_attribs} =~ /\bExported\b/i; + return OK(); +} + +sub call_authenticate { + my $self = shift; + return $self->model_class->authenticate($self) if + $self->model_class->can("authenticate"); + return $self->authenticate(); +} + +sub additional_data {} + +sub authenticate { return OK } + +1; + +=head1 NAME + +Maypole - MVC web application framework + +=head1 SYNOPSIS + +See L. + +=head1 DESCRIPTION + +A large number of web programming tasks follow the same sort of pattern: +we have some data in a datasource, typically a relational database. We +have a bunch of templates provided by web designers. We have a number of +things we want to be able to do with the database - create, add, edit, +delete records, view records, run searches, and so on. We have a web +server which provides input from the user about what to do. Something in +the middle takes the input, grabs the relevant rows from the database, +performs the action, constructs a page, and spits it out. + +Maypole aims to be the most generic and extensible "something in the +middle" - an MVC-based web application framework. + +An example would help explain this best. You need to add a product +catalogue to a company's web site. Users need to list the products in +various categories, view a page on each product with its photo and +pricing information and so on, and there needs to be a back-end where +sales staff can add new lines, change prices, and delete out of date +records. So, you set up the database, provide some default templates +for the designers to customize, and then write an Apache handler like +this: + + package ProductDatabase; + use base 'Apache::MVC'; + __PACKAGE__->set_database("dbi:mysql:products"); + BeerDB->config->{uri_base} = "http://your.site/catalogue/"; + ProductDatabase::Product->has_a("category" => ProductDatabase::Category); + # ... + + sub authenticate { + my ($self, $request) = @_; + return OK if $request->{ar}->get_remote_host() eq "sales.yourcorp.com"; + return OK if $request->{action} =~ /^(view|list)$/; + return DECLINED; + } + 1; + +You then put the following in your Apache config: + + + SetHandler perl-script + PerlHandler ProductDatabase + + +And copy the templates found in F into the +F directory off the web root. When the designers get +back to you with custom templates, they are to go in +F. If you need to do override templates on a +database-table-by-table basis, put the new template in +F>. + +This will automatically give you C, C, C, C and +C commands; for instance, a product list, go to + + http://your.site/catalogue/product/list + +For a full example, see the included "beer database" application. + +=head1 HOW IT WORKS + +There's some documentation for the workflow in L, +but the basic idea is that a URL part like C gets +translated into a call to Clist>. This +propagates the request with a set of objects from the database, and then +calls the C template; first, a C template if it +exists, then the C and finally C. + +If there's another action you want the system to do, you need to either +subclass the model class, and configure your class slightly differently: + + package ProductDatabase::Model; + use base 'Apache::MVC::Model::CDBI'; + + sub supersearch :Exported { + my ($self, $request) = @_; + # Do stuff, get a bunch of objects back + $r->objects(\@objects); + $r->template("template_name"); + } + + ProductDatabase->config->{model_class} = "ProductDatabase::Model"; + +(The C<:Exported> attribute means that the method can be called via the +URL C/supersearch/...>.) + +Alternatively, you can put the method directly into the specific model +class for the table: + + sub ProductDatabase::Product::supersearch :Exported { ... } + +By default, the view class uses Template Toolkit as the template +processor, and the model class uses C; it may help you to be +familiar with these modules before going much further with this, +although I expect there to be other subclasses for other templating +systems and database abstraction layers as time goes on. The article at +C is a great +introduction to the process we're trying to automate. + +=head1 AUTHOR + +Simon Cozens, C + +=head1 LICENSE + +You may distribute this code under the same terms as Perl itself. -- 2.39.2